Presentation held at the 2015 ACI Spring Convention

1. Challenge the future
Delft
University of
Technology
Testing to failure of the Ruytenschildt
Bridge
Comparison between predicted capacity and test results
Eva Lantsoght, Cor van der Veen, Ane de Boer

2. 2
Overview
• Introduction to case
• Predictions based on code equations
• Failure probability in shear vs flexure
• Test results
• First conclusions
Slab shear experiments, TU Delft

3. 3
Proofloading
Case Ruytenschildt Bridge
• Proofloading to assess capacity of
existing bridge
• ASR affected bridges
• Unaffected bridges
• Study cracks and deformations for
applied loads
• Crack formation: acoustic emissions
measurements
• Control load process
• Ruytenschildt Bridge: testing to
failure

4. 4
Proofloading Ruytenschildt Bridge
Existing bridge Partial demolition and building new bridge

5. 5
Proofloading
Case Ruytenschildt Bridge

6. 6
Cross-sections Ruytenschildt Bridge
• Cross-sections to check for 5-span beam
• Check sup 1-2, sup 2-1 and sup 2-3
• Testing in span 1 and span 2
• close to end support
• close to mid support

7. 7
Uncertainties in calculations
• Predictions: not all material parameters known beforehand
• Assume QR24 steel
• Some test results of concrete cores: compression and splitting
• Skew 72º angle
• Skew factors as used in QS
TS Edge distance Skew Factor For 0.7m
TS1 0.5m 1.08
1.084
0.95m 1.09
TS2 0.5m 1.23
1.239
0.95m 1.25

8. 8
Capacity cross-section
Introduction
• Average material properties
• Two loading possibilities:
• Battens + big bags
• 4 wheel loads: simulating 1 load tandem
• Skew factors as in Quick Scan
• Saw cut at 7.365m over full length of bridge
• Average vRd,c
• Averagevmin : transform formula to average instead of
characteristic
3/2 1/2
1/2
1.08 0.163
0.12
ck
min
yk
k f
v
f


9. 9
Capacity cross-section
Selection loading scenario (1)
• Scenario 1: big bags sand + battens load
=> Flexural failure before shear failure
Effective width battens

10. 10
Capacity cross-section
Selection loading scenario (2)
• Scenario 2: only battens load + self-weight as distributed
load
=> Failure in flexure before shear

11. 11
Capacity cross-section
Selection loading scenario (3)
• Scenario 3: Wheel loads + self-weight
Flexural failure before shear failure in span 1
Possible shear failure in span 2

12. 12
Capacity cross-section
Effective width for skewed slab

13. 13
Capacity cross-section
Calculations (1)
• Moment capacity
• Myield : fy = 282 MPa
• Mu : fult= 383 MPa
Cross-section Mcr
(kNm)
Myield
(kNm)
Mu
(kNm)
Sup 1-2 1334 3519 4388
Sup 2-3, span 1358 3372 4192
Sup 2-3, support 1421 5118 6333

14. 14
Capacity cross-section
Calculations (2)
• Shear capacity
• Pshear : calculated shear capacity
• Pshear,skew: including skew factors
• Pshear,test : increased average Test/Prediction slab experiments
• Pshear,skew,test : Skew factors + slab increase
• Most likely: Pshear,test+ some skew effect
• Punching is not governing
Support Pshear
(kN)
Pshear,skew
(kN)
Pshear,test
(kN)
Pshear,skew,test
(kN)
Sup 1-2 1340 2140 2711 4390
Sup 2-3 975 1626 1972 3289

15. 15
Probability of shear failure
• Monte Carlo simulation
 shear < flexurefp P
( )f shear flexurep P UC UC 
 
 
1/3,
1/3
,
, , ,
100
100
Rd c
l ck
Ed c
shear
Rd c
Rd c test l c mean
C
k f
v
UC
Testv C k f
Predicted



 
2
2
s y
Ed
flexure
Rd
s u
M
a
A f d
M
UC
Test aM
A f d
Predicted
 
 
  
   
   
   

16. 16
Probability of shear failure
Test/Predicted shear
Based on slab shear experiments TU Delft

17. 17
Probability of shear failure
Limit state function

18. 18
Probability of shear failure
Results
• Span 1: 85.2% probability of failure in flexure before shear
• Span 2: 45.9% probability of failure in flexure before shear
• Span 2: 98.2% probability of failure in flexure before shear
when considering from
V
Test
Predicted
 
 
 
exp
pred
V
V

19. 19
Uncertainties in predictions
• Effect skew angle on effective
width
• Effect skew on shear capacity of
slabs
• Concrete compressive strength
(assumed B45)
• Yield strength of steel (fy = 282
MPa assumed)

20. 20
Test results proofloading
Span 1
• Maximum load 3049 kN
• Maximum available load for span 1
• Flexural cracks
• No failure
• Order additional load for test 2!
0
500
1000
1500
2000
2500
3000
3500
0 5000 10000 15000 20000 25000
Load(kN) time (s)

21. 21
Test results proofloading
Span 2
• Maximum load 3991 kN
• Large flexural cracks
• Flexural failure
• yielding of reinforcement
• Settlement of bridge pier
with 1.5cm
• Elastic recovery to 8mm
0
500
1000
1500
2000
2500
3000
3500
4000
4500
0 2000 4000 6000 8000 10000
Load(kN) Time(s)

22. 22
Conclusions
• Predicted failure modes:
• Span 1: flexural failure
• Span 2: shear failure or flexural failure
• Calculation probability of failure modes
• Span 1: flexural failure
• Span 2: flexural failure when
considering results of slab shear
experiments
• Experiments: proofloading
• Span 1: flexural failure (no failure in
experiment)
• Span 2: flexural failure

23. 23
Contact:
Eva Lantsoght
E.O.L.Lantsoght@tudelft.nl // elantsoght@usfq.edu.ec
+31(0)152787449