On the computational evaluation of carbon dioxide emissions of concrete mixes incorporating waste materials: A strength-based approach

Abstract

In the last decades, the high emissions of carbon dioxide during concrete production have pushed the scientific community to develop innovative ways towards reductions of such carbon dioxide emissions. An effective way is to use waste materials to replace conventional concrete materials, but this may come at the cost of reduced concrete performance. Hence, there is a need to link the carbon dioxide emission of concrete with concrete strength (strength-carbon dioxide emission relationship). This study bridges this gap by investigating the possibility of reducing carbon dioxide emissions in concrete by incorporating waste brick powder (WBP) and waste tire rubber (WTR) using a strength-based approach. This resulted in the formulation of three concrete grades of 20 MPa, 25 MPa and 30 MPa. It is shown that the impacts of including WBP and WTR on carbon dioxide emissions of concrete mixes are significant. Moreover, the compressive strength values corresponding to contents of 5 % WBP and 20 % WTR reduce dramatically by more than 32.57 % in comparison with conventional concrete mixes. However, 5P0T and 5P10T concrete mixes reveal both the reductions in carbon dioxide emissions and reasonable concrete strength. The present research therefore shows that certain concrete mixes incorporating WBP and WTR can provide the driving force for reducing carbon dioxide emissions and preventing substantial compressive strength reductions.