Shear and Flexural Capacity of Four 50-Year-Old Post-Tensioned Concrete Bridge Girders

• Main Author: Lo, Wing Hong Louis
• Format: Others
• Published: DigitalCommons@USU 2014
• Subjects: Shear; Flexural Capacity; Post-Tensioned; Concret Bridge Girders; Civil and Environmental Engineering
• Online Access: https://digitalcommons.usu.edu/etd/3553; https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=4576&context=etd

During the fall of 2012, two separate Interstate 15 highway bridges over the 400 South roadway in Orem, Utah were demolished after 50 years of service. Four post-tensioned girders were salvaged from both the north-bound and south-bound bridge. A series of tests was performed with these girders in the System Material And Structural Health Laboratory (SMASH Lab). The girders were tested with different loading criteria to determine the strength and material properties of the girder. The experimental results were compared with the American Association of State Highway and Transportation Officials Load Resistance Factored Design (AASHTO LRFD) Bridge Design Specifications and a finite-element model using ANSYS. The AASHTO LRFD Specification was fairly conservative on predicting capacity and capable of predicting the type of failure that occurred. The ANSYS model was developed and calibrated to model the girder behavior. The concrete properties in the model were significantly adjusted in order to be comparable to the experimental results. Further exploration in ANSYS needs to be done to precisely model the actual behavior of the girder.