Low Carbon Cement, SCMs, and Embodied Carbon of Concrete

This chapter provides a comprehensive overview of 26 types of low-carbon cement and associated supplementary cementitious materials (SCMs) specified in the British Standards. It defines SCM, hydraulic, and pozzolanic materials, and addresses challenges in replacing cement with SCMs, including their efficiency factors. The confirmatory criteria for cements required by standards, along with methods for measuring the strength, pozzolanicity, and soundness of cementitious binders, are presented. The chapter details the basic physical and chemical properties of traditional cement and commonly used SCMs.

A thorough review and summary of the latest developments and proven benefits of incorporating fly ash, GGBS, and silica fume as SCMs in concrete and mortar are included. The role of SCMs in enhancing durability and sustainability is explored, alongside the definition of lower-carbon concrete and key design guidelines for sustainable concrete and embodied carbon of concrete. Additionally, the chapter highlights sectoral initiatives to promote alternative binder systems, including the introduction of Flex 350, paving the way for a more sustainable concrete industry.