Behaviour of reinforced concrete structures following high temperature exposure

A study of reinforced concrete beams affected by elevated temperatures was made. The effect of material properties (in the residual condition) on the structural behaviour of reinforced concrete beams subjected to external forces was compared for different levels of temperature treatment and protective concrete cover to the reinforcement. The behaviour of bond at the interface of steel and concrete tinder elevated temperatures as well as in the residual conditions was examined and the analysis of the bond stress-slip relationship in a pull-out test applied to the provision for anchorage bond at critical points in beam design. Material properties and bond behaviour of steel and concrete under residual conditions following heat treatment were compared with previous similar work. The behaviour of flexural members and of pull-out specimens were also studied with respect to acoustic emission activity and attempts made to formulate a relationship between acoustic emission activity and externally applied forces. A simulation of crack patterns at failure in reinforced concrete beams was made both at ambient and in the residual condition by a computer program using a finite element approach