Evaluation asphalt concrete mixture with plastic waste and crumb rubber as fine aggregate replacement in Iraq

The massive accumulation of waste materials crumb rubber (CR) and plastic waste (PW), represents a global environmental concern particularly regions like Iraq. This study investigates of using waste materials as partial replacement for fine-aggregates to production of modified hot mix asphalt. Marshall and wheel track tests were performed on samples were prepared by partially replacing the fine-aggregate with CR and PW at five replacement percentages (1%, 3%, 6%, 9% and 12%) are used by weight of fine-aggregate. The objective was explaining the effect waste additives on asphalt mixture performance. Performance was assessed using the Marshall and wheel truck tests. The laboratory results indicate that partial substitution of fine-aggregate by waste materials showed a difference in Marshall’s characteristics and rutting resistance compared to control mix. Based on result, the optimal amount of CR and PW that can add to mixture is 3% and 6%, respectively. The 3% CR mixture exhibited reduction in stability about11.9%, but remained within SCRB specifications. In contrast, the 6% PW mixture showed a 20.8% stability increase. Moreover, rutting resistance at 55°C was significantly enhanced, it has reduced by 32.6% and 14.7% for 3% CR and 6% PW, respectively. Consequently, using waste materials enhance asphalt mixtures performance and promotes sustainable construction.