Evaluation of plastic–rubber asphalt: Engineering property and environmental concern

• SBS asphalt is slightly better than PRA in terms of softening point, elastic recovery and fatigue performance.
• PRA mixture and SBS asphalt mixture have similar high-, low-temperature and water durability performances.
• PRA mixture is more environmental-friendly.

Waste rubber and plastic are accumulating heavily in China and causing significant environmental issues. In this study, the rubber and one kind of plastic, polypropylene (PP), were powdered and mixed with base asphalt to form plastic–rubber asphalt (PRA). This study evaluated PRA and the mixture in two-folds, engineering properties and environmental concerns. SBS asphalt, one commonly used asphalt binder in China, was adopted as a control. To evaluate the environmental burdens of PRA mixture and SBS asphalt mixture, a cradle-to-gate life cycle assessment (LCA) modeling was performed. Throughout the study, it is revealed that: (1) as a binder, PRA is weaker in terms of softening point, elastic recovery and fatigue performance versus SBS asphalt, but the differences are limited; (2) PRA mixture are close to SBS asphalt mixture for the high temperature, low temperature performances and water durability; (3) PRA mixture is more environmental-friendly compared to SBS asphalt mixture.