A coupled thermo-hydro-mechanical framework for simulating the failure response of asphalt concrete under freezing conditions

Freezing-induced damage occurs in extremely cold regions in the form of sudden and simultaneous formation of cracks in dry and wet asphalt concrete. This work investigates the mechanical response, up to and including final failure, of dry and partially saturated asphalt concrete at freezing temperatures as low as - 30 degrees (-22 degrees F). A coupled thermo-hydro-mechanical constitutive framework is proposed within the context of finite element simulation. The framework contains nonlinear viscoelastic-viscodamage constitutive equations, the swelling strain effect associated with the freezing of water content, and the moisture damage constitutive equation. The stress induced in dry and partially saturated asphalt concrete samples due to reducing temperatures is simulated and compared with those of a studied experiment, and an excellent agreement is achieved in terms of the critical features, including the final brittle failure and the swelling effect. A parametric study is then performed to discover the effects of the microstructural constituents of asphalt concrete on its mechanical response under freezing conditions. This work provides a reliable computational framework that can predict deterioration and damage in asphalt concrete structures in extremely cold weather and further leads to the development of novel construction materials that can resist the negative effects of cold temperatures, e.g., in the Arctic.