Research ArticleStress Corrosion Behavior of Ungrouted PretensionedConcrete Beams

Velu Saraswathy12 Han-Seung Lee2 Subbiah Karthick2 and Seung-Jun Kwon 3

1Corrosion and Materials Protection Division CSIR-Central Electrochemical Research Institute Karaikudi 630003Tamil Nadu India2Department of Architectural Engineering Hanyang University Erica Campus Sangrok-gu Ansan Gyeonggi-do 15588Republic of Korea3Department of Civil Engineering Hannam University Daejeon 34430 Republic of Korea

Correspondence should be addressed to Seung-Jun Kwon jjuni98hannamackr

Received 18 September 2017 Revised 7 November 2017 Accepted 27 November 2017 Published 21 January 2018

Academic Editor Michael J Schutze

Copyright copy 2018 Velu Saraswathy et al is is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Prestressed concrete beams of size 150times150times1000mmwere designed and two bonded cold-drawn 7mm steel wires were stressedat 70 UTS under service conditions before concreting e beams were cast with M40 grade concrete mix with variouspercentages of chlorides ranging from 0 1 2 and 3 by weight of cement and cured for 28 days After 28 days the stretchingforces were released the prestressing steel wire was allowed to regain its original length the tensile stresses were transformed intoa compressive stress in the concrete and the stress corrosion behavior was assessed Stress corrosion cracking (SCC) is due to thesimultaneous action of stress corrosive media and material properties e stress corrosion behavior of ungrouted pretensionedsteel was assessed by using various electrochemical techniques such as electrochemical noise open-circuit potential measurementAC impedance and potentiodynamic polarization measurements e same experiments were conducted for rebars embedded inthe concrete beam with various percentages of chlorides ranging from 0 1 2 and 3 by weight of chloride After 30 days ofexposure the beams were tested for their flexural strength measurements to find out the load-bearing capacity

1 Introduction

Prestressed concrete (PC) structures are commonly used forlong-span bridges dams silos and tanks industrial pave-ments and nuclear containment structures [1] Compressivestresses are induced in prestressed concrete either by pre-tensioning or posttensioning In pretensioning the steel isstretched before concreting Pretensioned concrete is used inprecast members such as roof slabs piles poles bridgegirders wall panels and railroad ties In posttensioning thesteel is stretched after the concrete hardens [2] Posttensionedconcrete is used for bridges large girders floor slabs shellsroofs and pavements PC is used in school auditoriumsgymnasiums and cafeterias because of its acoustical prop-erties and its ability to provide long open spaces One of themost widespread uses of PC is parking garages [3] PC hashigh ability to resist the impact high fatigue resistance andhigh live load-carrying capacity and is highly crack resistant

e PC structures have smaller deformation and can absorbmore tension than the nonprestressed concrete structure [4]PC structures are usually constructed by using high-performance concrete containing high-strength steel undervery high levels of tensile load e damage due to micro-cracking leads to a loss of elastic modulus And the presenceor ingress of chloride ions may cause the corrosion of steelwires which will lead to sudden or brittle failure of steel wirescausing premature failure of concrete structures [5ndash9]

High-strength steel is susceptible to stress corrosioncracking hydrogen embrittlement or a combination of bothmechanisms called hydrogen-induced stress corrosioncracking in the presence of aggressive environments AndSCC is caused due to the combined effect of mechanicalloading aggressive environment and some defects in thematerial [10ndash13] e defects present in the steel wires arethe weaker spots from which corrosion initiates and they actas a stress concentrated area where diffusion of hydrogen

HindawiAdvances in Materials Science and EngineeringVolume 2018 Article ID 8585162 11 pageshttpsdoiorg10115520188585162

contributes towards the SCC damage process [14 15] Pittingcorrosion is considered as a signicant cause of brittle failureof prestressed concrete structures [16 17] Pitting corrosionreduces the cross-sectional area of the prestressing steel andhence the load-carrying capacity of the structure [18] ereported failures due to SCC are the collapse of the BerlinCongress Hall [19] accident at the Uster indoor swimmingpool in Switzerland collapse of a railway overpass at BerghausenGermany [20] and collapse of the BicktonMeadows bridge theYnys-Y-Gwas bridge inUK [21] and the Saint Stefano bridge inItaly [22] Many researchers have studied the corrosion be-havior of PC structures [23ndash25] Studies revealed that strandcorrosion decreases the ultimate strength and the ductility ofpretensioned members [26 27] Strand corrosion will aectthe structural stability in terms of prestress loss strengthdegradation structural cracking and failure of structures[28ndash32] e eect of strand corrosion on structural be-havior was studied bymany researchers [33ndash35] Li et al [36]reported that the combined eect of fatigue and corrosionbehavior decreased the bond with increased fatigue stressunder a constant action of corrosion It was reported that thecorrosion of the strand in the pretensioned PC structure wasfound to degrade the tensile strength of the strand instead ofits bond strength [37] It has been found that the stresscorrosion is more dominant than pitting corrosion [18] Pitsmay be an initiation site for SCC or hydrogen embrittlement(HE) [5 6]

In the present investigation prestressed concrete beamsof size 150times150times1000mm were cast with two pretensionedsteel wires and M40 grade concrete with 1 2 and 3

chloride by weight of cement e stress corrosion behaviorof ungrouted pretensioned steel wires was assessed by usingvarious electrochemical techniques such as open-circuitpotential AC impedance linear polarization Tafel extrap-olation noise measurements and weight loss measure-ments All these measurements were made by using thefabricated embedded corrosion rate monitoring probe(ECMP) e sensor was fabricated as per the procedurereported elsewhere [38] e schematic representation of theECMP used for the investigation is given in Figure 1 [39]e experiments were carried out for the rebars embedded inthe concrete beam and the results are discussed in detail

2 Experimental

21MaterialsUsed in theTest Ordinary Portland Cement 43grade as per the Indian standard (IS) 8112 was used for theinvestigation e specic gravity of the cement used was314 e properties of OPC are shown in Table 1 Naturalriver sand of size below 475mm conforming to zone III of IS383-1970 was used as ne aggregates Coarse aggregates usedin this study consist of crushed stone of size 12mm andbelow e specic gravity of the ne and coarse aggregatesused was 264 and 263 Cold-drawn stress-relieved pre-stressing plain steel wire of 7mm diameter having an ul-timate tensile strength of 1470Nmm2 conforming to IS1785 Part 1 was used for the study e chemical com-position of the prestressing steel used was given in Table 2AR (analytical grade) NaCl purchased from Fischer Scien-tic was used for the investigation

Counterelectrodeconnected wire

PVC

5 cm

5 cm

SSREconnected wire

MnO2 SSRE

(a)

5 cm

Stainless steelcounterelectrode

Reference electrodeSSRE

40

cm

22 cm

20 cm

05 cm

(b)

Figure 1 Schematic diagram of the ECMP [17] (a) Top view (b) Side view

Table 1 Chemical composition of OPC

Compound SiO2 Al2O3 Fe2O3 CaO MgO SO3 LOIWt 20ndash21 52ndash56 44ndash48 62ndash63 05ndash07 24ndash28 15ndash25

Table 2 Chemical composition of alloying elements of the prestressing steel

Composition C Mn Si P S Cr Cu Ni Ti AlWt 082 074 021 012 0008 017 009 003 003 003

2 Advances in Materials Science and Engineering

22 Material PropertiesNominal diameter of the prestressing steel 7mmUltimate tensile stress of the prestressing steel (fpk)1470Nmm2

Cube compressive strength (fck) 40Nmm2

Mix ratio used (mass by weight) 1 098 296 04Cement FA CA water (kgm3) 450 444 1333 180ermomechanically treated (TMT) rebar 12mmdiameter 450 gradeSize of the beam (btimes dtimes l) 150times150times1000mmCross-sectional area of the beam 22500mm2

Area of the steel wire (Aps) 382mm2

Eccentricity from the center (e) 10mmPrestressing force (P) 1078 kN

23 Casting Procedure

231 Pretensioning of Strands Casting and CuringProcedure In general there are two ways in which pre-stressing of concrete by steel elements can be accomplishednamely pretensioning and posttensioning In pretensioningthe strands are tensioned before the casting of the concreteand in posttensioning the strands are tensioned after theconcrete hardens enough to support the stress In this workthe pretensioning technique was adopted

e prestressed concrete beam of size 150times150times1000mmwas designed and two bonded steel wires of 7mm diameterwere stressed at 70 UTS (ultimate tensile strength) underservice conditions before concreting e ultimate tensilestrength of the 7mm steel wire was 1470Nmm2 e av-erage yield strength of the 10mm TMT steel rebar was454Nmm2 and 6mm stirrup was 210Nmm2 e elastic

modulus of the prestressing steel wire and the TMT rebarwas 210 kNmm2 and 200 kNmm2 respectively e re-sultant stress diagram is given in Figure 2 e beams arereinforced with two 10mm diameter rebars at the bottomtwo 12mm diameter rebars at the top and 6mm stirrups at150mm spacing ECMP was embedded very near to thepretensioned steel e schematic of the reinforcementconcrete details is given in Figure 3 e beams were castwith M40 grade concrete mix of 1 098 296 with 04 wcratio While casting the concrete mix was admixed with 12 and 3 by weight of cement of NaCl to accelerate thecorrosion process e cast specimens were allowed to re-main in the steel mould for 24 hours at room temperatureAfter 24 hrs the specimens were demolded with care so thatno edges were broken and were subjected to cure for 28 daysby covering with the wet sack For each system triplicatebeams were cast After 28 days of curing the beams weresubjected to corrosion over the period of 30 days the stresswas released and the measurements were made At the endof 30 days the prestressed steel wire and the rebar embeddedin the concrete beams were subjected to electrochemicalnoise AC impedance and potentiodynamic polarizationmeasurements But the open-circuit potential measurementswere made after the curing period was over until the end ofthe 30th day

232 Flexure Test e prestressed beams were subjected tothe yenexural test to nd out the load-bearing capacity After28 days of curing the beams were allowed to corrode overa period of 30 days and the stress was released After thatthe beams were dried in the open atmosphere for 24 hoursand subjected to the yenexural testing in the UTM (universaltesting machine) of 100T capacity under two-point loadingand the load versus deyenection curve and the initial crack loadversus nal crack load were recorded e experimental

477 1925 012 089 3855 Nmm2

477

++

++ +

minus =minus

minus

minus

+ ++

150 mm

150

mm

0121925 089 5685 Nmm2

Figure 2 Resultant stress in concrete

Striupps of 6 mm diameter 150 mm CC4 nos of 10 mm diameter hanger bar

1501000

60

150

2 nos of 7 mm diameter prestressingstrand

Figure 3 Schematic diagram of prestressing concrete specimen details

Advances in Materials Science and Engineering 3

setup is shown in Figure 4 Modulus of rupture (Fb) wascalculated using the formula

Fb 3PL

2bd2(1)

where P is the maximum load at failure L is the span lengthof the beam b is the breadth of the beam and d is the depthof the beam

24 Electrochemical Studies

241 Electrochemical Noise (ECN) e ECN is one of thenondestructive and nonintrusive techniques being used inmonitoring the corrosion process of various metallic ma-terials [40] and it can provide information about the cor-rosion mechanism [41] It was found that the sensitivity ofthe ECN is much higher than that of the other techniques inidentifying the localized corrosion process [42] e ECN isachieved by simultaneous measurement of fluctuation ofcurrent and potential caused by the spontaneous electro-chemical reactions [43] e technique of measuring theelectrochemical noise uses no applied external signal for thecollection of experimental data

e ECN technique measures the signal perturbationswith low-level fluctuations of the corrosion potential be-tween two nominally identical electrodes which can be usedin the automatic determination of corrosion type and speede noise corresponds with the low-level frequency noise(differential of the ZRA) signal but has much lower am-plitude when general corrosion is involved [44] e tech-nique is widely used within the corrosion engineering asa useful corrosion monitoring technique ECN measure-ments were carried out for the prestressed steel and em-bedded rebars in the chloride-contaminated concrete

242 Open-Circuit Potential Measurements After 28 daysof curing the prestressing steel under stressed conditionsand rebars embedded in the concrete beams with andwithout various percentages of chloride were subjected toopen-circuit potential measurements with respect to ECMPe positive terminal of the microammeter was connected tothe prestressing steel and the negative terminal to the ECMPand the potential versus time plot was plotted for the pre-stressed steel and rebars Potential measurements were takenfor a period of 30 days

243 AC Impedance Spectroscopy An electrochemicalimpedance measurement is an appropriate method forcorrosion studies particularly for corrosion rate de-terminations passivation and passivity process and for theevaluation of different inhibitors Here the prestressing steelacts as a working electrode and the stainless steel and ECMPact as a counterelectode and a reference electrode re-spectively Impedance measurements were carried out forthe prestressed steel and rebars embedded in the chloride-contaminated concrete A time interval of 10 to 15min wasgiven for the OCP to reach a steady state value e im-pedance spectroscopymeasurement was carried out by using

ACM Instruments UK e real part (Zprime) and the imaginarypart (minusZPrime) of the cell impedance was measured for variousfrequencies (30 kHZ to 10mHz) Plots Zprime versus minusZPrime weremade Impedance measurements were carried out at the endof the exposure period of 30 days

244 Potentiodynamic Polarization Technique e sameexperimental setup used in the AC impedance technique wasused here also e ACM instrument has provisions forprograms to evaluate corrosion kinetic parameters such asIcorr and Ecorr e potentiodynamic condition correspondsto a potential sweep rate of 01mVsminus1 and a potential rangeof +200 to minus200mV from OCP Polarization studies werecarried out for all the systems All the experiments werecarried out at a room temperature of 30plusmn 2degC

3 Results and Discussion

31 Electrochemical Studies

311 Electrochemical Noise (ECN) e ECN measurementwas performed using ACM instruments UK at the end of the30-day exposure period e two-electrode system was usedfor taking the measurements Two identical prestressing steelswere used as the working electrode 1 and working electrode 2and the ECMP was used as the reference electrode eelectrochemical current noise and the potential noise betweenthe coupled working electrodes and the reference electrodewere measured simultaneously ECN records were taken for1000 s containing 1000 data points recorded with a data-sampling interval of 10 s (1Hz)e current versus time noiseand potential versus time noise plots for the rebars andprestressed steel are given in Figures 5 and 6 From Figure 5 itis observed that the potential and current noise exhibit dif-ferent characteristics during the experimental period epotential signal is found to have less fluctuation whencompared to the current noise signal Subsequently theamplitude of fluctuation was found to increase with the in-crease in chloride content in both the prestressed steel and therebar e current signal fluctuation was found to vary be-tween 05microA and 55 microA e potential fluctuation shift wasfound to be minus190mV minus290mV minus375mV and minus440mV for0 1 2 and 3 chloride level respectively in the rebar em-bedded in concrete It indicates that in the rebars embeddedin 3 chloride only the corrosion was initiated

Figure 4 Flexural test experimental setup

4 Advances in Materials Science and Engineering

In the case of the prestressed steel (Figure 6) the po-tential yenuctuation was found to be minus175 minus280 minus410 andminus510mV respectively at 0 1 2 and 3 respectively in-dicating the active condition of the steel wire at 2 and 3chloride levelse potential noise yenuctuation at 3 chloridewas found to be 291 times higher than that at 0 chlorideAs the chloride level increases the potential noise yenuctua-tion was also found to increase e current yenuctuation wasvaried from 050 microA to 100 microAe current noise yenuctuationat 3 chloride level was found to be 20 times higher thanthat at 0 chloride level which indicates the severity of thecorrosion in the stressed condition ere is a sudden shiftobserved in both the potential and current noise at 1 to 2chloride levels and from 2 to 3 chloride the potential andcurrent noise yenuctuation is found to be lesser when com-pared to 1 to 2 chloride levels Zhao et al [45] observed the

same trend of ECN behavior in chloride-contaminatedcement mortar-containing reinforcing steel

312 Open-Circuit Potential Measurement e open-circuit potential measured for the prestressed steel againstthe ECMP in various chloride concentrations is illustrated inFigure 7 From the gure (Figure 7(a)) it is observed that thepotential of the prestressed steel (without chloride) is foundto vary between minus121 and minus225mV versus ECMP indicatingthe passive condition of the steel wire throughout the ex-posure period of 30 days However in 1 chloride-contaminated concrete the potential was found to varybetween minus242mV during the starting period and it crossedthe threshold limit of minus275mV after the 4th day of exposureand the potential was shifted towards the negative direction

minus700

minus600

minus500

minus400

minus300

minus200

minus100

00 200 400 600 800 1000

Pote

ntia

l (m

V) v

ersu

s ECM

P

Time (s)

Control1 NaCl2 NaCl

(a)

0

1

2

3

4

5

6

7

8

9

10

0 200 400 600 800 1000

Curr

ent

(μA

)

Time (s)

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 5 Time records of the potential (a) and current (b) signalsfor the rebar embedded in chloride-contaminated concrete

minus700

minus600

minus500

minus400

minus300

minus200

minus100

00 200 400 600 800 1000

Pote

ntia

l (m

V) v

ersu

s ECM

P

Time (s)

Control1 NaCl2 NaCl3 NaCl

(a)

0

2

4

6

8

10

0 200 400 600 800 1000

Curr

ent (μA

)

Time (s)

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 6 Time records of the potential (a) and current (b) signalsfor the prestressed steel in chloride-contaminated concrete

Advances in Materials Science and Engineering 5

and it reached minus390mV at the end of the 30th day In 2 and3 chloride-contaminated concrete the rebar has shown theopen-circuit potential of minus450 and minus500mV at the end of theexposure period e higher shift in potential towards morenegative direction indicates the active condition of the rebarIn 3 chloride the rebar has shown a more negative po-tential of minus500mV versus ECMP at the end of the 30th dayindicating the active condition of the rebar

Figure 7(b) represents the potential versus time plot ofthe prestressed steel with various chloride levels From theresults it is found that the prestressed steel in controlconcrete is under passive condition showing the less negativepotential of minus250mV versus ECMP at the end of 30 daysWhereas in 1 2 and 3 chloride-contaminated con-crete the prestressed steel has shown more negative po-tentials than the unstressed steel indicating the active natureof the steel after 30 days of exposure In 3 chloride theprestressed steel has shown a more negative potential ofminus540mV versus ECMP after 30 days of the exposure in-dicating that the tendon has corroded severely

313 AC Impedance e Nyquist plot of the prestressedsteel and the rebar embedded in concrete with dierent ofchloride levels is given in Figure 8 e parameters obtainedfrom the impedance technique for the prestressed steel andthe rebar in various chloride-contaminated concrete after 30days of exposure are shown in Table 3 From the table it isfound that the stressed steel has shown higher corrosion ratethan the unstressed steel in all the chloride levels After 30days of exposure in chloride-contaminated concrete theprestressed steel has 106 103 and 148 times higher cor-rosion rate than the rebar embedded in 1 2 and 3chloride-contaminated concrete For example Icorr value forthe rebar and the stressed steel in 3 NaCl was1224times10minus3mAmiddotcm2 and 2098times10minus3mAmiddotcm2 respectively

Rct values of the rebar and prestressed steel in 3 NaCl were2131times104 and 1441times104Ωmiddotcm2 respectively e corrosionrate of the rebar and the prestressed steel in 3 NaCl was1419times10minus2mmpy and 2098times10minus2mmpy respectively Inboth the prestressed steel and rebar the Rct values werefound to decrease and Cdl values were found to increase withthe increase in chloride concentration respectively e Icorrvalues were found to increase with the chloride concen-trations irrespective of the stressed conditions Compared tothe stressed steel the rebar has lesser corrosion rate higherRct values and lower Cdl values

Figure 9 depicts the impedance modulus curve for therebar and prestressed steel with dierent percentages ofchloride levels after 30 days of exposure It is found that theimpedance values were found to decrease with the increasein chloride concentration When compared to the pre-stressed steel the rebar has lesser impedance values than theprestressed steel in all the chloride levels In the stressedcondition as the chloride level increases the impedancevalue was found to decrease by one order of magnitude ateach chloride level e lowest corrosion resistance of thesteel was observed in 3 NaCl in both the prestressed steeland the rebar Slight capacitive behavior with the low-frequency domain is observed in both the stressed andunstressed steel wires at all chloride levels ese resultscould be explained by taking into consideration that thechlorides present in the surrounding concrete reached thesteel wire and activatedinitiated the corrosion process [46]

314 Potentiodynamic Polarization Studies e potentio-dynamic polarization curve for the rebar and the prestressedsteel under various chloride concentration levels is depictedin Figure 10 e corrosion kinetic parameters obtainedfrom the potentiodynamic polarization studies are given inTable 4 From the table it is observed that the Ecorr values of

minus600

minus500

minus400

minus300

minus200

minus100

00 10 20 30

Pote

ntia

l (m

V) v

ersu

s EC

MP

Time (days)

Control1 NaCl2 NaCl3 NaCl

(a)

Control1 NaCl2 NaCl3 NaCl

minus600

minus500

minus400

minus300

minus200

minus100

00 10 20 30

Pote

ntia

l (m

V) v

ersu

s EC

MP

Time (days)

(b)

Figure 7 OCP curve for the rebar (a) and prestressed steel (b) in chloride-contaminated concrete

6 Advances in Materials Science and Engineering

the rebar after 30 days of exposure were minus291 minus388 andminus458 in 1 2 and 3 chloride levels respectively e Ecorrvalues for the rebar were minus424 minus518 and minus594mV

indicating the severity of the corrosion in the prestressedsteel when compared to the rebar After 30 days of exposurethe corrosion current (Icorr) and the corrosion rate of the

0

10000

20000

30000

40000

50000

40000 60000 80000 100000 120000 140000

ZPrime (Ω

cm2 )

Zprime (Ωcm2)

Control1 NaCl2 NaCl3 NaCl

(a)ZPrime

(Ωcm

2 )

Zprime (Ωcm2)

0

10000

20000

30000

40000

50000

20000 40000 60000 80000 100000 120000 140000

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 8 AC impedance curve for the rebar (a) and prestressed steel (b) in chloride-contaminated concrete

Table 3 Initial and nal crack load for the yenexural concrete beams

Designation Initial crack load (kN) Final crack load (kN) Modulus of rupture (Fb) (Nmm2)Control 78 1206 5361 NaCl 76 985 4382 NaCl 67 906 4033 NaCl 64 809 360

40000

60000

80000

100000

120000

140000

log

| Z |(

Ωcm

2 )

Control1 NaCl2 NaCl3 NaCl

1Eminus01 1E+00 1E+01 1E+02 1E+03 1E+04 1E+05log f (Hz)

(a)

log

| Z |(

Ωcm

2 )

log f (Hz)

40000

60000

80000

100000

120000

140000

1Eminus01 1E+00 1E+01 1E+02 1E+03 1E+04 1E+05

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 9 Impedance modulus curve for the rebar (a) and prestressed steel (b) in chloride-contaminated concrete

Advances in Materials Science and Engineering 7

prestressed steel were found to be higher when compared tothe rebar e corrosion rate of the rebar was 0721 11671524times10minus3mmpy in 1 2 and 3 chloride levels re-spectively e corrosion rate of the prestressed steel was0771 1374 1586times10minus3mmpy in 1 2 and 3 chloridelevels respectively e stressed steel has 104 118 and 104times higher corrosion rate than the rebar at 1 2 and 3chloride levels respectively From the potentiodynamicpolarization curve it is observed that the stressed steel hascorroded severely than the rebar

From the abovementioned electrochemical studies itis found that the shift in the corrosion rate was higher at2 chloride level when compared to 1 and 3 chloridelevels is may be due to the fact that initially during thehydration at 1 chloride levels the chlorides combinedwith the cement to form a complex called the Friedel salt[47 48] and it reduced the availability of free chlorideions At 2 chloride the complex formation was foundto be lower and the free chloride ions may be higher tocause more corrosion both in the case of the rebar andprestressed steel

32 Flexure Test Figure 11 shows the load versus dis-placement behavior of 0 1 2 and 3 chloride-admixedprestressed concrete beams tested under two-point loadingTable 5 shows the initial and nal crack load and themodulus of rupture for the various chloride-admixedconcrete beams after 30 days of exposure From Figure 10it is found that the cracks appeared in the midspan Anadditional increase in load under various stages resulted inthe formation of additional cracks and widening of someearlier formed cracks e cracks from the tension zonetraversed up to the neutral axis and cracking of the concretetook place at later stages e failure of the specimen oc-curred due to the fast propagation of the cracks From theload versus displacement curve it is found that the maxi-mum ultimate load for 0 1 2 and 3 of the chloride-contaminated concretes is 1206 985 906 and 809 kNrespectively From the results it is observed that whencompared to the control concrete the chloride-contaminated concrete has reduced the load-carrying ca-pacity of 183 249 and 329 for 1 2 and 3 chloride-admixed concreteemodulus of rupture was also found to

log i (mAcmminus2)

minus700

minus600

minus500

minus400

minus300

minus200

minus100

0

1Eminus06 1Eminus05 1Eminus04 1Eminus03 1Eminus02 1Eminus01

Pote

ntia

l (m

V) v

ersu

s ECM

P

Control1 NaCl2 NaCl3 NaCl

(a)

log i (mAcmminus2)

minus900

minus800

minus700

minus600

minus500

minus400

minus300

minus200

minus100

0

1Eminus06 1Eminus05 1Eminus04 1Eminus03 1Eminus02 1Eminus01

Pote

ntia

l (m

V) v

ersu

s ECM

P

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 10 Potentiodynamic polarization curve for the rebar (a) and prestressed steel (b) in chloride-contaminated concrete

Table 4 AC impedance parameters for the rebar and prestressed steel in chloride-contaminated concrete

System

AC impedance parametersRebar Prestressed steel wire

Rct (Ωmiddotcm2)times104

Cdl (Fmiddotcmminus2)times10minus5

Icorr(mAmiddotcm2)times

10minus3CR (mmpy)times

10minus2Rct (Ωmiddotcm2)times

104Cdl (Fmiddotcmminus2)times

10minus5Icorr

(mAmiddotcm2)times10minus3

CR(mmpy)times

10minus2

Control 4897 1733 0533 0617 4355 1623 0599 06941NaCl 4010 2225 0651 0754 3766 2088 0692 0803

2NaCl 2357 2417 1107 1283 2286 3174 1141 1323

3NaCl 2131 2618 1224 1419 1441 5125 1810 2098

8 Advances in Materials Science and Engineering

decrease with increase in the chloride concentration edecrease in the modulus of rupture is due to the presence ofchloride ions which caused the corrosion of reinforcementand prestressed steel leading to the reduction in the load-carrying capacity of the beam [49 50]

4 Conclusions

(1) e yenexural strength of the prestressed concretebeam was decreased by 329 as the chloride contentwas increased to 3

(2) e corrosion rate of the prestressed steel is found tobe higher than that of the rebar

(3) e present investigation further demonstrates thatthe ECN measurement combined with other elec-trochemical techniques is used to study the corrosionprocess of the prestressing steel e ECN results arein good agreement with those of the OCP and EISmeasurements

(4) e ECN clearly indicated the potential and currentshift with chloride contents e potential shiftsobserved were found to be minus190mV for 0 Clminus and

minus510mV for 3 Clminus in the stressed condition esedata showed 268 times shift for chloride-contaminated prestressed concrete beam

(5) From the abovementioned experiments it is foundthat the ECN clearly indicated the corrosion status ofthe chloride-contaminated and -uncontaminatedprestressed steel and rebar

