On-site recycling reduces waste

The M4 Smart Motorway project involved replacing 11 bridges, the installation of a concrete safety barrier in the central reservation and extensive earthworks. 

The original materials strategy for the project was for all site-won materials, demolition arisings from the 11 bridges and any other concrete that was extracted to go to landfill. All of the required aggregates and fill material needed for the project was to be sourced from multiple suppliers which would have created significant pressure on the local market.

Through My Contribution - our employee-led change programme - an idea was submitted to reuse materials that would have gone to landfill during project delivery. Working with the project’s designers, we developed a strategy to incorporate site won fill within the core of the embankments and to produce recycled aggregates from waste materials. The recycled aggregates were used to construct verge embankments, piling platforms, side road embankments and the foundations of the concrete safety barrier in the central reservation.

Our new approach meant that waste was reduced as materials that would have previously gone to landfill were reused on site. Those that could not be reused were sent to a local soil washing facility where they were processed for other uses out with the project.


of material was used in landscaping


of site clay was used in the construction of side road embankments


tonnes of recycled aggregate was produced on site