Impact of Concrete Properties on the Carbon Footprint of a Structure When Using Green Concrete

Green concrete is now promoted to replace conventional concrete to improve the sustainability of the structure. While compressive strength is commonly used to evaluate the performance of green concrete, other properties such as modulus of elasticity, durability, and fire performance are also crucial in determining the required volume of concrete and, thus, the carbon footprint of the structure. These properties of green concrete may vary significantly from those of conventional concrete, even when their compressive strengths are the same. This study aims to assess the impact of variations in concrete properties on the carbon footprint of a structure when using green concrete. A reference structure is designed as per AS3600.2018, and multiple designs of the same structure are calculated to account for different loads, durability, and fire performance requirements. Each design is optimised for minimum concrete volume, which is considered as the reference design for conventional concrete. A parametric study is conducted to determine changes in concrete volume resulting from variations in concrete properties, and the carbon footprints of different green concretes are computed and compared to that of conventional concrete. The results of the study reveal that the variations in modulus of elasticity, durability, and fire performance affect the required volume of concrete, which in turn influences the carbon footprint of the structure. The findings of this study can be used to guide the selection of green concrete for structures, considering not only its compressive strength but also its other properties to minimise the carbon footprint of the structure.