NRRA: Design and Performance of Unbonded Concrete Overlays on Concrete Pavement - A Synthesis Status: CompleteReport Date: 10/15/2020 Summary: Due to increased traffic congestion and reduced budgets, National Road Research Alliance (NRRA) states are seeking effective rehabilitation techniques for older concrete pavements. Unbonded concrete overlays have a successful history as a rehabilitation option, and there is interest by NRRA member states to assemble information on best practices for the design, construction, and maintenance that relate to field performance. The goal of this project is to produce a brief technical document synthesizing the design, construction, maintenance, best practices, and performance observations of unbonded concrete overlays in NRRA member states. Final Deliverables: NRRA: Design and Performance of Unbonded Concrete Overlays on Concrete Pavement - A Synthesis (Synthesis #NRRA202006) Related Materials: Related Research: