In-situ methods used in the UK recycle rolled asphalt wearing courses are outlined. Observations covering the period of introduction of repavers into the UK and the early small-scale trials are described. The obvious need to improve the surface finish produced by the early repavers is noted, together with the efforts made by the contractors to remedy the situation. Details are given of three trials, completed in 1978, in which repaving and conventional resurfacing were compared on the same stretch of road. After plant modifications, the measured riding quality of some of the repaving on motorways in 1979 and 1980 is found to be variable. A brief description is given of a small trial of a repaver fitted with a mixing unit located just behind the scarifiers. The uncertain long-term economics and the energy aspects of in-situ recycling are mentioned. The identification of sites suitable for in-situ recycling and the requirements for a specification are defined. Repaving requires extra care to ensure that the surface finish is completely acceptable and the 'new' surfacing has improved mechanical properties. (Author/publisher)
Abstract