Comparative Analysis of Long-Term Field Performance of Recycled Asphalt in California Environmental Zones

Abstract

A study was performed to evaluate the long-term performance of different pavement materials in California. The performance of many special materials, including recycled asphalt pavement (RAP), was evaluated for actual field performance rather than laboratory-based performance. The sections considered in this study were selected to allow the environmental impact on the performance of a specific treatment to be addressed and comparative analysis between two or more treatments to be performed. This paper focuses on a comparative analysis performed on 47 RAP sections located in three California environmental zones: desert, mountain, and north coast. Comparisons were made between the performance of the RAP sections and those of other treatments located within a reasonable distance on the same route. In total, 131 sections covering seven different treatments were considered. The performance comparisons were made with respect to in situ structural capacity, distress condition, roughness condition, and consistency of construction. Deterioration models were developed and used to estimate the in situ structural capacity, distress condition, and roughness condition for all sections at the same age (5 years) to allow fair comparisons. The expected structural, distress, and roughness service lives were also estimated for all treatments on the basis of the field-observed conditions. The results of the analyses suggested that in all three environmental zones, long-term RAP performance is likely to be comparable to other treatments located within a reasonable distance on the same route.