Conflicts of Interest

e authors declare that there are no conyenicts of interest inpublishing this paper

Acknowledgments

is research was supported by the Basic Science ResearchProgram through the National Research Foundation ofKorea (NRF) funded by the Ministry of Science ICT andFuture Planning (no 2015R1A5A1037548) Velu Saraswathythanks the Director CECRI and CSIR for the permission topursue the fellowship at Hanyang University Erica campusKorea

0

20

40

60

80

100

120

140

0 2 4 6 8 10

Load

(kN

)

Displacement (mm)

Control1 NaCl2 NaCl3 NaCl

Figure 11 Load versus displacement behavior of corroded prestressed concrete beams after 30 days of exposure under variouschloride levels

Table 5 Potentiodynamic polarization parameters for the rebar and prestressed steel in chloride-contaminated concrete

System

Potentiodynamic polarization parametersRebar Prestressed steel

Ecorr (mV) Icorr (mAmiddotcm2)times 10minus4 Corrosion rate(mmpy)times 10minus3 Ecorr (mV) Icorr (mAmiddotcm2)times 10minus4 Corrosion rate

(mmpy)times 10minus3

Control minus250 0455 0527 minus340 0630 07301 NaCl minus291 0622 0721 minus424 0648 07712 NaCl minus388 1007 1167 minus518 1186 13743 NaCl minus458 1315 1524 minus594 1374 1586

Advances in Materials Science and Engineering 9

References

[1] Post-Tensioning Institute Post-Tensioning Manual pp 5ndash54PTI Phoenix AZ USA 6th edition 2006

[2] T Y Lin and N H Burns Design of Prestressed ConcreteStructures John Wiley amp Sons New York NY USA 3rdedition 1981

[3] R F Warner and K A Faulkes Prestressed Concrete pp 1ndash13Longman Cheshire Melbourne VIC Australia 2nd edition1988

[4] A S El-Amoush and S A Al-Duheisat ldquoCathodic polari-zation behavior of the structural steel wires under differentprestressing conditionsrdquo Journal of Materials Research andTechnology 2017 in press

[5] M S Darmawan and M G Stewart ldquoSpatial time-dependentreliability analysis of corroding pretensioned prestressedconcrete bridge girdersrdquo Structural Safety vol 29 no 1pp 16ndash31 2007

[6] M S Darmawan and M G Stewart ldquoEffect of pitting cor-rosion on capacity of prestressing wiresrdquo Magazine of Con-crete Research vol 59 no 2 pp 131ndash139 2007

[7] P Gardoni R G Pillai M B D Hueste K Reinschmidt andD Trejo ldquoProbabilistic capacity models for corroding post-tensioning strands calibrated using laboratory resultsrdquoJournal of Engineering Mechanics vol 135 no 9 pp 906ndash9162009

[8] R G Pillai P Gardoni D Trejo M B D Hueste andK F Reinschmidt ldquoProbabilistic models for the tensilestrength of corroding strands in post-tensioned segmentalconcrete bridgesrdquo Journal of Materials in Civil Engineeringvol 22 no 10 pp 967ndash977 2010

[9] N A Vu A Castel and R Franccedilois ldquoEffect of stress corrosioncracking on stressndashstrain response of steel wires used inprestressed concrete beamsrdquo Corrosion Science vol 51 no 6pp 1453ndash1459 2009

[10] J Woodtli and R Kieselbach ldquoDamage due to hydrogenembrittlement and stress corrosion crackingrdquo EngineeringFailure Analysis vol 7 no 6 pp 427ndash450 2000

[11] J Toribio ldquoe role of crack tip strain rate in hydrogenassisted crackingrdquo Corrosion Science vol 39 no 9pp 1687ndash1697 1997

[12] N A Vu A Castel and R Franccedilois ldquoResponse of post-tensioned concrete beams with unbonded tendons includingserviceability and ultimate staterdquo Engineering Structurevol 32 no 2 pp 556ndash569 2010

[13] D G Cavell and P Waldron ldquoA residual strength model fordeteriorating post-tensioned concrete bridgesrdquo Computers ampStructures vol 79 no 4 pp 361ndash373 2001

[14] M Grinfeld ldquoStress corrosion cracking of an elastic platerdquoActa Materialia vol 46 no 2 pp 631ndash636 1998

[15] A Toshimitsu Yokobori Jr Y Chinda T Nemoto K Satohand T Yamada ldquoe characteristics of hydrogen diffusionand concentration around a crack tip concerned with hy-drogen embrittlementrdquo Corrosion Science vol 44 no 3pp 407ndash424 2002

[16] A Turnbull L N McCartney and S Zhou ldquoModelling of theevolution of stress corrosion cracks from corrosion pitsrdquoScripta Materialia vol 54 no 4 pp 575ndash578 2006

[17] F Li Y Yuan and C Q Li ldquoCorrosion propagation ofprestressing steel strands in concrete subject to chloride at-tackrdquo Construction and Building Materials vol 25 no 10pp 3878ndash3885 2011

[18] A Valiente ldquoStress corrosion failure of large diameterpressure pipelines of prestressed concreterdquo EngineeringFailure Analysis vol 8 no 3 pp 245ndash261 2001

[19] R Helmerich and A Zunkel ldquoPartial collapse of the BerlinCongress Hall on May 21st 1980rdquo Engineering FailureAnalysis vol 43 pp 107ndash119 2014

[20] S Ramadan L Gaillet C Tessier and H Idrissi ldquoDetection ofstress corrosion cracking of high-strength steel used in pre-stressed concrete structures by acoustic emission techniquerdquoApplied Surface Science vol 254 no 8 pp 2255ndash2261 2008

[21] R W Posten and J P Wouters Durability of Precast Seg-mental Bridges NCHRP Web Document No 15 Project20ndash7Task 92 Transportation Research Board National Re-search Council Washington DC USA 1998

[22] M S Darmawan ldquoPitting corrosion model for partial pre-stressed concrete (PC) structures in a chloride environmentrdquoJournal of Technology Science vol 20 no 3 pp 109ndash118 2009

[23] L Dai L Wang J Zhang and X Zhang ldquoA global model forcorrosion-induced cracking in prestressed concrete struc-turesrdquo Engineering Failure Analysis vol 62 pp 263ndash2752016

[24] W Zhang X Liu and X Gu ldquoFatigue behavior of corrodedprestressed concrete beamsrdquo Construction and BuildingsMaterials vol 106 pp 198ndash208 2016

[25] X Zhang L Wang J Zhang Y Ma and Y Liu ldquoFlexuralbehavior of bonded post-tensioned concrete beams understrand corrosionrdquo Nuclear Engineering and Design vol 313pp 414ndash424 2017

[26] K A Harries ldquoStructural testing of prestressed concretegirders from the Lake View Drive Bridgerdquo Journal of BridgeEngineering vol 14 no 2 pp 78ndash92 2009

[27] M Kiviste and J Miljan ldquoEvaluation of residual flexuralcapacity of existing pre-cast pre-stressed concrete panelsmdashacase studyrdquo Engineering Structure vol 32 no 10 pp 3377ndash3383 2010

[28] D Coronelli A Castel N A Vu and R Franccedilois ldquoCorrodedpost-tensioned beams with bonded tendons and wire failurerdquoEngineering Structure vol 31 no 8 pp 1687ndash1697 2009

[29] C Q Li Y Yang and R E Melchers ldquoPrediction of re-inforcement corrosion in concrete and its effects on concretecracking and strength reductionrdquo ACI Materials Journalvol 105 no 1 pp 3ndash10 2008

[30] A A Torres-Acosta and M Martıınez-Madrid ldquoResidual lifeof corroding reinforced concrete structures in marine envi-ronmentrdquo Journal of Materials in Civil Engineering vol 15no 4 pp 344ndash353 2003

[31] H Minh H Mutsuyoshi and K Niitani ldquoInfluence ofgrouting condition on crack and load-carrying capacity ofpost-tensioned concrete beam due to chloride-induced cor-rosionrdquo Construction and Building Materials vol 21 no 7pp 1568ndash1575 2007

[32] H Minh H Mutsuyoshi H Taniguchi and K NiitanildquoChloride-induced corrosion in insufficiently grouted post-tensioned concrete beamsrdquo Journal of Materials in CivilEngineering vol 20 no 1 pp 85ndash91 2008

[33] A Castel D Coronelli N A Vu and R Franccedilois ldquoStructuralresponse of corroded unbonded post-tensioned beamsrdquoJournal of Structural Engineering vol 137 no 7 pp 761ndash7712010

[34] R G Pillai D Trejo P Gardoni M B D Hueste andK Reinschmidt ldquoTime-variant flexural reliability of post-tensioned segmental concrete bridges exposed to corrosiveenvironmentsrdquo Journal of Structural Engineering vol 140no 8 p A4014018 2014

10 Advances in Materials Science and Engineering

[35] A Torres-Acosta S Navarro-Gutierrez and J Teran-GuillenldquoResidual flexure capacity of corroded reinforced concretebeamsrdquo Engineering Structure vol 29 no 6 pp 1145ndash11522007

[36] F Li Y Qu and J Wang ldquoBond life degradation of steelstrand and concrete under combined corrosion and fatiguerdquoEngineering Failure Analysis vol 80 no 10 pp 186ndash196 2017

[37] F Li and Y Yuan ldquoEffects of corrosion on bond behaviorbetween steel strand and concreterdquo Construction and BuildingMaterials vol 38 pp 413ndash422 2013

[38] S Muralidharan T H Ha J H Bae et al ldquoElectrochemicalstudies on the solid embeddable reference sensors for cor-rosion monitoring in concrete structurerdquo Materials Lettersvol 60 no 5 pp 651ndash655 2006

[39] K Subbiah S Velu S-J Kwon H-S Lee N Rethinam andD-J Park ldquoA novel in-situ corrosion monitoring electrodefor reinforced concrete structuresrdquo Electrochimica Acta 2017in press

[40] M Aballe F J Bethencourt M Botana J M Marcos andA Sanchez ldquoInfluence of the degree of polishing of alloy AA5083 on its behavior against localized alkaline corrosionrdquoCorrosion Science vol 46 no 8 pp 1909ndash1920 2004

[41] S Girija U K Mudali V R Raju R K Dayal H S Khatakand B Raj ldquoDetermination of corrosion types for AISI type304L stainless steel using electrochemical noise methodrdquoMaterials Science and Engineering A vol 407 no 1-2pp 188ndash195 2005

[42] R J K Wood J A Wharton A J Speyer and K S TanldquoInvestigation of erosion-corrosion processes using electro-chemical noise measurementsrdquo Tribology Internationalvol 35 no 10 pp 631ndash634 2002

[43] M C Deya B del Amo E Spinelli and R Romagnoli ldquoeassessment of a smart anticorrosive coating by the electro-chemical noise techniquerdquo Progress Organic Coatings vol 76no 14 pp 525ndash532 2013

[44] H W Song and V Saraswathy ldquoCorrosion monitoring ofreinforced concrete structures-a reviewrdquo International Jour-nal of Electrochemical Science vol 2 pp 1ndash28 2007

[45] B Zhao J H Li R G Hu R G Du and C J Lin ldquoStudy onthe corrosion behavior of reinforcing steel in cement mortarby electrochemical noise measurementsrdquo Electrochimica Actavol 52 no 12 pp 3976ndash3984 2007

[46] R G Duarte A S Castela R Neves L Freire andM F Montemor ldquoCorrosion behaviour of stainless steelrebars embedded in concrete an electrochemical impedancespectroscopy studyrdquo Electrochimica Acta vol 124 pp 218ndash224 2014

[47] Kangavel S Muralidharan V Saraswathy K Y Ann andL Balamurugan ldquoRelationship between alumina and chloridecontent on their physical and corrosion resistance propertiesof concreterdquo Arabian Journal for Science and Engineeringvol 35 no 28 pp 27ndash38 2009

[48] S P Karthick S Muralidharan V Saraswathy andS J Kwon ldquoEffect of different alkali salt additions on concretedurability propertyrdquo Journal of Structural Integrity andMaintenance vol 1 no 1 pp 35ndash42 2016

[49] M Moawad H EI-Karmoty and A EI Zanaty ldquoBehavior ofcorroded bonded fully prestressed and conventional concretebeamsrdquo HBRC Journal 2016 in press

[50] M Moawad A Mahmoud H EI-Karmoty and A EI ZanatyldquoBehavior of corroded bonded partially prestressed concretebeamsrdquo HBRC Journal 2016 in press

Advances in Materials Science and Engineering 11

CorrosionInternational Journal of

Hindawiwwwhindawicom Volume 2018

Advances in

Materials Science and EngineeringHindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Analytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

ScienticaHindawiwwwhindawicom Volume 2018

Polymer ScienceInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Advances in Condensed Matter Physics

Hindawiwwwhindawicom Volume 2018

International Journal of

BiomaterialsHindawiwwwhindawicom

Journal ofEngineeringVolume 2018

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Hindawiwwwhindawicom Volume 2018

High Energy PhysicsAdvances in

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

ChemistryAdvances in

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom Volume 2018

BioMed Research InternationalMaterials

Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

22 Material PropertiesNominal diameter of the prestressing steel 7mmUltimate tensile stress of the prestressing steel (fpk)1470Nmm2

Cube compressive strength (fck) 40Nmm2

Mix ratio used (mass by weight) 1 098 296 04Cement FA CA water (kgm3) 450 444 1333 180ermomechanically treated (TMT) rebar 12mmdiameter 450 gradeSize of the beam (btimes dtimes l) 150times150times1000mmCross-sectional area of the beam 22500mm2

Area of the steel wire (Aps) 382mm2

Eccentricity from the center (e) 10mmPrestressing force (P) 1078 kN

23 Casting Procedure

231 Pretensioning of Strands Casting and CuringProcedure In general there are two ways in which pre-stressing of concrete by steel elements can be accomplishednamely pretensioning and posttensioning In pretensioningthe strands are tensioned before the casting of the concreteand in posttensioning the strands are tensioned after theconcrete hardens enough to support the stress In this workthe pretensioning technique was adopted

e prestressed concrete beam of size 150times150times1000mmwas designed and two bonded steel wires of 7mm diameterwere stressed at 70 UTS (ultimate tensile strength) underservice conditions before concreting e ultimate tensilestrength of the 7mm steel wire was 1470Nmm2 e av-erage yield strength of the 10mm TMT steel rebar was454Nmm2 and 6mm stirrup was 210Nmm2 e elastic

modulus of the prestressing steel wire and the TMT rebarwas 210 kNmm2 and 200 kNmm2 respectively e re-sultant stress diagram is given in Figure 2 e beams arereinforced with two 10mm diameter rebars at the bottomtwo 12mm diameter rebars at the top and 6mm stirrups at150mm spacing ECMP was embedded very near to thepretensioned steel e schematic of the reinforcementconcrete details is given in Figure 3 e beams were castwith M40 grade concrete mix of 1 098 296 with 04 wcratio While casting the concrete mix was admixed with 12 and 3 by weight of cement of NaCl to accelerate thecorrosion process e cast specimens were allowed to re-main in the steel mould for 24 hours at room temperatureAfter 24 hrs the specimens were demolded with care so thatno edges were broken and were subjected to cure for 28 daysby covering with the wet sack For each system triplicatebeams were cast After 28 days of curing the beams weresubjected to corrosion over the period of 30 days the stresswas released and the measurements were made At the endof 30 days the prestressed steel wire and the rebar embeddedin the concrete beams were subjected to electrochemicalnoise AC impedance and potentiodynamic polarizationmeasurements But the open-circuit potential measurementswere made after the curing period was over until the end ofthe 30th day

232 Flexure Test e prestressed beams were subjected tothe yenexural test to nd out the load-bearing capacity After28 days of curing the beams were allowed to corrode overa period of 30 days and the stress was released After thatthe beams were dried in the open atmosphere for 24 hoursand subjected to the yenexural testing in the UTM (universaltesting machine) of 100T capacity under two-point loadingand the load versus deyenection curve and the initial crack loadversus nal crack load were recorded e experimental

477 1925 012 089 3855 Nmm2

477

++

++ +

minus =minus

minus

minus

+ ++

150 mm

150

mm

0121925 089 5685 Nmm2

Figure 2 Resultant stress in concrete

Striupps of 6 mm diameter 150 mm CC4 nos of 10 mm diameter hanger bar

1501000

60

150

2 nos of 7 mm diameter prestressingstrand

Figure 3 Schematic diagram of prestressing concrete specimen details

Advances in Materials Science and Engineering 3

setup is shown in Figure 4 Modulus of rupture (Fb) wascalculated using the formula

Fb 3PL

2bd2(1)

where P is the maximum load at failure L is the span lengthof the beam b is the breadth of the beam and d is the depthof the beam

24 Electrochemical Studies

241 Electrochemical Noise (ECN) e ECN is one of thenondestructive and nonintrusive techniques being used inmonitoring the corrosion process of various metallic ma-terials [40] and it can provide information about the cor-rosion mechanism [41] It was found that the sensitivity ofthe ECN is much higher than that of the other techniques inidentifying the localized corrosion process [42] e ECN isachieved by simultaneous measurement of fluctuation ofcurrent and potential caused by the spontaneous electro-chemical reactions [43] e technique of measuring theelectrochemical noise uses no applied external signal for thecollection of experimental data

e ECN technique measures the signal perturbationswith low-level fluctuations of the corrosion potential be-tween two nominally identical electrodes which can be usedin the automatic determination of corrosion type and speede noise corresponds with the low-level frequency noise(differential of the ZRA) signal but has much lower am-plitude when general corrosion is involved [44] e tech-nique is widely used within the corrosion engineering asa useful corrosion monitoring technique ECN measure-ments were carried out for the prestressed steel and em-bedded rebars in the chloride-contaminated concrete

242 Open-Circuit Potential Measurements After 28 daysof curing the prestressing steel under stressed conditionsand rebars embedded in the concrete beams with andwithout various percentages of chloride were subjected toopen-circuit potential measurements with respect to ECMPe positive terminal of the microammeter was connected tothe prestressing steel and the negative terminal to the ECMPand the potential versus time plot was plotted for the pre-stressed steel and rebars Potential measurements were takenfor a period of 30 days

243 AC Impedance Spectroscopy An electrochemicalimpedance measurement is an appropriate method forcorrosion studies particularly for corrosion rate de-terminations passivation and passivity process and for theevaluation of different inhibitors Here the prestressing steelacts as a working electrode and the stainless steel and ECMPact as a counterelectode and a reference electrode re-spectively Impedance measurements were carried out forthe prestressed steel and rebars embedded in the chloride-contaminated concrete A time interval of 10 to 15min wasgiven for the OCP to reach a steady state value e im-pedance spectroscopymeasurement was carried out by using

ACM Instruments UK e real part (Zprime) and the imaginarypart (minusZPrime) of the cell impedance was measured for variousfrequencies (30 kHZ to 10mHz) Plots Zprime versus minusZPrime weremade Impedance measurements were carried out at the endof the exposure period of 30 days

244 Potentiodynamic Polarization Technique e sameexperimental setup used in the AC impedance technique wasused here also e ACM instrument has provisions forprograms to evaluate corrosion kinetic parameters such asIcorr and Ecorr e potentiodynamic condition correspondsto a potential sweep rate of 01mVsminus1 and a potential rangeof +200 to minus200mV from OCP Polarization studies werecarried out for all the systems All the experiments werecarried out at a room temperature of 30plusmn 2degC

3 Results and Discussion

31 Electrochemical Studies

311 Electrochemical Noise (ECN) e ECN measurementwas performed using ACM instruments UK at the end of the30-day exposure period e two-electrode system was usedfor taking the measurements Two identical prestressing steelswere used as the working electrode 1 and working electrode 2and the ECMP was used as the reference electrode eelectrochemical current noise and the potential noise betweenthe coupled working electrodes and the reference electrodewere measured simultaneously ECN records were taken for1000 s containing 1000 data points recorded with a data-sampling interval of 10 s (1Hz)e current versus time noiseand potential versus time noise plots for the rebars andprestressed steel are given in Figures 5 and 6 From Figure 5 itis observed that the potential and current noise exhibit dif-ferent characteristics during the experimental period epotential signal is found to have less fluctuation whencompared to the current noise signal Subsequently theamplitude of fluctuation was found to increase with the in-crease in chloride content in both the prestressed steel and therebar e current signal fluctuation was found to vary be-tween 05microA and 55 microA e potential fluctuation shift wasfound to be minus190mV minus290mV minus375mV and minus440mV for0 1 2 and 3 chloride level respectively in the rebar em-bedded in concrete It indicates that in the rebars embeddedin 3 chloride only the corrosion was initiated

Figure 4 Flexural test experimental setup

4 Advances in Materials Science and Engineering

In the case of the prestressed steel (Figure 6) the po-tential yenuctuation was found to be minus175 minus280 minus410 andminus510mV respectively at 0 1 2 and 3 respectively in-dicating the active condition of the steel wire at 2 and 3chloride levelse potential noise yenuctuation at 3 chloridewas found to be 291 times higher than that at 0 chlorideAs the chloride level increases the potential noise yenuctua-tion was also found to increase e current yenuctuation wasvaried from 050 microA to 100 microAe current noise yenuctuationat 3 chloride level was found to be 20 times higher thanthat at 0 chloride level which indicates the severity of thecorrosion in the stressed condition ere is a sudden shiftobserved in both the potential and current noise at 1 to 2chloride levels and from 2 to 3 chloride the potential andcurrent noise yenuctuation is found to be lesser when com-pared to 1 to 2 chloride levels Zhao et al [45] observed the

same trend of ECN behavior in chloride-contaminatedcement mortar-containing reinforcing steel

312 Open-Circuit Potential Measurement e open-circuit potential measured for the prestressed steel againstthe ECMP in various chloride concentrations is illustrated inFigure 7 From the gure (Figure 7(a)) it is observed that thepotential of the prestressed steel (without chloride) is foundto vary between minus121 and minus225mV versus ECMP indicatingthe passive condition of the steel wire throughout the ex-posure period of 30 days However in 1 chloride-contaminated concrete the potential was found to varybetween minus242mV during the starting period and it crossedthe threshold limit of minus275mV after the 4th day of exposureand the potential was shifted towards the negative direction

minus700

minus600

minus500

minus400

minus300

minus200

minus100

00 200 400 600 800 1000

Pote

ntia

l (m

V) v

ersu

s ECM

P

Time (s)

Control1 NaCl2 NaCl

(a)

0

1

2

3

4

5

6

7

8

9

10

0 200 400 600 800 1000

Curr

ent

(μA

)

Time (s)

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 5 Time records of the potential (a) and current (b) signalsfor the rebar embedded in chloride-contaminated concrete

minus700

minus600

minus500

minus400

minus300

minus200

minus100

00 200 400 600 800 1000

Pote

ntia

l (m

V) v

ersu

s ECM

P

Time (s)

Control1 NaCl2 NaCl3 NaCl

(a)

0

2

4

6

8

10

0 200 400 600 800 1000

Curr

ent (μA

)

Time (s)

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 6 Time records of the potential (a) and current (b) signalsfor the prestressed steel in chloride-contaminated concrete

Advances in Materials Science and Engineering 5

and it reached minus390mV at the end of the 30th day In 2 and3 chloride-contaminated concrete the rebar has shown theopen-circuit potential of minus450 and minus500mV at the end of theexposure period e higher shift in potential towards morenegative direction indicates the active condition of the rebarIn 3 chloride the rebar has shown a more negative po-tential of minus500mV versus ECMP at the end of the 30th dayindicating the active condition of the rebar

Figure 7(b) represents the potential versus time plot ofthe prestressed steel with various chloride levels From theresults it is found that the prestressed steel in controlconcrete is under passive condition showing the less negativepotential of minus250mV versus ECMP at the end of 30 daysWhereas in 1 2 and 3 chloride-contaminated con-crete the prestressed steel has shown more negative po-tentials than the unstressed steel indicating the active natureof the steel after 30 days of exposure In 3 chloride theprestressed steel has shown a more negative potential ofminus540mV versus ECMP after 30 days of the exposure in-dicating that the tendon has corroded severely

313 AC Impedance e Nyquist plot of the prestressedsteel and the rebar embedded in concrete with dierent ofchloride levels is given in Figure 8 e parameters obtainedfrom the impedance technique for the prestressed steel andthe rebar in various chloride-contaminated concrete after 30days of exposure are shown in Table 3 From the table it isfound that the stressed steel has shown higher corrosion ratethan the unstressed steel in all the chloride levels After 30days of exposure in chloride-contaminated concrete theprestressed steel has 106 103 and 148 times higher cor-rosion rate than the rebar embedded in 1 2 and 3chloride-contaminated concrete For example Icorr value forthe rebar and the stressed steel in 3 NaCl was1224times10minus3mAmiddotcm2 and 2098times10minus3mAmiddotcm2 respectively

Rct values of the rebar and prestressed steel in 3 NaCl were2131times104 and 1441times104Ωmiddotcm2 respectively e corrosionrate of the rebar and the prestressed steel in 3 NaCl was1419times10minus2mmpy and 2098times10minus2mmpy respectively Inboth the prestressed steel and rebar the Rct values werefound to decrease and Cdl values were found to increase withthe increase in chloride concentration respectively e Icorrvalues were found to increase with the chloride concen-trations irrespective of the stressed conditions Compared tothe stressed steel the rebar has lesser corrosion rate higherRct values and lower Cdl values

Figure 9 depicts the impedance modulus curve for therebar and prestressed steel with dierent percentages ofchloride levels after 30 days of exposure It is found that theimpedance values were found to decrease with the increasein chloride concentration When compared to the pre-stressed steel the rebar has lesser impedance values than theprestressed steel in all the chloride levels In the stressedcondition as the chloride level increases the impedancevalue was found to decrease by one order of magnitude ateach chloride level e lowest corrosion resistance of thesteel was observed in 3 NaCl in both the prestressed steeland the rebar Slight capacitive behavior with the low-frequency domain is observed in both the stressed andunstressed steel wires at all chloride levels ese resultscould be explained by taking into consideration that thechlorides present in the surrounding concrete reached thesteel wire and activatedinitiated the corrosion process [46]

314 Potentiodynamic Polarization Studies e potentio-dynamic polarization curve for the rebar and the prestressedsteel under various chloride concentration levels is depictedin Figure 10 e corrosion kinetic parameters obtainedfrom the potentiodynamic polarization studies are given inTable 4 From the table it is observed that the Ecorr values of

minus600

minus500

minus400

minus300

minus200

minus100

00 10 20 30

Pote

ntia

l (m

V) v

ersu

s EC

MP

Time (days)

Control1 NaCl2 NaCl3 NaCl

(a)

Control1 NaCl2 NaCl3 NaCl

minus600

minus500

minus400

minus300

minus200

minus100

00 10 20 30

Pote

ntia

l (m

V) v

ersu

s EC

MP

Time (days)

(b)

Figure 7 OCP curve for the rebar (a) and prestressed steel (b) in chloride-contaminated concrete

6 Advances in Materials Science and Engineering

the rebar after 30 days of exposure were minus291 minus388 andminus458 in 1 2 and 3 chloride levels respectively e Ecorrvalues for the rebar were minus424 minus518 and minus594mV

indicating the severity of the corrosion in the prestressedsteel when compared to the rebar After 30 days of exposurethe corrosion current (Icorr) and the corrosion rate of the

0

10000

20000

30000

40000

50000

40000 60000 80000 100000 120000 140000

ZPrime (Ω

cm2 )

