According to Nassiri, the results were very surprising. When she and Englund first began the project, she was simply hoping the strength of the concrete would not decline. “And then all of a sudden our test results came out, and we were having 20 to 60 percent improvement in bending strength,” says Nassiri. “I would call that a nice, pleasant surprise.”
Currently, the permeable pavement is undergoing tests at a closed location to collect data on how the pavement performs in a real-world environment but with controlled traffic loading.
While Englund and Nassiri have received a lot of interest from various cities and agencies who want to adopt the material, they still have a long way to go before it is ready for mainstream application. One challenge is developing sufficient milling capacity for large paving projects.
“The interest is out there. We just have to produce more data and catch up,” says Englund. “One of our biggest hurdles is going to be getting the supply chain for it. And if we could build a market and build a value add for that, I think you’ll start to see people taking on that challenge pretty quickly.”
Making Military Vehicles Smarter
Project: Magnetic damage detection
School: Clemson University
Location: Clemson, S.C.
Principal Investigator: Oliver Myers, Ph.D.
In the U.S. Army, soldiers depend on regular maintenance of helicopters and tanks to ensure safety. However, in many cases, the Army replaces parts of vehicles based on how long they have been in service, whether they appear damaged or not. As a result, many Army vehicles are replaced prematurely by new ones that are destined for the same fate. For years, the Army has looked for ways to break the cycle and reduce sustainment costs. One way to accomplish that is by making it easier to determine if a vehicle has been damaged.
Last December, the U.S. Army Research Laboratory awarded $993,492 to Oliver Myers, Ph.D., an associate professor of mechanical engineering at Clemson University, to develop a solution that enables military vehicles to self-detect damage. Unlike typical sensors, which are attached externally to structures, Myers envisions sensors that can be integrated in the structure itself. He and his team are creating epoxy-based CFRP prepreg laminates embedded with Terfenol-D, a rare earth metal alloy that changes shape when exposed to a magnetic field. The technology can detect everything from impacts and cracks to abnormal mechanical loads.