The problem of corrosion in precast concrete is often attributed to the steel rebar reinforcement; steel being a corrodible material, it is especially vulnerable during the curing and drying process, when it is locked into an environment that is very wet. AltusGroup, a national organization composed of 13 precast companies, and Chomarat, a producer of carbon fiber grids, answered by replacing the steel rebar in concrete with a carbon fiber grid. The grid is thinner and lighter than the steel, and it requires less concrete to cover it. The result: thinner, lighter panels (up to 75 percent lighter architectural wall panels) and increased insulation, because the carbon fiber doesn't conduct heat or cold. This new material already has been used in architectural and insulated sandwich wall panels.
The jury wished that the submission had included more information on testing done during the product-development process, as well as on the lifecycle benefits. Ultimately, they decided to cite the product because of its potential for revolutionizing the use of concrete, one of the most ubiquitous materials in construction today.
“From an engineering standpoint, a structural standpoint,” said Blaine Brownell, “the fact that you can use less material makes it part of the trajectory of doing more with less, which has an environmental aspect to it as well as a trend of hybridization—of using different types of materials to make a sum that's greater than the parts.” The jury also appreciated the product's simplicity. “I found it pretty interesting as a new technology, and one which might be really very helpful,” said Andres Lepik. “Somebody had a very simple, basic, and strong idea.”
PRODUCT Carbon Fiber Grid Reinforced Precast Concrete
MANUFACTURER AltusGroup and Chomarat
PATENT HOLDERS Kenneth Baur, John Carson, Harry Gleich, Gary C. Graziano, Thomas G. Harmon, Harold G. Messenger