Recycling road making material has the potential to save money, energy and scarce resources; these advantages can be realised provided the in-service performance of recycled material is similar to that of comparable new material. In this report the performance and cost of in-situ wearing course replacement by the repave and remix processes have been investigated and information is presented on wearing course replacement using off-site recycling. The performance of these processes has been evaluated by comparison with conventional wearing course replacement, at the same site. Measurement of rut, profile, texture, skidding resistance and visual condition, made annually, provided the data for comparisons and it was found that deterioration under traffic was similar for conventional and recycled wearing course. The traffic level at which deterioration started and its rate were found to be more dependent on the site than on whether virgin or recycled material had been used. The texture and skidding resistance showed no systematic difference between treatments. Cost savings of up to .1/Sq m were made using repave and remix instead of conventional wearing course. Energy savings although small in terms of total cost, are worthwhile in warm weather. (A)
Abstract