A groundbreaking UK research project reveals a technique to reduce carbon emissions in cement using reclaimed clay and brick dust.
- The Mineral Products Association led a study demonstrating brick dust can lower cement carbon content by up to 3%.
- As traditional decarbonising agents dwindle, calcined clays from waste provide a promising alternative.
- The initiative highlights the potential to redirect substantial waste into construction materials.
- Economic benefits anticipated include job security and investment in the UK.
A groundbreaking project spearheaded by the Mineral Products Association (MPA) has demonstrated that utilising reclaimed clay and finely ground brick dust can significantly reduce carbon emissions in cement production by up to 3%. This innovative approach, supported by funding from Innovate UK, shows a promising alternative to current cementitious materials, particularly in light of diminishing resources such as ground granulated blast-furnace slag (GGBS) and fly-ash.
This two-year study underscores the potential of UK-sourced calcined clays to transform construction practices by acting as a secondary cementitious material in cement and concrete manufacturing. The adoption of these materials could prevent approximately 1.4 million tonnes of potential waste, thus aligning with the country’s growing emphasis on sustainability in construction.
Crucially, the research compared two heating methods for preparing the clay: the conventional rotary kilns and the innovative ‘flash heating’ technique. Both methods were validated to produce high-quality calcined clays with no notable difference in the output, underscoring the versatility and adaptability of the process in various industrial settings.
Diana Casey, MPA director, highlighted the transformative impact of incorporating brick waste and reclaimed clays into construction materials: “Using brick waste and reclaimed clays will not only lower carbon and reduce waste but has the potential to create a whole new market,” she stated, pointing to potential economic benefits such as job security and attracting investment within the UK.
The use of calcined clays as a low-carbon alternative in cement and concrete represents one of the seven key strategies outlined in MPA UK Concrete’s Roadmap to Beyond Net Zero. This strategy complements the concrete and cement industry’s commitment to achieving net zero carbon emissions, continuing a trend of substantial reductions since 1990.
The research into using brick dust as a low-carbon cement alternative marks a significant advance towards sustainable construction practices.
