Additives, Base course (Pavements), Fabrics, Geotextiles, recycled concrete aggregate, Recycled materials, Subbase (Pavements), Virginia
Special provisions of the Virginia Department of Transportation (VDOT) allow the use of recycled concrete aggregate in a base course and subbase under a road. However, the chemical makeup of the concrete in the recycled aggregate could cause calcium-based ions to leach into geotextile fabric used in required underdrain systems in the pavement structure. This reaction could clog the fabric and inhibit water moving through the fabric wrapped around aggregate to promote drainage. Based on this limitation, VDOT does not use recycled concrete aggregate as a base course or subbase. In this study, researchers will add various percentages of recycled concrete aggregate to 21B virgin aggregate to evaluate the potential of the respective mixtures to clog underdrain geotextile fabric. The team also will provide guidelines for revising VDOT specifications as they relate to appropriate blends of recycled and virgin aggregate and estimating the suitability of a recycled concrete aggregate source.