Evaluation of recycled waste plastics as modifiers for performance-graded asphalt binders
Loading...
Date
2022-01
Authors
Osei, Paul
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The use of recycled plastics in asphalt has gained more attention in the last few years. The objective of this study is to evaluate the performance of asphalt binders that have been modified using recycled polyethylene-based plastic pellets (RPE) using the Superpave Performance Grading and the Multiple Stress Creep and Recovery (MSCR) Tests. The study will also focus on the influence of the chemical modifiers Elvaloy and Polyphosphoric Acid (PPA) on the performance of the RPE-modified binders. Two different types of RPE pellets were blended in a PG 58-28 base binder during this study. Eight (8) different modified blends were developed, four (4) of which were blended with only RPE pellets and the other four (4) included the RPE, Elvaloy, and PPA modifiers. The dosages of the RPE pellets were 2% and 4% by weight of the mix, while the Elvaloy and PPA had fixed dosages of 1% and 0.002% by weight of the mix. The study showed that the addition of the RPE to the asphalt binders improved the high-temperature performance of the binders. The 2% dosage of the RPE led to a high temperature-grade increment of the binder (from PG-58 to PG-64) while the 4% dosage led to the increment of the high-temperature grade by 2-levels (PG-58 to PG-70). The presence of the Elvaloy and PPA also affected the performance of the binder in very similar ways as compared to the RPE only. The RPE, Elvaloy and PPA modified binders showed marginally better rutting resistance than the binder with RPE only. The fatigue resistance of the modified binders was also improved after the modification process. The low-temperature performance of the modified binders was minimally affected after the modification process. The modified binders showed increased stiffnesses at low temperatures, however, the increase in stiffness was not sufficient enough to alter the low-temperature grades of the modified binders.
Description
Keywords
Asphalt modification, Recycled waste plastics, High-temperature performance, Elvaloy, MSCR