In an attempt to find new, cost effective pavement rehabilitation techniques Mn/DOT has constructed ten unbonded concrete overlays since 1977. The design and construction of each successive project built on the experiences gained from the previous project. Unbonded concrete overlays have now developed to the point where Mn/DOT feels it is appropriate to review these past experiences and develop policy on further construction of these projects. Sufficient time has also elapsed to evaluate the long term performance of specific projects and unbonded overlays in general.
