A11, Fiveways to Thetford road Improvement scheme, Norfolk.

Tarmac were appointed as key supplier to this £100m Highways Agency project to upgrade the last remaining single carriageway section of the strategic M11/A11 route to Norwich, between Fiveways and Thetford.

Given the scale of the project and the stated aim of minimising its impact on the local community and the local environment, the Highways Agency required a more innovative and sustainable approach to management of materials excavated from the old highway. Hazardous levels of tar had been found in the existing road, which required binding up into a permitted product to avoid very high disposal costs.

Our ULTIFOAM recycled asphalt system was recommended, to enable tar bound road arisings to be recycled on-site and used in the new pavement construction on side roads as a direct replacement for hotmix asphalt. ULTIFOAM uses proven foamed bitumen and cold-paving technology in an EA permitted system for encapsulating RAP with coal tar.

In a highly controlled process, the old asphalt road is crushed and screened before being combined with additional aggregate, foamed bitumen and hydraulic binder to produce a consistent paving product to HA specification.

The ULTIFOAM mobile plant was installed in October 2013 and processed 3,685t of tar bound planings over the duration of the project. Using ULTIFOAM directly reduced disposal costs, minimised transport and reduced the quantity of imported asphalt.

As a result it saved significant time and cost for the client and reduced disruption from site traffic for local road users. Replacing primary aggregate with road arisings also reduced inbound haulage and helped to reduce the carbon footprint of the contract.