A new approach for determination of the coefficient of thermal expansion of asphalt concrete

• The theoretical model and experimental design for CTE investigation have been established.
• Six levels of thermal flux and three interpretation approaches are used and the results are compared.
• Study results show rational agreement with prior literature values.

A new approach for determining the coefficient of thermal expansion (CTE) of asphalt concrete (AC), based on thermoelasticity and using a distributed thermocouple and strain gauge apparatus, is proposed. The thermoelastic model for an instrumented hollow cylindrical AC specimen was established. Experiments were conducted with six scenarios of thermal flux for simulating different levels of heating on AC pavement. Three approaches for interpreting the CTE according to the readings of the thermocouple and strain gauge are provided, with different CTE measurements expected and observed. Terms associated with strain measuring accuracy derived from thermoelasticity are defined. The thermal calibration of instrument readings was shown to be necessary for obtaining accurate CTE readings for AC specimens. The CTE readings obtained in this study showed strong agreement with values reported in the literature. The proposed measuring approach is shown to be simple to install and theoretically founded.