surface resistivity as a performance test for transport

Surface Resistivity as a PerformanceTest for Transport Properties

Francisco J. Presuel-Moreno, Y. LiuFlorida Atlantic University, OME, Dania Beach, FL

Mario ParedesFlorida Department of Transportation, Gainesville, FL

Andrew J. Boyd, McGill University, Montreal, QC, Canada

Motivation Deterioration of reinforcement concrete Cracking, spalling, reduction, Loss of structural capacity

Background• Resistivity of the concrete is used to estimate the

quality of concrete (High resistivity – less permeable concrete)

• Low resistivity with corrosion initiated likely indicative of potentially high corrosion rate

• Recently a good correlation has been established between rapid chloride permeability test and Resistivity on laboratory specimens

• Good correlation chloride diffusivity vs. surface Resistivity on lab saturated conditions has been obtained

BackgroundSurface Resistivity

Non-destructive method. Used to estimate the quality of concrete.

(permeability) (semi infinite)

Indicative of potentially high corrosion rate when corrosion has initiated. (Langford)

2 aVI

IVa

IVKRK 2

Modeling of apparent resistivity of single layer concrete with single rebar with different cover concrete, specimen dimension: 1mx1mx1m vs. 30 cm x 30 cm x 15 cm

Rebar Presence and Concrete Cover effect on SR

0

0.2

0.4

0.6

0.8

1

0 2 4 6 8Electrode spacing (cm)

ρa kΩ

cm

Cover Concrete = 2.5cm; 30x30x15cm

Cover Concrete = 5cm; 30x30x15cm

Cover Concrete = 7.5cm; 30x30x15cm

Cover Concrete = 2.5cm; 1x1x1m

Cover Concrete = 5cm; 1x1x1m

Cover Concrete = 7.5cm; 1x1mx1m

a(%

of

bulk

)

Surface Resistivity vs. RCPR.J. Kessler et.al. CBC2008

*Normalized SR i.e. geometry corrected

Kessler et.al. Corrosion/2005

Normalized

Accelerated CuringConcrete with Slow Reacting Pozzolans (Celik Ozyildirim 2000)

FA: Fly ashw/cm =0.45

No Surface Resistivity was performed by VTRC

0

1000

2000

3000

4000

5000

6000

7000

8000

OPC 85/15FA 75/25FA 65/35FA

RC

P (C

oulo

mbs

)

RT28daysRT7/HR21RT 1 year

1

10

100

0.01 0.1 1 10 100

Diffusivity (x10-12 m2/s)

Res

istiv

ity K

ohm

-cm

Lab-3yrDvsRhoField_RvsD15yr D -FAU15yr D FAU w/CN

Surface Resistivity on saturated concrete

Surface Resistivity vs. DCl-Kessler, 2008Sagues, 1992Presuel, 2011Presuel, 2011

Note: 15 yr – w/cm 0.37*2- Concrete with FA (20,35, 50),**3 Concrete with SF (6, 15, 27), not marked OPC

*2

*3

1

10

100

0.01 0.10 1.00 10.00

Dapp (m2/s)

Res

istiv

ity (K

Ohm

-cm

) Nor

mal

ized

15 yr D3.3yr D

Surface Resistivity vs. DCl-D measured after 3.3 yrs and 15 yrs

15 yr D - Presuel, 20113.3 yr D - Hartt, 1999

Note: SR at 3.3 yr was not measured

Normalized Average Cylinders 1 to 3 - OPC group

0

5

10

15

20

0 100 200 300 400 500 600 700 800Time (Days)

Res

istiv

ity (k

Ohm

-cm

)

3cm

5cm

Lab T & RH ~95 RH


0

5

10

15

20

0 200 400 600 800

Time (Days)

Res

istiv

ity (k

Ohm

-cm

)

3cm

5cm

Stored in container with ~95% RH


0

5

10

15

20

0 200 400 600 800

Time (Days)

Res

istiv

ity (k

Ohm

-cm

)

3cm

5cm

Stored in fog room all the time


0

5

10

15

20

0 100 200 300 400 500 600 700 800Time (Days)

Res

istiv

ity (k

Ohm

-cm

)

3cm

5cm

Lab T & RH ~95 RH


0

5

10

15

20

0 200 400 600 800

Time (Days)

Res

istiv

ity (k

Ohm

-cm

)

3cm

5cm

Stored in container with ~95% RH


0

5

10

15

20

0 200 400 600 800

Time (Days)

Res

istiv

ity (k

Ohm

-cm

)

3cm

5cm

Stored in fog room all the time

Normalized Resistivity 2cy7 to 2cy12

0

5

10

15

20

25

30

0 100 200 300 400 500 600 700

Time (days)

ρ n kΩ

cm

3cm5cm


0

5

10

15

20

25

30

0 100 200 300 400 500 600 700

Time (days)

