Embodied carbon of Australian-first calcined clay concrete

This paper provides an evaluation of the upfront carbon footprint of a concrete mix containing 30% calcined clay designed for construction of up to 100 m³ of concrete for an Australian-first use in low-risk non-structural road assets in metropolitan Melbourne. Clay used for the trial was produced at full scale in Victoria, utilising a clay residue from sand washing operations in an aggregate quarry. The evaluation was conducted using precise energy, fuel and material consumption data. Gaps in data were estimated using Australian Environmental Product Declarations (EPDs), databases or relevant and appropriate literature sources. A sensitivity analysis was also conducted on the data obtained in this study, demonstrating that efficiency of the pre and post-processing of the clay, distance from the quarry or source material, refinement of the concrete mix and substitution of the gas used for calcination are crucial in reducing the embodied carbon of calcined clay.