Full-Scale Testing of Shear Key Details for Precast Concrete Box-Beam Bridges

Box-beam bridge shear key connection designs are investigated by conducting full-scale structural tests. The authors’ evaluation included connection details, which are considered current good practice using high-strength nonshrink grout in combination with transverse posttensioning and novel details using ultra-high-performance concrete (UHPC). The factors that affect shear key performance, including simulated traffic loading, thermal loads, level of transverse posttensioning, and different connection designs, are presented in this paper. A simplified model for calculating the transverse shear is proposed, and the possible transverse tensile force caused by eccentrically placed loads is discussed. The performances of different connection details are presented and compared. The findings of the research can be used to assist bridge owners in the use of this economical bridge type and can provide innovative solutions that advance state-of-the-practice in bridge construction.