jsce specifications on stainless steel bars and new...
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JSCE specifications on stainless JSCE specifications on stainless steel bars and newsteel bars and newanchorage/splice technologiesanchorage/splice technologies
Takumi ShimomuraNagaoka University of Technology
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Standard Specifications for Standard Specifications for Concrete StructuresConcrete Structures
2007 editionDesignMaterials and ConstructionMaintenanceDam ConcreteTest Methods and Specifications for Concrete
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Recommendations and Recommendations and GuidelinesGuidelines
Recent publications:Recommendations on Environmental Performance Verification for Concrete Structures (Draft)Recommendations for Mix Design of Fresh Concrete and Construction Placement related Performance EvaluationRecommendations for Design and Construction of High Performance FiberReinforced Cement Composite with Multiple Fine Cracks (HPFRCC)Ancient Roman Concrete
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Publications in EnglishPublications in EnglishMost JSCE Standard Specifications for Concrete Structures, Recommendations and Guidelines have been translated into English.You can purchase them from our web site. http://www.jsce.or.jp/
JSCE Standards on Test Method for Diffusion Coefficient of Chloride Ion in Concrete
RECOMMENDATIONS FOR SHOTCRETING (DRAFT)
STANDARD SPECIFICATIONS FOR CONCRETE STRUCTURES-2002 "Structural Performance Verification"
STANDARD SPECIFICATIONS FOR CONCRETE STRUCTURES -2002 "Seismic Performance Verification"
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Topics todayTopics today
Recommendations for Design, Fabrication and Evaluation of Anchorages and Joints in Reinforcing Bars [2007] (August 2007)Recommendations for Design and Construction of Concrete Structures Using Stainless Steel Bars –Draft- (August 2008)
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Anchorages and Joints in Reinforcing Bars
Anchorages and Joints in Anchorages and Joints in Reinforcing BarsReinforcing Bars
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Background of revision of the Background of revision of the guidelineguideline
Anchorages and Joints in Reinforcing Bars
Previous guideline on joints in reinforcing bars was published in 1982.Reinforcing bar arrangement has become denser due to highly required seismic performance.A lot of technologies of anchorages and joints have been developed.The design methods of concrete structures have been shifted to the performance-based design, recently.
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Anchorages and Joints in Reinforcing Bars
Characteristics of new editionCharacteristics of new edition
Anchorages in reinforcing bars are included as well as joints.Joints are evaluated not only by their performance but also considering the reliability of construction and inspection, which are practically significant.
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Anchoring methodsAnchoring methods
Mechanical anchoring methods involving the installation of anchorage elements at the ends of reinforcing bars,Methods using the bond strength between concrete and reinforcing bars
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Anchorages and Joints in Reinforcing Bars
mechanical anchorage
bonding
bearing
conventional anchorage
Development of mechanical Development of mechanical anchorageanchorage
Anchorages and Joints in Reinforcing Bars
Mechanical anchorage was developed to reduce complexity in arrangement of reinforcement.Benefit:
improvement of constructabilityshorten construction periodcost downimprovement of reliability in compaction of concrete
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Variation in mechanical Variation in mechanical anchorageanchorage
Flash-welded anchorage
Threaded deformed bar anchorage
Friction-welded anchorage
Enlarged-ended bar anchorage
Anchorages and Joints in Reinforcing Bars
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Verification method for Verification method for anchorageanchorage
Anchorages and Joints in Reinforcing Bars
If the anchorage under consideration follows the performance requirements for the performance items, which is necessary at the design stage such as strength and pullout resistance, high-stress cyclic loading capacity, and fatigue strength, the mechanical anchorage may be needed for design purposes to be equivalent to a standard hook.
