CEE’s Simos Gerasimidis and Chengbo Ai Obtain NSF Award to Support Pioneering Method for Repairing Bridge Corrosion

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Members of the UMass Amherst and MIT Department of Mechanical Engineering research team with the 3D printed patch

Across the United States, tens of thousands of steel bridges are in deteriorating condition, primarily due to corrosion-related damage and leading to increased maintenance costs and reduced safety. In answer to this mushrooming problem, Associate Professors Simos Gerasimidis (principal investigator or PI) and Chengbo Ai (co-PI) of the UMass Amherst Civil and Environmental Engineering (CEE) Department have received a three-year, $352,752 award from the National Science Foundation (NSF) to support their groundbreaking research on “cold spray metal additive manufacturing” as a method to restore corroded steel bridges directly on-site. 

According to Gerasimidis, the cold-spray technique involves heating up steel particles in a powder form, thus accelerating their velocity, then applying the particles to the bridge surface. The speed involved allows the particles to bond with the steel surface, and the metal powder is then sprayed on in layers, building up thickness and repairing corrosion. 

Unlike traditional repair techniques that require extensive welding, cutting, or complete replacement, cold spray offers the ability to apply new metal onto corroded areas without melting, allowing for localized repairs with minimal surface preparation. 

Professor John Hart, head of the Department of Mechanical Engineering at the Massachusetts Institute of Technology (MIT) and the PI at MIT, is among the additional collaborators on this NSF project because of his sophisticated expertise in metals. UMass Amherst is the lead institution for this NSF project, whose total funding is $716,000 (UMass portion is $352,752).

With support from the Massachusetts Department of Transportation, the Massachusetts Technology Collaborative, the U.S. Department of Transportation, and the Federal Highway Administration, Gerasimidis and Ai have recently partnered with Hart’s group at MIT to explore different techniques for restoring steel structures. They found the cold-spray technique to be optimal for bridge repairs. 

As the research team says about its new NSF project, “Through full-scale testing on real corroded bridge beams, the research will evaluate whether this technique can restore the mechanical properties of damaged steel members to levels suitable for structural use. The approach could minimize waste and lead contamination while enabling targeted repairs using portable, field-deployable equipment.” 

By integrating advanced scanning, quality control, and durability analysis, the trailblazing study intends to support a safer and longer-lasting bridge infrastructure. 

According to the research team, key objectives include: achieving deposition with mechanical properties comparable to structural-grade steel; validating portable cold-spray equipment on full-scale, naturally corroded bridge beams; and integrating lead removal, waste-capture systems, and a novel durability life analysis into the repair process. 

The researchers stress that “Repaired bridge beams will undergo full-scale mechanical testing to validate restoration of load-carrying capacity.” 

As the research team summarizes its NSF project, “Outcomes look to include validated protocols for field application of cold spray in infrastructure repair, new modeling frameworks for corrosion mitigation, and contributions to the fundamental understanding of solid-state, additive-repair systems for civil infrastructure.”

In general, the Gerasimidis Research Group (Personal Academic Webpage) studies numerical, analytical, and experimental methods to describe the stability of structural systems across scales. The Ai Lab (Personal Academic Website) seeks to establish a comprehensive, spatially enabled transportation infrastructure and asset-data platform to better manage, support, and sustain the current and future transportation infrastructure. (September 2025)