ASTM E998-19

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.
Designation:E998 −19
Standard Test Method for
Structural Performance of Architectural Glass Products
Under the Influence of Uniform Static Loads
This standard is issued under the fixed designation E998; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope C1048 Specification for Heat-Strengthened and Fully Tem-
pered Flat Glass
1.1 Thistestmethodisageneraltestprocedureforloadtests
C1172 Specification for Laminated Architectural Flat Glass
of glass subjected to uniform static loads. It is applicable for
C1376 Specification for Pyrolytic and Vacuum Deposition
test protocols involving specified loads, load durations, and
Coatings on Flat Glass
loading rates.
E631 Terminology of Building Constructions
1.2 This test method is applicable to architectural flat glass
E1237 Guide for Installing Bonded Resistance Strain Gages
of various types; for example, annealed, heat-strengthened,
E1561 Practice for Analysis of Strain Gage Rosette Data
fully tempered, laminated, insulating, and combinations
thereof. 3. Terminology
1.3 Thistestmethoddescribesaprocessofapplyingspecific 3.1 Definitions—For definitions of general terms related to
test loads to glass. The test may be conducted using a standard building construction used in this test method refer to Termi-
test frame specified herein or a test frame of the user’s design. nology E631.
3.2 Definitions of Terms Specific to This Standard:
1.4 The values stated in SI units are to be regarded as
3.2.1 aspect ratio, n—a ratio of long side to short side of the
standard. The values given in parentheses after SI units are
glass lite.
provided for information only and are not considered standard.
3.2.2 dry glazed system, n—a system with perimeter support
1.5 This standard does not purport to address all of the
designed to limit lateral (out-of-plane) displacements of the
safety problems, if any, associated with its use. It is the
glass specimen edges while minimizing rotational and in-plane
responsibility of the user of this standard to establish appro-
restraints of the glass specimen edges without adhesive mate-
priate safety, health, and environmental practices and deter-
rial.
mine the applicability of regulatory limitations prior to use.
For specific precautionary statements see Section 7. 3.2.3 glass specimen, n—the glass to be tested, for example,
a single lite, an insulating glass unit, laminated glass, and so
1.6 This international standard was developed in accor-
dance with internationally recognized principles on standard- forth (does not include test frame).
ization established in the Decision on Principles for the
3.2.4 negative load, n—a load that results in the indoor side
Development of International Standards, Guides and Recom-
of a glass specimen being the high-pressure side.
mendations issued by the World Trade Organization Technical
3.2.5 permanent set of test frame, n—a load-induced perma-
Barriers to Trade (TBT) Committee.
nent displacement from an original position of the test frame.
3.2.6 positive load, n—a load that results in the outdoor side
2. Referenced Documents
of a glass specimen being the high-pressure side.
2.1 ASTM Standards:
3.2.7 specifying authority, n—the professional or profes-
C1036 Specification for Flat Glass
sionals responsible for determining and furnishing the infor-
mation required to perform this test method as described in
Section 10.
This test method is under the jurisdiction of ASTM Committee E06 on
Performance of Buildings and is the direct responsibility of Subcommittee E06.52
3.2.8 test load, n—magnitude of uniform load, load
on Glass Use in Buildings.
duration, and loading rate selected by the specifying authority.
Current edition approved Oct. 1, 2019. Published December 2019. Originally
approved in 1984. Last previous edition approved in 2012 as E998–12. DOI:
4. Summary of Test Method
10.1520/E0998–19.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
4.1 This test method consists of:
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
4.1.1 Glazing the test specimen into a test frame that is
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. mounted on or against a test chamber.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E998−19
4.1.2 Supplying or exhausting air from the chamber at a rate 6.2.5 Deflection Measuring System—Ameans of measuring
required to maintain a test-pressure difference across the test deflections within an accuracy of 60.25 mm (0.01 in.).
specimen. 6.2.5.1 The deflection indicator shall be mounted so that
4.1.3 Measuring and observing deflections, deformations, deflection of the test chamber or test frame is not included in
the deflection gage reading. Provisions shall be made to ensure
specimen strains, and the nature of failures, if applicable.
that readings can be made from a safe location.
