UTILIZATION OF POLYPROPYLENE TO SUBSTITUTE BITUMEN FOR ASPHALT CONCRETE WEARING COURSE (AC-WC)

Abstract

In this study, Polypropylene (PP) plastics waste with various concentrations of 0.5%, 0.8%, and1% were investigated to substitute bitumen’s mass. The mixing of plastics and asphalt was conducted by wetmethod, which added PP plastic into the asphalt when being heated so it produced a homogeneous mixture.Then, AC-WC mixture was made with bitumen contents of 5%, 5.5%, 6%, 6.5%, and 7%. Each mixture wascarried out in triplicate for every plastic’s concentrations. Five parameters of mixtures were tested by MarshallMethod, as follows: VIM, VMA, VFA, stability, and flow. Then, all the parameters were plotted in bar chartto determine an OBC (optimum bitumen content). Changes in rheological properties after the addition of PPplastics occurs which indicates the increasing of viscosity, softening point, flash point, and the decreasing ofdensity, penetration and solubility. Based on Marshall Test, the OBC for asphalt pen 60/70 was 5.4% while theOBC with PP plastic content of 0.5%, 0.8% and 1%, consecutively, were 5.41%, 5.43% and 5.45%. Despitethe increasing of OBC, this substitution of bitumen to plastics has some advantages such as increasing stabilityand remaining strength index (RSI), reducing plastic waste generation and asphalt cost. However, it hasdisadvantages such as it consumes more energy and it increases gas emission.