Staffordshire County Council is monitoring the performance of PFA-treated, recycled resurfacing on the A52. SCC selected the process from the draft European standard for fly ash-bound mixtures, as a way of using the county's stocks of PFA. Currently 4Mt of PFA are landfilled each year.
Tilcon carried out the contract which involved removing a 400mm depth of pavement along 1km of the road. The top 300mm was removed by planer and taken to a storage and mixing area where the oversize material was crushed and screened to produce a sand fraction and a 20mm to 5mm fraction. The fractions were mixed with 3% lime and 12% PFA, with the mix returned to site as two 150mm layers of sub-base and road base. This was then overlaid with a 70mm dense bitumen macadam basecourse and a 30mm stone mastic asphalt wearing course.
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