Feasibility of concrete mixtures containing cross-linked polyethylene waste materials

Abstract

Post-consumer plastics made of thermosetting polymers such as crosslinked polyethylene (XLPE) cannot be easily fused or dissolved during recycling. As a result, such wastes are often incinerated or landfilled with adverse consequences on the environment. This work addresses the feasibility of incorporating XLPE waste materials in concrete by testing the fresh and hardened properties of several sets of mixtures prepared with various cement and free water contents. The XLPE was shredded to different sizes and incorporated up to 8% of cement mass. Test results showed that concrete workability and air content are marginally affected by XLPE inclusions, while the unit weight decreases due to the difference in density between aggregates and XLPE shreds. XLPE inclusions also result in superior concrete performance in terms of water permeability. Concrete strengths and shrinkage suffer moderately from increasing XLPE content and particle size. However, these shortcomings can be mitigated by decreasing the water-to-cement ratio. The thermal degradation of XLPE following exposure to heat reduces the residual compressive strengths of XLPE modified concrete mixtures.