Deterioration of HMA partially saturated with water or brine subjected to freeze-thaw cycles

Abstract

In the province of Quebec, during winter and spring, hot mix asphalt (HMA), constituting the pavement, is subjected to freeze-thaw cycles (FTC). This paper presents a part of a general research program aimed at characterizing damage generated on bituminous mixes by thermal tests, including FTC, under dry (D) and partially saturated (PS) conditions, with water (PSW) or brine (PSB). The samples were subjected to mechanical testing and the complex modulus test is used to assess the evolution of their damage after different sequences of FTC. The test results and rheological model 2S2P1D were used to simulate the behaviour of the HMA according to the various states. The 2S2P1D model simulates the linear viscoelastic behaviour of the asphalt mix following different states very well. Over FTC, damage is observed for all samples, but is seen to be much higher for the PSW sample. Moreover, for PS samples, the principle of equivalent temperature-time is less valid over the FTC, and a double behaviour is observable: below and above the ice formation. Indeed, damage to the asphalt mix seems to have a greater impact at high temperatures and low frequencies.