Feasibility of Using Crumb Rubber Modifier in Hot-Mix Asphalt Pavement Applications in Puerto Rico Author(s): Colucci, Dr. Benjamin, Prieto, Jorge, and Dayton, David Origin: Puerto Rico Date: March 1994 Categories: Performance Key Words: Crumb rubber modifier Summary: This report presents the findings of a study to assess the feasibility of using crumb rubber modifier (CRM) in hot-mix asphalt (HMA) pavement applications in Puerto Rico, as required by Section 1038 (d) of the 1991 Intermodal Surface Transportation Efficiency Act (ISTEA). The study was undertaken at the request of the DOT and Public Works, with the join support of the Puerto Rico Transportation Technology Transfer center. Early in the course of this study, the investigators found that CRM utilization in HMA pavement applications is inextricably linked to the problem of scrap tire recycling.