1、 Test Standard for Impact Resistance Testing of Rigid Roofing Materials by Impacting with Freezer Ice Balls ANSI FM 4473 January 2011 2011 FM Approvals LLC. All rights reserved. Foreword NOTE: This foreword is introductory only and is not part of American National Standard FM 4473. This standard sta
2、tes the test requirements and procedures for the assessment of impact resistance of new rigid roofing materials. Rigid roofing materials are manufactured in a rigid configuration and remain rigid during usage. These roof materials are manufactured as tiles or planks from materials such as slate, con
3、crete or clay. Appendix A to this American National Standard is informative and is not part of the requirements of the standard. Appendixes B, C and D are test procedures and are informative for the performance of the tests and associated pass/fail criteria. This American National Standard has been
4、developed by the canvass method of standards development of the American National Standards Institute (ANSI). FM Approvals is an ANSI-accredited standards developing organization (SDO). Approval of an American National Standard requires verification by ANSI that the principles of openness and due pr
5、ocess have been followed and that a consensus of those directly and materially affected by the standard has been achieved. Consensus requires that all views and objections be considered, and that a concerted effort be made toward their resolution. Consensus is established when, in the judgment of th
6、e ANSI Board of Standards Review, substantial agreement has been reached. The American National Standards Institute does not develop standards nor will it in any circumstances give an interpretation of any American National Standard. Requests for interpretations of this test standard should be addre
7、ssed to FM Approvals. ANSI regulations require that this American National Standard shall be revised, reaffirmed or withdrawn within five years of the date of publication. FM Approvals 1151 Boston-Providence Turnpike P. O. Box 9102 Norwood, MA 02062 U. S. A. Phone: 781-762-4300 Fax: 781-762-9375 E-m
8、ail: A TABLE OF CONTENTS 1. INTRODUCTION 1 1.1 Purpose 1 1.2 Scope . 1 1.3 Basis for Requirements . 1 1.4 Applicable Documents 2 1.5 Definitions. 2 1.6 System of Units . 2 2. TEST REQUIREMENTS . 3 2.1 Classification. 3 2.2 Calibration. 3 3. TEST PROTOCOL . 3 3.1 Sample Preparation . 3 3.2 Ice Ball S
9、ample Preparation 4 3.3 Test Conditions . 4 4. PASS/FAIL CRITERIA 5 5. REPORTING 6 APPENDIX A: Units of Measurement . 7 January 2011 ANSI/FM 4473 FM Approvals 1 1. INTRODUCTION 1.1 Purpose This test standard states the test requirements and procedures for the assessment of impact resistance of new r
10、igid roofing materials. Rigid roofing materials are manufactured in a rigid configuration and remain rigid during usage. These roof materials are manufactured as tiles or planks from materials such as slate, concrete or clay. 1.2 Scope 1.2.1 This test standard provides a procedure for determining th
11、e impact resistance performance of new prepared rigid roofing materials which are intended for use mainly on, but not restricted to, Steep Slope roof systems. The test uses the impact forces of freezer ice balls propelled to develop free-fall kinetic energies of the same size hail. 1.2.1.1 Slope as
12、defined by the National Roofing Contractors Association (NRCA) is the incline of the roof expressed either in percent or in the number of vertical units of rise per horizontal unit of run. It is generally measured in inches per foot. The NRCA ranks slope as follows: Low Slope Less than 3 inches per
13、foot (3 in 12) 1.2.1.2 Ice balls are used in this test method to simulate hailstones. Hailstones are variable in properties such as shape, density and frangibility. These properties affect factors such as the duration and magnitude of the impulsive force acting on the roof and the area over which th
14、e impulse is distributed. Ice balls (with a density, frangibility, and terminal velocity near the range of hailstones) are the nearest hailstone approximation known at this time. Ice balls generally are harder and denser than hailstones; therefore, an ice ball simulates the worst case hailstone. A m
15、ajor difference between ice balls and hailstones is that hailstones are more variable than ice balls. Ice balls can be uniformly and repeatedly prepared to assure a projectile with known properties. 1.2.2 This test method defines test specimens and test panels, defines a procedure for determining im
16、pact locations on test specimens, provides kinetic energies of propelled ice balls, provides a method for impacting test specimens with ice balls, and specifies parameters that must be recorded and reported. 1.2.3 This standard is intended to verify that the product as described will meet minimum sp
