Abstract: To investigate the impact of temperature on the strength and dilatancy behaviors of hydraulic asphalt concrete, triaxial shear tests were conducted on asphalt concrete samples at controlled temperatures of -1 ℃, 5 ℃, 10 ℃, and 15 ℃. The results demonstrate a strong correlation between temperature and the mechanical response of the asphalt concrete. At temperatures below 0 ℃, the samples exhibit evident strain softening and dilatancy behaviors. However, as temperature rises, the strain softening transforms into strain hardening, and the degree of dilatancy decreases. Moreover, the shear strength of asphalt concrete reduces with increasing temperature, with the decrease in cohesion being more pronounced compared to the internal friction angle. Specifically, as temperature rises from -1 ℃ to 15 ℃, the internal friction angle declines by 4.7°, while cohesion drops from 1.11 MPa to 0.28 MPa. Additionally, the dilatancy angle expands with the increase of axial strain and eventually stabilizes, exhibiting a suitable fit using a hyperbolic function. Remarkably, the parameters of the hyperbola model demonstrate a strong correlation with temperature, making them useful for developing a thermal-mechanic constitutive model for asphalt concrete.

Key words: asphalt concrete, temperature, strength, dilatancy, rockfill dam