Effects of aggregate type and SBS copolymer on the interfacial heat transport ability of asphalt mixture using molecular dynamics simulation

•Propose a new interface system of asphalt mixture at nanoscale.•Simulate the interfacial heat transport by MD simulations for the first time.•Evaluate effects of SBS molecules and aggregate types on heat transport ability. The interface between the asphalt and the aggregate contributes significantly to the thermal performance of asphalt mixture. This paper employs non-equilibrium molecular dynamics simulations utilizing the Langevin method, and reveals the interfacial heat transport of asphalt mixture. Kapitza thermal resistance is applied as the assessment index of interfacial thermal properties. The effects of styrene–butadienestyrene (SBS) copolymers and chemical components of aggregates on the interfacial heat transport ability are investigated respectively. The Kapitza resistance of silica-virgin asphalt system decreases with the increase of temperature, while the values of calcium carbonate-virgin asphalt system have a slightly fluctuation with temperatures, which shows a better thermal stability of asphalt mixture with calcium carbonate aggregates. In addition, the interfacial heat transport ability is improved significantly with the addition of SBS molecules, and the linear structure of SBS molecules has a better effects than radial structure. Furthermore, compared with 7.9 wt% SBS, higher content of SBS (20 wt%) hardly further reduces the Kapitza resistance value. The research findings can provide insights to better understand the interfacial heat transport ability of asphalt mixture.