Use of Recycled Plastics in Asphalt Pavement Year 2
Dr. Jenny Liu, PI, Missouri University of Science & Technology
Xinhua Liang, Co-PI, Missouri University of Science & Technology
Over the last few years, there has been increasing interest in using recycled plastics in asphalt pavements. Recent studies have suggested that recycling plastics in asphalt mixtures is a great opportunity to improve the performance of pavements while eliminating the growing amount of
waste plastics being landfilled or polluting the environment through litter. The goal of this study is to conduct a preliminary laboratorial investigation to explore the viability of using recycled plastics in asphalt in the state of Missouri. During the first phase of the project, the effects of
high-density polyethylene (HDPE) on a typical Missouri asphalt binder PG 64-22 was investigated. 5% of HDPE (with or without pretreatment; flake or ground) by weight of neat binder was introduced into asphalt binder through wet process. Preliminary results indicated the size of recycled plastic flakes had significant effects on some properties of asphalt binders. The addition of HDPE greatly improved the rutting resistance of asphalt binders, and the binder modified with pretreated HDPE powders (with one physical treatment used in this study) has exhibited reasonable storage stability. The next phase of the project will aim to further investigate the methods to increase the compatibilization of waste plastics with asphalt and thus
enhance mechanical properties of modified asphalt cement. The tests on binders with other plastics (e.g., polyethylene terephthalate (PET) and low-density polyethylene (LDPE)) as well as the mixture performance tests (i.e., semi-circular bending (SCB), Hamburg wheel tracking (HWT), and indirect tension (IDT) tests) will be conducted to evaluate the effects of different recycled plastics on the properties/performances of asphalt binders/mixtures. The results of this study are expected to identify whether recycled plastics can be successfully incorporated into asphalt with improved properties/performance. The issues resulted from the asphalt binders/mixtures modified by recycled plastics will also be identified.