ACI 325.13R-06

This report provides information on the use of concrete overlays for rehabilitation of both concrete (rigid) and asphalt (flexible) pavements.Selection, design, and construction of both bonded and unbonded overlaysare discussed. The overlay categories reviewed include bonded concrete overlays, unbonded concrete overlays, whitetopping overlays, and concrete overlays bonded to asphalt (ultra-thin and thin whitetopping). Information is also provided on selecting overlay alternatives. Significant portions of this document are based on a synthesis report prepared for the Federal Highway Administration (FHWA) by Applied Pavement Technology, Inc., under contract number DTFH61-00-P-00507. The report, "PortlandCement Concrete Overlays: State of the Technology Synthesis," is availablefrom the FHWA as publication FHWA-IF-02-045.