Temperature-Dependent Model of the Mechanical Properties of Surface-Layer Materials for Asphalt Pavements

This study investigates the influence of temperature on the mechanical properties of surface-layer asphalt pavement materials through indoor experiments. Key properties analyzed include compressive strength, splitting strength, resilience modulus, internal friction angle, and cohesion. A temperature-dependent model for these mechanical properties is proposed. The mechanical properties and cohesion of the asphalt mixture significantly decrease with an increasing temperature over the temperature range of −5°C to 45°C, which corresponds to the inflection point of the inverse S-curve. Beyond this range, temperature has minimal effect on the mechanical performance or cohesion. The transition temperatures of the thermal-performance model for the mechanical properties and cohesion of the 70#, 50#, 30#, styrene–butadiene–styrene (SBS)-modified, and high-modulus bitumen (HMB) asphalt mixtures increase sequentially, indicating that the asphalt mixtures compacted by using SBS or HMB have better mechanical properties than the base asphalts. The correlation coefficient of the temperature-dependent model for the mechanical properties and cohesion exceeds 0.97, demonstrating its strong predictive capability for mechanical strength and cohesion in asphalt mixtures.