Abstract: To predict the fracture properties of concrete exposed to different temperatures, variations in activation energy with age are examined for different fracture parameters. A best-fit maturity method for determining the fracture properties is developed and verified using laboratory experimental data. The effect of activation energy and datum temperature on the prediction accuracy of fracture parameters is discussed. The results show that activation energy differs between different fracture properties and varies at different development levels of a given fracture parameter, and its values determined using different temperature ranges are unequal. The method developed in this study can accurately predict the fracture properties of concrete. The optimal activation energy (or datum temperature) varies with temperature ranges and fracture properties. No constant optimal activation energy (or datum temperature) can be found for prediction of the fracture properties of concrete at different temperatures.

Key words: concrete, best-fit maturity method, fracture parameters, curing temperature, activation energy