Evaluation of Cold In-Place and Cold Central-Plant Recycling Methods Using Laboratory Testing of Field-Cored Specimens

Abstract

During the 2011 construction season, the Virginia Department of Transportation (VDOT) completed a major pavement recycling project that marked the first time full-depth reclamation (FDR), cold in-place recycling (CIR), and cold central-plant recycling (CCPR) were used together on a single project on the US interstate system. The CIR and CCPR mixtures were produced by using foamed asphalt and hydraulic cement as the stabilizing agents. After completing the pavement rehabilitation project, engineering properties of the CIR and CCPR mixtures were determined in the laboratory from field-cored specimens. VDOT conducted this study because the agency was considering using a single set of construction specifications for both CIR and CCPR materials if the engineering properties of the two processes were found to be similar. This project offered a unique opportunity to evaluate the two recycling methods by using materials from the same location. Laboratory tests included gradation, binder content, density measurements, indirect tensile strength (ITS) measurements, and resilient modulus (