Rehabilitation of Longitudinal Joints in Double-Tee Girder Bridges

Abstract

Precast prestressed double-tee girder bridges are common on county bridges in South Dakota. However, the longitudinal joints of these bridges are rapidly deteriorating, causing girder replacement after only 45 years of service. The present study was conducted to develop, construct, and evaluate rehabilitation methods for the longitudinal joint of double-tee bridges. Twenty joint rehabilitation detailing alternatives are proposed and ranked in the present study. Thirteen large-scale beams were tested to investigate the performance of the best four rehabilitation details. Ultrahigh-performance concrete (UHPC) and latex modified concrete (LMC) were selected as the filler materials. Subsequently, two joint concepts, “pocket” and “continuous,” were developed based on the experimental and analytical studies. A full-scale 12.19-m (40-ft) long double-tee girder bridge was constructed using conventional longitudinal joint detailing and was tested under fatigue loads. Subsequently, the bridge was rehabilitated using the two proposed details and was tested under fatigue and strength loading. No significant damage, beyond initial shrinkage cracks in LMC, was observed throughout the fatigue testing. Furthermore, the stiffness of the bridge did not degrade. No significant damage or yielding of the reinforcement in the rehabilitated joints was observed throughout the strength testing. Overall, the rehabilitated bridge met all current code requirements indicating sufficient structural performance. The rehabilitation cost of a double-tee bridge with pocket detailing is expected to be less than 30% of the bridge superstructure replacement cost.