Tobias Huber, Dipl.-Ing. BSc.
TU Wien, Austria
Bending moments cause deviation forces in concrete structures with kinked or curved surfaces. This action may decrease the loading capacity of the structure if no reinforcement is provided to cover the resulting tensile stresses. The absence of the required supplementary reinforcement is being investigated at the Institute for Structural Engineering, TU WIEN. Herefore large-scale bending tests of two saddle roof t-beams, with a total length of 14.0 metres, were performed. Both experiments showed the expected detachment of the compression flange before the flexural strength was reached. Due to the fact that the remaining cross section was able to carry the load, the loss of the flange did not lead to sudden failure.
The tests were modelled using ATENA from Červenka Consulting with the model being calibrated to fit the load-deflection curve of the actual test. Comparing the load levels at first flexural crack, detachment of the flange and failure, the finite-element analysis showed good correlation to the test results. Therefore, it can be assumed that ATENA is able to fully map the load-bearing behaviour in this region which provides the possibility to investigate the stress state of the tested beams more precisely than with the attached conventional measurement systems. This allows further investigations with respect to variations of the concrete class and the corner angle to be carried out, without the need of additional big-scale experiments.