Evaluation of Full-Depth Reclamation and Cold Central-Plant Recycling Mixtures for Laboratory Compaction,Mechanistic Response,and Performance Properties

Abstract

Cold recycled mixtures (CRM) are gaining wider acceptability in the United States for rehabilitating existing pavement or new construction while reducing construction costs, environmental impacts, and construction time. However, the technology is still in development owing to inconsistency in design and limited research on mechanistic and engineering properties. To this end, this study evaluates full-depth reclamation (FDR) and cold central-plant recycling (CCPR) materials for evaluating (i) laboratory compaction protocols, (ii) mechanistic properties, and (iii) engineering performances. Two compaction methods—the Superpave gyratory compaction and the modified proctor—were developed for designing test specimens with adequate design properties. The mechanistic properties resilient modulus (M_R) and dynamic modulus (|E*|) were evaluated. Laboratory performance testing such as Texas overlay tester, semi-circular bending, and a modified Hamburg wheel tracking (HWT) were performed. This study also proposed a new parameter, loading limit (N_max), based on the modified HWT test configuration. The study found that the FDR exhibits less temperature dependency compared with the CCPR while subjecting to loading. Based on damage properties such as critical fracture energy, J-integral, crack propagation index, and N_max, the CCPR exhibits more flexibility and damage resistance than FDR.