Abstract:
Road industry is highest material consuming sector, causing the depletion of natural resources with the passage of time and now a day’s world is moving towards sustainable construction. Waste material from demolition causes environmental and economic problems in developing countries. This research study aims to evaluate the effect of coarse recycled concrete aggregates (CRCA) on the rutting and Resilient modulus in hot asphalt mixtures. The waste material was collected from old, demolished building sites and physical and mechanical properties were evaluated in the laboratory. The physical and mechanical properties of CRCA were improved by heat and short mechanical treatment method. The percentages of CRCA (diameter>4.75mm) used were 15%, 25%, and 35% in place of natural aggregates (NAg), and stone dust used as filler. Different bituminous mixes were prepared by combination of CRCA and NAg, and impact on performance was investigated in terms of Marshall parameters, permanent deformation, Indirect tensile strength (ITS), and modulus of resilience. As the percentage of CRCA was increased 0 to 35%, optimum bitumen content (OBC) was also increased due to the attached mortar's high absorptive tendency. The 25% CRCA proportion was found as optimum, showing highest resistance to permanent deformation, almost 66% higher than control mix, measured with double wheel tracker at higher temperature (50℃) and shows highest resilient modulus values, which is almost 20% higher than the control mix value. Based on a research study, it is concluded that recycled material shows better performance than control mixes in terms of deformation resistance and resilient modulus, so can be successfully used in HMA mixes reducing the dumping issues related to this building waste.
