The British Standards Institution (BSI) has published its latest code of practice, “Lower Carbon Concrete – Alternative Binder Systems (ABS) – BSI Flex 350 Version 2”, aimed at reducing embedded carbon in concrete by promoting cement substitutes.

This new guidance provides a framework for assessing alternative binder systems (ABS) as viable low-carbon alternatives to traditional Portland cement-based concrete. The recommendations cover the properties of ABS, as well as testing and monitoring procedures to ensure compliance with performance standards across various applications.

The UK consumes 11.7Mta of Portland cement, contributing to nearly 90 per cent of the greenhouse gas emissions related to concrete production, according to the European Ready Mixed Concrete Organisation. ABS, such as geopolymer or alkali-activated materials, can significantly reduce these emissions.

Clare Price, built environment sector lead at BSI, commented: “The built environment plays a crucial role in the transition to net zero. This guidance enables engineers to make sustainable choices, reducing carbon emissions in construction projects while ensuring material suitability. Initiatives like this are essential to creating a sustainable built environment that benefits both people and the planet.”