Optimizing Use of Crumb Rubber Modifier (CRM) with PA Asphalt Mixes

Purpose:  Crumb Rubber Modifier (CRM) has been shown to benefit pavement performance while helping environment in reducing the amount of waste to be landfilled.   PA has experience with such mixes, especially in District 3, within the last few years with relative success.  With performance testing of asphalt mixes to become a requirement for some of our projects, it is important to determine how Pennsylvania CRM asphalt mixes perform in such tests in terms of low temperature cracking, fatigue cracking, and rutting.  The final goal would be to optimize the type (for example, conventional CRM versus Activated-Reactivated-Rubber) and amount of CRM for best performance while reducing the overall life-cycle cost of the project, and develop a relevant mix design guide.

Construction - Project No: PSU WO 011

Anticipated Outcomes

Determine how different crumb-rubber modified (CRM) asphalt binders perform under asphalt mixture performance testing for low temperature cracking, fatigue cracking, and rutting. Optimization of the type (conventional CRM versus Activated-Reactivated-Rubber) and amount of CRM in asphalt binder that optimizes the asphalt mixture performance tests for cracking and rutting. Development of a relevant mix design guide for using CRM asphalt binders in asphalt mixtures.