1、Designation: E997 12E997 14Standard Test Method forStructural Performance of Glass in Exterior Windows,Curtain Walls, and Doors Evaluating Glass BreakageProbability Under the Influence of Uniform Static Loads byDestructive MethodsProof Load Testing1This standard is issued under the fixed designation
2、 E997; the number immediately following the designation indicates the year oforiginal adoption or, in 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 reapp
3、roval.1. Scope1.1 This proof load test method is a procedure to determine determine, with a 90 % confidence level, if the probability ofbreakage under design loads for a given population of glass specimens tested is significantly greater than, significantly less than,or not significantly different t
4、han the specified probability of breakage when exposed to a specified design load. is less than aselected value. It is not intended to be a design standard for determining the load resistance of glass. Practice E1300 shall be usedfor this purpose.1.2 This test method describes apparatus and procedur
5、es to select and apply a proof load to glass specimens, to determine thenumber of glass specimens to be tested, and to evaluate statistically the probability of breakage.This test method may be conductedusing the standard test frame specified herein or a test frame of the users design.1.3 Proper use
6、 of this test method requires a knowledge of the principles of pressure measurement and an understanding ofrecommended glazing practices.1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematicalconversions to SI units that are provided
7、 for information only and are not considered standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability o
8、f regulatorylimitations prior to use. Specific precautionary statements are given in Section 7.2. Referenced Documents2.1 ASTM Standards:2E631 Terminology of Building ConstructionsE1300 Practice for Determining Load Resistance of Glass in Buildings3. Terminology3.1 Definitions:3.1.1 For definitions
9、of general terms related to building construction used in this test method refer to Terminology E631.3.2 Definitions of Terms Specific to This Standard:3.2.1 coeffcient of variation, nvratio of the standard deviation of the breakage load to the mean breakage load.3.2.2 equivalent design load, nthe s
10、pecified uniform design load converted to specified duration (see load and loadduration.4.2).3.2.3 glass specimen, nthe glass to be tested, for example, a single pane, an insulating glass unit, laminated glass, etc. (doesnot include test frame).3.2.4 glass specimen breakage, nthe fracture or crackin
11、g of any glass component of a glass specimen.1 This test method is under the jurisdiction of ASTM Committee E06 on Performance of Buildings and is the direct responsibility of E06.51 on Performance of Windows,Doors, Skylights and Curtain Walls.Current edition approved April 15, 2012June 1, 2014. Pub
12、lished May 2012September 2014. Originally approved in 1984. Last previous edition approved in 20092012as E997 11.E99712. DOI: 10.1520/E0997-12.10.1520/E0997-14.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of
13、ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically
14、 possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C70
15、0, West Conshohocken, PA 19428-2959. United States13.2.5 negative load, nan outward-acting load that results in the indoor side of a glass specimen being the high-pressure side.3.2.6 positive load, nan inward-acting load that results in the outdoor side of a glass specimen being the high-pressure si
16、de.3.2.7 probability of breakage, nthe probability that a glass specimen will break when tested at a given load. General industrypractice is to express the probability of breakage as lites per 1000 lites.3.2.8 proof load, na magnitude of uniform load at which glass specimens shall be tested.3.2.9 pr
17、oof load factor, a, nthe constant which, when multiplied by the design load, determines the proof load.3.2.10 specifying authority, nprofessional(s) responsible for determining and furnishing information required to perform thetest.4. Summary of Test Method4.1 This test method consists of individual
18、ly glazing glass specimens in a test frame that is mounted into or against one faceof a test chamber and supplying air to, or exhausting air from, the test chamber so that each glass specimen is exposed to a specifiedduration proof load. Load-time records shall be kept for each glass specimen. Each
19、glass specimen break shall be recorded.4.2 After testing the required number of glass specimens, it is determined determined, with a 90 % confidence level, if theprobability of breakage is significantly less than, significantly greater than, or not significantly different than the specified underdes
20、ign loads for the given population of glass specimens is less than a specified allowable probability of breakage.5. Significance and Use5.1 Glass specimens to be tested shall be mounted in a standard test frame with four sides supported, or in a test frame designedto represent specific glazing condi
