Recycling Waste Cigarette Butts in Dense Graded Asphalt.

Trillions of cigarette butts (CBs) are dumped into landfills globally. CBs leach toxic components into the soil, including heavy metals, tar, and many other chemical compounds. Approximately 7.2 billion CBs are discarded every year in Australia, and 16.8 billion CBs accumulate in the waste management system annually. In previous work, the encapsulation method for CB with bitumen and paraffin wax was developed and encapsulated CB in dense graded asphalt (DGA) was evaluated using bitumen classes C320, C170, and C600. In recent studies, the encapsulation method was improved, and the possible use of bitumen-encapsulated CB (BECB) in stone mastic asphalt (SMA) was demonstrated. To build on this foundational research, the current work aimed to investigate the use of improved BECB in heavy-duty DGA prepared with polymer-modified bitumen (PMB) class A10E. Samples were prepared following VicRoads and Austroads guidelines. In this research, the Marshall stability and flow, resilient modulus, dynamic creep, tensile strength ratio, and indirect tension fatigue test were performed to evaluate the performance of BECB-modified DGA. The results were compared with the control DGA prepared with industry-standard conventional materials. Test results suggested that using 0.5% and 1% BECB in DGA met the industry requirements and endorsed the recycling method of CB in asphalt concrete. [ABSTRACT FROM AUTHOR]