Precast concrete products make a significant contribution to the built environment; they range from small hydraulically pressed products, to mass-produced products manufactured in highly automated factories, such as concrete bricks, paving, roof tiles, pipes, piles and floor beams, to highly-customised structural units manufactured to specific engineering and architectural requirements.
The materials that are used to make precast concrete products come from natural and recycled sources, mainly inorganic. Most of these materials are subject to minimal processing or chemical treatment to render them suitable for use, resulting in concrete having a relatively low embodied energy footprint compared to other highly processed materials.
Precast concrete products are locally sourced. Most of the UK needs for precast products are met locally, so there is no need to import materials from thousands of miles away - thus omitting the potential environmental impact from shipping for example. The local availability of aggregates makes for low carbon footprint deliveries to the precast factory. In fact, it is quite common to see rail and rivers being used to transport millions of tonnes of aggregate every year in the UK. Local sourcing also supports regional economies and employment.
Sustainability in the precast factory is about improving resource efficiency, reducing waste and ensuring that production and management systems compliant to standards such as ISO 14001, ISO 50001 or BES 6001, are maintained. New factories incorporate major recycling systems and act as role models in UK manufacturing. Over 90% of MPA Precast and MPA Masonry’s members' production is covered by UKAS accredited ISO 14001 environmental management system. The highly effective recycling systems used in precast factories enable virtually all process water, slurry, aggregates or cement to be safely re-captured and put back into production. This means that a closed-loop system is in operation - one which minimises any outgoing waste materials. UK’s average precast factory’s waste-to-landfill has dropped by almost 95% since 2008.
Carbon emissions associated with the manufacture of precast concrete and masonry products have dropped significantly over the last two decades. Since 2010, factory carbon emissions went down by around 50%. Most precast concrete and masonry products manufacturers also employ low-carbon cementitious alternatives to Portland Cement to further reduce the overall embodied carbon of their products. Portland cement replacement levels reached 24% across the sector in 2021.
During its lifetime, precast units, aggregate blocks and aircrete will effectively re-absorb much of the carbon dioxide that was used to create them; a process called carbonation that accelerates when products are crushed for recycling at end of life.
More information on carbon measurement and EPDs
The choice of precast concrete in a building or structure means that resilience is built in. The inherent properties of the material help it to withstand all manner of weather conditions, infestations and other less common threats such as explosions.Quality of life is a clear priority in sustainability, as is ensuring that a built environment that will last for successive generations is constructed. Precast concrete offers significant sustainable benefits in these areas.
More information about fire resistance.
Making progress towards sustainability is about continuously improving economic, social and environmental performance...
For the precast concrete industry, this means looking at our products and the way we manufacture them. In the UK, we are already making progress in both these areas. Further evidence is given in the MPA Precast and MPA Masonry annual Sector Sustainability report.