Effect of exposure time and rates of heating and cooling on residual strength of heated concrete

Abstract

Synopsis The paper describes tests on 100 mm concrete cubes heated to temperatures in the range of 200–800°C to determine the effect of varying time of exposure and rates of heating and cooling on the residual compressive strength of concrete. These variables were found to have a significant effect on concrete heated to the lower range of temperatures but their effect became less pronounced at high temperatures. Almost all the loss of compressive strength occurred within two hours of exposure to the maximum temperature. Pulse velocity measurements did not predict the residual strengths accurately and appeared to be more indicative of the levels of temperature to which the concrete had been exposed.