Presentation of ACI Fall Convention 2017

1. Assessment of slab bridges through proofAssessment of slab bridges through proof
loading in the Netherlandsloading in the Netherlands
Eva Lantsoght, Cor van der Veen, Ane de Boer,
Dick Hordijk

2. OverviewOverviewOverviewOverview
• Introduction
• Pilot proof load tests
• Laboratory experiments
• Recommendations
• Preparation of proof load tests
• Execution of proof load tests
• Analysis of proof load tests
• Summary and conclusions
Slab shear experiments, TU Delft

3. Why load testing?Why load testing?
Bridges from 60s and 70s
The Hague in 1959
Increased live loads
common heavy and long truck (600 kN)
End of service life + larger loads

4. Safety philosphy of proof load testingSafety philosphy of proof load testing
• Safety philosophy
• Stop criteria:
•Further loading not
permitted
•Failure near
•Irreversible damage
near
MSc Thesis W. Vos

5. Research needResearch needResearch needResearch need
Guideline for proof loading of existing
(RC slab) bridges for the Netherlands
Flexure + shear

6. TU Delft Proof Load TestsTU Delft Proof Load Tests
• Proof load tests:
•Heidijk 2007
•Medemblik 2009
•Vlijmen-Oost 2013
•Halvemaans Bridge 2014
•Ruytenschildt Bridge 2014
•Viaduct Zijlweg 2015
•Viaduct De Beek 2015
TU Delft proof load tests

7. Laboratory testingLaboratory testingLaboratory testingLaboratory testing
• Ruytenschildt beams
• Cyclic loading protocol
• Analysis of stop criteria
• Beams with plain bars
• Effect of number of cycles
• Effect of loading speed
• Load levels
• Analysis of stop criteria
Beams RSB01 after failure (Yang, 2015)
Yang, Y. (2015). "Experimental Studies on the Structural Behaviours of Beams from Ruytenschildt Bridge,"
Stevin Report 25.5-15-09, Delft University of Technology, Delft, 76 pp.
Beams RSB02B after failure (Yang, 2015)

8. Preparation steps (1)Preparation steps (1)
• Preliminary inspection and
rating
• Dimensions and material
properties
• Live load: lane load +
design tandem
• RBK load levels
•Different β
•Different load factors
•γsw = 1.1 for proof load testing

9. Preparation steps (2)Preparation steps (2)
• Critical position
•Bending moment: largest
moment
•Shear: 2.5d from support
• Required proof load
•Same shear or bending
moment as with load
combination
•Value → considered safety
level

10. Preparation steps (3)Preparation steps (3)
• Sensor plan:
•Deflection profiles in longitudinal and
transverse direction
•Deflection at supports
•Strain on bottom of cross-section
•Reference strain measurements to
correct for T
•Opening existing cracks
•Opening new cracks
•Applied load => load cells
•Acoustic emission measurements
(current research)

11. Execution steps (1)Execution steps (1)
• Cyclic loading scheme
•Check linearity and reproducibility of measurements
•Baseline load level
• Load levels ≈ safety levels CC3 RBK:
• Low level to check instrumentation
• SLS
• Intermediate level
• Target proof load

12. Execution steps (2)Execution steps (2)

13. Execution steps (3)Execution steps (3)Execution steps (3)Execution steps (3)

14. Analysis StepsAnalysis Steps
• Data analysis
•Correct for T
•Correct for support
displacements
•Make final plots for report

15. Summary and conclusionsSummary and conclusions
• Proof loading to approve existing
bridges, also for shear
• Pilot proof load tests in the
Netherlands + laboratory tests
• Current recommendations
• Further laboratory testing on slabs in
shear is necessary Ruytenschildt Bridge

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