Having adequate reliable infrastructures, including bridges, has been crucial to the process of economic and social development of any country. Bridges are exposed to man-made and natural hazards such as earthquakes, floods, and impact loads. Vehicles and vessels may impact bridge columns, piers, and girders causing severe damage and yielding losses of human lives and economy. Based on bridge failure incidents occurred between 1967 and 2006, vessel and vehicles impacts are the second highest cause of bridge failure in the U.S. Failure occurred due to damage to bridge girders and columns. This project focuses on the behavior and repair of bridge girders subjected to over-height truck impacts.

Vehicle impact is one of the major causes for bridge collapse in the U.S. The overarching goal of this project is to assess the damage to and repair of bridge girders due to the over-height truck impact using comprehensive experimental testing and analytical models. In particular, this project aims to determine: • The remaining carrying capacity of bridge girders damaged due to over-height truck impact which will allow stakeholders (e.g., DOT engineers) to prioritize girders needing repairs. • Determine the carrying capacity of the damaged girders after being repaired using different repair measures. The repaired beams will be investigated under static and fatigue loads to determine their capacities.

This project will include the following eleven main tasks: 1. Conduct an extensive literature review on bridge girders subjected to over-height truck impacts (OHTI), including the current carrying-capacity assessment of damaged girders and repair procedures. 2. Carry out experimental testing of approximately fourteen 50 ft long full-scale prestressed bridge girders subjected to OHTI. The girders will be subjected to different impact speeds and/or weights. The final spans and cross-sections will be determined considering the inputs from the participating DOTs to include the most common bridge girders in the participant states. The impact will be designed to cause the following damage in the investigated girders: • Severe damage to the bottom flanges associated with rupture of different numbers of the prestressing tendons at the mid-spans of the girders. • Severe damage of the girder and rupture of different numbers of the prestressing tendons near the shear-critical sections. 3. Four of the impact-tested girders will be experimentally tested to determine their residual load carrying capacities under static load. The remaining ten girders will be reserved to be repaired using the different repair options. 4. Develop high-fidelity finite element models to determine the extent of damage and predict the remaining load-carrying capacity of the damaged girders. The models will be calibrated versus experimental testing. The models will be used to determine the most influential parameters on the response of the girders. 5. Conduct an extensive literature review and survey of the different repair options used by the different DOTs for girders subjected to OHTI. The review and survey will conclude with a summary of the standard details and best practice for the repair of damaged girders. 6. Repair ten of the impact-tested girders using alternative repair options, including those currently in use by the participant DOTs such as carbon fiber reinforced polymer as well as other solutions including re-prestressing the cables. The final details of the repair will be submitted to the participant DOTs for their approval before executing them to ensure their practicality. 7. Testing eight of the repaired girders to determine their load carrying capacities under static loads. 8. The remaining two repaired girders will be used to determine their load carrying capacities under fatigue loads. 9. Different material characterization and bond testing will be carried out while optimizing the repair. This task will be finalized based on the selected repair options. For example, for the CFRP repair option, pullout tests using ASTM D7522 will be carried out. 10. Develop high-fidelity finite element models to predict the performance of the repaired girders. The models will be calibrated versus experimental testing. The models will be used to optimize the different repair options. 11. Propose standard detailing and design provisions for the proposed repair technique.

The Missouri Department of Transportation (MoDOT) is seeking a minimum of five (5) partner states to commit funds in the amount of $45,000 per year for 3 years. The total funding amount per partner is $135,000. MoDOT will be the lead agency.