MT. VERNON, IOWA - The Tilt-Up Concrete Association (TCA) - a non-profit international organization that serves to expand and improve the use of site-cast Tilt-Up as the preferred construction method - has announced the availability of a video discussing the findings from research with the Air Force Research Laboratory (AFRL). In conjunction with the Portland Cement Association (PCA), the wall tests series define the resistance and failure mode of standard Tilt-Up concrete insulated sandwich walls subjected to Department of Defense (DoD) compliant forces.
"The video was commissioned to show evidence of the testing and to discuss the benefits that will come from the research," said Jim Baty, technical director of the TCA. "The goal of this program is to lead to new design documentation and engineering level predictive tools for blast resistant sandwich concrete walls meeting both protection and energy performance regulations."
For these tests, the Air Force Research Lab (AFRL) provided oversight. The program was funded through a federal grant. Phase I involved the construction of full-thickness test strips for panels that were to undergo blast testing. The strips were constructed at the University of Missouri in Columbia, Mo. at their remote test facility. Phase II involved the construction of full-scale test panels to be placed in test frames and exposed to a variety of explosive charges. These tests were performed this summer and fall at the blast testing range located at Tyndall Air Force Base near Panama City, Fla.
"The Air Force is rewriting criteria for blast resistance," said Michael Hammons, Ph.D., P.E. "Data from this program will factor in heavily. We will be able to establish new limit states for construction and extreme events."
"The goal of the research program is to both evaluate the performance of standard insulated concrete sandwich walls against blast demands and develop models to more accurately predict the response," said Clay Naito, Ph.D., P.E. and Associate Professor in the Department of Civil and Environmental Engineering at Lehigh University as well TCA task leader for the AFRL research project.
According to Naito, the tests studied several types of conventional concrete wall construction used in the U.S. "In the past, different panels had been studied statically," said Naito. "This testing studied walls panels in dynamic loads to look at the performance of panels under blast loads, particularly threats such as car bombs and anti-terrorism force protection type applications."
"The use of design-build in the military arena is an avenue Tilt-Up contractors are very versed in," said Mike Sugrue, Principal at LJB, Inc. "This opens Tilt-Up to a whole new arena to be considered as a viable method for extreme blast resistance. Based on these tests, Tilt-Up has a great future."