Researchers from the US-based University of Massachusetts Amherst (UMass), in collaboration with the Massachusetts Institute of Technology (MIT) Department of Mechanical Engineering, have applied cold spray to repair the deteriorating “Brown Bridge” in Great Barrington, built in 1949. The project marks the first known use of this method on bridge infrastructure and aims to evaluate its effectiveness as a faster, more cost-effective, and less disruptive alternative to conventional repair techniques.
“Now that we’ve completed this proof-of-concept repair, we see a clear path to a solution that is much faster, less costly, easier, and less invasive,” said Simos Gerasimidis, associate professor of civil and environmental engineering at the University of Massachusetts Amherst. “To our knowledge, this is a first. Of course, there is some R&D that needs to be developed, but this is a huge milestone to that,” he added.
The pilot project is also a collaboration with the Massachusetts Department of Transportation (MassDOT), the Massachusetts Technology Collaborative (MassTech), the U.S. Department of Transportation, and the Federal Highway Administration. It was supported by the Massachusetts Manufacturing Innovation Initiative, which provided essential equipment for the demonstration.
Tackling America’s Bridge Crisis with Cold Spray Technology
Nearly half of the bridges across the United States are in “fair” condition, while 6.8% are classified as “poor,” according to the 2025 Report Card for America’s Infrastructure. In Massachusetts, about 9% of the state’s 5,295 bridges are considered structurally deficient. The costs of restoring this infrastructure are projected to exceed $190 billion—well beyond current funding levels.
The cold spray method consists of propelling metal powder particles at high velocity onto the beam’s surface. Successive applications build up additional layers, helping restore its thickness and structural integrity. This method has successfully been used to repair large structures such as submarines, airplanes, and ships, but this marks the first instance of its application to a bridge.
One of cold spray’s key advantages is its ability to be deployed with minimal traffic disruption. “Every time you do repairs on a bridge you have to block traffic, you have to make traffic controls for substantial amounts of time,” explained Gerasimidis. “This will allow us to [apply the technique] on this actual bridge while cars are going [across].”
To enhance precision, the research team integrated 3D LiDAR scanning technology into the process. Unlike visual inspections, which can be subjective and time-consuming, LiDAR creates high-resolution digital models that pinpoint areas of corrosion. This allows teams to develop targeted repair plans and deposit materials only where needed—reducing waste and potentially extending a bridge’s lifespan.
Next steps: Testing Cold-Sprayed Repairs
The bridge is scheduled for demolition in the coming years. When that happens, researchers will retrieve the repaired sections for further analysis. They plan to assess the durability, corrosion resistance, and mechanical performance of the cold-sprayed steel in real-world conditions, comparing it to results from laboratory tests.
“This is a tremendous collaboration where cutting-edge technology is brought to address a critical need for infrastructure in the commonwealth and across the United States,” said John Hart, Class of 1922 Professor in the Department of Mechanical Engineering at MIT. “I think we’re just at the beginning of a digital transformation of bridge inspection, repair and maintenance, among many other important use cases.”
3D Printing for Infrastructure Repairs
Beyond cold spray techniques, other innovative 3D printing methods are emerging to address construction repair challenges. For example, researchers at University College London (UCL) have developed an asphalt 3D printer specifically designed to repair road cracks and potholes. “The material properties of 3D printed asphalt are tunable, and combined with the flexibility and efficiency of the printing platform, this technique offers a compelling new design approach to the maintenance of infrastructure,” the UCL team explained.
Similarly, in 2018, Cintec, a Wales-based international structural engineering firm, contributed to restoring the historic Government building known as the Red House in the Republic of Trinidad and Tobago. This project, managed by Cintec’s North American branch, marked the first use of additive manufacturing within sacrificial structures. It also featured the installation of what are claimed to be the longest reinforcement anchors ever inserted into a structure—measuring an impressive 36.52 meters.
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Featured image shows members of the UMass Amherst and MIT Department of Mechanical Engineering research team, led by Simos Gerasimidis (left, standing). Photo via UMass Amherst.