Zprime (Ωcm2)

Control1 NaCl2 NaCl3 NaCl

(a)ZPrime

(Ωcm

2 )

Zprime (Ωcm2)

0

10000

20000

30000

40000

50000

20000 40000 60000 80000 100000 120000 140000

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 8 AC impedance curve for the rebar (a) and prestressed steel (b) in chloride-contaminated concrete

Table 3 Initial and nal crack load for the yenexural concrete beams

Designation Initial crack load (kN) Final crack load (kN) Modulus of rupture (Fb) (Nmm2)Control 78 1206 5361 NaCl 76 985 4382 NaCl 67 906 4033 NaCl 64 809 360

40000

60000

80000

100000

120000

140000

log

| Z |(

Ωcm

2 )

Control1 NaCl2 NaCl3 NaCl

1Eminus01 1E+00 1E+01 1E+02 1E+03 1E+04 1E+05log f (Hz)

(a)

log

| Z |(

Ωcm

2 )

log f (Hz)

40000

60000

80000

100000

120000

140000

1Eminus01 1E+00 1E+01 1E+02 1E+03 1E+04 1E+05

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 9 Impedance modulus curve for the rebar (a) and prestressed steel (b) in chloride-contaminated concrete

Advances in Materials Science and Engineering 7

prestressed steel were found to be higher when compared tothe rebar e corrosion rate of the rebar was 0721 11671524times10minus3mmpy in 1 2 and 3 chloride levels re-spectively e corrosion rate of the prestressed steel was0771 1374 1586times10minus3mmpy in 1 2 and 3 chloridelevels respectively e stressed steel has 104 118 and 104times higher corrosion rate than the rebar at 1 2 and 3chloride levels respectively From the potentiodynamicpolarization curve it is observed that the stressed steel hascorroded severely than the rebar

From the abovementioned electrochemical studies itis found that the shift in the corrosion rate was higher at2 chloride level when compared to 1 and 3 chloridelevels is may be due to the fact that initially during thehydration at 1 chloride levels the chlorides combinedwith the cement to form a complex called the Friedel salt[47 48] and it reduced the availability of free chlorideions At 2 chloride the complex formation was foundto be lower and the free chloride ions may be higher tocause more corrosion both in the case of the rebar andprestressed steel

32 Flexure Test Figure 11 shows the load versus dis-placement behavior of 0 1 2 and 3 chloride-admixedprestressed concrete beams tested under two-point loadingTable 5 shows the initial and nal crack load and themodulus of rupture for the various chloride-admixedconcrete beams after 30 days of exposure From Figure 10it is found that the cracks appeared in the midspan Anadditional increase in load under various stages resulted inthe formation of additional cracks and widening of someearlier formed cracks e cracks from the tension zonetraversed up to the neutral axis and cracking of the concretetook place at later stages e failure of the specimen oc-curred due to the fast propagation of the cracks From theload versus displacement curve it is found that the maxi-mum ultimate load for 0 1 2 and 3 of the chloride-contaminated concretes is 1206 985 906 and 809 kNrespectively From the results it is observed that whencompared to the control concrete the chloride-contaminated concrete has reduced the load-carrying ca-pacity of 183 249 and 329 for 1 2 and 3 chloride-admixed concreteemodulus of rupture was also found to

log i (mAcmminus2)

minus700

minus600

minus500

minus400

minus300

minus200

minus100

0

1Eminus06 1Eminus05 1Eminus04 1Eminus03 1Eminus02 1Eminus01

Pote

ntia

l (m

V) v

ersu

s ECM

P

Control1 NaCl2 NaCl3 NaCl

(a)

log i (mAcmminus2)

minus900

minus800

minus700

minus600

minus500

minus400

minus300

minus200

minus100

0

1Eminus06 1Eminus05 1Eminus04 1Eminus03 1Eminus02 1Eminus01

Pote

ntia

l (m

V) v

ersu

s ECM

P

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 10 Potentiodynamic polarization curve for the rebar (a) and prestressed steel (b) in chloride-contaminated concrete

Table 4 AC impedance parameters for the rebar and prestressed steel in chloride-contaminated concrete

System

AC impedance parametersRebar Prestressed steel wire

Rct (Ωmiddotcm2)times104

Cdl (Fmiddotcmminus2)times10minus5

Icorr(mAmiddotcm2)times

10minus3CR (mmpy)times

10minus2Rct (Ωmiddotcm2)times

104Cdl (Fmiddotcmminus2)times

10minus5Icorr

(mAmiddotcm2)times10minus3

CR(mmpy)times

10minus2

Control 4897 1733 0533 0617 4355 1623 0599 06941NaCl 4010 2225 0651 0754 3766 2088 0692 0803

2NaCl 2357 2417 1107 1283 2286 3174 1141 1323

3NaCl 2131 2618 1224 1419 1441 5125 1810 2098

8 Advances in Materials Science and Engineering

decrease with increase in the chloride concentration edecrease in the modulus of rupture is due to the presence ofchloride ions which caused the corrosion of reinforcementand prestressed steel leading to the reduction in the load-carrying capacity of the beam [49 50]

4 Conclusions

(1) e yenexural strength of the prestressed concretebeam was decreased by 329 as the chloride contentwas increased to 3

(2) e corrosion rate of the prestressed steel is found tobe higher than that of the rebar

(3) e present investigation further demonstrates thatthe ECN measurement combined with other elec-trochemical techniques is used to study the corrosionprocess of the prestressing steel e ECN results arein good agreement with those of the OCP and EISmeasurements

(4) e ECN clearly indicated the potential and currentshift with chloride contents e potential shiftsobserved were found to be minus190mV for 0 Clminus and

minus510mV for 3 Clminus in the stressed condition esedata showed 268 times shift for chloride-contaminated prestressed concrete beam

(5) From the abovementioned experiments it is foundthat the ECN clearly indicated the corrosion status ofthe chloride-contaminated and -uncontaminatedprestressed steel and rebar

Conflicts of Interest

e authors declare that there are no conyenicts of interest inpublishing this paper

Acknowledgments

is research was supported by the Basic Science ResearchProgram through the National Research Foundation ofKorea (NRF) funded by the Ministry of Science ICT andFuture Planning (no 2015R1A5A1037548) Velu Saraswathythanks the Director CECRI and CSIR for the permission topursue the fellowship at Hanyang University Erica campusKorea

0

20

40

60

80

100

120

140

0 2 4 6 8 10

Load

(kN

)

Displacement (mm)

Control1 NaCl2 NaCl3 NaCl

Figure 11 Load versus displacement behavior of corroded prestressed concrete beams after 30 days of exposure under variouschloride levels

Table 5 Potentiodynamic polarization parameters for the rebar and prestressed steel in chloride-contaminated concrete

System

Potentiodynamic polarization parametersRebar Prestressed steel

Ecorr (mV) Icorr (mAmiddotcm2)times 10minus4 Corrosion rate(mmpy)times 10minus3 Ecorr (mV) Icorr (mAmiddotcm2)times 10minus4 Corrosion rate

(mmpy)times 10minus3

Control minus250 0455 0527 minus340 0630 07301 NaCl minus291 0622 0721 minus424 0648 07712 NaCl minus388 1007 1167 minus518 1186 13743 NaCl minus458 1315 1524 minus594 1374 1586

Advances in Materials Science and Engineering 9

References

[1] Post-Tensioning Institute Post-Tensioning Manual pp 5ndash54PTI Phoenix AZ USA 6th edition 2006

[2] T Y Lin and N H Burns Design of Prestressed ConcreteStructures John Wiley amp Sons New York NY USA 3rdedition 1981

[3] R F Warner and K A Faulkes Prestressed Concrete pp 1ndash13Longman Cheshire Melbourne VIC Australia 2nd edition1988

[4] A S El-Amoush and S A Al-Duheisat ldquoCathodic polari-zation behavior of the structural steel wires under differentprestressing conditionsrdquo Journal of Materials Research andTechnology 2017 in press

[5] M S Darmawan and M G Stewart ldquoSpatial time-dependentreliability analysis of corroding pretensioned prestressedconcrete bridge girdersrdquo Structural Safety vol 29 no 1pp 16ndash31 2007

[6] M S Darmawan and M G Stewart ldquoEffect of pitting cor-rosion on capacity of prestressing wiresrdquo Magazine of Con-crete Research vol 59 no 2 pp 131ndash139 2007

[7] P Gardoni R G Pillai M B D Hueste K Reinschmidt andD Trejo ldquoProbabilistic capacity models for corroding post-tensioning strands calibrated using laboratory resultsrdquoJournal of Engineering Mechanics vol 135 no 9 pp 906ndash9162009

[8] R G Pillai P Gardoni D Trejo M B D Hueste andK F Reinschmidt ldquoProbabilistic models for the tensilestrength of corroding strands in post-tensioned segmentalconcrete bridgesrdquo Journal of Materials in Civil Engineeringvol 22 no 10 pp 967ndash977 2010

[9] N A Vu A Castel and R Franccedilois ldquoEffect of stress corrosioncracking on stressndashstrain response of steel wires used inprestressed concrete beamsrdquo Corrosion Science vol 51 no 6pp 1453ndash1459 2009

[10] J Woodtli and R Kieselbach ldquoDamage due to hydrogenembrittlement and stress corrosion crackingrdquo EngineeringFailure Analysis vol 7 no 6 pp 427ndash450 2000

[11] J Toribio ldquoe role of crack tip strain rate in hydrogenassisted crackingrdquo Corrosion Science vol 39 no 9pp 1687ndash1697 1997

[12] N A Vu A Castel and R Franccedilois ldquoResponse of post-tensioned concrete beams with unbonded tendons includingserviceability and ultimate staterdquo Engineering Structurevol 32 no 2 pp 556ndash569 2010

[13] D G Cavell and P Waldron ldquoA residual strength model fordeteriorating post-tensioned concrete bridgesrdquo Computers ampStructures vol 79 no 4 pp 361ndash373 2001

[14] M Grinfeld ldquoStress corrosion cracking of an elastic platerdquoActa Materialia vol 46 no 2 pp 631ndash636 1998

[15] A Toshimitsu Yokobori Jr Y Chinda T Nemoto K Satohand T Yamada ldquoe characteristics of hydrogen diffusionand concentration around a crack tip concerned with hy-drogen embrittlementrdquo Corrosion Science vol 44 no 3pp 407ndash424 2002

[16] A Turnbull L N McCartney and S Zhou ldquoModelling of theevolution of stress corrosion cracks from corrosion pitsrdquoScripta Materialia vol 54 no 4 pp 575ndash578 2006

[17] F Li Y Yuan and C Q Li ldquoCorrosion propagation ofprestressing steel strands in concrete subject to chloride at-tackrdquo Construction and Building Materials vol 25 no 10pp 3878ndash3885 2011

[18] A Valiente ldquoStress corrosion failure of large diameterpressure pipelines of prestressed concreterdquo EngineeringFailure Analysis vol 8 no 3 pp 245ndash261 2001

[19] R Helmerich and A Zunkel ldquoPartial collapse of the BerlinCongress Hall on May 21st 1980rdquo Engineering FailureAnalysis vol 43 pp 107ndash119 2014

[20] S Ramadan L Gaillet C Tessier and H Idrissi ldquoDetection ofstress corrosion cracking of high-strength steel used in pre-stressed concrete structures by acoustic emission techniquerdquoApplied Surface Science vol 254 no 8 pp 2255ndash2261 2008

[21] R W Posten and J P Wouters Durability of Precast Seg-mental Bridges NCHRP Web Document No 15 Project20ndash7Task 92 Transportation Research Board National Re-search Council Washington DC USA 1998

[22] M S Darmawan ldquoPitting corrosion model for partial pre-stressed concrete (PC) structures in a chloride environmentrdquoJournal of Technology Science vol 20 no 3 pp 109ndash118 2009

[23] L Dai L Wang J Zhang and X Zhang ldquoA global model forcorrosion-induced cracking in prestressed concrete struc-turesrdquo Engineering Failure Analysis vol 62 pp 263ndash2752016

[24] W Zhang X Liu and X Gu ldquoFatigue behavior of corrodedprestressed concrete beamsrdquo Construction and BuildingsMaterials vol 106 pp 198ndash208 2016

[25] X Zhang L Wang J Zhang Y Ma and Y Liu ldquoFlexuralbehavior of bonded post-tensioned concrete beams understrand corrosionrdquo Nuclear Engineering and Design vol 313pp 414ndash424 2017

[26] K A Harries ldquoStructural testing of prestressed concretegirders from the Lake View Drive Bridgerdquo Journal of BridgeEngineering vol 14 no 2 pp 78ndash92 2009

[27] M Kiviste and J Miljan ldquoEvaluation of residual flexuralcapacity of existing pre-cast pre-stressed concrete panelsmdashacase studyrdquo Engineering Structure vol 32 no 10 pp 3377ndash3383 2010

[28] D Coronelli A Castel N A Vu and R Franccedilois ldquoCorrodedpost-tensioned beams with bonded tendons and wire failurerdquoEngineering Structure vol 31 no 8 pp 1687ndash1697 2009

[29] C Q Li Y Yang and R E Melchers ldquoPrediction of re-inforcement corrosion in concrete and its effects on concretecracking and strength reductionrdquo ACI Materials Journalvol 105 no 1 pp 3ndash10 2008

[30] A A Torres-Acosta and M Martıınez-Madrid ldquoResidual lifeof corroding reinforced concrete structures in marine envi-ronmentrdquo Journal of Materials in Civil Engineering vol 15no 4 pp 344ndash353 2003

[31] H Minh H Mutsuyoshi and K Niitani ldquoInfluence ofgrouting condition on crack and load-carrying capacity ofpost-tensioned concrete beam due to chloride-induced cor-rosionrdquo Construction and Building Materials vol 21 no 7pp 1568ndash1575 2007

[32] H Minh H Mutsuyoshi H Taniguchi and K NiitanildquoChloride-induced corrosion in insufficiently grouted post-tensioned concrete beamsrdquo Journal of Materials in CivilEngineering vol 20 no 1 pp 85ndash91 2008

[33] A Castel D Coronelli N A Vu and R Franccedilois ldquoStructuralresponse of corroded unbonded post-tensioned beamsrdquoJournal of Structural Engineering vol 137 no 7 pp 761ndash7712010

[34] R G Pillai D Trejo P Gardoni M B D Hueste andK Reinschmidt ldquoTime-variant flexural reliability of post-tensioned segmental concrete bridges exposed to corrosiveenvironmentsrdquo Journal of Structural Engineering vol 140no 8 p A4014018 2014

10 Advances in Materials Science and Engineering

[35] A Torres-Acosta S Navarro-Gutierrez and J Teran-GuillenldquoResidual flexure capacity of corroded reinforced concretebeamsrdquo Engineering Structure vol 29 no 6 pp 1145ndash11522007

[36] F Li Y Qu and J Wang ldquoBond life degradation of steelstrand and concrete under combined corrosion and fatiguerdquoEngineering Failure Analysis vol 80 no 10 pp 186ndash196 2017

[37] F Li and Y Yuan ldquoEffects of corrosion on bond behaviorbetween steel strand and concreterdquo Construction and BuildingMaterials vol 38 pp 413ndash422 2013

[38] S Muralidharan T H Ha J H Bae et al ldquoElectrochemicalstudies on the solid embeddable reference sensors for cor-rosion monitoring in concrete structurerdquo Materials Lettersvol 60 no 5 pp 651ndash655 2006

[39] K Subbiah S Velu S-J Kwon H-S Lee N Rethinam andD-J Park ldquoA novel in-situ corrosion monitoring electrodefor reinforced concrete structuresrdquo Electrochimica Acta 2017in press

[40] M Aballe F J Bethencourt M Botana J M Marcos andA Sanchez ldquoInfluence of the degree of polishing of alloy AA5083 on its behavior against localized alkaline corrosionrdquoCorrosion Science vol 46 no 8 pp 1909ndash1920 2004

[41] S Girija U K Mudali V R Raju R K Dayal H S Khatakand B Raj ldquoDetermination of corrosion types for AISI type304L stainless steel using electrochemical noise methodrdquoMaterials Science and Engineering A vol 407 no 1-2pp 188ndash195 2005

[42] R J K Wood J A Wharton A J Speyer and K S TanldquoInvestigation of erosion-corrosion processes using electro-chemical noise measurementsrdquo Tribology Internationalvol 35 no 10 pp 631ndash634 2002

[43] M C Deya B del Amo E Spinelli and R Romagnoli ldquoeassessment of a smart anticorrosive coating by the electro-chemical noise techniquerdquo Progress Organic Coatings vol 76no 14 pp 525ndash532 2013

[44] H W Song and V Saraswathy ldquoCorrosion monitoring ofreinforced concrete structures-a reviewrdquo International Jour-nal of Electrochemical Science vol 2 pp 1ndash28 2007

[45] B Zhao J H Li R G Hu R G Du and C J Lin ldquoStudy onthe corrosion behavior of reinforcing steel in cement mortarby electrochemical noise measurementsrdquo Electrochimica Actavol 52 no 12 pp 3976ndash3984 2007

[46] R G Duarte A S Castela R Neves L Freire andM F Montemor ldquoCorrosion behaviour of stainless steelrebars embedded in concrete an electrochemical impedancespectroscopy studyrdquo Electrochimica Acta vol 124 pp 218ndash224 2014

[47] Kangavel S Muralidharan V Saraswathy K Y Ann andL Balamurugan ldquoRelationship between alumina and chloridecontent on their physical and corrosion resistance propertiesof concreterdquo Arabian Journal for Science and Engineeringvol 35 no 28 pp 27ndash38 2009

[48] S P Karthick S Muralidharan V Saraswathy andS J Kwon ldquoEffect of different alkali salt additions on concretedurability propertyrdquo Journal of Structural Integrity andMaintenance vol 1 no 1 pp 35ndash42 2016

[49] M Moawad H EI-Karmoty and A EI Zanaty ldquoBehavior ofcorroded bonded fully prestressed and conventional concretebeamsrdquo HBRC Journal 2016 in press

[50] M Moawad A Mahmoud H EI-Karmoty and A EI ZanatyldquoBehavior of corroded bonded partially prestressed concretebeamsrdquo HBRC Journal 2016 in press

Advances in Materials Science and Engineering 11

CorrosionInternational Journal of

Hindawiwwwhindawicom Volume 2018

Advances in

Materials Science and EngineeringHindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Analytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

ScienticaHindawiwwwhindawicom Volume 2018

Polymer ScienceInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Advances in Condensed Matter Physics

Hindawiwwwhindawicom Volume 2018

International Journal of

BiomaterialsHindawiwwwhindawicom

Journal ofEngineeringVolume 2018

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Hindawiwwwhindawicom Volume 2018

High Energy PhysicsAdvances in

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

ChemistryAdvances in

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom Volume 2018

BioMed Research InternationalMaterials

Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

setup is shown in Figure 4 Modulus of rupture (Fb) wascalculated using the formula

Fb 3PL

2bd2(1)

where P is the maximum load at failure L is the span lengthof the beam b is the breadth of the beam and d is the depthof the beam

24 Electrochemical Studies

241 Electrochemical Noise (ECN) e ECN is one of thenondestructive and nonintrusive techniques being used inmonitoring the corrosion process of various metallic ma-terials [40] and it can provide information about the cor-rosion mechanism [41] It was found that the sensitivity ofthe ECN is much higher than that of the other techniques inidentifying the localized corrosion process [42] e ECN isachieved by simultaneous measurement of fluctuation ofcurrent and potential caused by the spontaneous electro-chemical reactions [43] e technique of measuring theelectrochemical noise uses no applied external signal for thecollection of experimental data

e ECN technique measures the signal perturbationswith low-level fluctuations of the corrosion potential be-tween two nominally identical electrodes which can be usedin the automatic determination of corrosion type and speede noise corresponds with the low-level frequency noise(differential of the ZRA) signal but has much lower am-plitude when general corrosion is involved [44] e tech-nique is widely used within the corrosion engineering asa useful corrosion monitoring technique ECN measure-ments were carried out for the prestressed steel and em-bedded rebars in the chloride-contaminated concrete

242 Open-Circuit Potential Measurements After 28 daysof curing the prestressing steel under stressed conditionsand rebars embedded in the concrete beams with andwithout various percentages of chloride were subjected toopen-circuit potential measurements with respect to ECMPe positive terminal of the microammeter was connected tothe prestressing steel and the negative terminal to the ECMPand the potential versus time plot was plotted for the pre-stressed steel and rebars Potential measurements were takenfor a period of 30 days

243 AC Impedance Spectroscopy An electrochemicalimpedance measurement is an appropriate method forcorrosion studies particularly for corrosion rate de-terminations passivation and passivity process and for theevaluation of different inhibitors Here the prestressing steelacts as a working electrode and the stainless steel and ECMPact as a counterelectode and a reference electrode re-spectively Impedance measurements were carried out forthe prestressed steel and rebars embedded in the chloride-contaminated concrete A time interval of 10 to 15min wasgiven for the OCP to reach a steady state value e im-pedance spectroscopymeasurement was carried out by using

ACM Instruments UK e real part (Zprime) and the imaginarypart (minusZPrime) of the cell impedance was measured for variousfrequencies (30 kHZ to 10mHz) Plots Zprime versus minusZPrime weremade Impedance measurements were carried out at the endof the exposure period of 30 days

244 Potentiodynamic Polarization Technique e sameexperimental setup used in the AC impedance technique wasused here also e ACM instrument has provisions forprograms to evaluate corrosion kinetic parameters such asIcorr and Ecorr e potentiodynamic condition correspondsto a potential sweep rate of 01mVsminus1 and a potential rangeof +200 to minus200mV from OCP Polarization studies werecarried out for all the systems All the experiments werecarried out at a room temperature of 30plusmn 2degC

3 Results and Discussion

31 Electrochemical Studies

311 Electrochemical Noise (ECN) e ECN measurementwas performed using ACM instruments UK at the end of the30-day exposure period e two-electrode system was usedfor taking the measurements Two identical prestressing steelswere used as the working electrode 1 and working electrode 2and the ECMP was used as the reference electrode eelectrochemical current noise and the potential noise betweenthe coupled working electrodes and the reference electrodewere measured simultaneously ECN records were taken for1000 s containing 1000 data points recorded with a data-sampling interval of 10 s (1Hz)e current versus time noiseand potential versus time noise plots for the rebars andprestressed steel are given in Figures 5 and 6 From Figure 5 itis observed that the potential and current noise exhibit dif-ferent characteristics during the experimental period epotential signal is found to have less fluctuation whencompared to the current noise signal Subsequently theamplitude of fluctuation was found to increase with the in-crease in chloride content in both the prestressed steel and therebar e current signal fluctuation was found to vary be-tween 05microA and 55 microA e potential fluctuation shift wasfound to be minus190mV minus290mV minus375mV and minus440mV for0 1 2 and 3 chloride level respectively in the rebar em-bedded in concrete It indicates that in the rebars embeddedin 3 chloride only the corrosion was initiated

Figure 4 Flexural test experimental setup

4 Advances in Materials Science and Engineering

In the case of the prestressed steel (Figure 6) the po-tential yenuctuation was found to be minus175 minus280 minus410 andminus510mV respectively at 0 1 2 and 3 respectively in-dicating the active condition of the steel wire at 2 and 3chloride levelse potential noise yenuctuation at 3 chloridewas found to be 291 times higher than that at 0 chlorideAs the chloride level increases the potential noise yenuctua-tion was also found to increase e current yenuctuation wasvaried from 050 microA to 100 microAe current noise yenuctuationat 3 chloride level was found to be 20 times higher thanthat at 0 chloride level which indicates the severity of thecorrosion in the stressed condition ere is a sudden shiftobserved in both the potential and current noise at 1 to 2chloride levels and from 2 to 3 chloride the potential andcurrent noise yenuctuation is found to be lesser when com-pared to 1 to 2 chloride levels Zhao et al [45] observed the

same trend of ECN behavior in chloride-contaminatedcement mortar-containing reinforcing steel

312 Open-Circuit Potential Measurement e open-circuit potential measured for the prestressed steel againstthe ECMP in various chloride concentrations is illustrated inFigure 7 From the gure (Figure 7(a)) it is observed that thepotential of the prestressed steel (without chloride) is foundto vary between minus121 and minus225mV versus ECMP indicatingthe passive condition of the steel wire throughout the ex-posure period of 30 days However in 1 chloride-contaminated concrete the potential was found to varybetween minus242mV during the starting period and it crossedthe threshold limit of minus275mV after the 4th day of exposureand the potential was shifted towards the negative direction

minus700

minus600

minus500

minus400

minus300

minus200

minus100

00 200 400 600 800 1000

Pote

ntia

l (m

V) v

ersu

s ECM

P

Time (s)

Control1 NaCl2 NaCl

(a)

0

1

2

3

4

5

6

7

8

9

10

0 200 400 600 800 1000

Curr

ent

(μA

)

Time (s)

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 5 Time records of the potential (a) and current (b) signalsfor the rebar embedded in chloride-contaminated concrete

minus700

minus600

minus500

minus400

minus300

minus200

minus100

00 200 400 600 800 1000

Pote

ntia

l (m

V) v

ersu

s ECM

P

Time (s)

Control1 NaCl2 NaCl3 NaCl

(a)

0

2

4

6

8

10

0 200 400 600 800 1000

Curr

ent (μA

)

Time (s)

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 6 Time records of the potential (a) and current (b) signalsfor the prestressed steel in chloride-contaminated concrete

Advances in Materials Science and Engineering 5

and it reached minus390mV at the end of the 30th day In 2 and3 chloride-contaminated concrete the rebar has shown theopen-circuit potential of minus450 and minus500mV at the end of theexposure period e higher shift in potential towards morenegative direction indicates the active condition of the rebarIn 3 chloride the rebar has shown a more negative po-tential of minus500mV versus ECMP at the end of the 30th dayindicating the active condition of the rebar

Figure 7(b) represents the potential versus time plot ofthe prestressed steel with various chloride levels From theresults it is found that the prestressed steel in controlconcrete is under passive condition showing the less negativepotential of minus250mV versus ECMP at the end of 30 daysWhereas in 1 2 and 3 chloride-contaminated con-crete the prestressed steel has shown more negative po-tentials than the unstressed steel indicating the active natureof the steel after 30 days of exposure In 3 chloride theprestressed steel has shown a more negative potential ofminus540mV versus ECMP after 30 days of the exposure in-dicating that the tendon has corroded severely

313 AC Impedance e Nyquist plot of the prestressedsteel and the rebar embedded in concrete with dierent ofchloride levels is given in Figure 8 e parameters obtainedfrom the impedance technique for the prestressed steel andthe rebar in various chloride-contaminated concrete after 30days of exposure are shown in Table 3 From the table it isfound that the stressed steel has shown higher corrosion ratethan the unstressed steel in all the chloride levels After 30days of exposure in chloride-contaminated concrete theprestressed steel has 106 103 and 148 times higher cor-rosion rate than the rebar embedded in 1 2 and 3chloride-contaminated concrete For example Icorr value forthe rebar and the stressed steel in 3 NaCl was1224times10minus3mAmiddotcm2 and 2098times10minus3mAmiddotcm2 respectively

