A narrow, two-lane road in indiana was widened in 1986 by cold recycling the existing bituminous pavement in place. Bituminous binder and surface were placed over this base. A five-year research project was planned to compare the cost, strength and performance of the pavement with recycled base to a control section with conventional widening and resurfacing. The continuing evaluation of this recycled pavement includes measuring roughness and deflections annually. Visual inspections monitor development of cracking and other distress. Cores are analyzed for density, voids, asphalt content, and hveem stability. After one year in service, the recycled pavement is performing better than the conventional pavement. Transverse reflection and longitudinal widening cracks are beginning to develop on the resurfaced section. No racks have appeared in the recycled section. There is no significant difference between deflections on the two types ofpavement. The recycled section cost nearly twice as much as the conventional pavement, but initial costs are expected to drop somewhat as the technique becomes more common. Maintenance costs will likely be lower on the recycled pavement and may result in lower life-cyclecosts. This technique will likely be used again in indiana for roads with low to moderate traffic volumes (under 2, 500 directional adt). Evaluation will continue to assess the performance, service life, and life-cycle costs for this method. Cold, in-place recycling seemsto be a viable way to rehabilitate old pavements and seems especially well suited to widening pavements on fairly low-volume roads. This paper appears in transportation research record no. 1196, Pavementevaluation and rehabilitation.
Abstract