Recycled aggregate is nothing new but using an old road surfacings as the 'quarry' and foam mixing the new surface on site is an innovation that is set to save thousands of miles in lorry movements on a resurfacing scheme in Suffolk getting underway this week.
Contractor Alfred McAlpine is resurfacing a 3.5km section of the A1094 using planings excavated to a depth of 40mm from the existing surface and from stretches of the A12 trunk road nearby.
The new surface will be mixed up and laid in just three weeks, with 2,300t of planings needed for the new surface.
The team has therefore synergised the project with other resurfacing work Alfred McAlpine is doing in the county under its £9M a year framework agreement with Suffolk County Council. Tarmac is subcontracted to do the bulk of the work.
The planings vary from 10mm to 30mm in diameter.
They are loaded into a mobile foam mixing plant and the new surface is laid just 30 minutes later. The mix forms a 200mm road base which is then topped by 70mm of hot mix asphalt and Masterpave thin surfacing.
'We have brought our own plant as close to the site as possible in order to process the planings and return them to the site, ' says Tarmac project manager Craig Germaney.
'Usually the road base is mixed at static plants based around the country. The closest one to here is about 110km away so we've saved a lot of lorry movements.' 'It helps that under the framework agreement we can use other sites nearby to get the planings because there isn't enough on the site itself.
The operations are going on at the same time therefore we can keep the programme very tight.' And speed of construction is of the essence with the road closed for the duration of the job and principal contractor Alfred McAlpine overseeing trafc diversions.
Even in September the A1094 is busy with tourist trafc beating a path to the pretty seaside town of Aldeburgh that was the home and inspiration of composer Benjamin Britten.
'The location is quite critical because as a seaside resort we need to carry out the works as quickly as possible - just three weeks for the surfacing and drainage and kerb works at the same time, ' says Germaney.
Assistant area highway manager at Suffolk County Council David Fawcett hopes there will be many more such recycling jobs in the county.
'We would like to think we would do more and more of this because the surface materials on the A12 are conducive to being reused. Unlike urban roads which are of variable quality and have bits of utilities, the material is consistent and of good quality.' The work costs about the same as with using quarried aggregate but the government could make it more common by hiking up the tax on aggregate from primary sources.
'We want to recycle aggregate more and ultimately if the aggregate tax keeps going up the economic benets become greater, ' he says.