Effects of High Temperature on the Residual Performance of Portland Cement Concretes

In this work we analyzed the “residual ” performance of Portland cement concretes heat-treated at 600 °C after cooling down to room temperature. Concretes with characteristic compressive strength at 28 days of 45 MPa and of 60 MPa were studied. The heat-treatment was carried out without any imposed load. We measured the residual compressive strength and modulus of elas-ticity. The geometry of the structure was described by mercury intrusion porosimetry and nitrogen sorption tests. We observed a decrease of residual compressive strength and modulus of elasticity, with the raise of heat-treatment temperature, as a result of heat-induced material degradation. The results also indicated that the microstructural damage increased steadily with increasing tempera-ture. Based on the results of this experimental work we concluded that residual mechanical prop-erties of concrete are dependent of their original non heat-treated values