Longitudinal joint details with tight bend diameter U-bars

This paper focuses on the investigation of longitudinal joint details with tight bend diameter U-bars for accelerated bridge construction. It presents the test results of potential alternate reinforcing materials and joint details in two phases. Headed bar and U-bar specimens made of stainless steel (SS) and deformed wire reinforcement (DWR) with the same joint detail confgurations were tested and compared in Phase I, followed by the testing of U-bars (DWR) with varied concrete strengths, bar spacings, and overlap lengths in Phase II. Test results were evaluated based on moment capacity, cracking at service and failure load, and steel strains. It was found that a 16 mm (No. 5) U-bar detail with a minimum bend diameter of three times the diameter of the bar can be used to facilitate accelerated bridge construction.