The asphalt layer of pavement constitutes the most important part of pavement because of its direct exposure to various damaging factors including weather changes and traffic loads. For this reason, researchers have always tried to find methods to reduce damages and lower the costs of repair and maintenance. In cold and freezing weather, the surface layer of pavement is exposed to intense stresses, which increases the risk of damage. In cold areas, moisture susceptibility is a critical factor in damaging the surface layer of asphalt. Little research has been conducted on the bitumen content as a factor reducing moisture susceptibility. In this study, the effect of bitumen content on moisture susceptibility in freezing and cold weather and under freeze-thaw cycles has been examined and the changes in moisture susceptibility have been compared to those in the specimen made with optimum bitumen content. To this end, asphalt mixtures with various bitumen content were prepared and subjected to Marshall Immersion Test and Indirect Tensile under various cycles. The results show that as the number of cycle increases, the resistance of the specimens reduces and as the increases in the bitumen content, the reduction becomes less. Also, the specimens with a higher bitumen content than that of optimum bitumen content show less moisture susceptibility.

Full text: IJEIR_1304_Final.pdf