Meta-analysis on PET plastic as concrete aggregate using response surface methodology and regression analysis

This paper aims to thoroughly analyze the effect of polyethylene terephthalate (PET) plastic aggregate on concrete compressive strength using a meta-analysis. Forty-three datasets for concrete containing PET coarse aggregate and 60 data sets for concrete containing PET fine aggregate were collected. The input variables used were percentage and nominal maximum size of PET aggregate along with the concrete mix proportions. Main effect plots, contour plots, and surface plots of the expressions were presented to demostrate the effect of PET aggregate on the 28-day compressive strength of concrete. The statistical parameters of the regression equations, such as R2, adjusted R2 and root-mean-square error (RMSE), indicated that the RSM approach is a powerful tool to describe the change of concrete compressive strength by PET aggregate addition. In addition, the study showed that using PET plastic as a fine aggregate replacement performed better than using it as a coarse aggregate replacement in concrete. At up to 30% replacement, concrete containing PET plastic as a fine aggregate can have satisfactory compressive strength. © The Author(s) 2023.