Towards the low-energy usage of high viscosity asphalt in porous asphalt pavements: A case study of warm-mix asphalt additives

The problems of energy waste and pollutant gas emissions caused by the high-temperature construction of high viscosity asphalt (HVA) for porous pavements may be effectively solved by the warm-mix asphalt (WMA) additives. In this paper, the rheological properties of HVA with WMA additives were investigated considering the application in porous pavement. First, the influences of different dosages of Sasobit, EC120, Evotherm, foaming water on the conventional properties of HVA were investigated by rotational viscosity, absolute viscosity (60 °C), toughness and tenacity, penetration, softening point, and ductility (5 °C). The four optimum dosages of Sasobit (3%), EC120 (3%), Evotherm (1%), and foaming water (4%) were determined. Second, the rheological properties at the high-temperature, intermediate-temperature, and low-temperature of HVA with the four optimum dosages of WMA additives were studied by dynamic shear rheometer (DSR) test and bending beam rheometer (BBR) test. The result showed that the rotational viscosity (135 °C) of HVA was significantly reduced by the WMA additives, thereby improving the workability of the HVA. Meanwhile, the WMA additives at optimum dosage can improve the high-temperature rheological properties of HVA except for foaming water. However, Sasobit, EC120, and foaming water have adverse effects on the intermediate-temperature fatigue performance and low-temperature crack resistance of HVA. By comprehensive comparison, it is suggested that HVA with 1% Evotherm is more suitable for the construction in porous asphalt pavements.