Monitoring shear-induced degradation of reinforced and pre- tensioned concrete members

In the frame of a research project funded by the Austrian Research Foundation (FFG) 2 series of 4 pre-tensioned and non prestressed beams with rectangular and T-shaped cross-sections have been produced in order to investigate the behaviour under shear loading and also the effect of the prestress on load bearing capacity and on ductility. In order to investigate the interaction between shear force, bending moment und normal force the pre-tensioning was varied between 100% and 50%. Special focus was laid on the crack development and SLS criteria as well as the ductility after reaching ultimate load level. During the first test series different conventional measuring methods were used to monitor the external and internal deformations caused by shear loading, in order to evaluate the sensitivity and correlation of the different measurements. As a result of the first test series, the monitoring layout and the performed numerical analyses were optimized and modern measurement methods in terms of DIC step wisely integrated into the further test series. Finally, the suitability of the different applied measuring techniques for recording shear behaviour and the potential to optimize the monitoring of shear degradation was evaluated.