Temperature-Dependent Coefficient of Thermal Expansion of Concrete in Freezing Process

The coefficient of thermal expansion (CTE) of concrete depends on temperature, the internal structure of concrete, and the moisture content in concrete. An analytical model was developed to characterize the CTE of concrete under low temperatures. Three pore configurations are defined as pores with water and pores with ice. The effective strain of concrete is a combination of three processes during the cooling process, each containing a different configuration of pores. A general multiphase model for the effective expansion (and contraction) of concrete with a certain amount of ice was developed. The model can predict effective strain at different temperatures, which can reflect the influences of concrete pore size distribution and volume fractions of different phases. The predictions by the present model were compared with some available experimental data, and they agreed very well.