This discussion document aims to demonstrate the viability of calcined clays as a Supplementary Cementitious Material (SCM) in concrete.

The paper recommends a series of interventions to enable behavioural change, demand signalling, and widespread adoption of calcined clay in the UK. The recommended strategy and mitigations aim to overcome the barriers to adoption and enable the widespread use of calcined clay in the UK, contributing significantly to the UK’s Net Zero journey.

This discussion document is published by the Concrete Society on behalf of a Task and Finish Group led by HS2, Expedition Engineering, PA Consulting and MTC.

Published: December 2025