Temperature effects on strength evaluation of cement-based materials with ultrasonic wave reflection technique

Among the various factors that influence the strength gain of cementitious materials at early age, curing temperature can be regarded as an important parameter due to its great effect on the hydration kinetics of portland cement. The temperature effects on the relationship between the compressive strength of paste, mortar or concrete and the reflection loss obtained with ultrasonic shear-wave reflection measurements were observed. In the study,. three different constant curing temperatures (15, 25, and 35 degrees C) were used for a given paste or mortar The temperature effects were observed by comparing the established relationship between reflection loss and compressive strength for portland cement mortar under different isothermal curing conditions. Additionally, the established correlations between the two studied parameters were verified by applying alternating curing temperatures to the mortar As a third step, the temperature dependence of the relationship between the two studied parameters was further verified by observing concrete cured under various conditions. The study shows that for a given material, the relationship between the reflection loss and the compressive strength is independent of curing temperature.