Presentation at ACI Virtual Days 2020

1. Challenge the future
Delft
University of
Technology
Shear Testing of Prestressed Concrete Bridge Girders
Eva Lantsoght , Gabriela Zarate, Fengqiao Zhang, Minkook Park, Yuguang Yang

2. 2Shear Testing of Prestressed Concrete Girder Bridges
Outline
• Introduction
• Experiments
• Results
• Recommendations for practice
• Summary and conclusions
Failure of HPZ03, north side

3. 3Shear Testing of Prestressed Concrete Girder Bridges
Introduction: Assessment of PC girder bridges (1)
• Prestressed concrete girder bridges in the Netherlands (+- 70)
• Prestressed girders
• Slab cast in between girders, transverse prestressing
• Diaphragm beams
• First research: capacity of slabs
• Compressive membrane action
• Fatigue capacity
• Sufficient capacity based on experiments
• Then: PC girders UC > 1 for shear-tension

4. 4Shear Testing of Prestressed Concrete Girder Bridges
Introduction: Assessment of PC girder bridges (2)
Slab-between-girder bridge during construction, 1965

5. 5Shear Testing of Prestressed Concrete Girder Bridges
Introduction: Assessment of PC girder bridges (3)
Amir, S., Van der Veen , C., Walraven, J. C., & de Boer, A. (2016). Experiments on Punching Shear Behavior of Prestressed
Concrete Bridge Decks. Aci Structural Journal, 113(3), 627-636.

6. 6Shear Testing of Prestressed Concrete Girder Bridges
Introduction: Helperzoom girders (1)
• Taken from demolished slab-between-
girder bridge
• Tendon profile
• Anchor end and tapered part
• Beams sawn in half for handling in lab
• 1.11 m height
• 10.51 m – 12.88 m length
• Single concentrated load
• a = 2.903 m & a = 4.4 m
• 4 experiments / 4 girders

7. 7Shear Testing of Prestressed Concrete Girder Bridges
Introduction: Helperzoom girders (2)

8. 8Shear Testing of Prestressed Concrete Girder Bridges
Introduction: Helperzoom girders (3)
Cross-section A-Aʹ Cross-section B-Bʹ (C.L)

9. 9Shear Testing of Prestressed Concrete Girder Bridges
Introduction: Goal of experiments
• Goal of research:
• Shear-tension capacity (UCs insufficient)
• Validate NLFEA
• Failure mode
• Effect of non-code-compliant stirrups?

10. 10Shear Testing of Prestressed Concrete Girder Bridges
Experiments: Test setup (1)

11. 11Shear Testing of Prestressed Concrete Girder Bridges
Experiments: Test setup (2)

12. 12Shear Testing of Prestressed Concrete Girder Bridges
Experiments: Test setup (3)

13. 13Shear Testing of Prestressed Concrete Girder Bridges
Experiments: Instrumentation (1)
• LVDT measurements
• Laser distance finders
• Acoustic emission sensors
• Smart aggregates
• Digital image correlation

14. 14Shear Testing of Prestressed Concrete Girder Bridges
Experiments: Instrumentation (2)
Sensor plan for HPZ03

15. 15Shear Testing of Prestressed Concrete Girder Bridges
Results: Material parameters
• Concrete: core testing => C55/67
• Prestressing steel tested in lab
• Mild steel tested in lab: QR40, 454
MPa
• Mild steel = plain bars
y = 4086.8x + 1605.6
0
400
800
1200
1600
2000
2400
0 0.02 0.04 0.06 0.08
Stress(MPa)
Strain (-)

16. 16Shear Testing of Prestressed Concrete Girder Bridges
Results: prestressing level
• 3 methods:
• cracking moment
• full sectional analysis (R2K &
layered model)
• Measurements
• cutting through tendon
• Drilling cores
test strain
(με)
stress
(MPa) %
1 3107 575 66
2 5606 1037 119
3 561 1039 120
4 5684 1052 121
Average 107
Cutting HPZ03

17. 17Shear Testing of Prestressed Concrete Girder Bridges
Results: Loading protocol
Loading protocol of HPZ03

