Evaluation of Recycled Aggregates Test Section Performance

The need to consider sustainability in design dictates that materials should be recycled and reused whenever possible. The Minnesota Department of Transportation (MnDOT) is quite progressive in allowing the use of recycled aggregates in new construction. While the use of recycled concrete aggregate (RCA) in the base course of new pavements is quite common in Minnesota and many other states; it is rarely used in the concrete pavement itself. In fact; Minnesota was one of the few states to build multiple trial projects and has one of the largest number of concrete pavements constructed using the RCA in the concrete itself. The performance of those pavements; most of which are still in service; has never been formally evaluated against similar conventional concrete pavements. This prompted the current research study. Additional objectives were to assess the current state of practice across the nation; conduct experimental investigations using RCA in concrete; assess the sustainability and in particular the economics of using RCA in concrete; and finally to provide some recommendations for guidelines on using RCA in concrete. It has been shown by the authors and other researchers that it is possible to create strong and durable concrete mixtures using RCA as coarse aggregate in volume replacement levels of natural coarse aggregate up to 100%.