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DelftUniversity ofTechnology

Shear capacity of the Ruytenschildt bridge

Eva Lantsoght, Cor van der Veen, Ane de Boer

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Overview

• Ruytenschildt Bridge testing• Prediction of shear capacity• Comparison test and predictions• Summary & Conclusions

Slab shear experiments, TU Delft

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Ruytenschildt Bridge (1)

• Existing reinforced concrete slab bridge (1962)

• Test to failure in two spans• 4 concentrated load – one

tandem• Cyclic loading protocol• Failure only achieved in span 2

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Ruytenschildt Bridge (2)

Existing bridge Partial demolition and building new bridge

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Ruytenschildt Bridge (3)

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Test resultsSpan 1

• Maximum load 3049 kN• Maximum available load for

span 1• Flexural cracks• No failure• Order additional load for

test 2!

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Test resultsSpan 2

• Maximum load 3991 kN• Large flexural cracks• Flexural failure

• yielding of reinforcement• Settlement of bridge pier

with 1.5cm• Elastic recovery to 8mm

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Quick Scan shear capacity (1)

• Method for rating bridges• Spreadsheet for rating all

sections in a span• Changing reinforcement• For EN 1991-2:2003 live loads• Load factors from NEN 8700• Skew factors• Result = Unity Check• Shear stress over shear

capacity

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Quick Scan shear capacity (2)

• Assuming C35/45• Max UC in span 1 = 0.88 close to support 2• Span 1: anchorage insufficient• Max UC in span 2 = 0.78 at x = 1.3 m

• Measured concrete compressive strength• Max UC in span 1: 1.14 close to Support 2• Max UC in span 2: 1.04 at x = 1.3 m

• Shear capacity insufficient at LoA I

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Shear capacity prediction (1)

• Based on average values• To find estimate of maximum load in test• Effective width in shear for skewed slab?• Skewed slab: obtuse corner is governing

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Shear capacity prediction (2)Span Span 1 Span 2Shear capacity

Ptot (kN) Ptot,slab (kN) Ptot (kN) Ptot,slab (kN)

bstr 3760 7606 4020 8132bpara 3236 6546 3432 6943bskew 4804 9718 5328 10779

• Increase in shear capacity measured in slabs: 2.023 (average value)• Based on straight slabs• Valid for skewed slabs?

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Comparison tested and predicted results

• Span 1: no failure• Span 2• Flexural failure• Shear capacity?

• Predictions:• Equal chance of shear and

flexural failure• Ductile vs brittle failure

mode• Shear capacity of skewed

slabs?

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Summary & Conclusions• Ruytenschildt Bridge

• Existing slab bridge scheduled for replacement

• Testing in 2 spans, failure in span 2

• Shear capacity prediction• Quick Scan for rating• Average prediction for test• Effect of skew on shear capacity of

slab and effective width?

• Flexural failure, ductile failure mode

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