Buy recycled to cut highway construction costs, WRAP says

The Waste and Resources Action Programme has said that “hundreds of thousands of pounds each year” could be saved if waste materials such as road planings and bitumen were recycled for re-use in the road maintenance process.

The call from WRAP came in response to press reports that highway authorities are bidding for extra funds for road maintenance following concerns that they will not achieve the targets laid out in the Government’s transport plan. Highways budgets are coming under strain as a result of construction inflation running at around 7%, WRAP said.

John Barritt, WRAP’s technical adviser on aggregates, explained: “Through a carefully planned procurement policy, highway authorities should be able to use their buying power within the supply chain to obtain the materials they need at a competitive price.”

WRAP has suggested the introduction of hot process plants to reactivate bitumen, while it said cold lay asphalt plants using foamed bitumen should be used for the recovery of aggregate materials. WRAP believes about 6 million tonnes of asphalt planings and asphalt process waste could be recycled in this way each year.

Industrial wastes including blast furnace slags, crushed glass and incinerator bottom ash can also be used, WRAP said, and have been “extensively proven to perform on a par with primary aggregates”.

Growth
Analysis of the growth potential for the use of recycled and secondary aggregates in the production of asphalt over the next ten years undertaken by WRAP indicates that around 40% of primary aggregates could be replaced by secondary alternatives, generating considerable cost savings.

Mr Barritt said: “The Highways Agency has been very pro-active in encouraging the use of more sustainable aggregates, and there is no doubt the potential growth of these materials could be enormous. Specification is not a deterrent to growth.”

Nationally, there are many examples of good practice being carried out by highways authorities – for example, in partnership with Lafarge, Norfolk County Council has used recycled asphalt in 16 different locations around the county to undertake both haunch and full width structural road maintenance. Total cost savings were over 26,000, WRAP said.

Similar cost benefits were achieved in Kent where the use of recycled asphalt in the replacement road base of the A21 by-pass produced savings of over 500,000 – more than 10% of the tendered price of the entire build contract.

For more information on the use of recycled aggregates in road construction and maintenance, visit WRAP's AggRegain website or telephone 0808 100 2040.