Rct values of the rebar and prestressed steel in 3 NaCl were2131times104 and 1441times104Ωmiddotcm2 respectively e corrosionrate of the rebar and the prestressed steel in 3 NaCl was1419times10minus2mmpy and 2098times10minus2mmpy respectively Inboth the prestressed steel and rebar the Rct values werefound to decrease and Cdl values were found to increase withthe increase in chloride concentration respectively e Icorrvalues were found to increase with the chloride concen-trations irrespective of the stressed conditions Compared tothe stressed steel the rebar has lesser corrosion rate higherRct values and lower Cdl values

Figure 9 depicts the impedance modulus curve for therebar and prestressed steel with dierent percentages ofchloride levels after 30 days of exposure It is found that theimpedance values were found to decrease with the increasein chloride concentration When compared to the pre-stressed steel the rebar has lesser impedance values than theprestressed steel in all the chloride levels In the stressedcondition as the chloride level increases the impedancevalue was found to decrease by one order of magnitude ateach chloride level e lowest corrosion resistance of thesteel was observed in 3 NaCl in both the prestressed steeland the rebar Slight capacitive behavior with the low-frequency domain is observed in both the stressed andunstressed steel wires at all chloride levels ese resultscould be explained by taking into consideration that thechlorides present in the surrounding concrete reached thesteel wire and activatedinitiated the corrosion process [46]

314 Potentiodynamic Polarization Studies e potentio-dynamic polarization curve for the rebar and the prestressedsteel under various chloride concentration levels is depictedin Figure 10 e corrosion kinetic parameters obtainedfrom the potentiodynamic polarization studies are given inTable 4 From the table it is observed that the Ecorr values of

minus600

minus500

minus400

minus300

minus200

minus100

00 10 20 30

Pote

ntia

l (m

V) v

ersu

s EC

MP

Time (days)

Control1 NaCl2 NaCl3 NaCl

(a)

Control1 NaCl2 NaCl3 NaCl

minus600

minus500

minus400

minus300

minus200

minus100

00 10 20 30

Pote

ntia

l (m

V) v

ersu

s EC

MP

Time (days)

(b)

Figure 7 OCP curve for the rebar (a) and prestressed steel (b) in chloride-contaminated concrete

6 Advances in Materials Science and Engineering

the rebar after 30 days of exposure were minus291 minus388 andminus458 in 1 2 and 3 chloride levels respectively e Ecorrvalues for the rebar were minus424 minus518 and minus594mV

indicating the severity of the corrosion in the prestressedsteel when compared to the rebar After 30 days of exposurethe corrosion current (Icorr) and the corrosion rate of the

0

10000

20000

30000

40000

50000

40000 60000 80000 100000 120000 140000

ZPrime (Ω

cm2 )

Zprime (Ωcm2)

Control1 NaCl2 NaCl3 NaCl

(a)ZPrime

(Ωcm

2 )

Zprime (Ωcm2)

0

10000

20000

30000

40000

50000

20000 40000 60000 80000 100000 120000 140000

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 8 AC impedance curve for the rebar (a) and prestressed steel (b) in chloride-contaminated concrete

Table 3 Initial and nal crack load for the yenexural concrete beams

Designation Initial crack load (kN) Final crack load (kN) Modulus of rupture (Fb) (Nmm2)Control 78 1206 5361 NaCl 76 985 4382 NaCl 67 906 4033 NaCl 64 809 360

40000

60000

80000

100000

120000

140000

log

| Z |(

Ωcm

2 )

Control1 NaCl2 NaCl3 NaCl

1Eminus01 1E+00 1E+01 1E+02 1E+03 1E+04 1E+05log f (Hz)

(a)

log

| Z |(

Ωcm

2 )

log f (Hz)

40000

60000

80000

100000

120000

140000

1Eminus01 1E+00 1E+01 1E+02 1E+03 1E+04 1E+05

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 9 Impedance modulus curve for the rebar (a) and prestressed steel (b) in chloride-contaminated concrete

Advances in Materials Science and Engineering 7

prestressed steel were found to be higher when compared tothe rebar e corrosion rate of the rebar was 0721 11671524times10minus3mmpy in 1 2 and 3 chloride levels re-spectively e corrosion rate of the prestressed steel was0771 1374 1586times10minus3mmpy in 1 2 and 3 chloridelevels respectively e stressed steel has 104 118 and 104times higher corrosion rate than the rebar at 1 2 and 3chloride levels respectively From the potentiodynamicpolarization curve it is observed that the stressed steel hascorroded severely than the rebar

From the abovementioned electrochemical studies itis found that the shift in the corrosion rate was higher at2 chloride level when compared to 1 and 3 chloridelevels is may be due to the fact that initially during thehydration at 1 chloride levels the chlorides combinedwith the cement to form a complex called the Friedel salt[47 48] and it reduced the availability of free chlorideions At 2 chloride the complex formation was foundto be lower and the free chloride ions may be higher tocause more corrosion both in the case of the rebar andprestressed steel

32 Flexure Test Figure 11 shows the load versus dis-placement behavior of 0 1 2 and 3 chloride-admixedprestressed concrete beams tested under two-point loadingTable 5 shows the initial and nal crack load and themodulus of rupture for the various chloride-admixedconcrete beams after 30 days of exposure From Figure 10it is found that the cracks appeared in the midspan Anadditional increase in load under various stages resulted inthe formation of additional cracks and widening of someearlier formed cracks e cracks from the tension zonetraversed up to the neutral axis and cracking of the concretetook place at later stages e failure of the specimen oc-curred due to the fast propagation of the cracks From theload versus displacement curve it is found that the maxi-mum ultimate load for 0 1 2 and 3 of the chloride-contaminated concretes is 1206 985 906 and 809 kNrespectively From the results it is observed that whencompared to the control concrete the chloride-contaminated concrete has reduced the load-carrying ca-pacity of 183 249 and 329 for 1 2 and 3 chloride-admixed concreteemodulus of rupture was also found to

log i (mAcmminus2)

minus700

minus600

minus500

minus400

minus300

minus200

minus100

0

1Eminus06 1Eminus05 1Eminus04 1Eminus03 1Eminus02 1Eminus01

Pote

ntia

l (m

V) v

ersu

s ECM

P

Control1 NaCl2 NaCl3 NaCl

(a)

log i (mAcmminus2)

minus900

minus800

minus700

minus600

minus500

minus400

minus300

minus200

minus100

0

1Eminus06 1Eminus05 1Eminus04 1Eminus03 1Eminus02 1Eminus01

Pote

ntia

l (m

V) v

ersu

s ECM

P

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 10 Potentiodynamic polarization curve for the rebar (a) and prestressed steel (b) in chloride-contaminated concrete

Table 4 AC impedance parameters for the rebar and prestressed steel in chloride-contaminated concrete

System

AC impedance parametersRebar Prestressed steel wire

Rct (Ωmiddotcm2)times104

Cdl (Fmiddotcmminus2)times10minus5

Icorr(mAmiddotcm2)times

10minus3CR (mmpy)times

10minus2Rct (Ωmiddotcm2)times

104Cdl (Fmiddotcmminus2)times

10minus5Icorr

(mAmiddotcm2)times10minus3

CR(mmpy)times

10minus2

Control 4897 1733 0533 0617 4355 1623 0599 06941NaCl 4010 2225 0651 0754 3766 2088 0692 0803

2NaCl 2357 2417 1107 1283 2286 3174 1141 1323

3NaCl 2131 2618 1224 1419 1441 5125 1810 2098

8 Advances in Materials Science and Engineering

decrease with increase in the chloride concentration edecrease in the modulus of rupture is due to the presence ofchloride ions which caused the corrosion of reinforcementand prestressed steel leading to the reduction in the load-carrying capacity of the beam [49 50]

4 Conclusions

(1) e yenexural strength of the prestressed concretebeam was decreased by 329 as the chloride contentwas increased to 3

(2) e corrosion rate of the prestressed steel is found tobe higher than that of the rebar

(3) e present investigation further demonstrates thatthe ECN measurement combined with other elec-trochemical techniques is used to study the corrosionprocess of the prestressing steel e ECN results arein good agreement with those of the OCP and EISmeasurements

(4) e ECN clearly indicated the potential and currentshift with chloride contents e potential shiftsobserved were found to be minus190mV for 0 Clminus and

minus510mV for 3 Clminus in the stressed condition esedata showed 268 times shift for chloride-contaminated prestressed concrete beam

(5) From the abovementioned experiments it is foundthat the ECN clearly indicated the corrosion status ofthe chloride-contaminated and -uncontaminatedprestressed steel and rebar

Conflicts of Interest

e authors declare that there are no conyenicts of interest inpublishing this paper

Acknowledgments

is research was supported by the Basic Science ResearchProgram through the National Research Foundation ofKorea (NRF) funded by the Ministry of Science ICT andFuture Planning (no 2015R1A5A1037548) Velu Saraswathythanks the Director CECRI and CSIR for the permission topursue the fellowship at Hanyang University Erica campusKorea

0

20

40

60

80

100

120

140

0 2 4 6 8 10

Load

(kN

)

Displacement (mm)

Control1 NaCl2 NaCl3 NaCl

Figure 11 Load versus displacement behavior of corroded prestressed concrete beams after 30 days of exposure under variouschloride levels

Table 5 Potentiodynamic polarization parameters for the rebar and prestressed steel in chloride-contaminated concrete

System

Potentiodynamic polarization parametersRebar Prestressed steel

Ecorr (mV) Icorr (mAmiddotcm2)times 10minus4 Corrosion rate(mmpy)times 10minus3 Ecorr (mV) Icorr (mAmiddotcm2)times 10minus4 Corrosion rate

(mmpy)times 10minus3

Control minus250 0455 0527 minus340 0630 07301 NaCl minus291 0622 0721 minus424 0648 07712 NaCl minus388 1007 1167 minus518 1186 13743 NaCl minus458 1315 1524 minus594 1374 1586

Advances in Materials Science and Engineering 9

References

[1] Post-Tensioning Institute Post-Tensioning Manual pp 5ndash54PTI Phoenix AZ USA 6th edition 2006

[2] T Y Lin and N H Burns Design of Prestressed ConcreteStructures John Wiley amp Sons New York NY USA 3rdedition 1981

[3] R F Warner and K A Faulkes Prestressed Concrete pp 1ndash13Longman Cheshire Melbourne VIC Australia 2nd edition1988

[4] A S El-Amoush and S A Al-Duheisat ldquoCathodic polari-zation behavior of the structural steel wires under differentprestressing conditionsrdquo Journal of Materials Research andTechnology 2017 in press

[5] M S Darmawan and M G Stewart ldquoSpatial time-dependentreliability analysis of corroding pretensioned prestressedconcrete bridge girdersrdquo Structural Safety vol 29 no 1pp 16ndash31 2007

[6] M S Darmawan and M G Stewart ldquoEffect of pitting cor-rosion on capacity of prestressing wiresrdquo Magazine of Con-crete Research vol 59 no 2 pp 131ndash139 2007

[7] P Gardoni R G Pillai M B D Hueste K Reinschmidt andD Trejo ldquoProbabilistic capacity models for corroding post-tensioning strands calibrated using laboratory resultsrdquoJournal of Engineering Mechanics vol 135 no 9 pp 906ndash9162009

[8] R G Pillai P Gardoni D Trejo M B D Hueste andK F Reinschmidt ldquoProbabilistic models for the tensilestrength of corroding strands in post-tensioned segmentalconcrete bridgesrdquo Journal of Materials in Civil Engineeringvol 22 no 10 pp 967ndash977 2010

[9] N A Vu A Castel and R Franccedilois ldquoEffect of stress corrosioncracking on stressndashstrain response of steel wires used inprestressed concrete beamsrdquo Corrosion Science vol 51 no 6pp 1453ndash1459 2009

[10] J Woodtli and R Kieselbach ldquoDamage due to hydrogenembrittlement and stress corrosion crackingrdquo EngineeringFailure Analysis vol 7 no 6 pp 427ndash450 2000

[11] J Toribio ldquoe role of crack tip strain rate in hydrogenassisted crackingrdquo Corrosion Science vol 39 no 9pp 1687ndash1697 1997

[12] N A Vu A Castel and R Franccedilois ldquoResponse of post-tensioned concrete beams with unbonded tendons includingserviceability and ultimate staterdquo Engineering Structurevol 32 no 2 pp 556ndash569 2010

[13] D G Cavell and P Waldron ldquoA residual strength model fordeteriorating post-tensioned concrete bridgesrdquo Computers ampStructures vol 79 no 4 pp 361ndash373 2001

[14] M Grinfeld ldquoStress corrosion cracking of an elastic platerdquoActa Materialia vol 46 no 2 pp 631ndash636 1998

[15] A Toshimitsu Yokobori Jr Y Chinda T Nemoto K Satohand T Yamada ldquoe characteristics of hydrogen diffusionand concentration around a crack tip concerned with hy-drogen embrittlementrdquo Corrosion Science vol 44 no 3pp 407ndash424 2002

[16] A Turnbull L N McCartney and S Zhou ldquoModelling of theevolution of stress corrosion cracks from corrosion pitsrdquoScripta Materialia vol 54 no 4 pp 575ndash578 2006

[17] F Li Y Yuan and C Q Li ldquoCorrosion propagation ofprestressing steel strands in concrete subject to chloride at-tackrdquo Construction and Building Materials vol 25 no 10pp 3878ndash3885 2011

[18] A Valiente ldquoStress corrosion failure of large diameterpressure pipelines of prestressed concreterdquo EngineeringFailure Analysis vol 8 no 3 pp 245ndash261 2001

[19] R Helmerich and A Zunkel ldquoPartial collapse of the BerlinCongress Hall on May 21st 1980rdquo Engineering FailureAnalysis vol 43 pp 107ndash119 2014

[20] S Ramadan L Gaillet C Tessier and H Idrissi ldquoDetection ofstress corrosion cracking of high-strength steel used in pre-stressed concrete structures by acoustic emission techniquerdquoApplied Surface Science vol 254 no 8 pp 2255ndash2261 2008

[21] R W Posten and J P Wouters Durability of Precast Seg-mental Bridges NCHRP Web Document No 15 Project20ndash7Task 92 Transportation Research Board National Re-search Council Washington DC USA 1998

[22] M S Darmawan ldquoPitting corrosion model for partial pre-stressed concrete (PC) structures in a chloride environmentrdquoJournal of Technology Science vol 20 no 3 pp 109ndash118 2009

[23] L Dai L Wang J Zhang and X Zhang ldquoA global model forcorrosion-induced cracking in prestressed concrete struc-turesrdquo Engineering Failure Analysis vol 62 pp 263ndash2752016

[24] W Zhang X Liu and X Gu ldquoFatigue behavior of corrodedprestressed concrete beamsrdquo Construction and BuildingsMaterials vol 106 pp 198ndash208 2016

[25] X Zhang L Wang J Zhang Y Ma and Y Liu ldquoFlexuralbehavior of bonded post-tensioned concrete beams understrand corrosionrdquo Nuclear Engineering and Design vol 313pp 414ndash424 2017

[26] K A Harries ldquoStructural testing of prestressed concretegirders from the Lake View Drive Bridgerdquo Journal of BridgeEngineering vol 14 no 2 pp 78ndash92 2009

[27] M Kiviste and J Miljan ldquoEvaluation of residual flexuralcapacity of existing pre-cast pre-stressed concrete panelsmdashacase studyrdquo Engineering Structure vol 32 no 10 pp 3377ndash3383 2010

[28] D Coronelli A Castel N A Vu and R Franccedilois ldquoCorrodedpost-tensioned beams with bonded tendons and wire failurerdquoEngineering Structure vol 31 no 8 pp 1687ndash1697 2009

[29] C Q Li Y Yang and R E Melchers ldquoPrediction of re-inforcement corrosion in concrete and its effects on concretecracking and strength reductionrdquo ACI Materials Journalvol 105 no 1 pp 3ndash10 2008

[30] A A Torres-Acosta and M Martıınez-Madrid ldquoResidual lifeof corroding reinforced concrete structures in marine envi-ronmentrdquo Journal of Materials in Civil Engineering vol 15no 4 pp 344ndash353 2003

[31] H Minh H Mutsuyoshi and K Niitani ldquoInfluence ofgrouting condition on crack and load-carrying capacity ofpost-tensioned concrete beam due to chloride-induced cor-rosionrdquo Construction and Building Materials vol 21 no 7pp 1568ndash1575 2007

[32] H Minh H Mutsuyoshi H Taniguchi and K NiitanildquoChloride-induced corrosion in insufficiently grouted post-tensioned concrete beamsrdquo Journal of Materials in CivilEngineering vol 20 no 1 pp 85ndash91 2008

[33] A Castel D Coronelli N A Vu and R Franccedilois ldquoStructuralresponse of corroded unbonded post-tensioned beamsrdquoJournal of Structural Engineering vol 137 no 7 pp 761ndash7712010

[34] R G Pillai D Trejo P Gardoni M B D Hueste andK Reinschmidt ldquoTime-variant flexural reliability of post-tensioned segmental concrete bridges exposed to corrosiveenvironmentsrdquo Journal of Structural Engineering vol 140no 8 p A4014018 2014

10 Advances in Materials Science and Engineering

[35] A Torres-Acosta S Navarro-Gutierrez and J Teran-GuillenldquoResidual flexure capacity of corroded reinforced concretebeamsrdquo Engineering Structure vol 29 no 6 pp 1145ndash11522007

[36] F Li Y Qu and J Wang ldquoBond life degradation of steelstrand and concrete under combined corrosion and fatiguerdquoEngineering Failure Analysis vol 80 no 10 pp 186ndash196 2017

[37] F Li and Y Yuan ldquoEffects of corrosion on bond behaviorbetween steel strand and concreterdquo Construction and BuildingMaterials vol 38 pp 413ndash422 2013

[38] S Muralidharan T H Ha J H Bae et al ldquoElectrochemicalstudies on the solid embeddable reference sensors for cor-rosion monitoring in concrete structurerdquo Materials Lettersvol 60 no 5 pp 651ndash655 2006

[39] K Subbiah S Velu S-J Kwon H-S Lee N Rethinam andD-J Park ldquoA novel in-situ corrosion monitoring electrodefor reinforced concrete structuresrdquo Electrochimica Acta 2017in press

[40] M Aballe F J Bethencourt M Botana J M Marcos andA Sanchez ldquoInfluence of the degree of polishing of alloy AA5083 on its behavior against localized alkaline corrosionrdquoCorrosion Science vol 46 no 8 pp 1909ndash1920 2004

[41] S Girija U K Mudali V R Raju R K Dayal H S Khatakand B Raj ldquoDetermination of corrosion types for AISI type304L stainless steel using electrochemical noise methodrdquoMaterials Science and Engineering A vol 407 no 1-2pp 188ndash195 2005

[42] R J K Wood J A Wharton A J Speyer and K S TanldquoInvestigation of erosion-corrosion processes using electro-chemical noise measurementsrdquo Tribology Internationalvol 35 no 10 pp 631ndash634 2002

[43] M C Deya B del Amo E Spinelli and R Romagnoli ldquoeassessment of a smart anticorrosive coating by the electro-chemical noise techniquerdquo Progress Organic Coatings vol 76no 14 pp 525ndash532 2013

[44] H W Song and V Saraswathy ldquoCorrosion monitoring ofreinforced concrete structures-a reviewrdquo International Jour-nal of Electrochemical Science vol 2 pp 1ndash28 2007

[45] B Zhao J H Li R G Hu R G Du and C J Lin ldquoStudy onthe corrosion behavior of reinforcing steel in cement mortarby electrochemical noise measurementsrdquo Electrochimica Actavol 52 no 12 pp 3976ndash3984 2007

[46] R G Duarte A S Castela R Neves L Freire andM F Montemor ldquoCorrosion behaviour of stainless steelrebars embedded in concrete an electrochemical impedancespectroscopy studyrdquo Electrochimica Acta vol 124 pp 218ndash224 2014

[47] Kangavel S Muralidharan V Saraswathy K Y Ann andL Balamurugan ldquoRelationship between alumina and chloridecontent on their physical and corrosion resistance propertiesof concreterdquo Arabian Journal for Science and Engineeringvol 35 no 28 pp 27ndash38 2009

[48] S P Karthick S Muralidharan V Saraswathy andS J Kwon ldquoEffect of different alkali salt additions on concretedurability propertyrdquo Journal of Structural Integrity andMaintenance vol 1 no 1 pp 35ndash42 2016

[49] M Moawad H EI-Karmoty and A EI Zanaty ldquoBehavior ofcorroded bonded fully prestressed and conventional concretebeamsrdquo HBRC Journal 2016 in press

[50] M Moawad A Mahmoud H EI-Karmoty and A EI ZanatyldquoBehavior of corroded bonded partially prestressed concretebeamsrdquo HBRC Journal 2016 in press

Advances in Materials Science and Engineering 11

CorrosionInternational Journal of

Hindawiwwwhindawicom Volume 2018

Advances in

Materials Science and EngineeringHindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Analytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

ScienticaHindawiwwwhindawicom Volume 2018

Polymer ScienceInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Advances in Condensed Matter Physics

Hindawiwwwhindawicom Volume 2018

International Journal of

BiomaterialsHindawiwwwhindawicom

Journal ofEngineeringVolume 2018

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Hindawiwwwhindawicom Volume 2018

High Energy PhysicsAdvances in

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

ChemistryAdvances in

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom Volume 2018

BioMed Research InternationalMaterials

Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

In the case of the prestressed steel (Figure 6) the po-tential yenuctuation was found to be minus175 minus280 minus410 andminus510mV respectively at 0 1 2 and 3 respectively in-dicating the active condition of the steel wire at 2 and 3chloride levelse potential noise yenuctuation at 3 chloridewas found to be 291 times higher than that at 0 chlorideAs the chloride level increases the potential noise yenuctua-tion was also found to increase e current yenuctuation wasvaried from 050 microA to 100 microAe current noise yenuctuationat 3 chloride level was found to be 20 times higher thanthat at 0 chloride level which indicates the severity of thecorrosion in the stressed condition ere is a sudden shiftobserved in both the potential and current noise at 1 to 2chloride levels and from 2 to 3 chloride the potential andcurrent noise yenuctuation is found to be lesser when com-pared to 1 to 2 chloride levels Zhao et al [45] observed the

same trend of ECN behavior in chloride-contaminatedcement mortar-containing reinforcing steel

312 Open-Circuit Potential Measurement e open-circuit potential measured for the prestressed steel againstthe ECMP in various chloride concentrations is illustrated inFigure 7 From the gure (Figure 7(a)) it is observed that thepotential of the prestressed steel (without chloride) is foundto vary between minus121 and minus225mV versus ECMP indicatingthe passive condition of the steel wire throughout the ex-posure period of 30 days However in 1 chloride-contaminated concrete the potential was found to varybetween minus242mV during the starting period and it crossedthe threshold limit of minus275mV after the 4th day of exposureand the potential was shifted towards the negative direction

minus700

minus600

minus500

minus400

minus300

minus200

minus100

00 200 400 600 800 1000

Pote

ntia

l (m

V) v

ersu

s ECM

P

Time (s)

Control1 NaCl2 NaCl

(a)

0

1

2

3

4

5

6

7

8

9

10

0 200 400 600 800 1000

Curr

ent

(μA

)

Time (s)

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 5 Time records of the potential (a) and current (b) signalsfor the rebar embedded in chloride-contaminated concrete

minus700

minus600

minus500

minus400

minus300

minus200

minus100

00 200 400 600 800 1000

Pote

ntia

l (m

V) v

ersu

s ECM

P

Time (s)

Control1 NaCl2 NaCl3 NaCl

(a)

0

2

4

6

8

10

0 200 400 600 800 1000

Curr

ent (μA

)

Time (s)

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 6 Time records of the potential (a) and current (b) signalsfor the prestressed steel in chloride-contaminated concrete

Advances in Materials Science and Engineering 5

and it reached minus390mV at the end of the 30th day In 2 and3 chloride-contaminated concrete the rebar has shown theopen-circuit potential of minus450 and minus500mV at the end of theexposure period e higher shift in potential towards morenegative direction indicates the active condition of the rebarIn 3 chloride the rebar has shown a more negative po-tential of minus500mV versus ECMP at the end of the 30th dayindicating the active condition of the rebar

Figure 7(b) represents the potential versus time plot ofthe prestressed steel with various chloride levels From theresults it is found that the prestressed steel in controlconcrete is under passive condition showing the less negativepotential of minus250mV versus ECMP at the end of 30 daysWhereas in 1 2 and 3 chloride-contaminated con-crete the prestressed steel has shown more negative po-tentials than the unstressed steel indicating the active natureof the steel after 30 days of exposure In 3 chloride theprestressed steel has shown a more negative potential ofminus540mV versus ECMP after 30 days of the exposure in-dicating that the tendon has corroded severely

313 AC Impedance e Nyquist plot of the prestressedsteel and the rebar embedded in concrete with dierent ofchloride levels is given in Figure 8 e parameters obtainedfrom the impedance technique for the prestressed steel andthe rebar in various chloride-contaminated concrete after 30days of exposure are shown in Table 3 From the table it isfound that the stressed steel has shown higher corrosion ratethan the unstressed steel in all the chloride levels After 30days of exposure in chloride-contaminated concrete theprestressed steel has 106 103 and 148 times higher cor-rosion rate than the rebar embedded in 1 2 and 3chloride-contaminated concrete For example Icorr value forthe rebar and the stressed steel in 3 NaCl was1224times10minus3mAmiddotcm2 and 2098times10minus3mAmiddotcm2 respectively

Rct values of the rebar and prestressed steel in 3 NaCl were2131times104 and 1441times104Ωmiddotcm2 respectively e corrosionrate of the rebar and the prestressed steel in 3 NaCl was1419times10minus2mmpy and 2098times10minus2mmpy respectively Inboth the prestressed steel and rebar the Rct values werefound to decrease and Cdl values were found to increase withthe increase in chloride concentration respectively e Icorrvalues were found to increase with the chloride concen-trations irrespective of the stressed conditions Compared tothe stressed steel the rebar has lesser corrosion rate higherRct values and lower Cdl values

Figure 9 depicts the impedance modulus curve for therebar and prestressed steel with dierent percentages ofchloride levels after 30 days of exposure It is found that theimpedance values were found to decrease with the increasein chloride concentration When compared to the pre-stressed steel the rebar has lesser impedance values than theprestressed steel in all the chloride levels In the stressedcondition as the chloride level increases the impedancevalue was found to decrease by one order of magnitude ateach chloride level e lowest corrosion resistance of thesteel was observed in 3 NaCl in both the prestressed steeland the rebar Slight capacitive behavior with the low-frequency domain is observed in both the stressed andunstressed steel wires at all chloride levels ese resultscould be explained by taking into consideration that thechlorides present in the surrounding concrete reached thesteel wire and activatedinitiated the corrosion process [46]

314 Potentiodynamic Polarization Studies e potentio-dynamic polarization curve for the rebar and the prestressedsteel under various chloride concentration levels is depictedin Figure 10 e corrosion kinetic parameters obtainedfrom the potentiodynamic polarization studies are given inTable 4 From the table it is observed that the Ecorr values of

minus600

minus500

minus400

minus300

minus200

minus100

00 10 20 30

Pote

ntia

l (m

V) v

ersu

s EC

MP

Time (days)

Control1 NaCl2 NaCl3 NaCl

(a)

Control1 NaCl2 NaCl3 NaCl

minus600

minus500

minus400

minus300

minus200

minus100

00 10 20 30

Pote

ntia

l (m

V) v

ersu

s EC

MP

Time (days)

(b)

Figure 7 OCP curve for the rebar (a) and prestressed steel (b) in chloride-contaminated concrete

