Abstract
This paper describes a nationwide pavement survey and evaluationof 14 unbonded concrete overlays. A comprehensive distress survey was performed, past traffic equivalent single-axle loads were estimated, and design, subgrade, and climatic data were obtained. The data were evaluated, and the results are summarized. Overall, unbonded overlays have performed quite well with little deterioration to date. Specific conclusions are presented to aid in the future design of unbonded overlays. This paper appears in transportation research record no. 1227, Rigid and flexible pavement design and analysis: unboundgranular materials, tire pressures, backcalculation, and design methods.