Thermal conductivity of bitumen concrete

Abstract

The thermal conductivity of bitumen concrete is a key parameter in the thermal analysis of pavements submitted to widely varying climate conditions. This paper presents the experimental results of thermal conductivity of bitumen concrete typically used in the Province of Quebec. The results show that the thermal conductivity of bitumen concrete is dependent on the aggregate's mineral origin and on the amount of air voids. It is also shown that the presence of bitumen increases thermal conductivity compared to unbound aggregates. The paper demonstrates that the effect of bitumen creates thermal bridges between aggregate particles similarly to other types of binders such as Portland cement and natural binders found in sedimentary rocks. Based on these observations and on the analyses of over 80 data sets from the literature, an existing model is used to develop a simplified thermal conductivity equation to estimate this parameter for bitumen concrete.