6 Advances in Materials Science and Engineering

the rebar after 30 days of exposure were minus291 minus388 andminus458 in 1 2 and 3 chloride levels respectively e Ecorrvalues for the rebar were minus424 minus518 and minus594mV

indicating the severity of the corrosion in the prestressedsteel when compared to the rebar After 30 days of exposurethe corrosion current (Icorr) and the corrosion rate of the

0

10000

20000

30000

40000

50000

40000 60000 80000 100000 120000 140000

ZPrime (Ω

cm2 )

Zprime (Ωcm2)

Control1 NaCl2 NaCl3 NaCl

(a)ZPrime

(Ωcm

2 )

Zprime (Ωcm2)

0

10000

20000

30000

40000

50000

20000 40000 60000 80000 100000 120000 140000

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 8 AC impedance curve for the rebar (a) and prestressed steel (b) in chloride-contaminated concrete

Table 3 Initial and nal crack load for the yenexural concrete beams

Designation Initial crack load (kN) Final crack load (kN) Modulus of rupture (Fb) (Nmm2)Control 78 1206 5361 NaCl 76 985 4382 NaCl 67 906 4033 NaCl 64 809 360

40000

60000

80000

100000

120000

140000

log

| Z |(

Ωcm

2 )

Control1 NaCl2 NaCl3 NaCl

1Eminus01 1E+00 1E+01 1E+02 1E+03 1E+04 1E+05log f (Hz)

(a)

log

| Z |(

Ωcm

2 )

log f (Hz)

40000

60000

80000

100000

120000

140000

1Eminus01 1E+00 1E+01 1E+02 1E+03 1E+04 1E+05

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 9 Impedance modulus curve for the rebar (a) and prestressed steel (b) in chloride-contaminated concrete

Advances in Materials Science and Engineering 7

prestressed steel were found to be higher when compared tothe rebar e corrosion rate of the rebar was 0721 11671524times10minus3mmpy in 1 2 and 3 chloride levels re-spectively e corrosion rate of the prestressed steel was0771 1374 1586times10minus3mmpy in 1 2 and 3 chloridelevels respectively e stressed steel has 104 118 and 104times higher corrosion rate than the rebar at 1 2 and 3chloride levels respectively From the potentiodynamicpolarization curve it is observed that the stressed steel hascorroded severely than the rebar

From the abovementioned electrochemical studies itis found that the shift in the corrosion rate was higher at2 chloride level when compared to 1 and 3 chloridelevels is may be due to the fact that initially during thehydration at 1 chloride levels the chlorides combinedwith the cement to form a complex called the Friedel salt[47 48] and it reduced the availability of free chlorideions At 2 chloride the complex formation was foundto be lower and the free chloride ions may be higher tocause more corrosion both in the case of the rebar andprestressed steel

32 Flexure Test Figure 11 shows the load versus dis-placement behavior of 0 1 2 and 3 chloride-admixedprestressed concrete beams tested under two-point loadingTable 5 shows the initial and nal crack load and themodulus of rupture for the various chloride-admixedconcrete beams after 30 days of exposure From Figure 10it is found that the cracks appeared in the midspan Anadditional increase in load under various stages resulted inthe formation of additional cracks and widening of someearlier formed cracks e cracks from the tension zonetraversed up to the neutral axis and cracking of the concretetook place at later stages e failure of the specimen oc-curred due to the fast propagation of the cracks From theload versus displacement curve it is found that the maxi-mum ultimate load for 0 1 2 and 3 of the chloride-contaminated concretes is 1206 985 906 and 809 kNrespectively From the results it is observed that whencompared to the control concrete the chloride-contaminated concrete has reduced the load-carrying ca-pacity of 183 249 and 329 for 1 2 and 3 chloride-admixed concreteemodulus of rupture was also found to

log i (mAcmminus2)

minus700

minus600

minus500

minus400

minus300

minus200

minus100

0

1Eminus06 1Eminus05 1Eminus04 1Eminus03 1Eminus02 1Eminus01

Pote

ntia

l (m

V) v

ersu

s ECM

P

Control1 NaCl2 NaCl3 NaCl

(a)

log i (mAcmminus2)

minus900

minus800

minus700

minus600

minus500

minus400

minus300

minus200

minus100

0

1Eminus06 1Eminus05 1Eminus04 1Eminus03 1Eminus02 1Eminus01

Pote

ntia

l (m

V) v

ersu

s ECM

P

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 10 Potentiodynamic polarization curve for the rebar (a) and prestressed steel (b) in chloride-contaminated concrete

Table 4 AC impedance parameters for the rebar and prestressed steel in chloride-contaminated concrete

System

AC impedance parametersRebar Prestressed steel wire

Rct (Ωmiddotcm2)times104

Cdl (Fmiddotcmminus2)times10minus5

Icorr(mAmiddotcm2)times

10minus3CR (mmpy)times

10minus2Rct (Ωmiddotcm2)times

104Cdl (Fmiddotcmminus2)times

10minus5Icorr

(mAmiddotcm2)times10minus3

CR(mmpy)times

10minus2

Control 4897 1733 0533 0617 4355 1623 0599 06941NaCl 4010 2225 0651 0754 3766 2088 0692 0803

2NaCl 2357 2417 1107 1283 2286 3174 1141 1323

3NaCl 2131 2618 1224 1419 1441 5125 1810 2098

8 Advances in Materials Science and Engineering

decrease with increase in the chloride concentration edecrease in the modulus of rupture is due to the presence ofchloride ions which caused the corrosion of reinforcementand prestressed steel leading to the reduction in the load-carrying capacity of the beam [49 50]

4 Conclusions

(1) e yenexural strength of the prestressed concretebeam was decreased by 329 as the chloride contentwas increased to 3

(2) e corrosion rate of the prestressed steel is found tobe higher than that of the rebar

(3) e present investigation further demonstrates thatthe ECN measurement combined with other elec-trochemical techniques is used to study the corrosionprocess of the prestressing steel e ECN results arein good agreement with those of the OCP and EISmeasurements

(4) e ECN clearly indicated the potential and currentshift with chloride contents e potential shiftsobserved were found to be minus190mV for 0 Clminus and

minus510mV for 3 Clminus in the stressed condition esedata showed 268 times shift for chloride-contaminated prestressed concrete beam

(5) From the abovementioned experiments it is foundthat the ECN clearly indicated the corrosion status ofthe chloride-contaminated and -uncontaminatedprestressed steel and rebar

Conflicts of Interest

e authors declare that there are no conyenicts of interest inpublishing this paper

Acknowledgments

is research was supported by the Basic Science ResearchProgram through the National Research Foundation ofKorea (NRF) funded by the Ministry of Science ICT andFuture Planning (no 2015R1A5A1037548) Velu Saraswathythanks the Director CECRI and CSIR for the permission topursue the fellowship at Hanyang University Erica campusKorea

0

20

40

60

80

100

120

140

0 2 4 6 8 10

Load

(kN

)

Displacement (mm)

Control1 NaCl2 NaCl3 NaCl

Figure 11 Load versus displacement behavior of corroded prestressed concrete beams after 30 days of exposure under variouschloride levels

Table 5 Potentiodynamic polarization parameters for the rebar and prestressed steel in chloride-contaminated concrete

System

Potentiodynamic polarization parametersRebar Prestressed steel

Ecorr (mV) Icorr (mAmiddotcm2)times 10minus4 Corrosion rate(mmpy)times 10minus3 Ecorr (mV) Icorr (mAmiddotcm2)times 10minus4 Corrosion rate

(mmpy)times 10minus3

Control minus250 0455 0527 minus340 0630 07301 NaCl minus291 0622 0721 minus424 0648 07712 NaCl minus388 1007 1167 minus518 1186 13743 NaCl minus458 1315 1524 minus594 1374 1586

Advances in Materials Science and Engineering 9

References

[1] Post-Tensioning Institute Post-Tensioning Manual pp 5ndash54PTI Phoenix AZ USA 6th edition 2006

[2] T Y Lin and N H Burns Design of Prestressed ConcreteStructures John Wiley amp Sons New York NY USA 3rdedition 1981

[3] R F Warner and K A Faulkes Prestressed Concrete pp 1ndash13Longman Cheshire Melbourne VIC Australia 2nd edition1988

[4] A S El-Amoush and S A Al-Duheisat ldquoCathodic polari-zation behavior of the structural steel wires under differentprestressing conditionsrdquo Journal of Materials Research andTechnology 2017 in press

[5] M S Darmawan and M G Stewart ldquoSpatial time-dependentreliability analysis of corroding pretensioned prestressedconcrete bridge girdersrdquo Structural Safety vol 29 no 1pp 16ndash31 2007

[6] M S Darmawan and M G Stewart ldquoEffect of pitting cor-rosion on capacity of prestressing wiresrdquo Magazine of Con-crete Research vol 59 no 2 pp 131ndash139 2007

[7] P Gardoni R G Pillai M B D Hueste K Reinschmidt andD Trejo ldquoProbabilistic capacity models for corroding post-tensioning strands calibrated using laboratory resultsrdquoJournal of Engineering Mechanics vol 135 no 9 pp 906ndash9162009

[8] R G Pillai P Gardoni D Trejo M B D Hueste andK F Reinschmidt ldquoProbabilistic models for the tensilestrength of corroding strands in post-tensioned segmentalconcrete bridgesrdquo Journal of Materials in Civil Engineeringvol 22 no 10 pp 967ndash977 2010

[9] N A Vu A Castel and R Franccedilois ldquoEffect of stress corrosioncracking on stressndashstrain response of steel wires used inprestressed concrete beamsrdquo Corrosion Science vol 51 no 6pp 1453ndash1459 2009

[10] J Woodtli and R Kieselbach ldquoDamage due to hydrogenembrittlement and stress corrosion crackingrdquo EngineeringFailure Analysis vol 7 no 6 pp 427ndash450 2000

[11] J Toribio ldquoe role of crack tip strain rate in hydrogenassisted crackingrdquo Corrosion Science vol 39 no 9pp 1687ndash1697 1997

[12] N A Vu A Castel and R Franccedilois ldquoResponse of post-tensioned concrete beams with unbonded tendons includingserviceability and ultimate staterdquo Engineering Structurevol 32 no 2 pp 556ndash569 2010

[13] D G Cavell and P Waldron ldquoA residual strength model fordeteriorating post-tensioned concrete bridgesrdquo Computers ampStructures vol 79 no 4 pp 361ndash373 2001

[14] M Grinfeld ldquoStress corrosion cracking of an elastic platerdquoActa Materialia vol 46 no 2 pp 631ndash636 1998

[15] A Toshimitsu Yokobori Jr Y Chinda T Nemoto K Satohand T Yamada ldquoe characteristics of hydrogen diffusionand concentration around a crack tip concerned with hy-drogen embrittlementrdquo Corrosion Science vol 44 no 3pp 407ndash424 2002

[16] A Turnbull L N McCartney and S Zhou ldquoModelling of theevolution of stress corrosion cracks from corrosion pitsrdquoScripta Materialia vol 54 no 4 pp 575ndash578 2006

[17] F Li Y Yuan and C Q Li ldquoCorrosion propagation ofprestressing steel strands in concrete subject to chloride at-tackrdquo Construction and Building Materials vol 25 no 10pp 3878ndash3885 2011

[18] A Valiente ldquoStress corrosion failure of large diameterpressure pipelines of prestressed concreterdquo EngineeringFailure Analysis vol 8 no 3 pp 245ndash261 2001

[19] R Helmerich and A Zunkel ldquoPartial collapse of the BerlinCongress Hall on May 21st 1980rdquo Engineering FailureAnalysis vol 43 pp 107ndash119 2014

[20] S Ramadan L Gaillet C Tessier and H Idrissi ldquoDetection ofstress corrosion cracking of high-strength steel used in pre-stressed concrete structures by acoustic emission techniquerdquoApplied Surface Science vol 254 no 8 pp 2255ndash2261 2008

[21] R W Posten and J P Wouters Durability of Precast Seg-mental Bridges NCHRP Web Document No 15 Project20ndash7Task 92 Transportation Research Board National Re-search Council Washington DC USA 1998

[22] M S Darmawan ldquoPitting corrosion model for partial pre-stressed concrete (PC) structures in a chloride environmentrdquoJournal of Technology Science vol 20 no 3 pp 109ndash118 2009

[23] L Dai L Wang J Zhang and X Zhang ldquoA global model forcorrosion-induced cracking in prestressed concrete struc-turesrdquo Engineering Failure Analysis vol 62 pp 263ndash2752016

[24] W Zhang X Liu and X Gu ldquoFatigue behavior of corrodedprestressed concrete beamsrdquo Construction and BuildingsMaterials vol 106 pp 198ndash208 2016

[25] X Zhang L Wang J Zhang Y Ma and Y Liu ldquoFlexuralbehavior of bonded post-tensioned concrete beams understrand corrosionrdquo Nuclear Engineering and Design vol 313pp 414ndash424 2017

[26] K A Harries ldquoStructural testing of prestressed concretegirders from the Lake View Drive Bridgerdquo Journal of BridgeEngineering vol 14 no 2 pp 78ndash92 2009

[27] M Kiviste and J Miljan ldquoEvaluation of residual flexuralcapacity of existing pre-cast pre-stressed concrete panelsmdashacase studyrdquo Engineering Structure vol 32 no 10 pp 3377ndash3383 2010

[28] D Coronelli A Castel N A Vu and R Franccedilois ldquoCorrodedpost-tensioned beams with bonded tendons and wire failurerdquoEngineering Structure vol 31 no 8 pp 1687ndash1697 2009

[29] C Q Li Y Yang and R E Melchers ldquoPrediction of re-inforcement corrosion in concrete and its effects on concretecracking and strength reductionrdquo ACI Materials Journalvol 105 no 1 pp 3ndash10 2008

[30] A A Torres-Acosta and M Martıınez-Madrid ldquoResidual lifeof corroding reinforced concrete structures in marine envi-ronmentrdquo Journal of Materials in Civil Engineering vol 15no 4 pp 344ndash353 2003

[31] H Minh H Mutsuyoshi and K Niitani ldquoInfluence ofgrouting condition on crack and load-carrying capacity ofpost-tensioned concrete beam due to chloride-induced cor-rosionrdquo Construction and Building Materials vol 21 no 7pp 1568ndash1575 2007

[32] H Minh H Mutsuyoshi H Taniguchi and K NiitanildquoChloride-induced corrosion in insufficiently grouted post-tensioned concrete beamsrdquo Journal of Materials in CivilEngineering vol 20 no 1 pp 85ndash91 2008

[33] A Castel D Coronelli N A Vu and R Franccedilois ldquoStructuralresponse of corroded unbonded post-tensioned beamsrdquoJournal of Structural Engineering vol 137 no 7 pp 761ndash7712010

[34] R G Pillai D Trejo P Gardoni M B D Hueste andK Reinschmidt ldquoTime-variant flexural reliability of post-tensioned segmental concrete bridges exposed to corrosiveenvironmentsrdquo Journal of Structural Engineering vol 140no 8 p A4014018 2014

10 Advances in Materials Science and Engineering

[35] A Torres-Acosta S Navarro-Gutierrez and J Teran-GuillenldquoResidual flexure capacity of corroded reinforced concretebeamsrdquo Engineering Structure vol 29 no 6 pp 1145ndash11522007

[36] F Li Y Qu and J Wang ldquoBond life degradation of steelstrand and concrete under combined corrosion and fatiguerdquoEngineering Failure Analysis vol 80 no 10 pp 186ndash196 2017

[37] F Li and Y Yuan ldquoEffects of corrosion on bond behaviorbetween steel strand and concreterdquo Construction and BuildingMaterials vol 38 pp 413ndash422 2013

[38] S Muralidharan T H Ha J H Bae et al ldquoElectrochemicalstudies on the solid embeddable reference sensors for cor-rosion monitoring in concrete structurerdquo Materials Lettersvol 60 no 5 pp 651ndash655 2006

[39] K Subbiah S Velu S-J Kwon H-S Lee N Rethinam andD-J Park ldquoA novel in-situ corrosion monitoring electrodefor reinforced concrete structuresrdquo Electrochimica Acta 2017in press

[40] M Aballe F J Bethencourt M Botana J M Marcos andA Sanchez ldquoInfluence of the degree of polishing of alloy AA5083 on its behavior against localized alkaline corrosionrdquoCorrosion Science vol 46 no 8 pp 1909ndash1920 2004

[41] S Girija U K Mudali V R Raju R K Dayal H S Khatakand B Raj ldquoDetermination of corrosion types for AISI type304L stainless steel using electrochemical noise methodrdquoMaterials Science and Engineering A vol 407 no 1-2pp 188ndash195 2005

[42] R J K Wood J A Wharton A J Speyer and K S TanldquoInvestigation of erosion-corrosion processes using electro-chemical noise measurementsrdquo Tribology Internationalvol 35 no 10 pp 631ndash634 2002

[43] M C Deya B del Amo E Spinelli and R Romagnoli ldquoeassessment of a smart anticorrosive coating by the electro-chemical noise techniquerdquo Progress Organic Coatings vol 76no 14 pp 525ndash532 2013

[44] H W Song and V Saraswathy ldquoCorrosion monitoring ofreinforced concrete structures-a reviewrdquo International Jour-nal of Electrochemical Science vol 2 pp 1ndash28 2007

[45] B Zhao J H Li R G Hu R G Du and C J Lin ldquoStudy onthe corrosion behavior of reinforcing steel in cement mortarby electrochemical noise measurementsrdquo Electrochimica Actavol 52 no 12 pp 3976ndash3984 2007

[46] R G Duarte A S Castela R Neves L Freire andM F Montemor ldquoCorrosion behaviour of stainless steelrebars embedded in concrete an electrochemical impedancespectroscopy studyrdquo Electrochimica Acta vol 124 pp 218ndash224 2014

[47] Kangavel S Muralidharan V Saraswathy K Y Ann andL Balamurugan ldquoRelationship between alumina and chloridecontent on their physical and corrosion resistance propertiesof concreterdquo Arabian Journal for Science and Engineeringvol 35 no 28 pp 27ndash38 2009

[48] S P Karthick S Muralidharan V Saraswathy andS J Kwon ldquoEffect of different alkali salt additions on concretedurability propertyrdquo Journal of Structural Integrity andMaintenance vol 1 no 1 pp 35ndash42 2016

[49] M Moawad H EI-Karmoty and A EI Zanaty ldquoBehavior ofcorroded bonded fully prestressed and conventional concretebeamsrdquo HBRC Journal 2016 in press

[50] M Moawad A Mahmoud H EI-Karmoty and A EI ZanatyldquoBehavior of corroded bonded partially prestressed concretebeamsrdquo HBRC Journal 2016 in press

Advances in Materials Science and Engineering 11

CorrosionInternational Journal of

Hindawiwwwhindawicom Volume 2018

Advances in

Materials Science and EngineeringHindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Analytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

ScienticaHindawiwwwhindawicom Volume 2018

Polymer ScienceInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Advances in Condensed Matter Physics

Hindawiwwwhindawicom Volume 2018

International Journal of

BiomaterialsHindawiwwwhindawicom

Journal ofEngineeringVolume 2018

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Hindawiwwwhindawicom Volume 2018

High Energy PhysicsAdvances in

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

ChemistryAdvances in

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom Volume 2018

BioMed Research InternationalMaterials

Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

and it reached minus390mV at the end of the 30th day In 2 and3 chloride-contaminated concrete the rebar has shown theopen-circuit potential of minus450 and minus500mV at the end of theexposure period e higher shift in potential towards morenegative direction indicates the active condition of the rebarIn 3 chloride the rebar has shown a more negative po-tential of minus500mV versus ECMP at the end of the 30th dayindicating the active condition of the rebar

Figure 7(b) represents the potential versus time plot ofthe prestressed steel with various chloride levels From theresults it is found that the prestressed steel in controlconcrete is under passive condition showing the less negativepotential of minus250mV versus ECMP at the end of 30 daysWhereas in 1 2 and 3 chloride-contaminated con-crete the prestressed steel has shown more negative po-tentials than the unstressed steel indicating the active natureof the steel after 30 days of exposure In 3 chloride theprestressed steel has shown a more negative potential ofminus540mV versus ECMP after 30 days of the exposure in-dicating that the tendon has corroded severely

313 AC Impedance e Nyquist plot of the prestressedsteel and the rebar embedded in concrete with dierent ofchloride levels is given in Figure 8 e parameters obtainedfrom the impedance technique for the prestressed steel andthe rebar in various chloride-contaminated concrete after 30days of exposure are shown in Table 3 From the table it isfound that the stressed steel has shown higher corrosion ratethan the unstressed steel in all the chloride levels After 30days of exposure in chloride-contaminated concrete theprestressed steel has 106 103 and 148 times higher cor-rosion rate than the rebar embedded in 1 2 and 3chloride-contaminated concrete For example Icorr value forthe rebar and the stressed steel in 3 NaCl was1224times10minus3mAmiddotcm2 and 2098times10minus3mAmiddotcm2 respectively

Rct values of the rebar and prestressed steel in 3 NaCl were2131times104 and 1441times104Ωmiddotcm2 respectively e corrosionrate of the rebar and the prestressed steel in 3 NaCl was1419times10minus2mmpy and 2098times10minus2mmpy respectively Inboth the prestressed steel and rebar the Rct values werefound to decrease and Cdl values were found to increase withthe increase in chloride concentration respectively e Icorrvalues were found to increase with the chloride concen-trations irrespective of the stressed conditions Compared tothe stressed steel the rebar has lesser corrosion rate higherRct values and lower Cdl values

Figure 9 depicts the impedance modulus curve for therebar and prestressed steel with dierent percentages ofchloride levels after 30 days of exposure It is found that theimpedance values were found to decrease with the increasein chloride concentration When compared to the pre-stressed steel the rebar has lesser impedance values than theprestressed steel in all the chloride levels In the stressedcondition as the chloride level increases the impedancevalue was found to decrease by one order of magnitude ateach chloride level e lowest corrosion resistance of thesteel was observed in 3 NaCl in both the prestressed steeland the rebar Slight capacitive behavior with the low-frequency domain is observed in both the stressed andunstressed steel wires at all chloride levels ese resultscould be explained by taking into consideration that thechlorides present in the surrounding concrete reached thesteel wire and activatedinitiated the corrosion process [46]

314 Potentiodynamic Polarization Studies e potentio-dynamic polarization curve for the rebar and the prestressedsteel under various chloride concentration levels is depictedin Figure 10 e corrosion kinetic parameters obtainedfrom the potentiodynamic polarization studies are given inTable 4 From the table it is observed that the Ecorr values of

minus600

minus500

minus400

minus300

minus200

minus100

00 10 20 30

Pote

ntia

l (m

V) v

ersu

s EC

MP

Time (days)

Control1 NaCl2 NaCl3 NaCl

(a)

Control1 NaCl2 NaCl3 NaCl

minus600

minus500

minus400

minus300

minus200

minus100

00 10 20 30

Pote

ntia

l (m

V) v

ersu

s EC

MP

Time (days)

(b)

Figure 7 OCP curve for the rebar (a) and prestressed steel (b) in chloride-contaminated concrete

6 Advances in Materials Science and Engineering

the rebar after 30 days of exposure were minus291 minus388 andminus458 in 1 2 and 3 chloride levels respectively e Ecorrvalues for the rebar were minus424 minus518 and minus594mV

indicating the severity of the corrosion in the prestressedsteel when compared to the rebar After 30 days of exposurethe corrosion current (Icorr) and the corrosion rate of the

0

10000

20000

30000

40000

50000

40000 60000 80000 100000 120000 140000

ZPrime (Ω

cm2 )

Zprime (Ωcm2)

Control1 NaCl2 NaCl3 NaCl

(a)ZPrime

(Ωcm

2 )

Zprime (Ωcm2)

0

10000

20000

30000

40000

50000

20000 40000 60000 80000 100000 120000 140000

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 8 AC impedance curve for the rebar (a) and prestressed steel (b) in chloride-contaminated concrete

Table 3 Initial and nal crack load for the yenexural concrete beams

Designation Initial crack load (kN) Final crack load (kN) Modulus of rupture (Fb) (Nmm2)Control 78 1206 5361 NaCl 76 985 4382 NaCl 67 906 4033 NaCl 64 809 360

40000

60000

80000

100000

120000

140000

log

| Z |(

Ωcm

2 )

Control1 NaCl2 NaCl3 NaCl

1Eminus01 1E+00 1E+01 1E+02 1E+03 1E+04 1E+05log f (Hz)

(a)

log

| Z |(

Ωcm

2 )

log f (Hz)

40000

60000

80000

100000

120000

140000

1Eminus01 1E+00 1E+01 1E+02 1E+03 1E+04 1E+05

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 9 Impedance modulus curve for the rebar (a) and prestressed steel (b) in chloride-contaminated concrete

Advances in Materials Science and Engineering 7

prestressed steel were found to be higher when compared tothe rebar e corrosion rate of the rebar was 0721 11671524times10minus3mmpy in 1 2 and 3 chloride levels re-spectively e corrosion rate of the prestressed steel was0771 1374 1586times10minus3mmpy in 1 2 and 3 chloridelevels respectively e stressed steel has 104 118 and 104times higher corrosion rate than the rebar at 1 2 and 3chloride levels respectively From the potentiodynamicpolarization curve it is observed that the stressed steel hascorroded severely than the rebar

From the abovementioned electrochemical studies itis found that the shift in the corrosion rate was higher at2 chloride level when compared to 1 and 3 chloridelevels is may be due to the fact that initially during thehydration at 1 chloride levels the chlorides combinedwith the cement to form a complex called the Friedel salt[47 48] and it reduced the availability of free chlorideions At 2 chloride the complex formation was foundto be lower and the free chloride ions may be higher tocause more corrosion both in the case of the rebar andprestressed steel

32 Flexure Test Figure 11 shows the load versus dis-placement behavior of 0 1 2 and 3 chloride-admixedprestressed concrete beams tested under two-point loadingTable 5 shows the initial and nal crack load and themodulus of rupture for the various chloride-admixedconcrete beams after 30 days of exposure From Figure 10it is found that the cracks appeared in the midspan Anadditional increase in load under various stages resulted inthe formation of additional cracks and widening of someearlier formed cracks e cracks from the tension zonetraversed up to the neutral axis and cracking of the concretetook place at later stages e failure of the specimen oc-curred due to the fast propagation of the cracks From theload versus displacement curve it is found that the maxi-mum ultimate load for 0 1 2 and 3 of the chloride-contaminated concretes is 1206 985 906 and 809 kNrespectively From the results it is observed that whencompared to the control concrete the chloride-contaminated concrete has reduced the load-carrying ca-pacity of 183 249 and 329 for 1 2 and 3 chloride-admixed concreteemodulus of rupture was also found to

log i (mAcmminus2)

minus700

minus600

minus500

minus400

minus300

minus200

minus100

0

1Eminus06 1Eminus05 1Eminus04 1Eminus03 1Eminus02 1Eminus01

Pote

ntia

l (m

V) v

ersu

s ECM

P

Control1 NaCl2 NaCl3 NaCl

(a)

log i (mAcmminus2)

minus900

minus800

minus700

minus600

minus500

minus400

minus300

minus200

minus100

0

1Eminus06 1Eminus05 1Eminus04 1Eminus03 1Eminus02 1Eminus01

Pote

ntia

l (m

V) v

ersu

s ECM

P

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 10 Potentiodynamic polarization curve for the rebar (a) and prestressed steel (b) in chloride-contaminated concrete