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Performance evaluation criteria Performance evaluation criteria for anchorages for anchorages
steel rod or invar wire
transducer
reference hook anchorage specimen
mechanical anchorage specimen
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Anchorages and Joints in Reinforcing Bars
Examples of test results of Examples of test results of static strength (D16)static strength (D16)
0.25 0.50 0.75 1.00 1.25
100
200
300
400
500
0
pullout (mm)
stre
ss(N
/mm
2 )
Mechanical anchorage reference hook
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Anchorages and Joints in Reinforcing Bars
(2)<(3)
(1) difference in pullout under upper limit stress during thirtieth loading cycle between mechanical anchorage and reference hook
(2) difference in pullout of mechanically anchored reinforcing bar between thirties and first loading cycles
(3) difference in pullout of reinforcing bar anchored by reference hook between thirtieth and first loading cycles
pullout
(2)(3)
stre
ss
0.95fyn
0.02fyn
mechanical anchorage
reference hook anchorage
(1)
Anchorages and Joints in Reinforcing Bars
Examples of results of Examples of results of highhigh--stress stress cyclic loading testcyclic loading test
Jointing methodsJointing methodsPressure-welded jointingWelded jointingMechanical jointingLap jointing (conventional)
Anchorages and Joints in Reinforcing Bars
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Pressure-welded jointing
Welded jointing
Lap jointing (conventional)
concrete
Mechanical jointing
General (for joints)General (for joints)
Anchorages and Joints in Reinforcing Bars
(1) It must be verified that all joint zones meet the performance requirements.
(2) The steel joints to be used must be selected appropriately according to such factors as the type of steel to be used as base metal, bar diameter, the state of stress, joint location and joint performance requirements.
(3) For all materials to be used for steel joints, it must be verified in advance that those materials conform to relevant quality standards such as JIS.
(4) When steel joints are used, their reliability resulting fromconstruction and inspection must be taken into consideration.
(5) Steel joints should not be located as much as possible in cross sections in which large stresses occur.
(6) Steel joints should be spaced apart and should not be concentrated in a cross section as much as possible.
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Examples of construction of jointExamples of construction of joint
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Anchorages and Joints in Reinforcing Bars
Examples of inspection of jointExamples of inspection of jointAnchorages and Joints in Reinforcing Bars
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Reliability resulting from Reliability resulting from construction and inspection construction and inspection
Anchorages and Joints in Reinforcing Bars
The reliability of reinforcing bar joints resulting from construction and inspection is classified in three classes: I, II and III.
Reliability determined by the reject rate of joints
Reliability of jointReject rate of joints considering reliability of construction and inspection
reject rate of joints
Level I The reject rate of joints is extremely low. 0.3% or less
Level II The reject rate of joints is low. 5% or less
Level III The reject rate of joints is at or below a certain level.
15% or less
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Reliability of joint affected by Reliability of joint affected by construction and inspection construction and inspection
Reliability of jointReliability of joint
Attentiveness of construction workers
Qualification Response to evaluation result
Human action
Accuracy Human error
Sampling ratio
Reliability of constructionReliability of construction
Reliability of inspectionReliability of inspection
Skills of construction workers
Anchorages and Joints in Reinforcing Bars
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Construction level and Construction level and inspection levelinspection level
Anchorages and Joints in Reinforcing Bars
(i) Construction levels1: The probability of occurrence of a defective joint is extremely low,
and few defective joints are produced unintentionally.2: The probability of occurrence of a defective joint is sufficiently low.3: The probability of occurrence of a defective joint is low.
(ii) Inspection levels1: The probability of judging a defective joint to be acceptable is
extremely low, and, as a general rule, a supervisor inspects all joints and few defective joints are overlooked.
2: The probability of judging a defective joint to be acceptable is sufficiently low.
3: The probability of judging a defective joint to be acceptable is low.
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Anchorages and Joints in Reinforcing Bars
Reliability of joints determined by Reliability of joints determined by construction and inspection levelsconstruction and inspection levels
Inspection levelConstruction level
1 2 3
1 Level I Level I Level II
2 Level I Level II Level III
3 Level II Level III Level III
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Stainless Steel Bars
Stainless Steel BarsStainless Steel Bars
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Background of stainless steel Background of stainless steel barsbars
Reinforcement corrosion in concrete due to chloride ingress or carbonation is most serious problem to reduce durability of concrete structures in Japan.Countermeasure to reinforcement corrosion:
low W/C concreteconcrete admixturesthick concrete coversurface protectionepoxy-coated barsFRP reinforcementelectrochemical corrosion control method
JIS for Stainless steel bars for concrete reinforcement was established in 2008.
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Stainless Steel Bars
epoxy-coated bars
reinforcement corrosion
Type of stainless steelType of stainless steelStainless Steel Bars
SUS304 (18%Cr-8%Ni, ASTM:A276 304)Basic steel alloy most widely used as stainless steel.
