Evaluation of Performance of Full-Depth Reclamation Mixes

The full-depth reclamation (FDR) process consists of reclaiming all of an asphalt-bound section along with a predetermined amount of underlying base, with some additive. The objectives of this study were to determine the suitable compactive effort for designing FDR mixes, evaluate the benefits of using different types of additives in terms of improvement of pavement life, and determine suitable structural numbers for pavements recycled with different types of additives. The scope of work for this part of the study consisted of conducting falling-weight deflectometer (FWD) tests, testing an existing pavement before FDR, sampling of materials during FDR, determining the density of in-place material after compaction, compacting of loose mix in the laboratory, determining the density of the compacted samples, conducting FWD testing on the finished pavement, determining the resilient modulus of in-place cores, and analyzing the data to determine the suitable number of gyrations, improvement in pavement life, and structural numbers. It was concluded that samples should be compacted to 50 gyrations during mix design and that a minimum of 98% of density of in-place loose mix samples, compacted to 50 gyrations, should be achieved in the field at the end of compaction. Cost comparison showed that for the options considered in this study, recycling with emulsion (3.4%) and lime (2%) is the most cost-effective option. A visual evaluation of recycled sections after one year showed no significant distress in any section except the one with water as additive, in which a moderate amount of edge cracking was noted.