Current specifications allow the use of recycled Portland cement concrete as a gravel cushion material under new PCC pavements. Supplemental specifications state: "Recycled Portland cement concrete pavement used as a granular base material shall not be used for Base Course, Salvaged Base Course, or in areas where drainage fabric, edge drains, or other similar drainage systems are present," effectively limiting use.
SDDOT needs to determine the appropriate material tests and construction requirements to ensure recycled concrete will produce a durable pavement base material. If it is determined that recycled concrete can be used with no detrimental effects, then guidelines and specifications for its use need to be developed. Research is needed to verify that the use of recycled concrete is advisable in this application and does not create issues with respect to pavement durability or performance.