Effects of temperature and strain rate on the damaging mechanism of asphalt concrete under uniaxial compression

To explore the effects of temperature and strain rate on the damaging mechanism of asphalt concrete under uniaxial compression, experimental and numerical investigations were conducted. Firstly, uniaxial compressive test of asphalt concrete at various temperatures (− 10 °C ~ 20 °C) and strain rates (10^–5/s ~ 10^–2/s) were conducted. Then, based on the viscoelastic-plastic damage constitutive model and discrete element method (DEM), the complete stress–strain curves of asphalt concrete at various temperatures and strain rates were well simulated. Finally, the damaging mechanisms of asphalt concrete under uniaxial compression were analyzed based simulated results. The results indicate that the interface between asphalt mortar and coarse aggregate is prone to damage, and there are more shear cracks compared to tensile cracks. In addition, the fragments number relates to crack evolution rate. Temperature effect on mechanical behaviors is mainly due to the gradual transformation between elasto-plasticity and viscoelasticity of asphalt concrete. The strain rate effect mainly affects crack evolution rate, meanwhile affects temperature effect to some extent.