Performance Evaluation of Concrete Pavement Granular Subbase

The objectives of this research project are to: 1. Determine if recycled PCC pavement subbase is performing adequately by evaluating representative pavement sections with comparisons to virgin aggregate subbase sections (in particular with respect to the specification changes since 1992). 2. Evaluate the variation in subbase stiffness and permeability by performing multiple tests within a given test section using semi non-destructive methods (i.e. permeability measurements through core hole, pavement FWD tests, and down hole LWD and DCP tests). 3. Determine the gradation of the subbase materials using bag samples and non-destructive X-Ray CT scanning of epoxy filled core samples. 4. Characterize the ride quality and geometric characteristics of the pavement layer for correlation to the subbase properties. 5. Evaluate the pavement drainage system at each test section site by inspecting the subdrain outlets. 6. Develop suggested material guidelines and specifications for construction of pavements using recycled PCC aggregate for subbase.