Predicting concrete coefficient of thermal expansion with an improved micromechanical model

The coefficient of thermal expansion (CTE) is a very important property of cement concrete. Concrete CTE represents the thermal expansion and/or contraction sensitivity of concrete, which highly relates to thermal cracks in concrete infrastructures, such as concrete dams and concrete pavements. The values of concrete CTE can be measured through laboratory testing or predicted using empirical models. While laboratory testing is time- and labor-consuming, the current concrete CTE prediction models are mainly based on empirical relationships. In this study, an improved micromechanical model was proposed to predict concrete CTE based on thermal mechanical analysis in which concrete was seen as a composite material. The original model developed by the authors can be found elsewhere. The improved CTE model was validated using a hierarchical approach with CTE measurements of cement paste, mortar, and concrete. The result indicates that the improved model was able to provide a better prediction on CTE values than the original model. Factors affecting concrete CTE were investigated utilizing the developed CTE prediction model. It was found that aggregate type was a major factor affecting concrete CTE, whereas water cement ratio did not have a significant effect on concrete CTE.