Rational Use of Terminal Anchorages in Portland Cement Concrete Pavement

摘要

Portland cement concrete (PCC) pavements have long been thought to expand and push bridgestructures, resulting in bridge damage. To protect bridge structures from the expansion of PCCpavements, three terminal systems are currently used in Texas: anchor lug (AL), wide-flange(WF), and expansion joint (EJ) systems. Even though the Texas Department of Transportation(TxDOT) uses all three systems in continuously reinforced concrete pavement (CRCP), theeffectiveness of these three systems has not been fully evaluated. This study investigated theparameters affecting the movements of CRCP near bridge terminal areas, whether thermalexpansion of CRCP is causing damage to bridge structures, and if it does, which terminal type ismost cost-effective. Extensive field evaluations revealed that slab movements at the end ofCRCP are substantially restrained by subbase friction. Slab length from the end of CRCP thatsignificantly contributes to the slab movements is limited to about 200 ft. (60.96 m) for theCRCP system with asphalt base typically used. Seasonal slab movement rates due to temperaturevariations are larger than daily slab movement rates. The movement at the end of CRCP can beaccommodated by a simple EJ with subbase friction that can be achieved with typical asphaltstabilized base. The use of an AL system is not needed to restrain concrete slab movements. Thebenefits of WF and AL systems are doubtful considering the higher cost of those systemscompared with the simpler EJ system.