Impact of Modified Post-Consumer Plastic (MPCP) Toner on Asphalt Binder Properties

Abstract

The utilization of recycled plastics in asphalt pavements has become increasingly popular because of its potential benefits for the environment and economy. Prior studies have concentrated on incorporating high- and low-density polyethylene into asphalt mixtures as an additive to enhance their rheological and mechanical properties. Nevertheless, new techniques have surfaced for utilizing post-consumer plastics (PCP) that cannot otherwise be recycled. One example of PCP is toner, an electronic waste that is challenging to recycle but contains polymeric components such as styrene-acrylate, styrene-butadiene, and polyester, making it a promising candidate for modifying asphalt binders. This research explores the feasibility and potential of modified post-consumer plastic (MPCP), predominately composed of toner, as an additive to improve asphalt binder performance and address issues such as rutting and low-temperature cracking. The research employs Superpave performance grading, phase separation, frequency sweep, and multiple stress creep and recovery testing to assess the effectiveness of different MPCP dosages. The results indicate that MPCP-modified asphalt binders exhibit increased stiffness and viscosity proportional to the MPCP content, resulting in improved resistance to permanent deformation. However, a 20% MPCP dosage level significantly increases phase separation and adversely affects the low-temperature performance grade (PG), while a 10% MPCP dosage does not affect PG. The research recommends limiting MPCP dosage to 10% for optimal storage stability, increased stiffness, improved rutting resistance, and minimal changes in cracking resistance. Overall, this study provides insights on the effective use of MPCP in asphalt binders and the potential influence on the performance of asphalt concrete mixtures.