17、ecific stated conditions of impact resistance performance. This performance criterion is useful in determining the potential suitability of these products under hailstorm conditions. 1.2.4 Exposure of roof coverings to the elements over an extended period of time has a potential to significantly low
18、er the hail resistance of the roof materials. This standard is intended for the testing of new rigid roof cover systems. 1.3 Basis for Requirements 1.3.1 The requirements of this test standard are based on experience, research and testing, and/or the standards of other organizations. The advice of m
19、anufacturers, users, trade associations, jurisdictions and/or loss control specialists has been considered. January 2011 ANSI/FM 4473 FM Approvals 2 1.4 Applicable Documents The following article is referenced in this standard: Hail Resistance of Roofing Products, Greenfeld, S.H., National Bureau of
20、 Standards, Building Science Series 23, Washington, D.C., August 1969. 1.5 Definitions For purposes of this test standard, the following terms apply: Molds devices for casting spherical ice balls of appropriate diameters Freezer appliance for making ice balls in the molds, controlled at -7 7F (-22 4
21、C) Balance for weighing the ice balls, weight measurement accurate within 0.0005 lbs (0.23 gr) Test Specimen the individual tile or plank to be impact-tested Test Panel the substrate for supporting the roofing material in a fashion that simulates typical application Test Assembly the completed appli
22、cation of a test specimen, consisting of multiple tiles or planks, secured on the test panel in accordance with the manufacturers specifications Launcher a device capable of propelling ice balls at speeds necessary to develop the intended kinetic energy. Aiming accuracy of the launcher must be suffi
23、cient to assure that the ice balls strike the specified impact areas; otherwise, the surrounding area must be masked for protection against inadvertent impacts Speed Meter a device for measuring ice ball speeds within 1 mph (0.45 m/s) Rigid Roofing material that lacks flexibility and cannot be bent
24、or deformed without cracking, fracturing or breaking 1.6 System of Units Units of measurement are U.S. customary units. These are followed by their arithmetic equivalents in International System (SI) units, enclosed in parentheses. Appendix A lists the selected units for qualities dealt with in test
25、ing these products; conversions to SI units are included. Conversion of U.S. customary units is in accordance with ANSI/IEEE/ASTM SI 10-97, Standard for Use of the International System of Units (SI): The Modern Metric System. January 2011 ANSI/FM 4473 FM Approvals 3 2. TEST REQUIREMENTS 2.1 Classifi
26、cation The sizes of freezer ice balls in the standard correspond to the classes shown below: Nominal Ice Ball Diameter in. (mm) Class 1 (31.8) 1 1 (38.1 ) 2 1 (44.5) 3 2 (50.8) 4 2.2 Calibration All examinations and tests performed in evaluation to this standard shall use calibrated measuring instru
27、ments traceable and certified to acceptable national standards. 3. TEST PROTOCOL 3.1 Sample Preparation 3.1.1 Test specimens are mounted on a minimum 3 3 ft (0.9 0.9 m) test panel simulating actual field applications using plywood decking having a minimum span rating 3216 typically 1532 in. (12 mm)
28、thick supported by a frame consisting of nominal 2 4 in. (50 100 mm) lumber perimeter elements and mid-span brace. The test specimen shall be applied to the test panel in accordance with the manufacturers instructions. Test specimens shall cover a minimum area of 3 3 ft (0.9 x 0.9 m) on the test pan
29、el. The sample shall be prepared in such a manner that the locations that are particularly sensitive to damage are positioned such that they can be impacted. Exception: Other test panels are permitted to be used in order to more accurately simulate actual field applications. Any deviation to the tes
30、t panel described in Section 3.1.1 shall be noted in the report and listing. 3.1.2 Condition the test samples at temperatures between 60 and 90F (15.6 and 32.2C) for the period of time sufficient to attain thermal equilibrium. When adhesives or sealants are used, the test assembly shall be permitted
31、 to be placed in an oven at temperatures between 135 and 140F (57 and 60C) for a continuous period for a maximum of 16 hours. The test assembly shall be positioned in the oven with test specimen materials on top. Test samples shall be allowed to cool to room temperature prior to testing. January 201
32、1 ANSI/FM 4473 FM Approvals 4 3.2 Ice Ball Sample Preparation Molds for casting spherical ice balls made of distilled water of 1 , 1, 1, and 2 in. (31.8, 38.1, 44.5 and 50.8 mm) diameters are placed in a freezer at a controlled temperature of -7 7F (-22 4C) until frozen solid (a minimum of 48 hours)
33、. Acceptable ice balls will be free of cracks and air bubbles and will meet the following criteria within 0 and + 10% of the values listed: Nominal ice ball diameter in. (mm) Mass lbs (gr) 1 (31.8) 0.0338 (15.3) 1 (38.1) 0.0584 (26.5) 1 (44.5) 0.0928 (42.1) 2 (50.8) 0.1385 (62.9) 3.3 Test Conditions
