Experimental study and modeling of the behavior of partially saturated asphalt concrete under freezing condition

Investigations reported in this paper rely on two types of experimental test carried out in the laboratory. The first is performed under free stress condition while the other is subjected to restrained strain. The experimental results from these two tests show the development of significant swelling strains and induced stresses in the partially saturated asphalt specimens, respectively. These two effects are attributed to the phase change of pore water from liquid to solid. A constitutive law taking into account viscoelasticity of AC, thermal expansion and swelling induced by frost is elaborated. This law is implemented in a numerical program and validated against the experimental results. In particular, it is shown that this law is able to make the connection between the magnitudes of the swelling strain and the frost-induced stress stemming from the two tests.