Statistical analysis and unified model for predicting the compressive strength of coarse recycled aggregate OPC concrete

Recycling construction and demolition waste (C&DW) is an effective way to promote sustainability in the construction industry. The focus of worldwide research has been on recycled coarse aggregate (RA) produced from C&DW as a substitute for natural coarse aggregate in concrete. However, due to the diverse sources and production processes, there is significant variability in the compositions and performance of RA, making it hesitant for use in structures. Although many studies have been conducted on RA concrete, few have attempted to integrate the findings. This study developed and analyzed a database on the performance of RA and the compressive strength of RA concrete, including the work of this study and 106 related publications. The results showed that adequate compressive strength can be achieved at all RA replacement ratios for various applications, such as plain, reinforced, and prestressed concrete structures, among others. The study found that the water absorption (WA) of RA has a strong correlation with the compressive strength of RA concrete and proposed a unified model using multiple linear regression to predict the compressive strength based on the RA replacement ratio and WA. The proposed model showed good accuracy in predicting compressive strength and provided a useful tool for designing RA concrete mixes.