Table 4 AC impedance parameters for the rebar and prestressed steel in chloride-contaminated concrete

System

AC impedance parametersRebar Prestressed steel wire

Rct (Ωmiddotcm2)times104

Cdl (Fmiddotcmminus2)times10minus5

Icorr(mAmiddotcm2)times

10minus3CR (mmpy)times

10minus2Rct (Ωmiddotcm2)times

104Cdl (Fmiddotcmminus2)times

10minus5Icorr

(mAmiddotcm2)times10minus3

CR(mmpy)times

10minus2

Control 4897 1733 0533 0617 4355 1623 0599 06941NaCl 4010 2225 0651 0754 3766 2088 0692 0803

2NaCl 2357 2417 1107 1283 2286 3174 1141 1323

3NaCl 2131 2618 1224 1419 1441 5125 1810 2098

8 Advances in Materials Science and Engineering

decrease with increase in the chloride concentration edecrease in the modulus of rupture is due to the presence ofchloride ions which caused the corrosion of reinforcementand prestressed steel leading to the reduction in the load-carrying capacity of the beam [49 50]

4 Conclusions

(1) e yenexural strength of the prestressed concretebeam was decreased by 329 as the chloride contentwas increased to 3

(2) e corrosion rate of the prestressed steel is found tobe higher than that of the rebar

(3) e present investigation further demonstrates thatthe ECN measurement combined with other elec-trochemical techniques is used to study the corrosionprocess of the prestressing steel e ECN results arein good agreement with those of the OCP and EISmeasurements

(4) e ECN clearly indicated the potential and currentshift with chloride contents e potential shiftsobserved were found to be minus190mV for 0 Clminus and

minus510mV for 3 Clminus in the stressed condition esedata showed 268 times shift for chloride-contaminated prestressed concrete beam

(5) From the abovementioned experiments it is foundthat the ECN clearly indicated the corrosion status ofthe chloride-contaminated and -uncontaminatedprestressed steel and rebar

Conflicts of Interest

e authors declare that there are no conyenicts of interest inpublishing this paper

Acknowledgments

is research was supported by the Basic Science ResearchProgram through the National Research Foundation ofKorea (NRF) funded by the Ministry of Science ICT andFuture Planning (no 2015R1A5A1037548) Velu Saraswathythanks the Director CECRI and CSIR for the permission topursue the fellowship at Hanyang University Erica campusKorea

0

20

40

60

80

100

120

140

0 2 4 6 8 10

Load

(kN

)

Displacement (mm)

Control1 NaCl2 NaCl3 NaCl

Figure 11 Load versus displacement behavior of corroded prestressed concrete beams after 30 days of exposure under variouschloride levels

Table 5 Potentiodynamic polarization parameters for the rebar and prestressed steel in chloride-contaminated concrete

System

Potentiodynamic polarization parametersRebar Prestressed steel

Ecorr (mV) Icorr (mAmiddotcm2)times 10minus4 Corrosion rate(mmpy)times 10minus3 Ecorr (mV) Icorr (mAmiddotcm2)times 10minus4 Corrosion rate

(mmpy)times 10minus3

Control minus250 0455 0527 minus340 0630 07301 NaCl minus291 0622 0721 minus424 0648 07712 NaCl minus388 1007 1167 minus518 1186 13743 NaCl minus458 1315 1524 minus594 1374 1586

Advances in Materials Science and Engineering 9

References

[1] Post-Tensioning Institute Post-Tensioning Manual pp 5ndash54PTI Phoenix AZ USA 6th edition 2006

[2] T Y Lin and N H Burns Design of Prestressed ConcreteStructures John Wiley amp Sons New York NY USA 3rdedition 1981

[3] R F Warner and K A Faulkes Prestressed Concrete pp 1ndash13Longman Cheshire Melbourne VIC Australia 2nd edition1988

[4] A S El-Amoush and S A Al-Duheisat ldquoCathodic polari-zation behavior of the structural steel wires under differentprestressing conditionsrdquo Journal of Materials Research andTechnology 2017 in press

[5] M S Darmawan and M G Stewart ldquoSpatial time-dependentreliability analysis of corroding pretensioned prestressedconcrete bridge girdersrdquo Structural Safety vol 29 no 1pp 16ndash31 2007

[6] M S Darmawan and M G Stewart ldquoEffect of pitting cor-rosion on capacity of prestressing wiresrdquo Magazine of Con-crete Research vol 59 no 2 pp 131ndash139 2007

[7] P Gardoni R G Pillai M B D Hueste K Reinschmidt andD Trejo ldquoProbabilistic capacity models for corroding post-tensioning strands calibrated using laboratory resultsrdquoJournal of Engineering Mechanics vol 135 no 9 pp 906ndash9162009

[8] R G Pillai P Gardoni D Trejo M B D Hueste andK F Reinschmidt ldquoProbabilistic models for the tensilestrength of corroding strands in post-tensioned segmentalconcrete bridgesrdquo Journal of Materials in Civil Engineeringvol 22 no 10 pp 967ndash977 2010

[9] N A Vu A Castel and R Franccedilois ldquoEffect of stress corrosioncracking on stressndashstrain response of steel wires used inprestressed concrete beamsrdquo Corrosion Science vol 51 no 6pp 1453ndash1459 2009

[10] J Woodtli and R Kieselbach ldquoDamage due to hydrogenembrittlement and stress corrosion crackingrdquo EngineeringFailure Analysis vol 7 no 6 pp 427ndash450 2000

[11] J Toribio ldquoe role of crack tip strain rate in hydrogenassisted crackingrdquo Corrosion Science vol 39 no 9pp 1687ndash1697 1997

[12] N A Vu A Castel and R Franccedilois ldquoResponse of post-tensioned concrete beams with unbonded tendons includingserviceability and ultimate staterdquo Engineering Structurevol 32 no 2 pp 556ndash569 2010

[13] D G Cavell and P Waldron ldquoA residual strength model fordeteriorating post-tensioned concrete bridgesrdquo Computers ampStructures vol 79 no 4 pp 361ndash373 2001

[14] M Grinfeld ldquoStress corrosion cracking of an elastic platerdquoActa Materialia vol 46 no 2 pp 631ndash636 1998

[15] A Toshimitsu Yokobori Jr Y Chinda T Nemoto K Satohand T Yamada ldquoe characteristics of hydrogen diffusionand concentration around a crack tip concerned with hy-drogen embrittlementrdquo Corrosion Science vol 44 no 3pp 407ndash424 2002

[16] A Turnbull L N McCartney and S Zhou ldquoModelling of theevolution of stress corrosion cracks from corrosion pitsrdquoScripta Materialia vol 54 no 4 pp 575ndash578 2006

[17] F Li Y Yuan and C Q Li ldquoCorrosion propagation ofprestressing steel strands in concrete subject to chloride at-tackrdquo Construction and Building Materials vol 25 no 10pp 3878ndash3885 2011

[18] A Valiente ldquoStress corrosion failure of large diameterpressure pipelines of prestressed concreterdquo EngineeringFailure Analysis vol 8 no 3 pp 245ndash261 2001

[19] R Helmerich and A Zunkel ldquoPartial collapse of the BerlinCongress Hall on May 21st 1980rdquo Engineering FailureAnalysis vol 43 pp 107ndash119 2014

[20] S Ramadan L Gaillet C Tessier and H Idrissi ldquoDetection ofstress corrosion cracking of high-strength steel used in pre-stressed concrete structures by acoustic emission techniquerdquoApplied Surface Science vol 254 no 8 pp 2255ndash2261 2008

[21] R W Posten and J P Wouters Durability of Precast Seg-mental Bridges NCHRP Web Document No 15 Project20ndash7Task 92 Transportation Research Board National Re-search Council Washington DC USA 1998

[22] M S Darmawan ldquoPitting corrosion model for partial pre-stressed concrete (PC) structures in a chloride environmentrdquoJournal of Technology Science vol 20 no 3 pp 109ndash118 2009

[23] L Dai L Wang J Zhang and X Zhang ldquoA global model forcorrosion-induced cracking in prestressed concrete struc-turesrdquo Engineering Failure Analysis vol 62 pp 263ndash2752016

[24] W Zhang X Liu and X Gu ldquoFatigue behavior of corrodedprestressed concrete beamsrdquo Construction and BuildingsMaterials vol 106 pp 198ndash208 2016

[25] X Zhang L Wang J Zhang Y Ma and Y Liu ldquoFlexuralbehavior of bonded post-tensioned concrete beams understrand corrosionrdquo Nuclear Engineering and Design vol 313pp 414ndash424 2017

[26] K A Harries ldquoStructural testing of prestressed concretegirders from the Lake View Drive Bridgerdquo Journal of BridgeEngineering vol 14 no 2 pp 78ndash92 2009

[27] M Kiviste and J Miljan ldquoEvaluation of residual flexuralcapacity of existing pre-cast pre-stressed concrete panelsmdashacase studyrdquo Engineering Structure vol 32 no 10 pp 3377ndash3383 2010

[28] D Coronelli A Castel N A Vu and R Franccedilois ldquoCorrodedpost-tensioned beams with bonded tendons and wire failurerdquoEngineering Structure vol 31 no 8 pp 1687ndash1697 2009

[29] C Q Li Y Yang and R E Melchers ldquoPrediction of re-inforcement corrosion in concrete and its effects on concretecracking and strength reductionrdquo ACI Materials Journalvol 105 no 1 pp 3ndash10 2008

[30] A A Torres-Acosta and M Martıınez-Madrid ldquoResidual lifeof corroding reinforced concrete structures in marine envi-ronmentrdquo Journal of Materials in Civil Engineering vol 15no 4 pp 344ndash353 2003

[31] H Minh H Mutsuyoshi and K Niitani ldquoInfluence ofgrouting condition on crack and load-carrying capacity ofpost-tensioned concrete beam due to chloride-induced cor-rosionrdquo Construction and Building Materials vol 21 no 7pp 1568ndash1575 2007

[32] H Minh H Mutsuyoshi H Taniguchi and K NiitanildquoChloride-induced corrosion in insufficiently grouted post-tensioned concrete beamsrdquo Journal of Materials in CivilEngineering vol 20 no 1 pp 85ndash91 2008

[33] A Castel D Coronelli N A Vu and R Franccedilois ldquoStructuralresponse of corroded unbonded post-tensioned beamsrdquoJournal of Structural Engineering vol 137 no 7 pp 761ndash7712010

[34] R G Pillai D Trejo P Gardoni M B D Hueste andK Reinschmidt ldquoTime-variant flexural reliability of post-tensioned segmental concrete bridges exposed to corrosiveenvironmentsrdquo Journal of Structural Engineering vol 140no 8 p A4014018 2014

10 Advances in Materials Science and Engineering

[35] A Torres-Acosta S Navarro-Gutierrez and J Teran-GuillenldquoResidual flexure capacity of corroded reinforced concretebeamsrdquo Engineering Structure vol 29 no 6 pp 1145ndash11522007

[36] F Li Y Qu and J Wang ldquoBond life degradation of steelstrand and concrete under combined corrosion and fatiguerdquoEngineering Failure Analysis vol 80 no 10 pp 186ndash196 2017

[37] F Li and Y Yuan ldquoEffects of corrosion on bond behaviorbetween steel strand and concreterdquo Construction and BuildingMaterials vol 38 pp 413ndash422 2013

[38] S Muralidharan T H Ha J H Bae et al ldquoElectrochemicalstudies on the solid embeddable reference sensors for cor-rosion monitoring in concrete structurerdquo Materials Lettersvol 60 no 5 pp 651ndash655 2006

[39] K Subbiah S Velu S-J Kwon H-S Lee N Rethinam andD-J Park ldquoA novel in-situ corrosion monitoring electrodefor reinforced concrete structuresrdquo Electrochimica Acta 2017in press

[40] M Aballe F J Bethencourt M Botana J M Marcos andA Sanchez ldquoInfluence of the degree of polishing of alloy AA5083 on its behavior against localized alkaline corrosionrdquoCorrosion Science vol 46 no 8 pp 1909ndash1920 2004

[41] S Girija U K Mudali V R Raju R K Dayal H S Khatakand B Raj ldquoDetermination of corrosion types for AISI type304L stainless steel using electrochemical noise methodrdquoMaterials Science and Engineering A vol 407 no 1-2pp 188ndash195 2005

[42] R J K Wood J A Wharton A J Speyer and K S TanldquoInvestigation of erosion-corrosion processes using electro-chemical noise measurementsrdquo Tribology Internationalvol 35 no 10 pp 631ndash634 2002

[43] M C Deya B del Amo E Spinelli and R Romagnoli ldquoeassessment of a smart anticorrosive coating by the electro-chemical noise techniquerdquo Progress Organic Coatings vol 76no 14 pp 525ndash532 2013

[44] H W Song and V Saraswathy ldquoCorrosion monitoring ofreinforced concrete structures-a reviewrdquo International Jour-nal of Electrochemical Science vol 2 pp 1ndash28 2007

[45] B Zhao J H Li R G Hu R G Du and C J Lin ldquoStudy onthe corrosion behavior of reinforcing steel in cement mortarby electrochemical noise measurementsrdquo Electrochimica Actavol 52 no 12 pp 3976ndash3984 2007

[46] R G Duarte A S Castela R Neves L Freire andM F Montemor ldquoCorrosion behaviour of stainless steelrebars embedded in concrete an electrochemical impedancespectroscopy studyrdquo Electrochimica Acta vol 124 pp 218ndash224 2014

[47] Kangavel S Muralidharan V Saraswathy K Y Ann andL Balamurugan ldquoRelationship between alumina and chloridecontent on their physical and corrosion resistance propertiesof concreterdquo Arabian Journal for Science and Engineeringvol 35 no 28 pp 27ndash38 2009

[48] S P Karthick S Muralidharan V Saraswathy andS J Kwon ldquoEffect of different alkali salt additions on concretedurability propertyrdquo Journal of Structural Integrity andMaintenance vol 1 no 1 pp 35ndash42 2016

[49] M Moawad H EI-Karmoty and A EI Zanaty ldquoBehavior ofcorroded bonded fully prestressed and conventional concretebeamsrdquo HBRC Journal 2016 in press

[50] M Moawad A Mahmoud H EI-Karmoty and A EI ZanatyldquoBehavior of corroded bonded partially prestressed concretebeamsrdquo HBRC Journal 2016 in press

Advances in Materials Science and Engineering 11

CorrosionInternational Journal of

Hindawiwwwhindawicom Volume 2018

Advances in

Materials Science and EngineeringHindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Analytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

ScienticaHindawiwwwhindawicom Volume 2018

Polymer ScienceInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Advances in Condensed Matter Physics

Hindawiwwwhindawicom Volume 2018

International Journal of

BiomaterialsHindawiwwwhindawicom

Journal ofEngineeringVolume 2018

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Hindawiwwwhindawicom Volume 2018

High Energy PhysicsAdvances in

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

ChemistryAdvances in

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom Volume 2018

BioMed Research InternationalMaterials

Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

the rebar after 30 days of exposure were minus291 minus388 andminus458 in 1 2 and 3 chloride levels respectively e Ecorrvalues for the rebar were minus424 minus518 and minus594mV

indicating the severity of the corrosion in the prestressedsteel when compared to the rebar After 30 days of exposurethe corrosion current (Icorr) and the corrosion rate of the

0

10000

20000

30000

40000

50000

40000 60000 80000 100000 120000 140000

ZPrime (Ω

cm2 )

Zprime (Ωcm2)

Control1 NaCl2 NaCl3 NaCl

(a)ZPrime

(Ωcm

2 )

Zprime (Ωcm2)

0

10000

20000

30000

40000

50000

20000 40000 60000 80000 100000 120000 140000

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 8 AC impedance curve for the rebar (a) and prestressed steel (b) in chloride-contaminated concrete

Table 3 Initial and nal crack load for the yenexural concrete beams

Designation Initial crack load (kN) Final crack load (kN) Modulus of rupture (Fb) (Nmm2)Control 78 1206 5361 NaCl 76 985 4382 NaCl 67 906 4033 NaCl 64 809 360

40000

60000

80000

100000

120000

140000

log

| Z |(

Ωcm

2 )

Control1 NaCl2 NaCl3 NaCl

1Eminus01 1E+00 1E+01 1E+02 1E+03 1E+04 1E+05log f (Hz)

(a)

log

| Z |(

Ωcm

2 )

log f (Hz)

40000

60000

80000

100000

120000

140000

1Eminus01 1E+00 1E+01 1E+02 1E+03 1E+04 1E+05

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 9 Impedance modulus curve for the rebar (a) and prestressed steel (b) in chloride-contaminated concrete

Advances in Materials Science and Engineering 7

prestressed steel were found to be higher when compared tothe rebar e corrosion rate of the rebar was 0721 11671524times10minus3mmpy in 1 2 and 3 chloride levels re-spectively e corrosion rate of the prestressed steel was0771 1374 1586times10minus3mmpy in 1 2 and 3 chloridelevels respectively e stressed steel has 104 118 and 104times higher corrosion rate than the rebar at 1 2 and 3chloride levels respectively From the potentiodynamicpolarization curve it is observed that the stressed steel hascorroded severely than the rebar

From the abovementioned electrochemical studies itis found that the shift in the corrosion rate was higher at2 chloride level when compared to 1 and 3 chloridelevels is may be due to the fact that initially during thehydration at 1 chloride levels the chlorides combinedwith the cement to form a complex called the Friedel salt[47 48] and it reduced the availability of free chlorideions At 2 chloride the complex formation was foundto be lower and the free chloride ions may be higher tocause more corrosion both in the case of the rebar andprestressed steel

32 Flexure Test Figure 11 shows the load versus dis-placement behavior of 0 1 2 and 3 chloride-admixedprestressed concrete beams tested under two-point loadingTable 5 shows the initial and nal crack load and themodulus of rupture for the various chloride-admixedconcrete beams after 30 days of exposure From Figure 10it is found that the cracks appeared in the midspan Anadditional increase in load under various stages resulted inthe formation of additional cracks and widening of someearlier formed cracks e cracks from the tension zonetraversed up to the neutral axis and cracking of the concretetook place at later stages e failure of the specimen oc-curred due to the fast propagation of the cracks From theload versus displacement curve it is found that the maxi-mum ultimate load for 0 1 2 and 3 of the chloride-contaminated concretes is 1206 985 906 and 809 kNrespectively From the results it is observed that whencompared to the control concrete the chloride-contaminated concrete has reduced the load-carrying ca-pacity of 183 249 and 329 for 1 2 and 3 chloride-admixed concreteemodulus of rupture was also found to

log i (mAcmminus2)

minus700

minus600

minus500

minus400

minus300

minus200

minus100

0

1Eminus06 1Eminus05 1Eminus04 1Eminus03 1Eminus02 1Eminus01

Pote

ntia

l (m

V) v

ersu

s ECM

P

Control1 NaCl2 NaCl3 NaCl

(a)

log i (mAcmminus2)

minus900

minus800

minus700

minus600

minus500

minus400

minus300

minus200

minus100

0

1Eminus06 1Eminus05 1Eminus04 1Eminus03 1Eminus02 1Eminus01

Pote

ntia

l (m

V) v

ersu

s ECM

P

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 10 Potentiodynamic polarization curve for the rebar (a) and prestressed steel (b) in chloride-contaminated concrete

Table 4 AC impedance parameters for the rebar and prestressed steel in chloride-contaminated concrete

System

AC impedance parametersRebar Prestressed steel wire

Rct (Ωmiddotcm2)times104

Cdl (Fmiddotcmminus2)times10minus5

Icorr(mAmiddotcm2)times

10minus3CR (mmpy)times

10minus2Rct (Ωmiddotcm2)times

104Cdl (Fmiddotcmminus2)times

10minus5Icorr

(mAmiddotcm2)times10minus3

CR(mmpy)times

10minus2

Control 4897 1733 0533 0617 4355 1623 0599 06941NaCl 4010 2225 0651 0754 3766 2088 0692 0803

2NaCl 2357 2417 1107 1283 2286 3174 1141 1323

3NaCl 2131 2618 1224 1419 1441 5125 1810 2098

8 Advances in Materials Science and Engineering

decrease with increase in the chloride concentration edecrease in the modulus of rupture is due to the presence ofchloride ions which caused the corrosion of reinforcementand prestressed steel leading to the reduction in the load-carrying capacity of the beam [49 50]

4 Conclusions

(1) e yenexural strength of the prestressed concretebeam was decreased by 329 as the chloride contentwas increased to 3

(2) e corrosion rate of the prestressed steel is found tobe higher than that of the rebar

(3) e present investigation further demonstrates thatthe ECN measurement combined with other elec-trochemical techniques is used to study the corrosionprocess of the prestressing steel e ECN results arein good agreement with those of the OCP and EISmeasurements

(4) e ECN clearly indicated the potential and currentshift with chloride contents e potential shiftsobserved were found to be minus190mV for 0 Clminus and

minus510mV for 3 Clminus in the stressed condition esedata showed 268 times shift for chloride-contaminated prestressed concrete beam

(5) From the abovementioned experiments it is foundthat the ECN clearly indicated the corrosion status ofthe chloride-contaminated and -uncontaminatedprestressed steel and rebar

Conflicts of Interest

e authors declare that there are no conyenicts of interest inpublishing this paper

Acknowledgments

is research was supported by the Basic Science ResearchProgram through the National Research Foundation ofKorea (NRF) funded by the Ministry of Science ICT andFuture Planning (no 2015R1A5A1037548) Velu Saraswathythanks the Director CECRI and CSIR for the permission topursue the fellowship at Hanyang University Erica campusKorea

0

20

40

60

80

100

120

140

0 2 4 6 8 10

Load

(kN

)

Displacement (mm)

Control1 NaCl2 NaCl3 NaCl

Figure 11 Load versus displacement behavior of corroded prestressed concrete beams after 30 days of exposure under variouschloride levels

Table 5 Potentiodynamic polarization parameters for the rebar and prestressed steel in chloride-contaminated concrete

System

Potentiodynamic polarization parametersRebar Prestressed steel

Ecorr (mV) Icorr (mAmiddotcm2)times 10minus4 Corrosion rate(mmpy)times 10minus3 Ecorr (mV) Icorr (mAmiddotcm2)times 10minus4 Corrosion rate

(mmpy)times 10minus3

Control minus250 0455 0527 minus340 0630 07301 NaCl minus291 0622 0721 minus424 0648 07712 NaCl minus388 1007 1167 minus518 1186 13743 NaCl minus458 1315 1524 minus594 1374 1586

Advances in Materials Science and Engineering 9

References

[1] Post-Tensioning Institute Post-Tensioning Manual pp 5ndash54PTI Phoenix AZ USA 6th edition 2006

[2] T Y Lin and N H Burns Design of Prestressed ConcreteStructures John Wiley amp Sons New York NY USA 3rdedition 1981

[3] R F Warner and K A Faulkes Prestressed Concrete pp 1ndash13Longman Cheshire Melbourne VIC Australia 2nd edition1988

[4] A S El-Amoush and S A Al-Duheisat ldquoCathodic polari-zation behavior of the structural steel wires under differentprestressing conditionsrdquo Journal of Materials Research andTechnology 2017 in press

[5] M S Darmawan and M G Stewart ldquoSpatial time-dependentreliability analysis of corroding pretensioned prestressedconcrete bridge girdersrdquo Structural Safety vol 29 no 1pp 16ndash31 2007

[6] M S Darmawan and M G Stewart ldquoEffect of pitting cor-rosion on capacity of prestressing wiresrdquo Magazine of Con-crete Research vol 59 no 2 pp 131ndash139 2007

[7] P Gardoni R G Pillai M B D Hueste K Reinschmidt andD Trejo ldquoProbabilistic capacity models for corroding post-tensioning strands calibrated using laboratory resultsrdquoJournal of Engineering Mechanics vol 135 no 9 pp 906ndash9162009

[8] R G Pillai P Gardoni D Trejo M B D Hueste andK F Reinschmidt ldquoProbabilistic models for the tensilestrength of corroding strands in post-tensioned segmentalconcrete bridgesrdquo Journal of Materials in Civil Engineeringvol 22 no 10 pp 967ndash977 2010

[9] N A Vu A Castel and R Franccedilois ldquoEffect of stress corrosioncracking on stressndashstrain response of steel wires used inprestressed concrete beamsrdquo Corrosion Science vol 51 no 6pp 1453ndash1459 2009

[10] J Woodtli and R Kieselbach ldquoDamage due to hydrogenembrittlement and stress corrosion crackingrdquo EngineeringFailure Analysis vol 7 no 6 pp 427ndash450 2000

[11] J Toribio ldquoe role of crack tip strain rate in hydrogenassisted crackingrdquo Corrosion Science vol 39 no 9pp 1687ndash1697 1997

[12] N A Vu A Castel and R Franccedilois ldquoResponse of post-tensioned concrete beams with unbonded tendons includingserviceability and ultimate staterdquo Engineering Structurevol 32 no 2 pp 556ndash569 2010

[13] D G Cavell and P Waldron ldquoA residual strength model fordeteriorating post-tensioned concrete bridgesrdquo Computers ampStructures vol 79 no 4 pp 361ndash373 2001

[14] M Grinfeld ldquoStress corrosion cracking of an elastic platerdquoActa Materialia vol 46 no 2 pp 631ndash636 1998

[15] A Toshimitsu Yokobori Jr Y Chinda T Nemoto K Satohand T Yamada ldquoe characteristics of hydrogen diffusionand concentration around a crack tip concerned with hy-drogen embrittlementrdquo Corrosion Science vol 44 no 3pp 407ndash424 2002

[16] A Turnbull L N McCartney and S Zhou ldquoModelling of theevolution of stress corrosion cracks from corrosion pitsrdquoScripta Materialia vol 54 no 4 pp 575ndash578 2006

[17] F Li Y Yuan and C Q Li ldquoCorrosion propagation ofprestressing steel strands in concrete subject to chloride at-tackrdquo Construction and Building Materials vol 25 no 10pp 3878ndash3885 2011

[18] A Valiente ldquoStress corrosion failure of large diameterpressure pipelines of prestressed concreterdquo EngineeringFailure Analysis vol 8 no 3 pp 245ndash261 2001

[19] R Helmerich and A Zunkel ldquoPartial collapse of the BerlinCongress Hall on May 21st 1980rdquo Engineering FailureAnalysis vol 43 pp 107ndash119 2014

[20] S Ramadan L Gaillet C Tessier and H Idrissi ldquoDetection ofstress corrosion cracking of high-strength steel used in pre-stressed concrete structures by acoustic emission techniquerdquoApplied Surface Science vol 254 no 8 pp 2255ndash2261 2008

[21] R W Posten and J P Wouters Durability of Precast Seg-mental Bridges NCHRP Web Document No 15 Project20ndash7Task 92 Transportation Research Board National Re-search Council Washington DC USA 1998

[22] M S Darmawan ldquoPitting corrosion model for partial pre-stressed concrete (PC) structures in a chloride environmentrdquoJournal of Technology Science vol 20 no 3 pp 109ndash118 2009

[23] L Dai L Wang J Zhang and X Zhang ldquoA global model forcorrosion-induced cracking in prestressed concrete struc-turesrdquo Engineering Failure Analysis vol 62 pp 263ndash2752016

[24] W Zhang X Liu and X Gu ldquoFatigue behavior of corrodedprestressed concrete beamsrdquo Construction and BuildingsMaterials vol 106 pp 198ndash208 2016

