Assessment of Permanent Deformation Properties of In-Place Recycled Pavement Mixtures

Abstract

Cold in-place recycling (CIR), cold central plant recycling (CCPR), and full depth reclamation (FDR) are techniques that can be used to rehabilitate deteriorated pavements or used in new pavement construction projects. Use of these techniques has been found to be both fiscally and environmentally beneficial. However, there is a lack of literature that examines the mechanistic behavior of these mixtures, particularly when it comes to asphalt mixture-related test methods. This paper presents a comprehensive analysis of data from repeated load permanent deformation (RLPD) testing, a laboratory test that describes a mixture’s rutting behavior, conducted on bituminously stabilized CIR, CCPR, and FDR mixtures. The mixtures were collected as a part of NCHRP 9-51, Material Properties of Cold In-Place Recycling and Full-Depth Reclamation Asphalt Concrete for Pavement Design. The permanent deformation behavior of specimens from 23 projects sampled between 12 and 24 months after construction is presented. The impact of stabilizing or recycling agent as well as the presence of chemical additives on the permanent deformation behavior was considered. Density, one of the most prevalent factors in field-based quality control and acceptance of cold recycled mixes was also examined with respect to its impact on permanent deformation behavior.