Experimental research on the residual mechanical properties of an ordinary concretes after fire

This paper summarizes the results of an experimental research to assess the residual mechanical properties of an ordinary concrete after fire. It was studied the influence of the cooling process, the maximum temperature that the concrete was subjected to and the loading level on the residual mechanical properties of calcareous and granite aggregate concretes. The properties studied were the residual compressive, tensile, splitting and flexural strengths and modulus of elasticity. Four levels of temperature; 20, 300, 500 and 700ºC; two loading levels (0.3f and 0.7fcd) and two cooling processes (cooling in the air and by water jet) were tested. The high temperatures attained and the sudden cooling down process on the concrete showed a negative effect on its residual mechanical properties. This effect was more notorious on the residual compression strength than in the other mechanical properties