R.T. Koekkoek
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7 records found
1
During static tests in the Stevin laboratory of the Delft University of Technology (DUT) on this type of concrete bridge decks it was found that compressive membrane action has been generated which results in a higher static bearing capacity. On the other hand it was found that when a load is applied stepwise with only three load cycles per step in about 8 h, the load capacity reduces about 16% with respect to the static capacity.
The Dutch Ministry of Infrastructure and the Environment and DUT decided that further experimental research on the influence of cyclic loading on the fatigue strength for this type of bridge deck was necessary. In total 3 static and 9 fatigue tests were performed. Based on the experimental results a relation was found between the relative fatigue strength and the logarithm of the applied number of load cycles. For 1 and 100 million load cycles a relative fatigue strength of respectively 0.54 and 0.42 was found. ...
During static tests in the Stevin laboratory of the Delft University of Technology (DUT) on this type of concrete bridge decks it was found that compressive membrane action has been generated which results in a higher static bearing capacity. On the other hand it was found that when a load is applied stepwise with only three load cycles per step in about 8 h, the load capacity reduces about 16% with respect to the static capacity.
The Dutch Ministry of Infrastructure and the Environment and DUT decided that further experimental research on the influence of cyclic loading on the fatigue strength for this type of bridge deck was necessary. In total 3 static and 9 fatigue tests were performed. Based on the experimental results a relation was found between the relative fatigue strength and the logarithm of the applied number of load cycles. For 1 and 100 million load cycles a relative fatigue strength of respectively 0.54 and 0.42 was found.
Towards standardisation of proof load testing
Pilot test on viaduct Zijlweg
Proof load tests of bridges can be very useful for structures with a lack of information, or for structures of which the effect of material degradation is difficult to assess. Contrary to diagnostic load testing, proof load testing is not well-defined in current standards in terms of required load and analysis of measurements. The risk related to the high loads used in proof load testing requires standardisation for these tests. The paper highlights important considerations for proof load testing that may lead to the development of guidelines in the Netherlands, by illustrating a pilot study on the viaduct Zijlweg in the Netherlands. This reinforced concrete bridge rates too low in shear. Topics of interest are the required load that the bridge has to withstand to be approved by the load test and the interpretation of the measurements during the test to avoid permanent damage to the structure. These measurements were compared to the stop criteria from existing codes for buildings, to examine if recommendations for the use with bridges can be formulated. The final result of the test on this case study is that the capacity of the viaduct is proven to be sufficient for shear and bending moment.