BOZEMAN — An exceptionally strong and durable concrete developed at Montana State University is slated to be used for the first time, paving the way for potential widespread future application in Montana.
Developed over the past five years in collaboration with Montana Department of Transportation, the ultra-high performance concrete will form parts of two replacement bridges scheduled for installation this summer on Highway 43 near the southwest Montana town of Wisdom.
Due to a specialized mixture that includes conventional concrete materials in addition to steel fibers, fly ash — a byproduct of coal-fired power plants — and chemicals that reduce the amount of added water, the material is roughly five times stronger than normal concrete, according to Mike Berry, associate professor in the Department of Civil Engineering in MSU's Norm Asbjornson College of Engineering. It also cures rapidly, potentially reducing construction time, and resists corrosion, which will extend the lifetime of the structure, he said.
"It's like normal concrete on steroids," said Berry, who is leading the MSU research project. "If we could make all our bridges out of this stuff, it would be magnificent."
The concrete is not new, Berry added, but until now its use has been limited due to high costs charged by companies that treat the mixture as proprietary, meaning only they can install it. The concrete developed at MSU uses the same principles but is non-proprietary and is designed to use locally available materials to further reduce costs.
According to Lenci Kappes, innovations and complex structures engineer in MDT's bridge bureau, the MSU project could potentially cut the cost of the material in half. That would mean significant savings for the state not only with construction costs but also with reduced long-term maintenance due to the material's durability.
"This is really moving Montana forward," Kappes said. "It has been great to work closely with MSU so that we have confidence with going ahead with this project."
The future cost savings are anticipated as MDT and contractors become more familiar with procuring, mixing, and installing the material with MSU's support, according to Kappes. Berry, along with Kirsten Matteson, assistant professor of civil engineering, and several MSU graduate students, will be on hand at the Wisdom construction site to advise the contractor with mixing and installing the concrete. The MSU team is also conducting practice runs with the contractor, Dick Anderson Construction, before construction begins. Contractors who gain experience with the material will be able to mix and use it independently on future projects.
"With any new material there's a lot of research and training that needs to happen before people are comfortable with it," said Matteson, who specializes in novel construction materials. She will be leading the next phase of the project, which will explore an even wider range of applications for the ultra-high performance concrete, such as layering the material on bridge decks to extend their service life. The MSU team, working with Kappes, will also monitor the Highway 43 bridges for a year after construction to ensure the material is performing as intended.
The MSU collaboration with MDT is part of a federal initiative to encourage states to adopt ultra-high performance concrete, according to Berry. Montana isn't alone in its efforts, but "you can count on one hand the number of states that have actually developed and used this material, so we're kind of unique in that way."
According to Kappes, Montana has lots of bridges in need of replacement or repair, so the money-saving MSU mixture is a particularly relevant material coming at an opportune time. "This is really a learning experience," he said. "We're excited to take what we learn and apply it around the state."
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