21、tions.5.1.1 Astandard test frame shall be used when it is desired to evaluate the probability of breakage of glass specimens with edgesupport conditions held constant.5.1.2 A test frame designed to represent a specific glazing condition shall be used when it is desired to evaluate the probabilityof
22、breakage of glass specimens in the specified glazing system.5.2 Loads on glass in windows, curtain walls, and doors may vary greatly in magnitude, direction, and duration. Any designload (wind, snow, etc.) that can be transformed into a specific duration reasonably be applied to the test specimens o
23、r transformedinto an equivalent uniform design load can be considered. Load transformation techniques are addressed in the literature (1, 2, 3).35.3 The strength of glass varies with many different factors including surface condition, load duration, geometry, relativehumidity, and temperature (4). A
24、 thorough understanding of those strength variations is required to interpret results of this testmethod.6. Apparatus6.1 The description of apparatus is general in nature. Any equipment capable of performing the test procedure within theallowable tolerances is permitted.6.2 Major Components:6.2.1 Te
25、st Frame, in which glass specimens are mounted for testing. The test frame shall provide either standardized supportconditions or specified support conditions. Specifications of standardized support conditions are presented in Annex A1.6.2.2 Test Chamber, sealed, with an opening in which or against
26、which the test frame is installed. At least one static pressuretap shall be provided to measure the test chamber pressure and shall be so located that the reading is minimally affected by thevelocity of the air supply to or from the test chamber or any air movement. The air supply opening into the t
27、est chamber shall bearranged so that the air does not impinge directly on the glass specimen with any significant velocity. A means of access into thetest chamber may be provided to facilitate adjustments and observations after the specimen has been installed.6.2.3 Air System, a controllable blower,
28、 compressed air supply, exhaust system, reversible blower, or other device designed toapply the proof load to the glass specimen with required control.6.2.4 Pressure Measuring Apparatus, to record continuous test chamber pressures within an accuracy of 62 %.6.2.5 Temperature Measuring Apparatus, to
29、measure the ambient temperature within an accuracy of 61F (0.6C).6.2.6 Relative Humidity Apparatus, to measure the relative humidity within an accuracy of 62 %.7. Safety Precautions7.1 Proper precautions shall be taken to protect observers in the event of glass breakage should be observed. breakage.
30、 At thepressures used in this test method, considerable energy and hazard are involved. In cases of breakage, the hazard to personnel isless with an exhaust system, as the specimen will tend to blow into rather than out of the test chamber. Personnel should not bepermitted in such chambers during te
31、sts.3 The boldface numbers in parentheses refer to a list of references at the end of this standard.E997 1428. Sampling and Glass Specimens8.1 Surface condition, cutting, fabrication, and packaging of the glass specimens shall be representative of the glass whosestrength is to be evaluated.8.2 All g
32、lass specimens shall be visually inspected for edge or surface irregularities prior to testing, and all questionable glassspecimens testing. All glass specimens with edge or surface irregularities not representative of the glass whose strength is to beevaluated shall not be tested.8.3 Glass specimen
33、s shall be handled carefully at all times because the strength of glass is influenced by its surface and edgeconditions.9. Calibration9.1 Pressure-measuring systems should be routinely checked. verified prior to testing. If calibration is required, themanufacturers recommendations or good engineerin
34、g practices shouldshall be followed.10. Required Information10.1 The specifying authority shall provide the magnitude of the equivalent design load (positive or negative), the orientationof the glass specimen to the test chamber, the design load allowable probability of breakage for the glass specim
35、ens, and thecoefficient of variation of the breakage loads typical of the glass specimens tested.10.2 The specifying authority shall state whether the glass specimens shall be glazed in a standard test frame (see Annex A1)or in a test frame designed to simulate a specific glazing system. If the test
36、 frame is to simulate a specific glazing system, completeglazing details and support conditions shall be provided by the specifying authority.11. Selection of Proof Load and Initial Sample Size11.1 The glass specimens shall be tested with a proof load that is larger than the equivalent design load.