ρ n kΩ

cm

3cm5cm

Stored in container with ~90 RH


0

5

10

15

20

25

30

0 100 200 300 400 500 600 700

Time (days)

ρn kΩ

cm

3cm5cm


0

10

20

30

40

50

60

70

80

90

0 100 200 300 400 500 600 700

Time (days)

ρn kΩ

cm

3cm5cm

Lab T & RH High RH

Res

istiv

ity (k

-c

m)

Res

istiv

ity (k

-c

m)

Res

istiv

ity (k

-c

m)


0

5

10

15

20

25

30

0 100 200 300 400 500 600 700

Time (days)

ρ n kΩ

cm

3cm5cm


0

5

10

15

20

25

30

0 100 200 300 400 500 600 700

Time (days)

ρ n kΩ

cm

3cm5cm

Stored in container with ~90 RH


0

5

10

15

20

25

30

0 100 200 300 400 500 600 700

Time (days)

ρn kΩ

cm

3cm5cm


0

10

20

30

40

50

60

70

80

90

0 100 200 300 400 500 600 700

Time (days)

ρn kΩ

cm

3cm5cm

Lab T & RH High RH

Res

istiv

ity (k

-c

m)

Res

istiv

ity (k

-c

m)

Res

istiv

ity (k

-c

m)

OPC Concrete 20% FA Concrete

Resistivity vs. Timeunder variousEnvironmentalExposures

Normalized Average Cyls - FA in 3.5 NaCl vs. Fog Room

0

10

20

30

40

0 100 200 300 400 500 600 700

Time (Days)

Res

istiv

ity (k

Ohm

-cm

)

3cm-NaCl5cm-NaCl3cm-Fog5cm-Fog


0

10

20

30

40

0 100 200 300 400 500 600 700

Time (Days)

Res

istiv

ity (k

Ohm

-cm

)

3cm-NaCl5cm-NaCl3cm-Fog5cm-Fog Group 2


0

10

20

30

40

0 100 200 300 400 500 600 700

Time (Days)

Res

istiv

ity (k

Ohm

-cm

)

3cm-NaCl5cm-NaCl3cm-Fog5cm-Fog


0

10

20

30

40

0 100 200 300 400 500 600 700

Time (Days)

Res

istiv

ity (k

Ohm

-cm

)

3cm-NaCl5cm-NaCl3cm-Fog5cm-Fog Group 2

Effect of NaCl on Surface Resistivity

4x8 -Concrete Cylinders. Those exposed to chlorides exposed to NaCl 60 days after casting.

Towards Performance Based ConcreteResistivity of Concrete with Slow Reacting Pozzolans Subjected to Accelerated Curing – Immersed in Ca(OH)2 at ~38 ºC

Bulk diffusivity tests in 15% NaCl are being performed on these concretes.

28-day Comp. Strength - FL Limestone

% FA0% 10% 20% 30% 40% 50% 60%

Com

pres

sive

Stre

ngth

MPa

0

20

40

60

80

2RT/26HT7RT/21HT14RT/14HT28RT

28-day Resistivity - FL Limestone

% FA0% 10% 20% 30% 40% 50% 60%

Res

istiv

ity k c

m

0

10

20

30

40


Field work objective• Investigate the feasibility of extending correlation DCl‐ vs. Lab. Surface Resistivity to field surface resistivity measurements

Approach• Surface resistivity measurements on

bridge substructures• Surface resistivity measurements on

cylindrical cores obtained during field visits• Chloride Diffusivity from field cores

Field: Surface Resistivity MeasurementsMeasured: Profiles of ρ vs. elevation.Approach: Increased moisture content with water.Method: 1.6 gallons plastic containers. Edge-grip rubber seal on containers, tied down to piles, and filled with fresh water. Track of SR during 3 to 4 days.

Additional Measurements:Concrete coverMoisture meter (0-20 scale)First measurements as-is. Then containers placed and measurements taken every 24 hours.

Conditioning using: 1.6 gallon filled water container, tie-down.

Field Obtained Concrete Cores

2 to 4 cores drilled per selected pile2 purposes:

SRwet (high humidity)DCl

More than 300 cores in ± 80 pile structures

Field results:

Turkey Creek, Melbourne FL.• Bent 5, Pile 14• 10 year-old• SR normalized (Temp. @ 21°C)• 135 ° orientation• SR decreases as moisture increases

1

10

100

1000

1 10 100 1000

Wet (kOhm-cm)

Fiel

d

(KO

hm-c

m)

a=3cma=5cm

SRfield vs. SRwet

SRwet vs. Age

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

0 10 20 30 40 50

Bridge Age (years)

Wet

Res

istiv

ity (K

ohm

-cm

)

Lower SR for > 20 year-old Higher SR for < 20 year-old

Most newer bridge structures have low DClOlder bridges show higher DCl

DCl vs. Age

1.E-10

1.E-09

1.E-08

1.E-07

1.E-06

0 10 20 30 40 50

Bridge Age (Years)

