Effect of using cement reactive powders on rheological performance of asphalt mastics

This study explores the interactions and compatibility of different types of cement as reactive powders with bitumen binders to evaluate the rheological performance of warm mix hybrid mastic systems. The binders were modified with a warm mix asphalt (WMA) additive. Two types of portland cement Type I (LF and SM), calcium sulfoaluminate cement (CSA), oil-well cement (OW), and high alumina cement (HA) were blended with asphalt binder and their physical and chemical properties were characterized. The cement properties include Rigden voids, specific gravity, particle size distribution, and chemical composition. The cement powders were incorporated into asphalt mastics at 5% (low), 15% (intermediate), and 25% (high) concentration by volume of the mastic. Fourier transform infrared spectroscopy (FTIR) test was performed to assess the chemical interactions between the cement powders and asphalt binder. The effects of cement type and filler volume concentration on the properties of mastics at high and low temperatures were studied using complex modulus, phase angle, high temperature creep and recovery, low temperature creep stiffness, and relaxation ability. Laboratory results indicate that using cement powders at 15% and higher filler volume concentrations the enhancement of high-temperature response can be attained. According to the Superpave specification, the low-temperature performance of cement-based mastics with 5% replacement of cement was acceptable.