SUS316 (16%Cr-10%Ni-2%Mo, ASTM:A276 316)
More corrosion-resistant steel alloy obtained by adding molybdenum to SUS304.
SUS410L (12%Cr-LowC, ASTM:A276 410L)Chromium stainless steel with a controlled alloy content.
Corrosion-resistance: SUS316 > SUS304 > SUS410
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Tests on corrosionTests on corrosion--resistance resistance of stainless steel barsof stainless steel bars
Stainless Steel Bars
Bare steel in solutionEmbedded in mortarEmbedded in concreteExposed to actual corrosive environmentTouching with different kind of metaletc.
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Corrosion test in solutionCorrosion test in solutionStainless Steel Bars
Potentiostat Solution
Reference Electrode
Thermostatic Tank (40deg)
Counter electrode
Specimen
3 types of solutionsNo.1: pH9.1-9.7 No.2: pH11.9-12.6 No.3: pH13.2-13.4
Duration of test:48hourscorrosion criterion :0.5mA/cm2
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Results of corrosion test in solutionResults of corrosion test in solution
corroded not corrodedin 0.5% Cl- in 0%
conventional carbon steel
corroded not corrodedin 0.5% Cl- in 0% Cl-
stainless steel: SUS410L
Stainless Steel Bars
pH 12.6
corroded not corrodedin 4.0% Cl- in 3.0% Cl-
stainless steel: SUS304
corroded not corrodedin 8.5% Cl- in 8.0% Cl-
stainless steel: SUS316
Corrosion criterion of chloride Corrosion criterion of chloride concentration in solutionconcentration in solution
0
2
4
6
8
10
12
14
16
8 9 10 11 12 13 14 15pH
corr
osi
on c
rite
ria(
%)
Carbon steel
SUS410L
SUS304
SUS316
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Stainless Steel Bars
conventional carbon steel
stainless steel
Accelerated corrosion test in concrete
40deg, 10% NaCl solution, 18.5monthsstainless steel bars: SUS304-SD, SUS316-SD, SUS410-SDconventional carbon steel: SD295Abar diameter: D13cover: 20mmconcrete (W/C 50%)
10% NaCl溶液
40℃
20mm
crack
10% NaCl solution 10% NaCl solution
Stainless Steel Bars
specimen without crack specimen with crack
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Results of accelerated Results of accelerated corrosion test in concretecorrosion test in concrete
stainless steel: SUS304-SD18.5months, crack width 0.18mm
stainless steel: SUS316-SD18.5months, crack width 0.18mm
not corroded not corroded
Stainless Steel Bars
not corrodedcorroded
stainless steel: SUS410-SD18.5months, crack width 0.18mm
conventional carbon steel3months, crack width 0.20mm
0
5
10
15
20
25
0 5 10 15 20
duration time(months)
Concentr
atio
ns
of chlo
ride
ion
(kg/
m3)
SUS410L SUS316 SUS304
seawater
Chloride concentration in Chloride concentration in concrete during the testconcrete during the test
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Stainless Steel Bars
Proposed durability design of Proposed durability design of RC using stainless steel barsRC using stainless steel bars
Stainless Steel Bars
Verification of corrosion resistance of RC structures by JSCEw < wa
w: crack widthwa: limit value of crack width
Cd < ClimCd: design value of chloride concentration at location of reinforcementClim: threshold value of chloride concentration for onset of corrosion
