ABSTRACT
During the service time of asphalt pavement, low-temperature cracking is one of the main deteriorations which could influence the performance of pavement and shorten the service life of the pavement. One of the main causes of low-temperature cracking is that the thermal stress inside the asphalt mixture cannot well relax along with time and then accumulate continuously until exceeding the tensile strength when the temperature drops suddenly in winter. To improve the thermal cracking resistance of asphalt mixture, zirconium tungstate (ZT) with a negative expansion property was introduced to partly replace the mineral powder in asphalt mortar and asphalt mixtures in this study. From the thermal contraction test, it was conducted that the ZT could reduce the low-temperature contraction coefficient of asphalt mortar as well as asphalt mixture. Besides, the contraction coefficient of mortar had a good positive correlation with the contraction coefficient of mixtures under different ZT content conditions. Results of the Thermal Stress Restrained Specimen Test showed that the cracking temperature and transition temperature of asphalt mixtures reduced with the increase of ZT contents. The research of this subject can provide a new idea for solving the low-temperature contraction cracking and design of asphalt pavement.