34、 3.3.1 Maintain temperature of the test area between 60 and 90F (15.6 and 32.2C) 3.3.2 Calibrate the speed of the ice ball launcher to meet the impact kinetic energy range shown below (between Target Kinetic Energy and Target Kinetic Energy +10%): Class Nominal ice ball in. (mm) Kinetic Energy Targe
35、t ft-lb (j) +10% ft-lb (j) 1 1 (31.8) 3.72 (5.0) 4.09 (5.5) 2 1 (38.1) 7.77 (10.4) 8.55 (11.6) 3 1 (44.5) 14.00 (19.0) 15.40 (20.9) 4 2 (50.8) 23.75 (32.2) 26.13 (35.5) Calculate the kinetic energy of the propelled ice ball using the following equation KE = (mVt 2)/64.34 Where: KE = ice ball kinetic
36、 energy, foot pound m = ice ball mass, pound Vt= ice ball free-fall speed, feet per second 3.3.3 Position the test deck on an incline of minimum 15 from vertical to allow the test specimens to seat properly against the test panel. Position the ice ball launcher and the test assembly to assure that t
37、he trajectory of the ice ball is perpendicular (90 5) to the test panel. Determine the target impact locations that are particularly sensitive to impact damage and impact the specimens at those locations. 3.3.4 Position the speed meter such that the ice ball speed will be measured between the launch
38、er and the January 2011 ANSI/FM 4473 FM Approvals 5 test specimen. The ice balls shall exit the speed meter not more than 5 ft (1.5 m) from the target impact location. Note: A shield should be fitted near the impact point for protection of the operator and the equipment. 3.3.5 The number of impact l
39、ocations shall be based on the exposed surface area of the test specimen as follows: Exposed Area of Test Specimen in.2 (mm2) Minimum Number of Impact Locations 125 (80,645) 2 125 195 (80,645 125,805) 3 1 for each multiple of 50 in.2(32,260 mm2) Round up for multiples 50 in.2(32,260 mm2) 195 (125,80
40、0) Additional test specimens or impact areas shall be required when the geometry or configuration of the test specimen cannot be adequately evaluated otherwise; e.g., a test specimen composed of more than one piece or section. 3.3.6 Launch an ice ball at a target impact point based upon examination
41、of vulnerability. Each target location shall be impacted twice, with a maximum 0.5 in. (13 mm) distance between impacts. Impact locations will include, but are not limited to edges, corners, unsupported areas, overlaps and joints. The outside edge of the ice ball shall be a minimum of 0.25 in. (6.4
42、mm) from the edge of the test specimen. Provide a minimum 6 in. (152 mm) distance between impact locations so that the effects of each impact location are independent. Calculate the kinetic energy of the ice ball impact using the formula stated in paragraph 3.3.2. 3.3.7 Ice balls shall impact the te
43、st specimen within 60 seconds after removal from the storage container. 3.3.8 After impact testing visually scrutinize top and bottom surfaces of the test specimen. Record any damage to the specimen such as splits, punctures, fractures, disengagement of lap elements, exposure of materials not so int
44、ended, etc. 4. PASS/FAIL CRITERIA 4.1.1 The test specimen shall show no evidence of visible cracking or breakage or any damage such as splits, punctures, fractures, disengagement of lap elements or exposure of materials not so intended. 4.1.2 When a test specimen fails to meet the acceptance criteri
45、a for a tested classification, two consecutive test specimens must successfully meet the acceptance criteria to qualify for the given classification. January 2011 ANSI/FM 4473 FM Approvals 6 5. REPORTING Report, as a minimum, the following information: 1) Roofing manufacturer and specific descriptio
46、n of test components including dimensions; 2) Specific details regarding the application including substrates, underlayments, method of installation and any deviations in the test panel assembly from the specifications given in Section 3.1.1; 3) Record of conditioning of sample and conditions during
47、 testing to include temperature, relative humidity, and duration of time; 4) Size, mass and speed of each ice ball used; 5) Target locations; 6) Kinetic energy of ice ball impacts; 7) Damage assessment, including a line drawing of the roofing with impact locations marked; 8) A description of the ice
48、 ball launcher and ice ball speed measurement equipment including any deviation from the test method; 9) Product Classification based on the test results January 2011 ANSI/FM 4473 FM Approvals 7 APPENDIX A: Units of Measurement LENGTH: in. -inches; (mm millimeters) mm = in. 25.4 ft feet;(m meters) m
49、=ft 0.3048 KINETIC ENERGY: ft-lb foot-pound;(j joule) j = ft-lb 1.3558 AREA: in.2 square inches; (mm2 square millimeters) mm2 = in.2 645.16 MASS: lb pounds;(g grams) g=lb 435.6 SPEED: mph miles per hour; f/s feet per second (m/s meter per second) m/s = mph 0.44704 m/s = f/s 0.3048 TEMPERATURE: F degrees Fahrenheit;(C degrees Celsius) C=(F 32) 0.556
