Use of Recycled Polymers in Asphalt Concrete for Infrastructural Applications

Abstract

This paper reports the characterization of properties and performance of hot mix asphalt, focusing on stone mastic asphalt (SMA), with various types of recycled polymers (waste plastics). Investigations were conducted on the performance grade of bitumen (penetration value and softening point) as well as mixture strength (Marshall stability, Marshall flow, and Marshall quotient) for different waste plastics blends. The binders studied were conventional bitumen, target bitumen (polymer-modified bitumen), and waste plastics (LDPE, PP, PS, and HDPE). The target bitumen and polymer-modified bitumen with recycled polymers (10 wt% LDPE, 10 wt% PP, 25 wt% PS, and 2 wt% HDPE) were more superior binders than conventional bitumen due to decreased penetration values and increased softening points. The target mixture showed the greatest Marshall stability and Marshall quotient, whereas conventional mixture displayed the lowest values, suggesting the advantageous role of polymer-modified bitumen in target bitumen. SMA mixtures having optimum individual contents of 10 wt% LDPE, 10 wt% PP, 25 wt% PS, and 2 wt% HDPE were found to be feasible design formulations for mixture strength.