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
wCl-
reinforcement
chloride ingress
Chloride concentrationC(x,t)
xCd
x
))2
1.0(1(0
tDc
erfCCd
dcld
⋅
⋅−⋅= γ
Limit value of crack width (Limit value of crack width (wwaa) ) For conventional carbon steel reinforcement
For stainless steel reinforcement
Stainless Steel Bars
Type of reinforcement
Environmental conditions for reinforcement corrosion
Normal Corrosive Severely corrosive
Deformed bar
Prestressing steel
0.005c 0.004c 0.0035c
0.004c
c: cover < 100mm
Type of stainless steel Limit value of crack width
SUS304-SD
SUS316-SD
0.5mm
0.5mm
min (0.5mm, 0.005c)SUS410-SD
c: cover < 100mmJAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Stainless Steel Bars
Threshold value of chloride concentration Threshold value of chloride concentration for onset of corrosion (for onset of corrosion (CClimlim) )
1.2 kg/m3 is recommended for conventional carbon steel reinforcementFollowing values are recommended for stainless steel reinforcement
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Type of stainless steelThreshold value of chloride concentration for onset of corrosion (kg/m3)
SUS304-SD 15
SUS316-SD 24
SUS410-SD 9
Mechanical properties of Mechanical properties of stainless steel reinforcementstainless steel reinforcement
Stainless Steel Bars
strengthfatigue strengthstress-strain curveYoung's modulusthermal expansion coefficient
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
StressStress--strain curvesstrain curves
0
100
200
300
400
500
0 5000 10000 15000 20000
ひずみ(×10-6)
応力
(N/m
m2)
D19
D25
SD345(D19)
0
100
200
300
400
500
0 5000 10000 15000 20000
ひずみ(×10-6)
応力
(N/m
m2)
D19
D25
SD345(D19)
0
100
200
300
400
500
0 5000 10000 15000 20000
ひずみ(×10-6)
応力
(N/m
m2)
D25
D19
SD345(D19)
0
100
200
300
400
500
0 5000 10000 15000 20000
ひずみ(×10-6)
応力
(N/m
m2)
D25
D19
SD345(D19)
similar with conventional
strain hardening
strain (x10-6) strain (x10-6)
strain (x10-6)strain (x10-6)
stre
ss (
N/m
m2 )
stre
ss (
N/m
m2 )
stre
ss (
N/m
m2 )
stre
ss (
N/m
m2 )
SUS340 -SD SUS316 -SD
SUS410 –SD295 SUS410 –SD345JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Stainless Steel Bars
Strength and stressStrength and stress--strain strain model for designmodel for designStress-strain model for stainless steel reinforcement
Definition of strength of stainless steel reinforcement
ε
σ
0
f yd
σ=E s・ ε
σ=f yd +E u ・ (ε-ε y )
ε y ε
σ
0
f yd
σ = E s・ ε
σ= f yd
SUS410-SD295 except SUS410-SD295
ε
σ
0
f yk
0.2%
E s
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Stainless Steel Bars
Stainless Steel Bars
Fatigue propertiesFatigue propertiesSUS304-SD, SUS316-SD: higher fatigue strengthSUS410-SD: fatigue strength is close to estimated by JSCE conventional design equation
100
150
200
250
300
350
400
0 500 1,000 1,500 2,000
破断繰返し数N(×103)
応力
振幅
σ0(N
/m
m2)
示方書式
SUS304-SD
SUS316-SD
SUS410-SD
100
150
200
250
300
350
0 500 1,000 1,500 2,000
破断繰返し数N(×103)
応力
振幅
σ0(N
/m
m2)
示方書式
SUS304-SD
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number of loading at fracture N (x103)
stre
ss a
mpl
itude
(N
/mm
2 )
JSCE eq.JSCE eq.
stre
ss a
mpl
itude
(N
/mm
2 )
JSCE equation can be used as well as conventional reinforcement.
