Aggregate Industries UK Limited

About the project

The project will help UK supply chains to manufacture and supply low carbon ready-mix concrete. To be more resource efficient through the mainstream use of calcined clays (CC), reducing the amount of CO2 through substituting Portland cement (PC, also known as CEMI) and the subsequent decarbonising of concrete. It will make UK supply chains more resilient by introducing an additional / alternative cement replacement to the UK market that can be locally sourced at scale, thereby reducing the current dependence on ground granulated blastfurnace slag (ggbs) and coal fly ash (FA). Industrial by-products to CEMI are in high demand not only in the UK but globally and experiencing limited /declining supply.

The project will look at the use of calcined clays as a carbon reducing cementitious replacement for FA and ggbs in concrete.

FA/ggbs significantly reduces the embodied carbon for concrete in comparison with equivalent CEM I (100% PC). The study will verify that highly durable concretes can also be obtained through using CC.

FA/ggbs availability is limited, both by origin (by-product of other industries) and global demand. This rising global demand presents a supply challenge to UK concrete producers, increasing costs whilst potentially increasing embodied carbon where reduced availability results in greater use of CEMI.

Whilst other cement binders are in development (as alternatives to PC), it is important that the availability of cement replacements is increased in order to accelerate decarbonisation and avoid the industrial return to energy intensive and environmentally damaging materials.

Calcined clays provide an alternative (materials for the future economy; new material applications for cutting-edge products that reduce emissions, energy consumption and costs). Calcined clays can be manufactured or ground in the UK. CC readily fit within existing standards framework, but there are no active UK calcining or grinding facilities.

The project will address the need to develop resilient supply chains (especially sustainable feedstocks) for calcined clays.

The project will address the need to integrate calcined clays into existing UK concrete manufacture. To enable ready-mix plants to adapt, to optimise use of FA, ggbs, yet go further with calcined clay in manufacturing. Enhance availability and knowledge of CC as a cement substitute enabling world-class production. (i.e. flexible production capacity, minimal material waste, high-quality products, high productivity, and full adaptivity).

The project needs to demonstrate resilience of new supply chains, integrate calcined clay into batching plants, support flexibility and demonstrate fitness-for-purpose for calcined clay concrete.