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Hail Resistance of Roofing Products
Sidney H. Greenfeld
出版Building Research Division, U.S. Institute for Applied Technology, 1969
URLhttp://books.google.com.hk/books?id=a4gFAAAAMAAJ&hl=&source=gbs_api
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註釋A test was developed for evaluating the hail resistance of roofings, in which synthetic hailstones (ice spheres) of various sizes were shot at roof assemblies at their free-fall terminal v * elocities.Indentations, granule loss and roofing fracture were observed.The principal conclusion is that:All roofing materials have some resistance to hail damage, but as the size of the hail increases, a level of impact energy is reached at which damage occurs.This level lies in the range of 1 1/2 to 2 inch (3.8-5.1 cm) hailstones for most prepared roofings.(Author).