Summary

The Paradigm in-place concrete pavement recycling system eliminates the cost of hauling old concrete to and from off-site crushing facilities. The Paradigm uses a guillotine pavement breaker to break the pavement into 14-16" pieces. Reinforcing steel and mesh are removed by workers using bolt cutters and torches. Concrete is fed into a self-mounted impact crusher. The crushed material is then fed into a secondary crusher towed behind the primary crusher. Here extra fines are removed and the granular subbase material produced. A grade trimmer trims the subgrade to the proper elevation. The granular subbase material is placed directly on the trimmed subgrade and leveled with a dozer or loader. At the end of this "train," a water truck was used to control dust and pre-wet the aggregate for compaction using conventional methods. The road is then ready for paving.

In addition to saving the cost of hauling materials, the Paradigm system also improves safety and reduces congestion and pollution by eliminating truck traffic on the road under repair or other routes.

John G. Everett is Assistant Professor of Civil and Environmental Engineering at the University of Michigan.