sud
spk
a
srd fNf γ
σ⎟⎟⎠
⎞⎜⎜⎝
⎛−= 110190s
ud
spk
a
srd fNf γ
σ⎟⎟⎠
⎞⎜⎜⎝
⎛−= 110190
number of loading at fracture N (x103)D19 D35
Test on seismic performance of RC member using stainless steel
reversed cyclic loading test of RC column specimen
-200
-150
-100
-50
0
50
100
150
200
-150 -100 -50 0 50 100 150
変位(mm)
荷重
(k
N)
displacement (mm)
load
(kN
)
lateralreinforcement (SUS304, D13)
longitudinal reinforcement (SUS304, D25)
loading point
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Stainless Steel Bars
Stainless Steel Bars
LCC assessment of RC LCC assessment of RC structure using stainless barsstructure using stainless bars
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Stainless Steel Bars
Objective structure: piled pierObjective structure: piled pier
HWL+2.36
LWL+0.00
20.0
(unit: m)
super structure
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Stainless Steel Bars
Calculation conditionCalculation condition
Service life t (year) 50 or 100
Concrete cover c (mm) 70
cement Ordinary Portland Cementconcrete
W/C 0.45
Reinforcement Conventional SUS410-SD SUS304-SD SUS316-SD
Clim(kg/m3) 1.2 9 15 24
Dd(cm2/year) 1.46
Surface chloride C0(kg/m3) 9 or 13
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Results: chloride concentration in Results: chloride concentration in concreteconcrete
Stainless Steel Bars
In case that C0=13kg/m3:conventional steel bars: corroded in 10yearsSUS410-SD: corroded at 43yearsother stainless bars: not corroded
In case that C0=9kg/m3:conventional steel bars: corroded in 10yearsstainless bars: not corroded
year
Chlo
ride
conc
entr
atio
n (k
g/m
3 )
SUS410
conventional steel
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Estimation of initial costEstimation of initial cost
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
N S-4 S-7 S-10
初期
建設
費用
の比
Conventional
Assumed material cost of stainless steel
SUS304-SD: 7 times of conventional steel
SUS316-SD: 11 times of conventional steel
SUS410-SD: 4 times of conventional steel
Calculated initial cost of structure
SUS304-SD: 1.3 times of conventional structure
SUS316-SD: 1.4 times of conventional structure
SUS410-SD: 1.2 times of conventional structure
SUS410-SD SUS304-SD SUS316-SD
Nor
mal
ized
initi
al c
ost
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Stainless Steel Bars
structures using stainless steel
Results of LCC assessmentResults of LCC assessment((CC00=9kg/m=9kg/m33 ))
0
1
2
3
4
0 10 20 30 40 50 60
LCC
比
時間(年)
B-1(表面被覆)
B-2(電気防食)
S-4(SUS410相当)
S-7(SUS304相当)
S-10(SUS316相当)
100
B-1
B-2
C0=9kg/m3 S-4
year
Nor
mal
ized
LCC
conventional steel + surface coating
conventional steel + electrochemical corrosion protection
LCC of structures using stainless steel
SUS410-SD
LCC of structures using SUS304-SD, SUS316-SD, SUS410-SD are just equal to their Initial Cost because of no corrosion.Due to the maintenance cost, LCC of conventional structures are higher than that of structures using stainless steel.
Stainless Steel Bars
Results of LCC assessmentResults of LCC assessment((CC00=13kg/m=13kg/m33 ))
0
1
2
3
4
0 10 20 30 40 50 60
LC
C比
時間(年)
B-1(表面被覆)
B-2(電気防食)
S-4(SUS410相当)
S-7(SUS304相当)
S-10(SUS316相当)
100
B-1
B-2
S-4
C0=13kg/m3
比year
Nor
mal
ized
LCC
conventional steel + surface coating
conventional steel + electrochemical corrosion protection
LCC of structures using stainless steel
SUS410-SD
LCC of structures using SUS304-SD, SUS316-SD are just equal to their Initial Cost because of no corrosion.Structure using SUS410-SD need to be repaired before 43 year due to reinforcement corrosion, which will affect its LCC.
Stainless Steel Bars
Stainless Steel Bars
Examples of concrete structures Examples of concrete structures using stainless steel using stainless steel reinforcementreinforcement
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
LeveeLeveeStainless Steel Bars
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Aomori Prefecture MuseumAomori Prefecture Museum
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Stainless Steel Bars
Stone cutters bridge (Hong Kong)Stone cutters bridge (Hong Kong)Stainless Steel Bars
main tower (height: 298m)
cable-stayed bridge (span: 1018m)
2882 ton of stainless steel reinforcements were used.
Design service life: 120years!
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KouriKouri ohashiohashi bridge (Okinawa, Japan)bridge (Okinawa, Japan)
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS
Stainless Steel Bars
PC continuous box girder + PC rigid frame bridge (length: 1960m), constructed in 2004
Stainless steel reinforcementswere adopted in wheel guard portion considering UV ray attack during construction.
severely corrosive environment, severe UV rays
Epoxy-coated reinforcements were mainly adopted.
box girder segment
Thank you for your kind Thank you for your kind attentionattention
JAPAN SOCIETY OF CIVIL ENGINEERSJAPAN SOCIETY OF CIVIL ENGINEERS