37、The proof load is foundby multiplying the design load by the proof load factor, a, as follows:qp 5aq d (1)where:qp = proof load,a = proof load factor, andqd = equivalent design load.qd = design load.11.1.1 If the glass specimens are to be tested in a standard test frame, the proof load factor, a, is
38、 found in Tables 1-4Table 1through Table 4, given the equivalent design load allowable probability of breakage and the appropriate coefficient of variation,. The proof load factor, a, corresponding to the minimum sample size or the is selected with due regard to the maximum capacityof the loading ap
39、paratus, test apparatus. The tables indicate the initial sample size, n, of glass specimens to be tested. If the samplesize entry in Table 1 through Table 4 is blank an alternate proof load factor shall be selected.TABLE 1 Required Zero Break Sample Size ( = 0.10)Proof Load Factor, a1.2 1.3Equivalen
40、t Design LoadProbability of Breakage0.010 11Design LoadProbability ofBreakage0.010 100.009 120.009 110.008 120.007 130.006 150.006 140.005 170.005 160.004 190.003 240.003 230.002 31 100.002 310.001 53A 150.001 14A Testing is not recommended because of excess expense.E997 14311.1.2 If the glass speci
41、mens are to be tested in a test frame that is representative of a specific glazing system, the maximumallowable proof load that can be resisted by the test frame shall be determined using engineering principles. The proof load factor,a, is then determined by dividing the maximum allowable proof load
42、 by the equivalent design load. Tables 1-4 are then enteredwith the calculated value of a, the specified coefficient of variation, , and the equivalent design load probability of breakage todetermine the number of glass specimens to be tested. If the corresponding entry in Table 1 is blank, then the
43、 proof load factorshould be reduced to a value based upon a minimum sample size.11.2 Rationale to develop Tables 1-4Table 1 through Table 4 is presented in Appendix X1.12. Procedure12.1 Measure and record the ambient temperature and the relative humidity.12.2 Install glass specimens in the test fram
44、e in accordance with recommendations presented in AnnexA1 for standard supportconditions or as specified for a specific glazing system.12.3 Apply one half of the proof load to the glass specimen and hold for 10 s. Reduce the test pressure to zero and vent thetest chamber for a period from 3 to 5 min
45、 before the pressure-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 whichleakage is occurring. However, tape shall not be used when there is a possibility that it will significantly restrict
46、differentialmovement between the glass specimen and the test frame.12.5 Apply the proof load to the glass specimen in a period from 40 to 60 s, maintain as quickly as possible, but no longer than15 s. Maintain the proof load for a specified period, the same duration as the specified design load, and
47、 then vent the test chamber.Continuous load-time records shall be kept for the duration of the loading.12.6 If the glass specimen does not break, remove it from the test frame, and discard it. frame. Select a new glass specimen,and repeat procedures in 12.2 12.512.2 through 12.5. If the glass specim
48、en does break, record the break and, if desired, determinefrom Table 5 through Table 8and continue. (using the design load probability of failure, the appropriate coefficient of variation,and the selected proof load factor) the “one break” sample size, N1. This sample size represents the total numbe
49、r of tests to beconducted with only one associated specimen break such that there is a 90 % confidence level that the actual probability ofbreakage at the design load is less than the allowable probability of breakage. If elected by the specifying authority or otherappropriate party, testing may then continue in accordance with procedures in 12.2 through 12.5.12.7 If, during the course of testing N1 samples, a second break occurs, record the break and, if desired, determine from Table9 through Table 12 (using the design load probability of failure, the appr