[25] X Zhang L Wang J Zhang Y Ma and Y Liu ldquoFlexuralbehavior of bonded post-tensioned concrete beams understrand corrosionrdquo Nuclear Engineering and Design vol 313pp 414ndash424 2017

[26] K A Harries ldquoStructural testing of prestressed concretegirders from the Lake View Drive Bridgerdquo Journal of BridgeEngineering vol 14 no 2 pp 78ndash92 2009

[27] M Kiviste and J Miljan ldquoEvaluation of residual flexuralcapacity of existing pre-cast pre-stressed concrete panelsmdashacase studyrdquo Engineering Structure vol 32 no 10 pp 3377ndash3383 2010

[28] D Coronelli A Castel N A Vu and R Franccedilois ldquoCorrodedpost-tensioned beams with bonded tendons and wire failurerdquoEngineering Structure vol 31 no 8 pp 1687ndash1697 2009

[29] C Q Li Y Yang and R E Melchers ldquoPrediction of re-inforcement corrosion in concrete and its effects on concretecracking and strength reductionrdquo ACI Materials Journalvol 105 no 1 pp 3ndash10 2008

[30] A A Torres-Acosta and M Martıınez-Madrid ldquoResidual lifeof corroding reinforced concrete structures in marine envi-ronmentrdquo Journal of Materials in Civil Engineering vol 15no 4 pp 344ndash353 2003

[31] H Minh H Mutsuyoshi and K Niitani ldquoInfluence ofgrouting condition on crack and load-carrying capacity ofpost-tensioned concrete beam due to chloride-induced cor-rosionrdquo Construction and Building Materials vol 21 no 7pp 1568ndash1575 2007

[32] H Minh H Mutsuyoshi H Taniguchi and K NiitanildquoChloride-induced corrosion in insufficiently grouted post-tensioned concrete beamsrdquo Journal of Materials in CivilEngineering vol 20 no 1 pp 85ndash91 2008

[33] A Castel D Coronelli N A Vu and R Franccedilois ldquoStructuralresponse of corroded unbonded post-tensioned beamsrdquoJournal of Structural Engineering vol 137 no 7 pp 761ndash7712010

[34] R G Pillai D Trejo P Gardoni M B D Hueste andK Reinschmidt ldquoTime-variant flexural reliability of post-tensioned segmental concrete bridges exposed to corrosiveenvironmentsrdquo Journal of Structural Engineering vol 140no 8 p A4014018 2014

10 Advances in Materials Science and Engineering

[35] A Torres-Acosta S Navarro-Gutierrez and J Teran-GuillenldquoResidual flexure capacity of corroded reinforced concretebeamsrdquo Engineering Structure vol 29 no 6 pp 1145ndash11522007

[36] F Li Y Qu and J Wang ldquoBond life degradation of steelstrand and concrete under combined corrosion and fatiguerdquoEngineering Failure Analysis vol 80 no 10 pp 186ndash196 2017

[37] F Li and Y Yuan ldquoEffects of corrosion on bond behaviorbetween steel strand and concreterdquo Construction and BuildingMaterials vol 38 pp 413ndash422 2013

[38] S Muralidharan T H Ha J H Bae et al ldquoElectrochemicalstudies on the solid embeddable reference sensors for cor-rosion monitoring in concrete structurerdquo Materials Lettersvol 60 no 5 pp 651ndash655 2006

[39] K Subbiah S Velu S-J Kwon H-S Lee N Rethinam andD-J Park ldquoA novel in-situ corrosion monitoring electrodefor reinforced concrete structuresrdquo Electrochimica Acta 2017in press

[40] M Aballe F J Bethencourt M Botana J M Marcos andA Sanchez ldquoInfluence of the degree of polishing of alloy AA5083 on its behavior against localized alkaline corrosionrdquoCorrosion Science vol 46 no 8 pp 1909ndash1920 2004

[41] S Girija U K Mudali V R Raju R K Dayal H S Khatakand B Raj ldquoDetermination of corrosion types for AISI type304L stainless steel using electrochemical noise methodrdquoMaterials Science and Engineering A vol 407 no 1-2pp 188ndash195 2005

[42] R J K Wood J A Wharton A J Speyer and K S TanldquoInvestigation of erosion-corrosion processes using electro-chemical noise measurementsrdquo Tribology Internationalvol 35 no 10 pp 631ndash634 2002

[43] M C Deya B del Amo E Spinelli and R Romagnoli ldquoeassessment of a smart anticorrosive coating by the electro-chemical noise techniquerdquo Progress Organic Coatings vol 76no 14 pp 525ndash532 2013

[44] H W Song and V Saraswathy ldquoCorrosion monitoring ofreinforced concrete structures-a reviewrdquo International Jour-nal of Electrochemical Science vol 2 pp 1ndash28 2007

[45] B Zhao J H Li R G Hu R G Du and C J Lin ldquoStudy onthe corrosion behavior of reinforcing steel in cement mortarby electrochemical noise measurementsrdquo Electrochimica Actavol 52 no 12 pp 3976ndash3984 2007

[46] R G Duarte A S Castela R Neves L Freire andM F Montemor ldquoCorrosion behaviour of stainless steelrebars embedded in concrete an electrochemical impedancespectroscopy studyrdquo Electrochimica Acta vol 124 pp 218ndash224 2014

[47] Kangavel S Muralidharan V Saraswathy K Y Ann andL Balamurugan ldquoRelationship between alumina and chloridecontent on their physical and corrosion resistance propertiesof concreterdquo Arabian Journal for Science and Engineeringvol 35 no 28 pp 27ndash38 2009

[48] S P Karthick S Muralidharan V Saraswathy andS J Kwon ldquoEffect of different alkali salt additions on concretedurability propertyrdquo Journal of Structural Integrity andMaintenance vol 1 no 1 pp 35ndash42 2016

[49] M Moawad H EI-Karmoty and A EI Zanaty ldquoBehavior ofcorroded bonded fully prestressed and conventional concretebeamsrdquo HBRC Journal 2016 in press

[50] M Moawad A Mahmoud H EI-Karmoty and A EI ZanatyldquoBehavior of corroded bonded partially prestressed concretebeamsrdquo HBRC Journal 2016 in press

Advances in Materials Science and Engineering 11

CorrosionInternational Journal of

Hindawiwwwhindawicom Volume 2018

Advances in

Materials Science and EngineeringHindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Analytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

ScienticaHindawiwwwhindawicom Volume 2018

Polymer ScienceInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Advances in Condensed Matter Physics

Hindawiwwwhindawicom Volume 2018

International Journal of

BiomaterialsHindawiwwwhindawicom

Journal ofEngineeringVolume 2018

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Hindawiwwwhindawicom Volume 2018

High Energy PhysicsAdvances in

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

ChemistryAdvances in

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom Volume 2018

BioMed Research InternationalMaterials

Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

prestressed steel were found to be higher when compared tothe rebar e corrosion rate of the rebar was 0721 11671524times10minus3mmpy in 1 2 and 3 chloride levels re-spectively e corrosion rate of the prestressed steel was0771 1374 1586times10minus3mmpy in 1 2 and 3 chloridelevels respectively e stressed steel has 104 118 and 104times higher corrosion rate than the rebar at 1 2 and 3chloride levels respectively From the potentiodynamicpolarization curve it is observed that the stressed steel hascorroded severely than the rebar

From the abovementioned electrochemical studies itis found that the shift in the corrosion rate was higher at2 chloride level when compared to 1 and 3 chloridelevels is may be due to the fact that initially during thehydration at 1 chloride levels the chlorides combinedwith the cement to form a complex called the Friedel salt[47 48] and it reduced the availability of free chlorideions At 2 chloride the complex formation was foundto be lower and the free chloride ions may be higher tocause more corrosion both in the case of the rebar andprestressed steel

32 Flexure Test Figure 11 shows the load versus dis-placement behavior of 0 1 2 and 3 chloride-admixedprestressed concrete beams tested under two-point loadingTable 5 shows the initial and nal crack load and themodulus of rupture for the various chloride-admixedconcrete beams after 30 days of exposure From Figure 10it is found that the cracks appeared in the midspan Anadditional increase in load under various stages resulted inthe formation of additional cracks and widening of someearlier formed cracks e cracks from the tension zonetraversed up to the neutral axis and cracking of the concretetook place at later stages e failure of the specimen oc-curred due to the fast propagation of the cracks From theload versus displacement curve it is found that the maxi-mum ultimate load for 0 1 2 and 3 of the chloride-contaminated concretes is 1206 985 906 and 809 kNrespectively From the results it is observed that whencompared to the control concrete the chloride-contaminated concrete has reduced the load-carrying ca-pacity of 183 249 and 329 for 1 2 and 3 chloride-admixed concreteemodulus of rupture was also found to

log i (mAcmminus2)

minus700

minus600

minus500

minus400

minus300

minus200

minus100

0

1Eminus06 1Eminus05 1Eminus04 1Eminus03 1Eminus02 1Eminus01

Pote

ntia

l (m

V) v

ersu

s ECM

P

Control1 NaCl2 NaCl3 NaCl

(a)

log i (mAcmminus2)

minus900

minus800

minus700

minus600

minus500

minus400

minus300

minus200

minus100

0

1Eminus06 1Eminus05 1Eminus04 1Eminus03 1Eminus02 1Eminus01

Pote

ntia

l (m

V) v

ersu

s ECM

P

Control1 NaCl2 NaCl3 NaCl

(b)

Figure 10 Potentiodynamic polarization curve for the rebar (a) and prestressed steel (b) in chloride-contaminated concrete

Table 4 AC impedance parameters for the rebar and prestressed steel in chloride-contaminated concrete

System

AC impedance parametersRebar Prestressed steel wire

Rct (Ωmiddotcm2)times104

Cdl (Fmiddotcmminus2)times10minus5

Icorr(mAmiddotcm2)times

10minus3CR (mmpy)times

10minus2Rct (Ωmiddotcm2)times

104Cdl (Fmiddotcmminus2)times

10minus5Icorr

(mAmiddotcm2)times10minus3

CR(mmpy)times

10minus2

Control 4897 1733 0533 0617 4355 1623 0599 06941NaCl 4010 2225 0651 0754 3766 2088 0692 0803

2NaCl 2357 2417 1107 1283 2286 3174 1141 1323

3NaCl 2131 2618 1224 1419 1441 5125 1810 2098

8 Advances in Materials Science and Engineering

decrease with increase in the chloride concentration edecrease in the modulus of rupture is due to the presence ofchloride ions which caused the corrosion of reinforcementand prestressed steel leading to the reduction in the load-carrying capacity of the beam [49 50]

4 Conclusions

(1) e yenexural strength of the prestressed concretebeam was decreased by 329 as the chloride contentwas increased to 3

(2) e corrosion rate of the prestressed steel is found tobe higher than that of the rebar

(3) e present investigation further demonstrates thatthe ECN measurement combined with other elec-trochemical techniques is used to study the corrosionprocess of the prestressing steel e ECN results arein good agreement with those of the OCP and EISmeasurements

(4) e ECN clearly indicated the potential and currentshift with chloride contents e potential shiftsobserved were found to be minus190mV for 0 Clminus and

minus510mV for 3 Clminus in the stressed condition esedata showed 268 times shift for chloride-contaminated prestressed concrete beam

(5) From the abovementioned experiments it is foundthat the ECN clearly indicated the corrosion status ofthe chloride-contaminated and -uncontaminatedprestressed steel and rebar

Conflicts of Interest

e authors declare that there are no conyenicts of interest inpublishing this paper

Acknowledgments

is research was supported by the Basic Science ResearchProgram through the National Research Foundation ofKorea (NRF) funded by the Ministry of Science ICT andFuture Planning (no 2015R1A5A1037548) Velu Saraswathythanks the Director CECRI and CSIR for the permission topursue the fellowship at Hanyang University Erica campusKorea

0

20

40

60

80

100

120

140

0 2 4 6 8 10

Load

(kN

)

Displacement (mm)

Control1 NaCl2 NaCl3 NaCl

Figure 11 Load versus displacement behavior of corroded prestressed concrete beams after 30 days of exposure under variouschloride levels

Table 5 Potentiodynamic polarization parameters for the rebar and prestressed steel in chloride-contaminated concrete

System

Potentiodynamic polarization parametersRebar Prestressed steel

Ecorr (mV) Icorr (mAmiddotcm2)times 10minus4 Corrosion rate(mmpy)times 10minus3 Ecorr (mV) Icorr (mAmiddotcm2)times 10minus4 Corrosion rate

(mmpy)times 10minus3

Control minus250 0455 0527 minus340 0630 07301 NaCl minus291 0622 0721 minus424 0648 07712 NaCl minus388 1007 1167 minus518 1186 13743 NaCl minus458 1315 1524 minus594 1374 1586

Advances in Materials Science and Engineering 9

References

[1] Post-Tensioning Institute Post-Tensioning Manual pp 5ndash54PTI Phoenix AZ USA 6th edition 2006

[2] T Y Lin and N H Burns Design of Prestressed ConcreteStructures John Wiley amp Sons New York NY USA 3rdedition 1981

[3] R F Warner and K A Faulkes Prestressed Concrete pp 1ndash13Longman Cheshire Melbourne VIC Australia 2nd edition1988

[4] A S El-Amoush and S A Al-Duheisat ldquoCathodic polari-zation behavior of the structural steel wires under differentprestressing conditionsrdquo Journal of Materials Research andTechnology 2017 in press

[5] M S Darmawan and M G Stewart ldquoSpatial time-dependentreliability analysis of corroding pretensioned prestressedconcrete bridge girdersrdquo Structural Safety vol 29 no 1pp 16ndash31 2007

[6] M S Darmawan and M G Stewart ldquoEffect of pitting cor-rosion on capacity of prestressing wiresrdquo Magazine of Con-crete Research vol 59 no 2 pp 131ndash139 2007

[7] P Gardoni R G Pillai M B D Hueste K Reinschmidt andD Trejo ldquoProbabilistic capacity models for corroding post-tensioning strands calibrated using laboratory resultsrdquoJournal of Engineering Mechanics vol 135 no 9 pp 906ndash9162009

[8] R G Pillai P Gardoni D Trejo M B D Hueste andK F Reinschmidt ldquoProbabilistic models for the tensilestrength of corroding strands in post-tensioned segmentalconcrete bridgesrdquo Journal of Materials in Civil Engineeringvol 22 no 10 pp 967ndash977 2010

[9] N A Vu A Castel and R Franccedilois ldquoEffect of stress corrosioncracking on stressndashstrain response of steel wires used inprestressed concrete beamsrdquo Corrosion Science vol 51 no 6pp 1453ndash1459 2009

[10] J Woodtli and R Kieselbach ldquoDamage due to hydrogenembrittlement and stress corrosion crackingrdquo EngineeringFailure Analysis vol 7 no 6 pp 427ndash450 2000

[11] J Toribio ldquoe role of crack tip strain rate in hydrogenassisted crackingrdquo Corrosion Science vol 39 no 9pp 1687ndash1697 1997

[12] N A Vu A Castel and R Franccedilois ldquoResponse of post-tensioned concrete beams with unbonded tendons includingserviceability and ultimate staterdquo Engineering Structurevol 32 no 2 pp 556ndash569 2010

[13] D G Cavell and P Waldron ldquoA residual strength model fordeteriorating post-tensioned concrete bridgesrdquo Computers ampStructures vol 79 no 4 pp 361ndash373 2001

[14] M Grinfeld ldquoStress corrosion cracking of an elastic platerdquoActa Materialia vol 46 no 2 pp 631ndash636 1998

[15] A Toshimitsu Yokobori Jr Y Chinda T Nemoto K Satohand T Yamada ldquoe characteristics of hydrogen diffusionand concentration around a crack tip concerned with hy-drogen embrittlementrdquo Corrosion Science vol 44 no 3pp 407ndash424 2002

[16] A Turnbull L N McCartney and S Zhou ldquoModelling of theevolution of stress corrosion cracks from corrosion pitsrdquoScripta Materialia vol 54 no 4 pp 575ndash578 2006

[17] F Li Y Yuan and C Q Li ldquoCorrosion propagation ofprestressing steel strands in concrete subject to chloride at-tackrdquo Construction and Building Materials vol 25 no 10pp 3878ndash3885 2011

[18] A Valiente ldquoStress corrosion failure of large diameterpressure pipelines of prestressed concreterdquo EngineeringFailure Analysis vol 8 no 3 pp 245ndash261 2001

[19] R Helmerich and A Zunkel ldquoPartial collapse of the BerlinCongress Hall on May 21st 1980rdquo Engineering FailureAnalysis vol 43 pp 107ndash119 2014

[20] S Ramadan L Gaillet C Tessier and H Idrissi ldquoDetection ofstress corrosion cracking of high-strength steel used in pre-stressed concrete structures by acoustic emission techniquerdquoApplied Surface Science vol 254 no 8 pp 2255ndash2261 2008

[21] R W Posten and J P Wouters Durability of Precast Seg-mental Bridges NCHRP Web Document No 15 Project20ndash7Task 92 Transportation Research Board National Re-search Council Washington DC USA 1998

[22] M S Darmawan ldquoPitting corrosion model for partial pre-stressed concrete (PC) structures in a chloride environmentrdquoJournal of Technology Science vol 20 no 3 pp 109ndash118 2009

[23] L Dai L Wang J Zhang and X Zhang ldquoA global model forcorrosion-induced cracking in prestressed concrete struc-turesrdquo Engineering Failure Analysis vol 62 pp 263ndash2752016

[24] W Zhang X Liu and X Gu ldquoFatigue behavior of corrodedprestressed concrete beamsrdquo Construction and BuildingsMaterials vol 106 pp 198ndash208 2016

[25] X Zhang L Wang J Zhang Y Ma and Y Liu ldquoFlexuralbehavior of bonded post-tensioned concrete beams understrand corrosionrdquo Nuclear Engineering and Design vol 313pp 414ndash424 2017

[26] K A Harries ldquoStructural testing of prestressed concretegirders from the Lake View Drive Bridgerdquo Journal of BridgeEngineering vol 14 no 2 pp 78ndash92 2009

[27] M Kiviste and J Miljan ldquoEvaluation of residual flexuralcapacity of existing pre-cast pre-stressed concrete panelsmdashacase studyrdquo Engineering Structure vol 32 no 10 pp 3377ndash3383 2010

[28] D Coronelli A Castel N A Vu and R Franccedilois ldquoCorrodedpost-tensioned beams with bonded tendons and wire failurerdquoEngineering Structure vol 31 no 8 pp 1687ndash1697 2009

[29] C Q Li Y Yang and R E Melchers ldquoPrediction of re-inforcement corrosion in concrete and its effects on concretecracking and strength reductionrdquo ACI Materials Journalvol 105 no 1 pp 3ndash10 2008

[30] A A Torres-Acosta and M Martıınez-Madrid ldquoResidual lifeof corroding reinforced concrete structures in marine envi-ronmentrdquo Journal of Materials in Civil Engineering vol 15no 4 pp 344ndash353 2003

[31] H Minh H Mutsuyoshi and K Niitani ldquoInfluence ofgrouting condition on crack and load-carrying capacity ofpost-tensioned concrete beam due to chloride-induced cor-rosionrdquo Construction and Building Materials vol 21 no 7pp 1568ndash1575 2007

[32] H Minh H Mutsuyoshi H Taniguchi and K NiitanildquoChloride-induced corrosion in insufficiently grouted post-tensioned concrete beamsrdquo Journal of Materials in CivilEngineering vol 20 no 1 pp 85ndash91 2008

[33] A Castel D Coronelli N A Vu and R Franccedilois ldquoStructuralresponse of corroded unbonded post-tensioned beamsrdquoJournal of Structural Engineering vol 137 no 7 pp 761ndash7712010

[34] R G Pillai D Trejo P Gardoni M B D Hueste andK Reinschmidt ldquoTime-variant flexural reliability of post-tensioned segmental concrete bridges exposed to corrosiveenvironmentsrdquo Journal of Structural Engineering vol 140no 8 p A4014018 2014

10 Advances in Materials Science and Engineering

[35] A Torres-Acosta S Navarro-Gutierrez and J Teran-GuillenldquoResidual flexure capacity of corroded reinforced concretebeamsrdquo Engineering Structure vol 29 no 6 pp 1145ndash11522007

[36] F Li Y Qu and J Wang ldquoBond life degradation of steelstrand and concrete under combined corrosion and fatiguerdquoEngineering Failure Analysis vol 80 no 10 pp 186ndash196 2017

[37] F Li and Y Yuan ldquoEffects of corrosion on bond behaviorbetween steel strand and concreterdquo Construction and BuildingMaterials vol 38 pp 413ndash422 2013

[38] S Muralidharan T H Ha J H Bae et al ldquoElectrochemicalstudies on the solid embeddable reference sensors for cor-rosion monitoring in concrete structurerdquo Materials Lettersvol 60 no 5 pp 651ndash655 2006

[39] K Subbiah S Velu S-J Kwon H-S Lee N Rethinam andD-J Park ldquoA novel in-situ corrosion monitoring electrodefor reinforced concrete structuresrdquo Electrochimica Acta 2017in press

[40] M Aballe F J Bethencourt M Botana J M Marcos andA Sanchez ldquoInfluence of the degree of polishing of alloy AA5083 on its behavior against localized alkaline corrosionrdquoCorrosion Science vol 46 no 8 pp 1909ndash1920 2004

[41] S Girija U K Mudali V R Raju R K Dayal H S Khatakand B Raj ldquoDetermination of corrosion types for AISI type304L stainless steel using electrochemical noise methodrdquoMaterials Science and Engineering A vol 407 no 1-2pp 188ndash195 2005

[42] R J K Wood J A Wharton A J Speyer and K S TanldquoInvestigation of erosion-corrosion processes using electro-chemical noise measurementsrdquo Tribology Internationalvol 35 no 10 pp 631ndash634 2002

[43] M C Deya B del Amo E Spinelli and R Romagnoli ldquoeassessment of a smart anticorrosive coating by the electro-chemical noise techniquerdquo Progress Organic Coatings vol 76no 14 pp 525ndash532 2013

[44] H W Song and V Saraswathy ldquoCorrosion monitoring ofreinforced concrete structures-a reviewrdquo International Jour-nal of Electrochemical Science vol 2 pp 1ndash28 2007

[45] B Zhao J H Li R G Hu R G Du and C J Lin ldquoStudy onthe corrosion behavior of reinforcing steel in cement mortarby electrochemical noise measurementsrdquo Electrochimica Actavol 52 no 12 pp 3976ndash3984 2007

[46] R G Duarte A S Castela R Neves L Freire andM F Montemor ldquoCorrosion behaviour of stainless steelrebars embedded in concrete an electrochemical impedancespectroscopy studyrdquo Electrochimica Acta vol 124 pp 218ndash224 2014

[47] Kangavel S Muralidharan V Saraswathy K Y Ann andL Balamurugan ldquoRelationship between alumina and chloridecontent on their physical and corrosion resistance propertiesof concreterdquo Arabian Journal for Science and Engineeringvol 35 no 28 pp 27ndash38 2009

[48] S P Karthick S Muralidharan V Saraswathy andS J Kwon ldquoEffect of different alkali salt additions on concretedurability propertyrdquo Journal of Structural Integrity andMaintenance vol 1 no 1 pp 35ndash42 2016

[49] M Moawad H EI-Karmoty and A EI Zanaty ldquoBehavior ofcorroded bonded fully prestressed and conventional concretebeamsrdquo HBRC Journal 2016 in press

[50] M Moawad A Mahmoud H EI-Karmoty and A EI ZanatyldquoBehavior of corroded bonded partially prestressed concretebeamsrdquo HBRC Journal 2016 in press

Advances in Materials Science and Engineering 11

CorrosionInternational Journal of

Hindawiwwwhindawicom Volume 2018

Advances in

Materials Science and EngineeringHindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Analytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

ScienticaHindawiwwwhindawicom Volume 2018

Polymer ScienceInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Advances in Condensed Matter Physics

Hindawiwwwhindawicom Volume 2018

International Journal of

BiomaterialsHindawiwwwhindawicom

Journal ofEngineeringVolume 2018

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Hindawiwwwhindawicom Volume 2018

High Energy PhysicsAdvances in

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

ChemistryAdvances in

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom Volume 2018

BioMed Research InternationalMaterials

Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

decrease with increase in the chloride concentration edecrease in the modulus of rupture is due to the presence ofchloride ions which caused the corrosion of reinforcementand prestressed steel leading to the reduction in the load-carrying capacity of the beam [49 50]

4 Conclusions

(1) e yenexural strength of the prestressed concretebeam was decreased by 329 as the chloride contentwas increased to 3

(2) e corrosion rate of the prestressed steel is found tobe higher than that of the rebar

(3) e present investigation further demonstrates thatthe ECN measurement combined with other elec-trochemical techniques is used to study the corrosionprocess of the prestressing steel e ECN results arein good agreement with those of the OCP and EISmeasurements

(4) e ECN clearly indicated the potential and currentshift with chloride contents e potential shiftsobserved were found to be minus190mV for 0 Clminus and

minus510mV for 3 Clminus in the stressed condition esedata showed 268 times shift for chloride-contaminated prestressed concrete beam

(5) From the abovementioned experiments it is foundthat the ECN clearly indicated the corrosion status ofthe chloride-contaminated and -uncontaminatedprestressed steel and rebar

Conflicts of Interest

e authors declare that there are no conyenicts of interest inpublishing this paper

Acknowledgments

is research was supported by the Basic Science ResearchProgram through the National Research Foundation ofKorea (NRF) funded by the Ministry of Science ICT andFuture Planning (no 2015R1A5A1037548) Velu Saraswathythanks the Director CECRI and CSIR for the permission topursue the fellowship at Hanyang University Erica campusKorea

0

20

40

60

80

100

120

140

0 2 4 6 8 10

Load

(kN

)

Displacement (mm)

Control1 NaCl2 NaCl3 NaCl

Figure 11 Load versus displacement behavior of corroded prestressed concrete beams after 30 days of exposure under variouschloride levels

Table 5 Potentiodynamic polarization parameters for the rebar and prestressed steel in chloride-contaminated concrete

System

Potentiodynamic polarization parametersRebar Prestressed steel

Ecorr (mV) Icorr (mAmiddotcm2)times 10minus4 Corrosion rate(mmpy)times 10minus3 Ecorr (mV) Icorr (mAmiddotcm2)times 10minus4 Corrosion rate

(mmpy)times 10minus3

Control minus250 0455 0527 minus340 0630 07301 NaCl minus291 0622 0721 minus424 0648 07712 NaCl minus388 1007 1167 minus518 1186 13743 NaCl minus458 1315 1524 minus594 1374 1586

Advances in Materials Science and Engineering 9

References

[1] Post-Tensioning Institute Post-Tensioning Manual pp 5ndash54PTI Phoenix AZ USA 6th edition 2006

[2] T Y Lin and N H Burns Design of Prestressed ConcreteStructures John Wiley amp Sons New York NY USA 3rdedition 1981

[3] R F Warner and K A Faulkes Prestressed Concrete pp 1ndash13Longman Cheshire Melbourne VIC Australia 2nd edition1988

[4] A S El-Amoush and S A Al-Duheisat ldquoCathodic polari-zation behavior of the structural steel wires under differentprestressing conditionsrdquo Journal of Materials Research andTechnology 2017 in press

