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Emergency Repair of a Bridge Girder Using SMARTUP UHPC

When an equipment failure during formwork installation caused significant damage to a bridge girder in Mississippi, an expedited repair was crucial to keep the construction schedule on track. Discover how Smart-Up's Ultra-High Performance Concrete (UHPC) provided the perfect solution, restoring the girder to better-than-new condition in just eight days. Read our case study to see how this innovative material tackled an unexpected challenge and ensured the project's success.
Smart-Up UHPC easily clears 10,000 psi compressive strength within 24 hours of placement, allowing the contractor to remove repair formwork and resume regular activity the next day.

Late one Monday morning in March 2024, the Smart-Up team received an urgent email requesting an emergency repair to a bridge girder in south-central Mississippi. The Mississippi Department of Transportation (MDOT) project included four single-span bridges, each constructed with four precast/prestressed I-girders and a cast-in-place concrete deck. During the formwork installation for the deck on the first bridge, an equipment failure caused significant damage to the top flange of an exterior girder. This unexpected incident required an expedited repair to keep the construction schedule on track.

Challenge

The contractor faced the challenge of repairing the damaged girder quickly and efficiently. The solution needed to be fast-acting, durable, and compatible with the existing structure. The goal was to find a material that could rapidly reach high strength, fit the irregular damage shape, and ensure long-term structural integrity.

Solution

MDOT turned to Smart-Up's Ultra-High Performance Concrete (UHPC) for several compelling reasons:

  • Accelerated Timeline: Smart-Up UHPC reaches a compressive strength of 10,000 psi within 24 hours, enabling the contractor to remove repair formwork and resume work the next day.
  • Constructability: The highly flowable UHPC could conform to the irregular damage shape, ensuring complete void filling while maneuvering around embedded steel bars.
  • Long-Term Durability: UHPC bonds exceptionally well with the original concrete, eliminating the risk of future delamination and restoring the girder to a better-than-new condition.

Implementation

Over the next few days, Smart-Up collaborated closely with MDOT, the precaster, and the contractor to orchestrate the repair. The Smart-Up team:

  • Provided engineering advice on the repair design.
  • Created a jobsite checklist of necessary equipment.
  • Secured materials and mixers from their inventory.
  • Updated the mix design to address job-specific concerns.
  • Scheduled the repair for the following week.

However, unexpected poor weather conditions in Mississippi threatened to delay the repair timeline. Demonstrating flexibility and commitment, the Smart-Up team adjusted their plans to deliver materials and equipment a day earlier than initially scheduled.

Execution

On the scheduled day, the contractor had prepped the rebar and formwork for the UHPC. Using a Mortarman 750 planetary-style mixer, three batches were mixed to fill the repair volume of approximately a quarter cubic yard. Fresh UHPC was transported roughly 50 feet from the mixer to the placement site using five-gallon buckets, due to jobsite constraints.

The entire onsite process, including setup, mixing, casting, cleanup, and breakdown of the UHPC mobile operation, was completed in just four hours in one morning. Remarkably, the overall girder repair—from planning to execution—took only eight days, allowing the contractor to promptly return to their schedule.

Conclusion

This case study illustrates how Smart-Up's UHPC provided a swift, reliable, and durable solution for the emergency repair of a bridge girder. The project showcased the advantages of UHPC in bridge rehabilitation, demonstrating its potential for both planned maintenance and emergency repairs. Smart-Up UHPC proved to be an invaluable asset, ensuring the bridge's structural integrity and the contractor's adherence to their construction timeline.

Acknowledgement

Special thanks to Mr. David Tomley, PE Chief Engineer- Gulf Coast Precast specified UHPC for the repair as well as the process of the repair. Thank you David for your confidence in UHPC.