Performance of sasobit modified asphalt binder in warm-mix asphalt technology

Abstract

Road maintenance is widely recognized, but not adequately maintained due to economic crisis of countries. Besides, increasing emission of greenhouse gases is an environmental issue, and it is a great concern to curb this problem from further harm to the environment and living things have captured attention of many parties, including pavement industries. Warm-mix asphalt (WMA) technologies could address the deterioration issues, reduce escalated energy costs, decrease global warming, reduce air pollution and increase environmental awareness. These matters have brought attention to the potential benefits of WMA in the developing countries. WMA technologies allow significant lowering of the production and paving temperature compared to conventional HMA (Hot-Mix Asphalt). In HMA production, the quarry mixing temperature is equivalent of asphalt’s viscosity of 170cP (0.17Pa.s), and gets sufficient fluidity to coat all the aggregates properly, whereas paving temperature is equivalent of a viscosity of 280cP (0.28Pa.s). Sasobit is an organic additive of warm mix asphalt technology, which used in this study as an asphalt binder modifier. The rates of sasobit were from 0.4% to 3.2% with interval 0.4 by mass of the asphalt binder. Two types of penetration asphalt binder (800-100 and 60-70) were used. The tests which conducted were penetration test, Rotational Viscosity (RV) test and Dynamic Shear Rheometer (DSR) test. In addition, The Rolling Thin Film Oven (RTFO) and the Pressure Aging Vessel (PAV) simulate the asphalt binder’s short-term aging and long-term aging respectively. Moreover, complex shear modulus (G*) was determined for finding the rutting factor (G/Sind) and fatigue factor (G*.Sind) for both asphalt binders. This study illustrates the optimum rate of sasobit is between 2.8 and 3.2% by weight of the asphalt binder.