Forensic Testing of Post Tensioned Concrete Girders.

摘要

Recently, two separate Interstate 15 highway bridges over the 400 South roadway in Orem, Utah were demolishednafter 50 years of service. A total of four post-tensioned girders were salvaged from both the north-bound andnsouth-bound bridge. A series of tests was performed with these girders in the System Material And StructuralnHealth Laboratory (SMASH Lab). The girders were tested with different loading criteria to determine thenstrength and material properties of the girder. The experimental results were compared with the AmericannAssociation of State Highway and Transportation Officials Load Resistance Factored Design (AASHTO LRFD)nBridge Design Speci#12;cations and a #12;nite-element model using ANSYS. The AASHTO LRFD Specification wasnfairly conservative on predicting capacity and capable of predicting the type of failure that occurred. The ANSYSnmodel was developed and calibrated to model the girder behavior. The concrete properties in the model werensignificantly adjusted in order to be comparable to the experimental results. Further exploration in ANSYS needsnto be done to precisely model the actual behavior of the girder.