Horizontal Shear Connectors for Precast Prestressed Bridge Decks

The full-width, full-depth precast panel system is very convenient for rehabilitation of deteriorated decks as well as for new bridge construction. The horizontal shear strength at the interface between the two interconnected elements is of primary importance in order to provide composite action. The strength of the bond between the two precast members should be high enough to prevent any progressive slip from taking place. Flexural strength, shear strength and deflection characteristics all depend on the satisfactory performance of the interface to provide composite action. However, the case when both of the interconnected elements are precast members bonded by means of grout, is not currently addressed by ACI or AASHTO. This is the main impetus for this project.

A total of 36 push-off tests were performed to develop a method for quantifying horizontal shear strength and to recommend the best practice for the system. Test parameters included different haunch heights, different grout types, different amount and different type of shear connectors. Two equations, for uncracked and cracked concrete interfaces, are proposed to be used in horizontal shear design when the precast panels are used.

Predictive equations are compared with available methods for the horizontal shear strength of the precast panel system. Conclusions and recommendations for the optimum system are made.