Engineers use space age coating to protect forces. (Security Beat).In response to global terrorist threats to U.S. forces, engineers from the materials and manufacturing directorate at the Air Force Research Laboratory have developed a method for providing crucial protection: a polyurethane, elastomer elastomer (ĭlăs`təmər), substance having to some extent the elastic properties of natural rubber. The term is sometimes used technically to distinguish synthetic rubbers and rubberlike plastics from natural rubber. coating suitable to strengthen concrete block walls, reinforced concrete reinforced concrete Concrete in which steel is embedded in such a manner that the two materials act together in resisting forces. The reinforcing steel—rods, bars, or mesh—absorbs the tensile, shear, and sometimes the compressive stresses in a concrete and lightweight, manufactured structures, such as trailers. The Defense Department has faced the threat of terrorist bombings for a long tim. During the last 15 years, 80 percent of the department's total casualties have resulted from terrorist activity, said Al Nease, chief of the force protection branch at Tyndall Air Force Base Tyndall Air Force Base is a base of the United States Air Force in Bay County, Florida, United States. The population was 2,757 at the 2000 census. The base is operated by the 325th Fighter Wing. in Florida. "In the past, Air Force engineers thought hardened structures were the best protection against the damaging and deadly effects of an explosion," said Nease. "Historically, the mindset mind·set or mind-set n. 1. A fixed mental attitude or disposition that predetermines a person's responses to and interpretations of situations. 2. An inclination or a habit. of civil engineers has been to make buildings stronger so they can withstand a blast," said Jon Porter Jonathan Christopher "Jon" Porter (born May 16 1955), an American politician, has been a Republican member of the United States House of Representatives since 2003, the first representative elected from the new 3rd Congressional district of Nevada, which includes much of suburban , branch senior research engineer. However, "all that's changing today," he said. Engineers have recently developed methods to retrofit ret·ro·fit v. ret·ro·fit·ted or ret·ro·fit, ret·ro·fit·ting, ret·ro·fits v.tr. 1. To provide (a jet, automobile, computer, or factory, for example) with parts, devices, or equipment not in existing, conventionally-built structures with spray-on, elastomeric coatings to provide protection from explosions, Porter explained. Using strong, stiff composite materials composite material or composite, any material made from at least two discrete substances, such as concrete. Many materials are produced as composites, such as the fiberglass-reinforced plastics used for automobile bodies and boat hulls, but the , the engineers began retrofitting existing structures, but soon discovered they were too stiff and brittle under dynamic loads. Engineers investigated a spray-on elastomer without the reinforcement provided by high-strength fabrics. After completing full-scale, explosive testing on concrete block wall and lightweight trailers at Tyndall's test range and in overseas locations, Porter said tests revealed the elastomeric retrofit was capable of providing adequate protection without any fiber reinforcement. During tensile tests, researchers discovered that elastomeric samples expanded to twice their original length before rupturing. This characteristic allows a retrofitted wall to flex and keeps blast fragments and pieces of a wall from harming personnel inside a structure. "Our primary concern was that the structure hold up well enough for people to get out safely following an explosion," Porter said. "The elastomer retrofit will do that." |
|
||||||||||||||||||||
Printer friendly
Cite/link
Email
Feedback
Reader Opinion