Sustainable Precast Concrete
Precast concrete products make a significant contribution to the built environment; they range from small hydraulically pressed items mass produced in highly automated factories, such as concrete bricks, paving and roof tiles, to larger mass produced items such as pipes, piles and floor beams, and 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 treatments to render them suitable for use, which results in concrete having a relatively low embodied energy value, unlike highly processed materials such as plastics.
Precast concrete products are locally sourced. Most of the UK needs for precast products can be 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 environmental management systems compliant to ISO 14001 and EMAS are maintained. New factories incorporate major recycling systems and act as role models in UK manufacturing. Over 80% of British Precast members' production is covered by and ISO 14001 or EMAS UKAS certified 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.
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.
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 - not just for today - is constructed. Precast concrete offers significant sustainable benefits in these areas.
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 our annual Sustainability Matters report.