【国外标准】 Standard Test Method for Determining Impact Resistance of New Low Slope Roof Membranes Using Steel Balls (Z8295Z)

6.1 This test method provides a means of evaluating new roof membranes for resistance to specific impact energies. The method evaluates new roof membranes when first applied and also after simulated deterioration caused by the ultraviolet radiation and moisture.6.2 Use Class 2 for an impact resistance of 11.0 ± 0.3 J [8.1 ± 0.2 ft-lb] and Class 3 for an impact resistance of 19.4 ± 0.4 J [14.3 ± 0.3 ft-lb].1.1 This test method covers the determination of impact resistance of new low slope roof membranes when applied directly over rigid insulation or cover board, or structural concrete, lightweight insulating concrete, gypsum, cementitious wood fiber, or wood roof decks. The procedures were developed to determine the potential for puncture or fracture of the new roof membrane resulting from impacts by free-falling steel balls resulting in specific impact energies when the new roof membrane is applied over its tested substrate within an assembly.1.2 This test method is intended to verify that products as described will meet a specific stated condition of impact resistance performance. Testing of asphalt shingles is beyond the scope of this test method. The tests yield classification identified as Class 2 and Class 3.1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.