Understanding Reaction Mechanisms, Kinetics and Structural Evolution in Low-Carbon Cements

Cement is the 'glue' in concrete, and provides the foundation on which modern civilisation is built. But this comes at a huge environmental cost - nearly half of all materials extracted from the Earth annually are used in concrete, and cement production alone accounts for 8% of human-caused CO2 emissions.

By replacing traditional Portland cement with low-CO2, alkali-activated or alkaline earth-activated cement (AAC/AEAC), we can reduce these CO2 emissions by more than 80%. However, uptake of these low-carbon cements within industry has been slow, due to difficulty controlling the reaction, setting and hardening processes, which in turn control the physical properties and performance of the cement.

There is currently limited understanding of the fundamental interactions that control reaction, setting and hardening of these cements. This is largely due to the wide variation in chemical and physical characteristics of the raw materials used to make these cements, which significantly affect the processes controlling physical property development. We aim to overcome this technological hurdle, and provide the fundamental understanding that will drive widespread use of these low-carbon cements within industry.

This project aims to reveal the composition-structure-property relationships, reaction mechanisms and kinetics in these low-carbon cements produced from industrial wastes and low-carbon activators, using an array of state-of-the-art characterisation approaches.

Specifically, the project aims to reveal how variation in the characteristics of the raw materials, and the reaction and usage conditions, affect: 1) Reaction mechanisms and kinetics, 2) Composition-structure-property relationships and 3) Evolution of cement structure and phase assemblage. This will enable optimisation of cement formulations for enhanced sustainability, performance and durability, and is crucial to drive widespread implementation in industry. This will help drive a circular economy, reduce CO2 emissions, and give humanity the best possible chance to mitigate climate change.