Behavior of Lime-Treated Cold In-Place Recycled Asphalt Pavements

Abstract

Use of recycled materials has great potential for rehabilitation of low to medium volume roads effectively and inexp ensively. However, cold in-place recycling (CIR) technology lacks performance data and field demonstration projects. In this study, the design and performance characteristics of the CIR materials from two sites namely, Salina and Osborne sites in Kansas are determined in the laboratory. The laboratory tests include physical property (e.g., moisture, gradation, air voids, and emulsion) and performance-related (e.g., resistance to deformation, and rutting) testing. Relative performances of the CIR mixes from these two sites are then analyzed. Results show that the CIR mixes from both Salina and Osborne sites exhibited good resistance to deformation, and other criteria for low to medium volume roads. Addition of lime slurry into a milling-emulsion mix caused a significant improvement in the dry and wet rutting. Samples with 2.5% Reflex emulsion and 4.0% lime slurry additive used in the Salina site exhibited lower rut depths compared to the samples with 2.0% Reflex emulsion and 2.5% lime slurry additive used in the Osborne site. The resistance to deformation values varied only slightly between the initial cured and fully cured samples,
indicating that R-values may not be a suitable property or indicator of the quality of a mix. It is believed that the data and results presented in this study will be useful in implementing the CIR technology for pavement rehabilitation.