Resurfacing work on the M25 has achieved the highest ever re-use of Recycled Asphalt Pavement material in the national motorway network.
Over 700 tonnes of existing porous surface course was recycled into the new road surface between junctions seven and six, using 40 per cent RAP material a first on a motorway or major A road maintained by the Highways Agency.
The project was undertaken through a joint partnership between consulting and business services group Mouchel and heavy building materials supplier Tarmac on behalf of the Highways Agency, as part of a programme of investment in maintaining more than 4,000 miles of motorway and major A roads in England.
Tarmac technical manager for London and South East Tim Smith said: This work sets a high benchmark for future road schemes on the national network and, as an industry we have an obligation to continue to develop innovative technology which can deliver a sustainable approach to road renewal.
Typically, RAP material is recycled in base and binder course materials, making it uncommon to use in thin surface course, which requires high Polished Stone Values to ensure good skid resistance. However, after Tarmac undertook extensive laboratory testing it ensured that the motorways 20mm sized thin surface could meet standards for texture, depth, skid-resistance, deformation resistance and durability for PSVs.
Across three nights 17,000 square metres of anti-clockwise carriageway surface near Reigate Hill was planed and removed. This was then reprocessed at Tarmacs recently upgraded Hayes asphalt plant - where a new state-of-the-art hot recycling drum plant has been installed and the new surface course was re-laid covering 6,900 square metres of carriageway.