Behavior of Horizontal Shear Connections for Full-Depth Precast Concrete Bridge Decks on Prestressed I-Girders

Abstract

This article reports on a study of the horizontal shear resistance of the connection between full-depth precast concrete bridge deck panels and prestressed concrete girders. This connection consists of isolated shear connectors extending from the precast I-girder into a block-out pocket in the precast deck panel. The blockouts and the haunch between the panel and the beam are grouted. In the study, 36 push-off tests were performed to investigate the strength and behavior of the connections. The factors investigated included type of grout, haunch height, and area of reinforcing steel crossing the interface. In addition, several alternate shear connector details were tested. Results showed that there was no significant difference in peak shear stress between specimens with 1, 2, and 3 in. haunch heights. The extended stirrups must be detailed to have a minimum of 5 in. embedment into the deck panel. The alternate shear connectors in this study are viable for use with the precast panel system. Proper embedment and spacing of connectors will ensure yielding of the steel and ductile behavior of the interface. The authors conclude that, of currently known horizontal shear resistance equations, the one presented in the AASHTO LRFD Bridge Design Specifications is the best predictor of the strength of the specimens.