Diff

usiv

ity (c

m2 /s

)

SRWet vs. DCl

1.00

10.00

100.00

1.E-10 1.E-09 1.E-08 1.E-07 1.E-06

D (cm2/s)

Wet

Res

istiv

ity (k

-c

m)

1-2021-40>40

yearsyearsyears

ConclusionsConcrete with Fly Ash replacement cured in a fog

room needs more than 400 days to reach finalresistivity value.Immersion in 3.5 NaCl solution reduced the SR

value measured by 20% on FA concrete whencompared to saturated SR measured value.Environmental conditions have a significant effect

on the SR value measured. Exposure to laboratorytemperature and relative humidity produces amonotonic increase in the measured SR value.

Conditioning method increase the moisture contentof the concrete layer closer to the surface. SRwet < 10 Kohm-cm for bridges > 20 year-old,

SRwet usually > 10 Kohm-cm for newer bridges SRwet vs. Dcl showed a good correlation, older

bridges had higher Dcl and lower SRwetWhen comparing SRwet to SRfield, showed that

conditioning approach does not completelysaturate the outer-surface concrete

Conclusions

Thank you for your attention!

Any Questions?

AcknowledgmentsThe authors are indebted to the Florida Department of Transportation (FDOT) for financial support of this research. The opinions expressed in presentation are those of the authors and not necessarily of the FDOT. FP also acknowledges travel assistance thru FAU‐RSY.

1

10

100

1.E-09 1.E-08 1.E-07 1.E-06

Dapp cm2/s

Res

istiv

ity (K

ohm

-cm

)

PseudoD-UFHamilton-2007ECR-USFBamfoth8yForce80sPolder-16yImPolderFogPolder-Rilem2

Hamilton, 2007Hamilton, 2007Sagues, 1994Bamforth, 1999Force, 1985Polder,Polder,Polder

1

10

100

1.E-09 1.E-08 1.E-07 1.E-06

Dapp cm2/s

Res

istiv

ity (K

ohm

-cm

)

PseudoD-UFHamilton-2007ECR-USFBamfoth8yForce80sPolder-16yImPolderFogPolder-Rilem2

Hamilton, 2007Hamilton, 2007Sagues, 1994Bamforth, 1999Force, 1985Polder,Polder,Polder

Dapp values vs. Resistivity

0.00

40.00

80.00

120.00

160.00

200.00

0.0% 0.5% 1.0% 1.5% 2.0%Weight increase (%)

Res

istiv

ity (K

Ohm

.cm

)

40a. UFA

41c. FA

42d. SF

43a. BFS

44b. MET

45d. OPC

UFA gained the most Weight

OPC clearly the lowest SRwet, followed by BFS

Note # in Series is CoreID

Weight increase due to water uptake after 1 dayat 60ºC, then exposed in high humidity environment.

Moisture content effect on Resistivity

28-day Comp. Strength- Granite

% FA0% 10% 20% 30% 40% 50% 60%

Com

pres

sive

Stre

ngth

MP

a

0

20

40

60

80

2RT/26HT 7RT/21HT 14RT/14HT 28RT

28-Day Resistivity- Granite

% FA0% 10% 20% 30% 40% 50% 60%

Res

istiv

ity k c

m

0

10

20

30

40

50


Towards Performance Based ConcreteResistivity of Concrete with Slow Reacting Pozzolans Subjected to Accelerated Curing – Immersed in Ca(OH)2 at ~38 C

Back-up slide

0

50

100

150

200

250

300

0.0% 0.5% 1.0% 1.5% 2.0% 2.5% 3.0% 3.5% 4.0%

M%

Nor

mal

ized

Res

istiv

ity (k

-cm

)

32C20A22A23C44B41C85A

0

20

40

60

80

100

120

140

160

0.0% 0.5% 1.0% 1.5% 2.0% 2.5% 3.0% 3.5% 4.0%

M%

Nor

mal

ized

Res

istiv

ity (k

ohm

-cm

)

72D 54D 53D

33A 31D 30D

8 9 40A

42D 43A

0

5

10

15

20

25

30

0.0% 0.5% 1.0% 1.5% 2.0% 2.5% 3.0% 3.5% 4.0%

M%

Nor

mal

ized

Res

istiv

ity (k

-c

m)

60D61D85A52B34A24A45D

Moisture content effect on Resistivity

Note # in Series is CoreID

0

1000

2000

3000

4000

5000

6000

7000

8000

OPC 85/20FA 100/20FA

RC

P (C

oulo

mbs

)

RT28daysRT7/HR21RT 1 year

Accelerated CuringConcrete with Slow Reacting Pozzolans (Celik Ozyildirim 1998)

FA: Fly ash

No Surface Resistivity was performed by VTRC

w/cm=0.4 0.38 0.33

surface resistivity as a performance test for transport

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