1、Designation: E997 15Standard Test Method forEvaluating Glass Breakage Probability Under the Influenceof Uniform Static Loads by Proof Load Testing1This standard is issued under the fixed designation E997; the number immediately following the designation indicates the year oforiginal adoption or, in
2、the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This proof load test method is a procedure to determine,with a 90 % confidence level
3、, if the probability of breakageunder design loads for a given population of glass specimens isless than a selected value. It is not intended to be a designstandard for determining the load resistance of glass. PracticeE1300 shall be used for this purpose.1.2 This test method describes apparatus and
4、 procedures toselect and apply a proof load to glass specimens, to determinethe number of glass specimens to be tested, and to evaluatestatistically the probability of breakage. This test method maybe conducted using the standard test frame specified herein ora test frame of the users design.1.3 Pro
5、per use of this test method requires a knowledge ofthe principles of pressure measurement and an understandingof recommended glazing practices.1.4 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are pro
6、vided for information onlyand are not considered standard.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bil
7、ity of regulatory limitations prior to use. Specific precau-tionary statements are given in Section 7.2. Referenced Documents2.1 ASTM Standards:2E631 Terminology of Building ConstructionsE1300 Practice for Determining Load Resistance of Glass inBuildings3. Terminology3.1 Definitions:3.1.1 For defini
8、tions of general terms related to buildingconstruction used in this test method refer to TerminologyE631.3.2 Definitions of Terms Specific to This Standard:3.2.1 coeffcient of variation, vratio of the standard devia-tion of the breakage load to the mean breakage load.3.2.2 design load, nthe specifie
9、d uniform load and loadduration.3.2.3 glass specimen, nthe glass to be tested, for example,a single pane, an insulating glass unit, laminated glass, etc.(does not include test frame).3.2.4 glass specimen breakage, nthe fracture or crackingof any glass component of a glass specimen.3.2.5 negative loa
10、d, nan outward-acting load that resultsin the indoor side of a glass specimen being the high-pressureside.3.2.6 positive load, nan inward-acting load that results inthe outdoor side of a glass specimen being the high-pressureside.3.2.7 probability of breakage, nthe probability that a glassspecimen w
11、ill break when tested at a given load.3.2.8 proof load, na uniform load at which glass speci-mens shall be tested.3.2.9 proof load factor, a, nthe constant which, whenmultiplied by the design load, determines the proof load.3.2.10 specifying authority, nprofessional(s) responsiblefor determining and
12、 furnishing information required to performthe test.4. Summary of Test Method4.1 This test method consists of individually glazing glassspecimens in a test frame that is mounted into or against oneface of a test chamber and supplying air to, or exhausting airfrom, the test chamber so that each glass
13、 specimen is exposedto a proof load. Load-time records shall be kept for each glassspecimen. Each glass specimen break shall be recorded.4.2 After testing the required number of glass specimens, itis determined, with a 90 % confidence level, if the probability1This test method is under the jurisdict
14、ion of ASTM Committee E06 onPerformance of Buildings and is the direct responsibility of E06.51 on Performanceof Windows, Doors, Skylights and Curtain Walls.Current edition approved May 1, 2015. Published June 2015. Originallyapproved in 1984. Last previous edition approved in 2014 as E99714. DOI:10
15、.1520/E0997-15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor
16、Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1of breakage under design loads for the given population ofglass specimens is less than a specified allowable probability ofbreakage.5. Significance and Use5.1 Glass specimens to be tested shall be mounted in astandard test frame wit
17、h four sides supported, or in a test framedesigned to represent specific glazing conditions.5.2 Loads on glass in windows, curtain walls, and doorsmay vary greatly in magnitude, direction, and duration. Anydesign load (wind, snow, etc.) that can reasonably be applied tothe test specimens or transfor
