Non-proprietary ultra high-performance concrete mixtures for pneumatic spray applications

Aging bridges pose a significant infrastructure challenge in the United States, with over 37% requiring repair. Ultra-High-Performance Concrete (UHPC) has emerged as a promising solution for bridge rehabilitation through Accelerated Bridge Construction (ABC). UHPC's significance includes rapid strength gain, enhanced durability, and corrosion resistance. Recent advancements in UHPC mixes have enabled pneumatic spray application, expanding its versatility. Pneumatically sprayed UHPC offers an effective solution for deck overlay, repairs, and structural upgrades. Achieving the optimal balance between pumpability and shootability is essential for successful UHPC application. Procedures have been developed, including the addition of a Viscosity Modifying Agent (VMA). UHPC is applied in thin layers and can be built up by spraying additional layers. Flexural beam test specimens treated with UHPC showed increased strength. This research focuses on adapting non-proprietary UHPC to pneumatic spray application, encompassing mix design, equipment considerations, and construction techniques, and a roadmap for utilizing UHPC in the pneumatic spray application to revolutionize repair methods and modernize U.S. infrastructure, including bridges.