Transverse Joint Details with Tight Bend Diameter U-Bars for Accelerated Bridge Construction

Abstract

This paper focuses on an investigation of transverse joint details with tight bend diameter U-bars for accelerated bridge construction. It presents the testing results of potential alternate reinforcing materials and joint details in two phases. Headed bar and U-bar [stainless steel and deformed wire reinforcement (DWR)] specimens with the same joint detail configuration were tested and compared in Phase I, followed by testing of U-bars (DWR) with varied concrete strength, bar spacing, and overlap length in Phase II. Test results were evaluated based on tension capacity, cracking at service loading and failure, and steel strain. A strut-and-tie model is proposed to predict the tension capacity of a transverse joint, which is capable of identifying the most critical parameters and yields safe and consistent predictions. Based on the experimental results, a No. 5 U-bar joint detail with no less than 152 mm (6 in.) overlap length and No. 4 lacer bars was recommended.