[5] M S Darmawan and M G Stewart ldquoSpatial time-dependentreliability analysis of corroding pretensioned prestressedconcrete bridge girdersrdquo Structural Safety vol 29 no 1pp 16ndash31 2007

[6] M S Darmawan and M G Stewart ldquoEffect of pitting cor-rosion on capacity of prestressing wiresrdquo Magazine of Con-crete Research vol 59 no 2 pp 131ndash139 2007

[7] P Gardoni R G Pillai M B D Hueste K Reinschmidt andD Trejo ldquoProbabilistic capacity models for corroding post-tensioning strands calibrated using laboratory resultsrdquoJournal of Engineering Mechanics vol 135 no 9 pp 906ndash9162009

[8] R G Pillai P Gardoni D Trejo M B D Hueste andK F Reinschmidt ldquoProbabilistic models for the tensilestrength of corroding strands in post-tensioned segmentalconcrete bridgesrdquo Journal of Materials in Civil Engineeringvol 22 no 10 pp 967ndash977 2010

[9] N A Vu A Castel and R Franccedilois ldquoEffect of stress corrosioncracking on stressndashstrain response of steel wires used inprestressed concrete beamsrdquo Corrosion Science vol 51 no 6pp 1453ndash1459 2009

[10] J Woodtli and R Kieselbach ldquoDamage due to hydrogenembrittlement and stress corrosion crackingrdquo EngineeringFailure Analysis vol 7 no 6 pp 427ndash450 2000

[11] J Toribio ldquoe role of crack tip strain rate in hydrogenassisted crackingrdquo Corrosion Science vol 39 no 9pp 1687ndash1697 1997

[12] N A Vu A Castel and R Franccedilois ldquoResponse of post-tensioned concrete beams with unbonded tendons includingserviceability and ultimate staterdquo Engineering Structurevol 32 no 2 pp 556ndash569 2010

[13] D G Cavell and P Waldron ldquoA residual strength model fordeteriorating post-tensioned concrete bridgesrdquo Computers ampStructures vol 79 no 4 pp 361ndash373 2001

[14] M Grinfeld ldquoStress corrosion cracking of an elastic platerdquoActa Materialia vol 46 no 2 pp 631ndash636 1998

[15] A Toshimitsu Yokobori Jr Y Chinda T Nemoto K Satohand T Yamada ldquoe characteristics of hydrogen diffusionand concentration around a crack tip concerned with hy-drogen embrittlementrdquo Corrosion Science vol 44 no 3pp 407ndash424 2002

[16] A Turnbull L N McCartney and S Zhou ldquoModelling of theevolution of stress corrosion cracks from corrosion pitsrdquoScripta Materialia vol 54 no 4 pp 575ndash578 2006

[17] F Li Y Yuan and C Q Li ldquoCorrosion propagation ofprestressing steel strands in concrete subject to chloride at-tackrdquo Construction and Building Materials vol 25 no 10pp 3878ndash3885 2011

[18] A Valiente ldquoStress corrosion failure of large diameterpressure pipelines of prestressed concreterdquo EngineeringFailure Analysis vol 8 no 3 pp 245ndash261 2001

[19] R Helmerich and A Zunkel ldquoPartial collapse of the BerlinCongress Hall on May 21st 1980rdquo Engineering FailureAnalysis vol 43 pp 107ndash119 2014

[20] S Ramadan L Gaillet C Tessier and H Idrissi ldquoDetection ofstress corrosion cracking of high-strength steel used in pre-stressed concrete structures by acoustic emission techniquerdquoApplied Surface Science vol 254 no 8 pp 2255ndash2261 2008

[21] R W Posten and J P Wouters Durability of Precast Seg-mental Bridges NCHRP Web Document No 15 Project20ndash7Task 92 Transportation Research Board National Re-search Council Washington DC USA 1998

[22] M S Darmawan ldquoPitting corrosion model for partial pre-stressed concrete (PC) structures in a chloride environmentrdquoJournal of Technology Science vol 20 no 3 pp 109ndash118 2009

[23] L Dai L Wang J Zhang and X Zhang ldquoA global model forcorrosion-induced cracking in prestressed concrete struc-turesrdquo Engineering Failure Analysis vol 62 pp 263ndash2752016

[24] W Zhang X Liu and X Gu ldquoFatigue behavior of corrodedprestressed concrete beamsrdquo Construction and BuildingsMaterials vol 106 pp 198ndash208 2016

[25] X Zhang L Wang J Zhang Y Ma and Y Liu ldquoFlexuralbehavior of bonded post-tensioned concrete beams understrand corrosionrdquo Nuclear Engineering and Design vol 313pp 414ndash424 2017

[26] K A Harries ldquoStructural testing of prestressed concretegirders from the Lake View Drive Bridgerdquo Journal of BridgeEngineering vol 14 no 2 pp 78ndash92 2009

[27] M Kiviste and J Miljan ldquoEvaluation of residual flexuralcapacity of existing pre-cast pre-stressed concrete panelsmdashacase studyrdquo Engineering Structure vol 32 no 10 pp 3377ndash3383 2010

[28] D Coronelli A Castel N A Vu and R Franccedilois ldquoCorrodedpost-tensioned beams with bonded tendons and wire failurerdquoEngineering Structure vol 31 no 8 pp 1687ndash1697 2009

[29] C Q Li Y Yang and R E Melchers ldquoPrediction of re-inforcement corrosion in concrete and its effects on concretecracking and strength reductionrdquo ACI Materials Journalvol 105 no 1 pp 3ndash10 2008

[30] A A Torres-Acosta and M Martıınez-Madrid ldquoResidual lifeof corroding reinforced concrete structures in marine envi-ronmentrdquo Journal of Materials in Civil Engineering vol 15no 4 pp 344ndash353 2003

[31] H Minh H Mutsuyoshi and K Niitani ldquoInfluence ofgrouting condition on crack and load-carrying capacity ofpost-tensioned concrete beam due to chloride-induced cor-rosionrdquo Construction and Building Materials vol 21 no 7pp 1568ndash1575 2007

[32] H Minh H Mutsuyoshi H Taniguchi and K NiitanildquoChloride-induced corrosion in insufficiently grouted post-tensioned concrete beamsrdquo Journal of Materials in CivilEngineering vol 20 no 1 pp 85ndash91 2008

[33] A Castel D Coronelli N A Vu and R Franccedilois ldquoStructuralresponse of corroded unbonded post-tensioned beamsrdquoJournal of Structural Engineering vol 137 no 7 pp 761ndash7712010

[34] R G Pillai D Trejo P Gardoni M B D Hueste andK Reinschmidt ldquoTime-variant flexural reliability of post-tensioned segmental concrete bridges exposed to corrosiveenvironmentsrdquo Journal of Structural Engineering vol 140no 8 p A4014018 2014

10 Advances in Materials Science and Engineering

[35] A Torres-Acosta S Navarro-Gutierrez and J Teran-GuillenldquoResidual flexure capacity of corroded reinforced concretebeamsrdquo Engineering Structure vol 29 no 6 pp 1145ndash11522007

[36] F Li Y Qu and J Wang ldquoBond life degradation of steelstrand and concrete under combined corrosion and fatiguerdquoEngineering Failure Analysis vol 80 no 10 pp 186ndash196 2017

[37] F Li and Y Yuan ldquoEffects of corrosion on bond behaviorbetween steel strand and concreterdquo Construction and BuildingMaterials vol 38 pp 413ndash422 2013

[38] S Muralidharan T H Ha J H Bae et al ldquoElectrochemicalstudies on the solid embeddable reference sensors for cor-rosion monitoring in concrete structurerdquo Materials Lettersvol 60 no 5 pp 651ndash655 2006

[39] K Subbiah S Velu S-J Kwon H-S Lee N Rethinam andD-J Park ldquoA novel in-situ corrosion monitoring electrodefor reinforced concrete structuresrdquo Electrochimica Acta 2017in press

[40] M Aballe F J Bethencourt M Botana J M Marcos andA Sanchez ldquoInfluence of the degree of polishing of alloy AA5083 on its behavior against localized alkaline corrosionrdquoCorrosion Science vol 46 no 8 pp 1909ndash1920 2004

[41] S Girija U K Mudali V R Raju R K Dayal H S Khatakand B Raj ldquoDetermination of corrosion types for AISI type304L stainless steel using electrochemical noise methodrdquoMaterials Science and Engineering A vol 407 no 1-2pp 188ndash195 2005

[42] R J K Wood J A Wharton A J Speyer and K S TanldquoInvestigation of erosion-corrosion processes using electro-chemical noise measurementsrdquo Tribology Internationalvol 35 no 10 pp 631ndash634 2002

[43] M C Deya B del Amo E Spinelli and R Romagnoli ldquoeassessment of a smart anticorrosive coating by the electro-chemical noise techniquerdquo Progress Organic Coatings vol 76no 14 pp 525ndash532 2013

[44] H W Song and V Saraswathy ldquoCorrosion monitoring ofreinforced concrete structures-a reviewrdquo International Jour-nal of Electrochemical Science vol 2 pp 1ndash28 2007

[45] B Zhao J H Li R G Hu R G Du and C J Lin ldquoStudy onthe corrosion behavior of reinforcing steel in cement mortarby electrochemical noise measurementsrdquo Electrochimica Actavol 52 no 12 pp 3976ndash3984 2007

[46] R G Duarte A S Castela R Neves L Freire andM F Montemor ldquoCorrosion behaviour of stainless steelrebars embedded in concrete an electrochemical impedancespectroscopy studyrdquo Electrochimica Acta vol 124 pp 218ndash224 2014

[47] Kangavel S Muralidharan V Saraswathy K Y Ann andL Balamurugan ldquoRelationship between alumina and chloridecontent on their physical and corrosion resistance propertiesof concreterdquo Arabian Journal for Science and Engineeringvol 35 no 28 pp 27ndash38 2009

[48] S P Karthick S Muralidharan V Saraswathy andS J Kwon ldquoEffect of different alkali salt additions on concretedurability propertyrdquo Journal of Structural Integrity andMaintenance vol 1 no 1 pp 35ndash42 2016

[49] M Moawad H EI-Karmoty and A EI Zanaty ldquoBehavior ofcorroded bonded fully prestressed and conventional concretebeamsrdquo HBRC Journal 2016 in press

[50] M Moawad A Mahmoud H EI-Karmoty and A EI ZanatyldquoBehavior of corroded bonded partially prestressed concretebeamsrdquo HBRC Journal 2016 in press

Advances in Materials Science and Engineering 11

CorrosionInternational Journal of

Hindawiwwwhindawicom Volume 2018

Advances in

Materials Science and EngineeringHindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Analytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

ScienticaHindawiwwwhindawicom Volume 2018

Polymer ScienceInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Advances in Condensed Matter Physics

Hindawiwwwhindawicom Volume 2018

International Journal of

BiomaterialsHindawiwwwhindawicom

Journal ofEngineeringVolume 2018

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Hindawiwwwhindawicom Volume 2018

High Energy PhysicsAdvances in

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

ChemistryAdvances in

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom Volume 2018

BioMed Research InternationalMaterials

Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

References

[1] Post-Tensioning Institute Post-Tensioning Manual pp 5ndash54PTI Phoenix AZ USA 6th edition 2006

[2] T Y Lin and N H Burns Design of Prestressed ConcreteStructures John Wiley amp Sons New York NY USA 3rdedition 1981

[3] R F Warner and K A Faulkes Prestressed Concrete pp 1ndash13Longman Cheshire Melbourne VIC Australia 2nd edition1988

[4] A S El-Amoush and S A Al-Duheisat ldquoCathodic polari-zation behavior of the structural steel wires under differentprestressing conditionsrdquo Journal of Materials Research andTechnology 2017 in press

[5] M S Darmawan and M G Stewart ldquoSpatial time-dependentreliability analysis of corroding pretensioned prestressedconcrete bridge girdersrdquo Structural Safety vol 29 no 1pp 16ndash31 2007

[6] M S Darmawan and M G Stewart ldquoEffect of pitting cor-rosion on capacity of prestressing wiresrdquo Magazine of Con-crete Research vol 59 no 2 pp 131ndash139 2007

[7] P Gardoni R G Pillai M B D Hueste K Reinschmidt andD Trejo ldquoProbabilistic capacity models for corroding post-tensioning strands calibrated using laboratory resultsrdquoJournal of Engineering Mechanics vol 135 no 9 pp 906ndash9162009

[8] R G Pillai P Gardoni D Trejo M B D Hueste andK F Reinschmidt ldquoProbabilistic models for the tensilestrength of corroding strands in post-tensioned segmentalconcrete bridgesrdquo Journal of Materials in Civil Engineeringvol 22 no 10 pp 967ndash977 2010

[9] N A Vu A Castel and R Franccedilois ldquoEffect of stress corrosioncracking on stressndashstrain response of steel wires used inprestressed concrete beamsrdquo Corrosion Science vol 51 no 6pp 1453ndash1459 2009

[10] J Woodtli and R Kieselbach ldquoDamage due to hydrogenembrittlement and stress corrosion crackingrdquo EngineeringFailure Analysis vol 7 no 6 pp 427ndash450 2000

[11] J Toribio ldquoe role of crack tip strain rate in hydrogenassisted crackingrdquo Corrosion Science vol 39 no 9pp 1687ndash1697 1997

[12] N A Vu A Castel and R Franccedilois ldquoResponse of post-tensioned concrete beams with unbonded tendons includingserviceability and ultimate staterdquo Engineering Structurevol 32 no 2 pp 556ndash569 2010

[13] D G Cavell and P Waldron ldquoA residual strength model fordeteriorating post-tensioned concrete bridgesrdquo Computers ampStructures vol 79 no 4 pp 361ndash373 2001

[14] M Grinfeld ldquoStress corrosion cracking of an elastic platerdquoActa Materialia vol 46 no 2 pp 631ndash636 1998

[15] A Toshimitsu Yokobori Jr Y Chinda T Nemoto K Satohand T Yamada ldquoe characteristics of hydrogen diffusionand concentration around a crack tip concerned with hy-drogen embrittlementrdquo Corrosion Science vol 44 no 3pp 407ndash424 2002

[16] A Turnbull L N McCartney and S Zhou ldquoModelling of theevolution of stress corrosion cracks from corrosion pitsrdquoScripta Materialia vol 54 no 4 pp 575ndash578 2006

[17] F Li Y Yuan and C Q Li ldquoCorrosion propagation ofprestressing steel strands in concrete subject to chloride at-tackrdquo Construction and Building Materials vol 25 no 10pp 3878ndash3885 2011

[18] A Valiente ldquoStress corrosion failure of large diameterpressure pipelines of prestressed concreterdquo EngineeringFailure Analysis vol 8 no 3 pp 245ndash261 2001

[19] R Helmerich and A Zunkel ldquoPartial collapse of the BerlinCongress Hall on May 21st 1980rdquo Engineering FailureAnalysis vol 43 pp 107ndash119 2014

[20] S Ramadan L Gaillet C Tessier and H Idrissi ldquoDetection ofstress corrosion cracking of high-strength steel used in pre-stressed concrete structures by acoustic emission techniquerdquoApplied Surface Science vol 254 no 8 pp 2255ndash2261 2008

[21] R W Posten and J P Wouters Durability of Precast Seg-mental Bridges NCHRP Web Document No 15 Project20ndash7Task 92 Transportation Research Board National Re-search Council Washington DC USA 1998

[22] M S Darmawan ldquoPitting corrosion model for partial pre-stressed concrete (PC) structures in a chloride environmentrdquoJournal of Technology Science vol 20 no 3 pp 109ndash118 2009

[23] L Dai L Wang J Zhang and X Zhang ldquoA global model forcorrosion-induced cracking in prestressed concrete struc-turesrdquo Engineering Failure Analysis vol 62 pp 263ndash2752016

[24] W Zhang X Liu and X Gu ldquoFatigue behavior of corrodedprestressed concrete beamsrdquo Construction and BuildingsMaterials vol 106 pp 198ndash208 2016

[25] X Zhang L Wang J Zhang Y Ma and Y Liu ldquoFlexuralbehavior of bonded post-tensioned concrete beams understrand corrosionrdquo Nuclear Engineering and Design vol 313pp 414ndash424 2017

[26] K A Harries ldquoStructural testing of prestressed concretegirders from the Lake View Drive Bridgerdquo Journal of BridgeEngineering vol 14 no 2 pp 78ndash92 2009

[27] M Kiviste and J Miljan ldquoEvaluation of residual flexuralcapacity of existing pre-cast pre-stressed concrete panelsmdashacase studyrdquo Engineering Structure vol 32 no 10 pp 3377ndash3383 2010

[28] D Coronelli A Castel N A Vu and R Franccedilois ldquoCorrodedpost-tensioned beams with bonded tendons and wire failurerdquoEngineering Structure vol 31 no 8 pp 1687ndash1697 2009

[29] C Q Li Y Yang and R E Melchers ldquoPrediction of re-inforcement corrosion in concrete and its effects on concretecracking and strength reductionrdquo ACI Materials Journalvol 105 no 1 pp 3ndash10 2008

[30] A A Torres-Acosta and M Martıınez-Madrid ldquoResidual lifeof corroding reinforced concrete structures in marine envi-ronmentrdquo Journal of Materials in Civil Engineering vol 15no 4 pp 344ndash353 2003

[31] H Minh H Mutsuyoshi and K Niitani ldquoInfluence ofgrouting condition on crack and load-carrying capacity ofpost-tensioned concrete beam due to chloride-induced cor-rosionrdquo Construction and Building Materials vol 21 no 7pp 1568ndash1575 2007

[32] H Minh H Mutsuyoshi H Taniguchi and K NiitanildquoChloride-induced corrosion in insufficiently grouted post-tensioned concrete beamsrdquo Journal of Materials in CivilEngineering vol 20 no 1 pp 85ndash91 2008

[33] A Castel D Coronelli N A Vu and R Franccedilois ldquoStructuralresponse of corroded unbonded post-tensioned beamsrdquoJournal of Structural Engineering vol 137 no 7 pp 761ndash7712010

[34] R G Pillai D Trejo P Gardoni M B D Hueste andK Reinschmidt ldquoTime-variant flexural reliability of post-tensioned segmental concrete bridges exposed to corrosiveenvironmentsrdquo Journal of Structural Engineering vol 140no 8 p A4014018 2014

10 Advances in Materials Science and Engineering

[35] A Torres-Acosta S Navarro-Gutierrez and J Teran-GuillenldquoResidual flexure capacity of corroded reinforced concretebeamsrdquo Engineering Structure vol 29 no 6 pp 1145ndash11522007

[36] F Li Y Qu and J Wang ldquoBond life degradation of steelstrand and concrete under combined corrosion and fatiguerdquoEngineering Failure Analysis vol 80 no 10 pp 186ndash196 2017

[37] F Li and Y Yuan ldquoEffects of corrosion on bond behaviorbetween steel strand and concreterdquo Construction and BuildingMaterials vol 38 pp 413ndash422 2013

[38] S Muralidharan T H Ha J H Bae et al ldquoElectrochemicalstudies on the solid embeddable reference sensors for cor-rosion monitoring in concrete structurerdquo Materials Lettersvol 60 no 5 pp 651ndash655 2006

[39] K Subbiah S Velu S-J Kwon H-S Lee N Rethinam andD-J Park ldquoA novel in-situ corrosion monitoring electrodefor reinforced concrete structuresrdquo Electrochimica Acta 2017in press

[40] M Aballe F J Bethencourt M Botana J M Marcos andA Sanchez ldquoInfluence of the degree of polishing of alloy AA5083 on its behavior against localized alkaline corrosionrdquoCorrosion Science vol 46 no 8 pp 1909ndash1920 2004

[41] S Girija U K Mudali V R Raju R K Dayal H S Khatakand B Raj ldquoDetermination of corrosion types for AISI type304L stainless steel using electrochemical noise methodrdquoMaterials Science and Engineering A vol 407 no 1-2pp 188ndash195 2005

[42] R J K Wood J A Wharton A J Speyer and K S TanldquoInvestigation of erosion-corrosion processes using electro-chemical noise measurementsrdquo Tribology Internationalvol 35 no 10 pp 631ndash634 2002

[43] M C Deya B del Amo E Spinelli and R Romagnoli ldquoeassessment of a smart anticorrosive coating by the electro-chemical noise techniquerdquo Progress Organic Coatings vol 76no 14 pp 525ndash532 2013

[44] H W Song and V Saraswathy ldquoCorrosion monitoring ofreinforced concrete structures-a reviewrdquo International Jour-nal of Electrochemical Science vol 2 pp 1ndash28 2007

[45] B Zhao J H Li R G Hu R G Du and C J Lin ldquoStudy onthe corrosion behavior of reinforcing steel in cement mortarby electrochemical noise measurementsrdquo Electrochimica Actavol 52 no 12 pp 3976ndash3984 2007

[46] R G Duarte A S Castela R Neves L Freire andM F Montemor ldquoCorrosion behaviour of stainless steelrebars embedded in concrete an electrochemical impedancespectroscopy studyrdquo Electrochimica Acta vol 124 pp 218ndash224 2014

[47] Kangavel S Muralidharan V Saraswathy K Y Ann andL Balamurugan ldquoRelationship between alumina and chloridecontent on their physical and corrosion resistance propertiesof concreterdquo Arabian Journal for Science and Engineeringvol 35 no 28 pp 27ndash38 2009

[48] S P Karthick S Muralidharan V Saraswathy andS J Kwon ldquoEffect of different alkali salt additions on concretedurability propertyrdquo Journal of Structural Integrity andMaintenance vol 1 no 1 pp 35ndash42 2016

[49] M Moawad H EI-Karmoty and A EI Zanaty ldquoBehavior ofcorroded bonded fully prestressed and conventional concretebeamsrdquo HBRC Journal 2016 in press

[50] M Moawad A Mahmoud H EI-Karmoty and A EI ZanatyldquoBehavior of corroded bonded partially prestressed concretebeamsrdquo HBRC Journal 2016 in press

Advances in Materials Science and Engineering 11

CorrosionInternational Journal of

Hindawiwwwhindawicom Volume 2018

Advances in

Materials Science and EngineeringHindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Analytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

ScienticaHindawiwwwhindawicom Volume 2018

Polymer ScienceInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Advances in Condensed Matter Physics

Hindawiwwwhindawicom Volume 2018

International Journal of

BiomaterialsHindawiwwwhindawicom

Journal ofEngineeringVolume 2018

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Hindawiwwwhindawicom Volume 2018

High Energy PhysicsAdvances in

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

ChemistryAdvances in

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom Volume 2018

BioMed Research InternationalMaterials

Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

[35] A Torres-Acosta S Navarro-Gutierrez and J Teran-GuillenldquoResidual flexure capacity of corroded reinforced concretebeamsrdquo Engineering Structure vol 29 no 6 pp 1145ndash11522007

[36] F Li Y Qu and J Wang ldquoBond life degradation of steelstrand and concrete under combined corrosion and fatiguerdquoEngineering Failure Analysis vol 80 no 10 pp 186ndash196 2017

[37] F Li and Y Yuan ldquoEffects of corrosion on bond behaviorbetween steel strand and concreterdquo Construction and BuildingMaterials vol 38 pp 413ndash422 2013

[38] S Muralidharan T H Ha J H Bae et al ldquoElectrochemicalstudies on the solid embeddable reference sensors for cor-rosion monitoring in concrete structurerdquo Materials Lettersvol 60 no 5 pp 651ndash655 2006

[39] K Subbiah S Velu S-J Kwon H-S Lee N Rethinam andD-J Park ldquoA novel in-situ corrosion monitoring electrodefor reinforced concrete structuresrdquo Electrochimica Acta 2017in press

[40] M Aballe F J Bethencourt M Botana J M Marcos andA Sanchez ldquoInfluence of the degree of polishing of alloy AA5083 on its behavior against localized alkaline corrosionrdquoCorrosion Science vol 46 no 8 pp 1909ndash1920 2004

[41] S Girija U K Mudali V R Raju R K Dayal H S Khatakand B Raj ldquoDetermination of corrosion types for AISI type304L stainless steel using electrochemical noise methodrdquoMaterials Science and Engineering A vol 407 no 1-2pp 188ndash195 2005

[42] R J K Wood J A Wharton A J Speyer and K S TanldquoInvestigation of erosion-corrosion processes using electro-chemical noise measurementsrdquo Tribology Internationalvol 35 no 10 pp 631ndash634 2002

[43] M C Deya B del Amo E Spinelli and R Romagnoli ldquoeassessment of a smart anticorrosive coating by the electro-chemical noise techniquerdquo Progress Organic Coatings vol 76no 14 pp 525ndash532 2013

[44] H W Song and V Saraswathy ldquoCorrosion monitoring ofreinforced concrete structures-a reviewrdquo International Jour-nal of Electrochemical Science vol 2 pp 1ndash28 2007

[45] B Zhao J H Li R G Hu R G Du and C J Lin ldquoStudy onthe corrosion behavior of reinforcing steel in cement mortarby electrochemical noise measurementsrdquo Electrochimica Actavol 52 no 12 pp 3976ndash3984 2007

[46] R G Duarte A S Castela R Neves L Freire andM F Montemor ldquoCorrosion behaviour of stainless steelrebars embedded in concrete an electrochemical impedancespectroscopy studyrdquo Electrochimica Acta vol 124 pp 218ndash224 2014

[47] Kangavel S Muralidharan V Saraswathy K Y Ann andL Balamurugan ldquoRelationship between alumina and chloridecontent on their physical and corrosion resistance propertiesof concreterdquo Arabian Journal for Science and Engineeringvol 35 no 28 pp 27ndash38 2009

[48] S P Karthick S Muralidharan V Saraswathy andS J Kwon ldquoEffect of different alkali salt additions on concretedurability propertyrdquo Journal of Structural Integrity andMaintenance vol 1 no 1 pp 35ndash42 2016

[49] M Moawad H EI-Karmoty and A EI Zanaty ldquoBehavior ofcorroded bonded fully prestressed and conventional concretebeamsrdquo HBRC Journal 2016 in press

[50] M Moawad A Mahmoud H EI-Karmoty and A EI ZanatyldquoBehavior of corroded bonded partially prestressed concretebeamsrdquo HBRC Journal 2016 in press

Advances in Materials Science and Engineering 11

CorrosionInternational Journal of

Hindawiwwwhindawicom Volume 2018

Advances in

Materials Science and EngineeringHindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Analytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

ScienticaHindawiwwwhindawicom Volume 2018

Polymer ScienceInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Advances in Condensed Matter Physics

Hindawiwwwhindawicom Volume 2018

International Journal of

BiomaterialsHindawiwwwhindawicom

Journal ofEngineeringVolume 2018

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Hindawiwwwhindawicom Volume 2018

High Energy PhysicsAdvances in

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

ChemistryAdvances in

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom Volume 2018

BioMed Research InternationalMaterials

Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

CorrosionInternational Journal of

Hindawiwwwhindawicom Volume 2018

Advances in

Materials Science and EngineeringHindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Analytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

ScienticaHindawiwwwhindawicom Volume 2018

Polymer ScienceInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Advances in Condensed Matter Physics

Hindawiwwwhindawicom Volume 2018

International Journal of

BiomaterialsHindawiwwwhindawicom

Journal ofEngineeringVolume 2018

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Hindawiwwwhindawicom Volume 2018

High Energy PhysicsAdvances in

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

ChemistryAdvances in

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom Volume 2018

BioMed Research InternationalMaterials

Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom