Workability of low-density polyethylene modified asphalt mixtures: A statistical analysis of particle kinematics

Abstract

The utilization of recycled plastics in asphalt pavements has gained considerable attention due to its economic, environmental, and engineering benefits. However, incorporating plastics into asphalt mixtures poses challenges to their workability, sometimes leading to a detrimental impact on engineering performance. To address this limitation, this study introduces an innovative analytical approach to examine the impact of Low-Density Polyethylene (LDPE) and its processing techniques on the workability of the asphalt mixture. A particle-size wireless sensor, SmartKli, was utilized to collect the particle kinematic behaviors during compaction. The effect of various mix designs or production methods on the mixture's workability was determined by statistically analyzing the sensing data, including Two One-Sided T-tests and one sample T-test. In this project, seven mixtures with various asphalt content, and LDPE dosage were studied. The recycled plastic-modified asphalt (RPMA) was produced using two dry processing methods and one wet processing method. The results validate the significance of asphalt content on the mixture's workability. A linear correlation was observed between the active asphalt content and the mixture's workability, even in the presence of plastics. Under the identical mix design, the wet processing method proved more effective than the dry methods in integrating LDPE, as evidenced by the workability of the RPMAs. For asphalt mixtures with plastics, ensuring sufficient binder content is essential for maintaining workability, particularly in RPMAs processed via dry methods.