Measuring the Thermal Properties of Pavement Materials

Thermal conductivity is an important material parameter that determines the thermal conditions in pavement and influences cracking, rutting, and fatigue. The test standard (ASTM C177) is not suitable for pavement samples. Research at Arizona State University has developed a test method that uses cylindrical samples to measure thermal conductivity. This paper proposes an improved and simplified ASU laboratory test procedure for measuring the thermal conductivity of pavement material using a cylindrical core sample, including a shorter core sample, a smaller hole drilled in the center, rubber retainers to place thermal couples on the outer face of the core and saturated sand to fill the voids in the inner hole. The test generally requires three hours to reach a steady state of heat flow. This test method is verified by more than 50 samples from four different locations across the United States.