18、med into an equivalent uniformdesign load can be considered. Load transformation techniquesare addressed in the literature (1, 2, 3).35.3 The strength of glass varies with many different factorsincluding surface condition, load duration, geometry, relativehumidity, and temperature (4). A thorough un
19、derstanding ofthose strength variations is required to interpret results of thistest method.6. Apparatus6.1 The description of apparatus is general in nature. Anyequipment capable of performing the test procedure within theallowable tolerances is permitted.6.2 Major Components:6.2.1 Test Frame, in w
20、hich glass specimens are mounted fortesting. The test frame shall provide either standardized sup-port conditions or specified support conditions. Specificationsof standardized support conditions are presented in Annex A1.6.2.2 Test Chamber, sealed, with an opening in which oragainst which the test
21、frame is installed. At least one staticpressure tap shall be provided to measure the test chamberpressure and shall be so located that the reading is minimallyaffected by the velocity of the air supply to or from the testchamber or any air movement. The air supply opening into thetest chamber shall
22、be arranged so that the air does not impingedirectly on the glass specimen with any significant velocity. Ameans of access into the test chamber may be provided tofacilitate adjustments and observations after the specimen hasbeen installed.6.2.3 Air System, a controllable blower, compressed airsuppl
23、y, exhaust system, reversible blower, or other devicedesigned to apply the proof load to the glass specimen withrequired control.6.2.4 Pressure Measuring Apparatus, to record continuoustest chamber pressures within an accuracy of 62%.6.2.5 Temperature Measuring Apparatus, to measure theambient tempe
24、rature within an accuracy of 61F (0.6C).6.2.6 Relative Humidity Apparatus, to measure the relativehumidity within an accuracy of 62%.7. Safety Precautions7.1 Proper precautions shall be taken to protect observers inthe event of glass breakage. At the pressures used in this testmethod, considerable e
25、nergy and hazard are involved. In casesof breakage, the hazard to personnel is less with an exhaustsystem, as the specimen will tend to blow into rather than outof the test chamber. Personnel should not be permitted in suchchambers during tests.8. Sampling and Glass Specimens8.1 Surface condition, c
26、utting, fabrication, and packaging ofthe glass specimens shall be representative of the glass whosestrength is to be evaluated.8.2 All glass specimens shall be visually inspected for edgeor surface irregularities prior to testing. All glass specimenswith edge or surface irregularities not representa
27、tive of theglass whose strength is to be evaluated shall not be tested.8.3 Glass specimens shall be handled carefully at all timesbecause the strength of glass is influenced by its surface andedge conditions.9. Calibration9.1 Pressure-measuring systems should be verified prior totesting. If calibrat
28、ion is required, the manufacturers recom-mendations or good engineering practices shall be followed.10. Required Information10.1 The specifying authority shall provide the design load(positive or negative), the orientation of the glass specimen tothe test chamber, the design load allowable probabili
29、ty ofbreakage for the glass specimens, and the coefficient ofvariation of the breakage loads typical of the glass specimenstested.10.2 The specifying authority shall state whether the glassspecimens shall be glazed in a standard test frame (see AnnexA1) or in a test frame designed to simulate a spec
30、ific glazingsystem. If the test frame is to simulate a specific glazingsystem, complete glazing details and support conditions shallbe provided by the specifying authority.11. Selection of Proof Load and Initial Sample Size11.1 The glass specimens shall be tested with a proof loadthat is larger than
31、 the design load. The proof load is found bymultiplying the design load by the proof load factor, a,asfollows:qp5 aqd(1)where:qp= proof load,a = proof load factor, andqd= design load.11.1.1 If the glass specimens are to be tested in a standardtest frame, the proof load factor, a, is found in Table 1
32、 throughTable 4, given the design load allowable probability of break-age and the appropriate coefficient of variation, . The proofload factor, a, is selected with due regard to the maximumcapacity of the test apparatus. The tables indicate the initialsample size, n, of glass specimens to be tested.
