Exploring the effect of different waste polypropylene matrix composites on service performance of modified asphalt using analytic hierarchy process

Abstract

Using end-of-life polypropylene (PP) as additive to modify base asphalt has received rapid-growing attention. However, the low flexibility of waste PP results in undesired low-temperature property so as to limit its application. Accordingly, three waste PP matrix copolymers were analyzed in this study, including laboratory-made PP, ethylene-propylene-rubber (EPR) and polyethylene (PE) copolymer, commercial highimpact PP (HIPP) and fiber reinforced PP (FRPP). Moreover, their modifying effects were measured with respect to creep recovery, force-ductility curve, fatigue resistance and storage stability. The fluorescence micrograph (FM) was also analyzed to reveal the modification mechanism. Analytic hierarchy process (AHP) was employed to determine the optimum waste PP matrix composite and concentration. Test results showed that mingling waste PP with rubber, elastomer or fiber was attributed to enhance the toughness of corresponding modified asphalt at low temperature. Considering the overall properties of modified asphalts, the PP/EPR/PE a top priority and followed by HIPP and FRPP.