Effect of pre-induced cyclic damage on the mechanical properties of concrete exposed to elevated temperatures

This research aims to investigate the effect of high temperature on concrete samples which have been previously damaged under cyclic loading. For this purpose, normal strength concrete samples are initially subjected to strain-controlled load cycles and then exposed to elevated temperatures. Residual mechanical properties of the samples are measured after allowing them to slowly cool down to room temperature. These properties are expressed in terms of two independent parameters, i.e. the level of damage induced by cyclic loading as well as the exposure temperature. It is shown that the variation of residual properties is simultaneously affected by both parameters, however, the influence of pre-induced damage diminishes as the exposure temperature increases. In addition, an effective approach is described for the numerical reproduction of stress-strain curves for any given level of damage and temperature.