Client: Highways Agency
Contractor: Balfour Beatty
Value: £148 million
Type of works: CEMEX supplied the 80,000m³ of ready-mixed concrete needed for widening the M25 from junction 12 to junction 15 involving bridges, underground installations, carriageway resurfacing and new safety barriers.

To meet demand, CEMEX erected a dedicated concrete batching plant on land it owned adjacent to the M25 site to ensure that concrete could be supplied day and night. The dedicated plant was capable of supplying up to 100m³ of concrete an hour but at peak times the project required additional capacity, which CEMEX met using four of its other established plants in the area. At the height of the project the company had a total of 15 dedicated truck mixers delivering concrete.

Where possible local materials were used to minimise traffic, and contractor Balfour Beatty established a recycling centre on the site to process materials from the site excavations.

CEMEX also provided water-reducing admixtures for all piling and structural concrete, while a combination of water-reducing and air-entraining admixtures was used in the slip-formed concrete.

A UKAS-accredited laboratory was also set up on the site to monitor the quality of the concrete and raw materials to ensure compliance with the requirements of the Highways Agency specification. During periods of 24-hour working, CEMEX technical staff worked alongside the main contractor’s team to ensure high levels of conformity were achieved.

This section of the M25 carries over 200,000 vehicles a day, the highest traffic levels in Europe. The two-year project started in January 2004 and when complete made a significant improvement to traffic flow in this previously congested area.