Balfour Beatty Civil Engineering Ltd

Recycling 1 million tonnes of aggregates on the M1 is an award winner

The Challenge

How to make the M1 widening project, south of Luton as sustainable as possible. The aggregate demand for this project was a huge 1.1 million tonnes. Sourcing and supplying enough recycled material to meet demand would be key as would guaranteeing product quality and avoiding timing delays to secure the necessary permissions for waste processing facilities. The Balfour Beatty Major Civil Engineering and Skanska joint venture team set about the challenge and applied a number of valuable lessons learnt during the widening of the M25 motorway near London's Heathrow airport during 2003-4.

The Solution

The demand for primary aggregates needed for the project was reduced through a combination of recycling waste materials from on-site demolition of structures and construction waste plus importing supplies of recycled aggregate construction and demolition waste from other projects. A massive 1 million tonnes of recycled aggregate were delivered in this way, 93% of the total required.

Early planning permission from the local authority and securing the required permits from the Environment Agency were critical in establishing the projects own recycling centres at junctions, 8, 9 and 10. An off-site recycling facility was secured first to facilitate the early supply of material and provide back-up at times of high demand. Planning this phase of the work and identifying sources of waste material for processing took place 6 months before the contract start date.

Careful planning continued with the positioning of the mobile crushing plant and stockpiling of processed aggregates to avoid cross-contamination and ensure the required material quality. Rigorous quality control procedures through waste acceptance testing and inspections by trained staff to screen out non-compliant material and regular analysis by UKAS accredited labs was undertaken to guarantee material quality.

Good management practices were also applied for other wastes generated by the project. A full time waste controller was appointed to manage dedicated skips on site, purchased specifically for this project to segregate construction and demolition waste. A waste compound was segregated to control and segregate waste into 6 separate types.

The Benefits

The benefits were fourfold:

• Reduction in primary aggregate demand of 1 million tonnes
• Avoidance of 800,000 tonnes of waste that would have otherwise gone to landfill
• Cost savings of £3 million due to avoidance of landfill tax and the aggregates levy
• 1 million fewer truck miles than would otherwise have been travelled, saving an estimated 1,700 tonnes of CO₂.

Award Winning

The M1 project was an example of embedding sustainable construction principles on a large scale. The BBS team were awarded a UK and an International Green Apple award for best practice in waste management in construction in 2008 and a Highways Agency environment award, as well as an considerate contractor award.

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