15 - Upcycling CO2 for enhanced performance of recycled aggregate concrete and modeling of properties

Abstract

This chapter discusses CO2 upcycling for enhancing the performance of recycled aggregate concrete (RAC) and also presents statistical models for estimating the strength properties of RAC. Tests on treated concrete have revealed that the strength and durability properties of the RAC, following rapid and complete carbonation, are enhanced from the CO2 conditioning. Models for determining RAC properties were developed using the Gene expression programming techniques. Input data (predictors) were recycled concrete aggregate (RCA) content, duration of carbonation, and carbonation pressure, while compressive strength was the output parameter (response). Data for the model were sourced from completed studies in the open literature, 80% of which were used for training, and the remaining 20% were used as the testing set. The error values R2, MSE, and RMSE, respectively, which imply that the developed model demonstrated a strong prediction of the experimental results. The model will serve as a working tool for concrete constructors.