Factors study in low-temperature fracture resistance of asphalt concrete

An investigation of various factors that can affect the fracture resistance of asphalt mixtures at low temperatures was conducted. The fracture resistance of 28 asphalt mixtures-which represent a combination of factors including binder type, binder modifier, aggregate type, asphalt content, and air voids-was evaluated by performing semi-circular bending fracture tests at three low temperatures. Two parameters, fracture energy and fracture toughness, were calculated from the experimental data. The statistical analysis indicated that fracture resistance is strongly dependent on temperature and significantly affected by the type of aggregate and air void content. The results of the analysis also confirmed the significance of binder grade and modifier type with relation to cracking resistance of asphalt mixtures. Asphalt content was also found to be significant for fracture energy but not a significant factor affecting fracture toughness.