Utilization of silicone maintenance materials to improve the moisture sensitivity of asphalt mixtures

Asphalt pavement preventive maintenance is of increasing interest in pavement industry all around the world recently. Moisture sensitivity of asphalt mixture is one of the biggest challenges for pavement maintenance. In China, Silicone Maintenance Materials (SMM) has been initially used to prevent moisture damage of asphalt pavements. This paper aims at investigating the effect of SMM on moisture sensitivity of asphalt mixtures in the laboratory. The characterization of SMM was researched by means of Fourier Transform Infrared Spectroscopy (FTIR) and contact angle test. In addition, the effect of SMM on moisture sensitivity of asphalt mixtures under multiple freeze–thaw cycles were evaluated by means of retained marshall stability, indirect tensile strength and modulus tests, as well as dynamic creep modulus test. The results indicate that the SMM could decrease the water absorption of mixtures and transfer the commutation void from closed void, as well as increase the retained marshall stability of mixtures. Moreover, compared to the untreated specimens, SMM increased the TSR value of asphalt mixtures after 1, 3, 7 freeze–thaw cycles and decreased the permanent deformation of asphalt mixtures under 7 and 14 freeze–thaw cycles. It can be concluded that the SMM could improve the moisture sensitivity of asphalt mixture under multiple freeze–thaw cycles. The research of this paper can support further application of SMM in China.