Estimation of compressive strength by a new apparent activation energy function

After reviews of the validity of models for estimating the compressive strength development of concrete subjected to various temperature histories, the shortcomings of present temperature functions are discussed. Based on the discussion, a model for compressive strength development that includes the new apparent activation energy function is proposed to correct the shortcomings of previous models that overestimate the effect of temperature on later-age strength development. The new model, with the apparent activation energy as a nonlinear function of temperature and age, provides good estimates of strength development obtained from the previous experimental studies. Finally, general equations based on regression analysis an proposed to estimate apparent activation energy and compressive strength development. (C) 2001 Elsevier Science Ltd. All rights reserved.