MIT and UMass Amherst test Cold Spray Additive Manufacturing for bridge repair
June 19, 2025
The University of Massachusetts Amherst (UMass Amherst) has collaborated with researchers from the Massachusetts Institute of Technology (MIT) Department of Mechanical Engineering, Cambridge, to test Cold Spray Additive Manufacturing as a cost-effective, minimally disruptive solution for bridge repair. The test repair was undertaken in Great Barrington, Massachusetts, on the red bridge, formerly known as the ‘Brown Bridge’, built in 1949.
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With more than half of the US’s 623,218 bridges experiencing significant deterioration, it is hoped that the test illustrates the excellent potential of Cold Spray Additive Manufacturing in their repair.
“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, and one of the principal investigators on the project.
“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.”
The red bridge is scheduled for demolition in a few years. After that, the UMass team will take the additively manufactured beams back to their lab and test them, measuring how successfully the deposited steel powder adhered to the structure in the field compared to in a controlled lab setting, if it corroded further after it was sprayed, and determining its mechanical strength properties.
Other collaborators on the project include the Massachusetts Department of Transportation (MassDOT), the Massachusetts Technology Collaborative (MassTech), the US Department of Transportation and the Federal Highway Administration.
“Any time you drive, you go under or over a corroded bridge,” Gerasimidis said. “They are everywhere. It’s impossible to avoid, and their condition often shows significant deterioration. We know the numbers.”
Across the US, 49% of the nation’s bridges are only in ‘fair’ condition, and 6.8% are rated ‘poor,’ according to the 2025 Report Card for America’s Infrastructure. The projected cost to restore them exceeds $191 billion. Roughly 9% of Massachusetts’ 5,295 bridges are structurally deficient and require repair, a need that far outpaces available funding.
Selecting Cold Spray Additive Manufacturing
Cold Spray Additive Manufacturing as a repair technique has proven to be an effective solution for other large structures like submarines, aircraft and ships, but this is thought to be the first time it’s been applied to a bridge. Bridges present unique challenges due to their size and because the AM machine must be brought on-site.
One of the biggest advantages of the technique noted by the team is that repairs can be made with minimal disruption to traffic. “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 [make repairs] on this actual bridge while cars are going [across].”
Part of this work has been developing 3D LiDAR (Light Detection And Ranging) scanning methods to replace subjective visual assessments. This technique enables researchers to precisely identify corrosion, develop a digital repair plan and deposit the material only where necessary.
“By combining scanning with precise material deposition, we can be very targeted and say, ‘We’re going to print here and here and here and we’re going to give this bridge another ten years of life,’ which is huge,” Gerasimidis added.
Gerasimidis and his team have been studying bridge deterioration and working with Massachusetts’s and other state DOTs for about a decade. “We know this problem quite well,” he stated. “We have seen thousands of inspection reports, we have gone to bridges. We have tested many beams in our lab, so we know how these things behave and exactly where we need to repair.”
Research reports on the use of Cold Spray AM can be found here.
