Effects of Filler Characteristics on the Performance of Asphalt Mastic: A Statistical Analysis of the Laboratory Testing Results

Filler is a fundamental component of asphalt mastic and asphalt mixture. According to previous literatures, the performances of asphalt mastic are susceptible to filler characteristics. In this study, effects of filler characteristics on the performance of asphalt mastic were evaluated using the Fourier-transform infrared spectroscopy (FTIR), complex modulus (G*), phase angle, non-recoverable creep compliance (J(nr)), creep stiffness and m value. Five limestone fillers were selected to produce asphalt mastics. The specific surface area (SSA), filler content finer than 0.02 mm (P20), density and hydrophilic coefficient (HC) were tested and selected as the characteristic parameters of fillers. Statistical analysis was employed to determine the significance of fillers characteristics effects on the asphalt mastics performances. Results showed that the interaction between asphalt and filler is a physical process. Fillers with different SSA, P20, density and HC had significant influences on G*, J(nr) and creep stiffness, but had insignificant effects on phase angle, m value. SSA and P20 were the main characteristics that affected high, low temperature performances of asphalt mastic.