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Innovating ways to strengthen infrastructure

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Category: research Video duration: Innovating ways to strengthen infrastructure
Faculty and students in the department of civil and environmental engineering are working together in the Thomas M. Murray Structures Lab to test the strength of reinforced concrete diaphragms. The goal is to come up with design guidance for the use of these reinforcements on structures around the world.
One of the major problems that we have as a society is our built environment as aging. And obviously we don't want to demolish and rebuild all of our existing infrastructure. We'd rather come up with innovative ways to strengthen them and bring them back up to an acceptable level of performance. And so what we're doing here today is we're testing reinforced concrete diaphragms. Specifically looking at retrofit techniques to strengthen them in shear. Engineers are using fiber reinforced polymer retrofits on slabs such as the ones we're testing to bring their shear capacity up to where it needs to be. Unfortunately, though there's no tests to demonstrate the performance of the retrofits that they're using. The project that we're looking at is to come up with design guidance for practitioners to be able to confidently used fiber reinforced polymer strengthening on diaphragms. A building is extremely large, obviously, even though we have a big structures lab, we can't test a full-size building. So what we've done is we've extracted a critical piece of a slab. The idea is much like an earthquake. We're going to load that slab back-and-forth in reverse cyclic loading, subjecting it to progressively larger and larger displacements or larger loads until it fails. And in doing so, in testing it up until failure will be able to understand what kinds of cracks, how big are the cracks going to be in the diaphragm? How does the steel perform in the existing slab, how does the FRP perform? And then ultimately we'll understand how the FRP fails. [Sheet one on this side is de-bonded maybe a fifth of the way and the anchor is holding] working here gives you a lot of hands-on experience. You're sitting in your office and you're designing something, but then you got to come out here and build it. So I think that's the biggest takeaway for me. As engineers, we don't tend to think about how this is gonna get built. It's more are the calcs going to work and can I draw it on CAD? You never thinking about the guy in the field building it. If I was a prospective student in the Department of Civil and Environmental Engineering at Virginia Tech, I would consider that our faculty are solving real-world problems. We are at the forefront of Civil and Environmental Engineering Science and our students are leading that charge through collaborations of faculty and students working together along with their sponsors and various partners and industry and government. We are addressing some of the biggest challenges at the intersection of the built and natural environment.