33、 If the samplesize entry in Table 1 through Table 4 is blank an alternate proofload factor shall be selected.3The boldface numbers in parentheses refer to a list of references at the end ofthis standard.E997 15211.2 Rationale to develop Table 1 through Table 4 ispresented in Appendix X1.12. Procedur
34、e12.1 Measure and record the ambient temperature and therelative humidity.12.2 Install glass specimens in the test frame in accordancewith recommendations presented in Annex A1 for standardsupport conditions or as specified for a specific glazing system.12.3 Apply one half of the proof load to the g
35、lass specimenand hold for 10 s. Reduce the test pressure to zero and vent thetest chamber for a period from 3 to 5 min before thepressure-measuring apparatus is adjusted to zero.12.4 If air leakage around the glass specimen is excessive,tape may be used to cover any cracks and joints through whichle
36、akage is occurring. However, tape shall not be used whenthere is a possibility that it will significantly restrict differentialmovement between the glass specimen and the test frame.12.5 Apply the proof load to the glass specimen as quicklyas possible, but no longer than 15 s. Maintain the proof loa
37、d forthe same duration as the specified design load, and then ventthe test chamber. Continuous load-time records shall be keptfor the duration of the loading.12.6 If the glass specimen does not break, remove it fromthe test frame. Select a new glass specimen, and repeatprocedures in 12.2 through 12.
38、5. If the glass specimen doesbreak, record the break and, if desired, determine from Table 5through Table 8 (using the design load probability of failure,the appropriate coefficient of variation, and the selected proofload factor) the “one break” sample size, N1. This sample sizerepresents the total
39、 number of tests to be conducted with onlyone associated specimen break such that there is a 90 %confidence level that the actual probability of breakage at thedesign load is less than the allowable probability of breakage.If elected by the specifying authority or other appropriate party,testing may
40、 then continue in accordance with procedures in12.2 through 12.5.12.7 If, during the course of testing N1samples, a secondbreak occurs, record the break and, if desired, determine fromTable 9 through Table 12 (using the design load probability offailure, the appropriate coefficient of variation, and
41、 the selectedproof load factor) the “two break” sample size, N2.This samplesize represents the total number of tests to be conducted withonly two associated specimen breaks such that there is a 90 %confidence level that the actual probability of breakage at thedesign load is less than the allowable
42、probability of breakage.If elected by the specifying authority or other appropriate party,testing may then continue in accordance with procedures in12.2 through 12.5.12.8 Inspect the test frame for permanent deformation orother failures of principal members. If failure of the standardtest frame occu
43、rs, it shall be appropriately stiffened andstrengthened and the test restarted. If failure occurs in a userspecified test frame, the proof load shall be reduced or the testframe appropriately stiffened or strengthened and the testrestarted.12.9 Rationale used to develop Table 5 through Table 12 ispr
44、esented in Appendix X1. Guidance for testing a sample ofglass specimens with more than two breaks is not given in thistest method, but may be determined using the principlesdescribed in Appendix X1.13. Interpretation of Results13.1 If no specimen breaks during the testing of the initialsample size,
45、n, given in Table 1 through Table 4, there is a90 % confidence level that the actual probability of breakage atthe design load is less than the allowable probability ofbreakage.13.2 If one specimen breaks during the testing of samplesize, N1, given in Table 5 through Table 8, there is a 90 %confiden
46、ce level that the actual probability of breakage at thedesign load is less than the allowable probability of breakage.13.3 If two specimens break during the testing of samplesize, N2, given in Table 9 through Table 12, there is a 90 %confidence level that the actual probability of breakage at thedes
47、ign load is less than the allowable probability of breakage.14. Report14.1 The report shall include the following information:14.1.1 The date of the test, the date of the report, theambient temperature, and the relative humidity.14.1.2 Identification of the glass specimens (manufacturer,source of su
48、pply, dimensions both nominal and measured,manufacturers designation, materials, and other pertinentinformation).14.1.3 Detailed drawings of the glass specimens, test frame,and test chamber indicating orientation of the glass specimen tothe test chamber.Acomplete description of pressure-measuringTAB
49、LE 1 Required Zero Break Sample Size ( = 0.10)Proof Load Factor, a1.2 1.3Design LoadProbability of Breakage0.010 100.009 110.008 120.007 130.006 140.005 160.004 190.003 230.002 310.001 14TABLE 2 Required Zero Break Sample Size ( = 0.15)Proof Load Factor, a1.3 1.4 1.5 1.6Design LoadProbability of Breakage0.010 140.009 160.008 170.007 19 100.006 22 110.005 25 130.004 31 150.003 39 19 100.002 26 130.001 47 23 13E997 153apparatus, and a statement that the test was conducted using astandard test frame or a test frame of the users design.14.1.4 Records of start/stop l