18. 18Shear Testing of Prestressed Concrete Girder Bridges
Results: Capacities and failure modes
HPZ01 HPZ02 HPZ03 HPZ04
Date 27/06/2019 12/09/2019 14/11/2019 16-17/12/2019
lgirder 10.51 m 11.1 m 12.28m 12.88 m
lspan 9.6 m 9.6 m 9.6 m 9.6 m
a 2903 mm 2903 mm 4400 mm 4400 mm
a/d 3.6 3.6 4.9 4.9
Fcrack 965 kN 1001 kN 1050 kN 1100 kN
Fshearcrack 1344 kN 1299 kN 1250 kN 1450 kN
FShear-tension crack 1480 kN 1350 kN 1600 kN 1750 kN
Fmax 1892.7 kN 1849 kN 1990 kN 2380 kN
δfail 51.5 mm 39.66 mm 60.91 mm 68.6 mm
Failure mode SC/FS SC/FS SC/CC SC/CC

19. 19Shear Testing of Prestressed Concrete Girder Bridges
HPZ04 test

20. 20Shear Testing of Prestressed Concrete Girder Bridges
Results: DIC measurements HPZ02

21. 21Shear Testing of Prestressed Concrete Girder Bridges
Global strain distribution with 20 mm lens Local strain distribution with 90 mm lens
Crack opening (w) in x-direction Crack sliding (∆) in y-direction
HPZ02 DIC
analysis

22. 22Shear Testing of Prestressed Concrete Girder Bridges
Results: AE monitoring
1st bending crack
Shear cracks

23. 23Shear Testing of Prestressed Concrete Girder Bridges
Results: Comparison to predicted capacity

24. 24Shear Testing of Prestressed Concrete Girder Bridges
Results: Influence of prestressing level

25. 25Shear Testing of Prestressed Concrete Girder Bridges
Results: Influence of prestressing level

26. 26Shear Testing of Prestressed Concrete Girder Bridges
Results: Influence of position of load
• Failure mode:
• For a = 2903 mm: Shear
cracking, then shear-compression
failure
• For a = 4400 mm: Shear
cracking, then local crushing of
concrete zone or crushing of
compression field
0
500
1000
1500
2000
2500
3000
0 10 20 30 40 50 60 70 80
Laod(kN) Deflection at loading point (mm)
HPZ01
HPZ02
HPZ03
HPZ04

27. 27Shear Testing of Prestressed Concrete Girder Bridges
Results: evaluation of angle of compression field
HPZ03

28. 28Shear Testing of Prestressed Concrete Girder Bridges
Recommendations for practice: Measurement
techniques
• AE measurements can capture
cracking early
• DIC: analysis of aggregate interlock
• LVDT and DIC: analysis of angle of
compression field
• Lasers: need sufficient range for
displacement under load
Rotating angle for HPZ03

29. 29Shear Testing of Prestressed Concrete Girder Bridges
Recommendations for practice: Load testing of PC
girder bridges
• Ongoing research on load testing of
bridges
• Collapse test of Vecht Bridge in 2016
• Relate insights from research to collapse
test
=> Future work
Collapse test of Vecht Bridge, 2016

30. 30Shear Testing of Prestressed Concrete Girder Bridges
Recommendations for practice: Assessment of
PC girder bridges
• Ongoing research
• System behavior and transverse
flexural distribution
• Best option: NLFEA (RTD 1016:2017)
• For sectional analysis: promising
results with draft new Eurocode and
Response-2000
Response 2000 vs experiments
Migalski, J. (2020). Analytical, Numerical and Experimental
Analysis of Helperzoom Post-Tensioned TGirders. Delft
University of Technology,

31. 31Shear Testing of Prestressed Concrete Girder Bridges
Next steps
• Finalize analysis of test results
• Assessment of these girder types
• Use insights from monitoring techniques
• (short-term) field tests / load testing
• long-term monitoring

32. 32Shear Testing of Prestressed Concrete Girder Bridges
Summary and Conclusions
• 4 experiments on PC girders failing in shear
• Failure modes related to concrete crushing
• Increase in shear capacity past inclined
cracking load
• Non-code-compliant stirrups
• Use of AE, SA, DIC + traditional
measurement techniques
• Future work: assessment of PC girder bridges
+ recommendations for field testing

33. 33Shear Testing of Prestressed Concrete Girder Bridges
Contact:
Eva Lantsoght
E.O.L.Lantsoght@tudelft.nl
elantsoght@usfq.edu.ec