Sponsor: Texas Department of Transportation

PI: Oguzhan Bayrak
Co-PI: Trevor Hrynyk

This project is examining the use of 0.7-inch prestressing strand for construction of prestressed concrete bridge girders. While future implementation of 0.7-inch prestressing strand may reduce fabrication costs and extend the working range of pretensioned concrete beams, the limits of the technology have yet to be defined. An innovative combination of analytical and experimental methods will be used to resolve the primary technical challenges to the fabrication of safe, serviceable TX girders with 0.7-inch strand.

End Region Serviceability - Effective doubling of the stress imposed by each strand within a standard (2-inch by 2-inch) grid is expected to have a dramatic effect on the performance of current end region details. Practical modifications to the prestressing and end region reinforcement schemes will be experimentally evaluated and refined to obtain serviceable behavior.
Ultimate Shear Strength - The unique end region stresses imposed by 0.7-inch strand may influence the failure mode and ultimate strength of shear-dominated TX girders. Full-scale shear tests will be completed to identify the controlling shear failure mechanisms and assess the conservatism of the corresponding shear capacities estimated through application of the AASHTO LRFD shear design provisions.

Implementation of 0.7-inch strand through application of the research findings will be greatly facilitated by continuous TxDOT and industry stakeholder involvement throughout the course of the project.