Evaluation of rubberised asphalt mixture including natural Zeolite as a warm mix asphalt (WMA) additive

Abstract

ABSTRACT One of the ways to modify bitumen and asphalt mixture characteristics is to use recycled Crumb Rubber (CR). Although using CR improves the mechanical properties of asphalt mixtures and rheological behavior of bituminous binders, it increases binder viscosity. Warm Mix Asphalt (WMA) is a practical technology to ameliorate the disadvantage of Rubberized-Asphalt (RA) mixtures. This study aimed to investigate the effect of zeolite as a WMA additive on Hot Mix Asphalt (HMA) and RA mixtures. These modifiers' effect on the properties of asphalt mixtures and binders was studied utilizing different tests such as resilient modulus, indirect tensile fatigue, dynamic creep, moisture susceptibility (TSR and RMR), and rotational viscosity (RV). The findings indicate that the addition of zeolite and CR improved mechanical properties. 16% CR along with 6% zeolite is the optimum dosage to enhance durability. Moreover, the addition of CR to mixtures without zeolite decreased the TSR, RMR, and workability of mixtures, while zeolite increased the durability and workability of HMA and RA mixtures. The cost-effective analysis results also indicated that not only does the simultaneous proper use of zeolite and CR decreases energy consumption, but it also decreases the production cost of modified asphalt mixture.