Investigation of mechanical properties of fine-grained concrete incorporating recycled PET flakes under thermal effects

Abstract

This study aims to determine the effects of high temperature on some mechanical properties of fine aggregate concrete with recycled PET (polyethylene terephthalate) flakes (Concrete with Waste Recycled Plastic – CWRP). Concrete mixtures with 10%, 15%, and 20% volume replacement of PET flakes are investigated for their thermal behavior. For this study, beam and cube specimens were cast to determine the flexural and compressive strength of the CWRP before and after exposure to heat, while simultaneously assessing the workability of the mixtures.The results indicate that as the percentage of substituted PET increases, the workability of the mixtures tends to decrease. Increasing the PET content also leads to reductions in both the flexural and compressive strength of CWRP at room temperature. Under high-temperature conditions, the study shows that the thermal sensitivity of CWRP increases with higher PET content. Based on the investigation, substituting around 10% PET appears to be optimal for maintaining acceptable workability and mechanical properties of CWRP under ambient temperature conditions.