4.1.4 Recording the results in an orderly manner.
6.2.6 Temperature Measuring Apparatus—Equipment to
measure the ambient temperature within an accuracy of
5. Significance and Use
60.6 °C (1 °F).
5.1 This test method is a general procedure for testing
6.2.7 Barometric Pressure Measuring Apparatus—
architectural glass products under uniform static loads.
Equipment to measure barometric pressure within an accuracy
5.2 Loads on glass in windows, curtain walls, and doors
of 6100 Pa (2 psf).
may vary greatly in magnitude, direction, and duration. An
7. Safety Precautions
understanding of wind loads on the building is required for
selection of test loads and interpretation of results with respect
7.1 This test method involves potentially hazardous situa-
to expected exposure at a particular site.
tions resulting primarily from glass breakage. In cases of
breakage or loss of support, the hazard to personnel is less with
5.3 A thorough understanding of the variations of the
a vacuum system, as the specimen will tend to blow into rather
strength of glass and the nature of loading is required to
thanoutofthetestchamber.Nopersonnelshallbepermittedin
interpret results of this test method.
such chambers during tests. Appropriate precautions shall be
5.4 The proper use of this test method requires a knowledge
exercised during conduct of the test to protect personnel,
of the principles of pressure, deflection, and strain measure-
especially in the case of breakage or loss of support.
ment.
8. Sampling and Glass Specimens
6. Apparatus
8.1 Surface condition, cutting, fabrication, and packaging of
6.1 The description of apparatus is general in nature. Any
the glass specimens to be tested shall be representative of
equipment capable of performing the test procedure within the
normal production of the particular glass type.
allowable tolerances shall be permitted.
8.2 All glass specimens shall be visually inspected for edge
6.2 Major Components:
or surface blemishes prior to testing in accordance with
6.2.1 Test Frame—The fixture in which glass specimens are
applicable standards (for example, Specifications C1036,
mounted for testing. The test frame shall provide either
C1048, C1172, and C1376). Depending on the purpose for
standardized simple support conditions or other specified
testing the glass, specimens with edge or surface blemishes
support conditions. Specifications of standardized support
shall be appropriately documented or culled from the sample.
conditions are presented in Annex A1.
All questionable glass specimens shall be reported to the
6.2.2 Test Chamber—Asealed enclosure with an opening in specifying authority.
which or against which the test frame with the test specimen
8.3 Glass specimens shall be handled carefully at all times
shall be installed. At least one static pressure tap shall be
because the strength of glass is influenced by its surface and
provided to measure the test chamber pressure and shall be so
edge conditions. If any further damage to a sample occurs as a
located that the reading is minimally affected by the velocity of
result of handling during the test procedure, this damage
the air supply to or from the test chamber or any other air
should be visually reviewed and documented in accordance
movement. The air supply opening into the test chamber shall
with 8.2.
be arranged so that the air does not impinge directly on the
glassspecimenwithanysignificantvelocity.Ameansofaccess
9. Calibration
into the test chamber shall be permitted to facilitate adjust-
9.1 Air pressure measuring apparatus, deflection measuring
ments and observations after the specimen has been installed.
systems, strain gages, temperature measuring apparatus, and
6.2.3 Air Pressure System—A controllable blower, com-
barometric pressure measuring apparatus shall be routinely
pressed air supply/vacuum system, or other suitable system
checked. If calibration is required, the manufacturer’s recom-
capable of providing the required maximum air pressure
mendations or good engineering practice shall be followed.
differential (positive or negative load) across the test specimen
with suitable control systems, such as manually operated
10. Required Information
valves, electronically operated valves, or computer controlled
10.1 The specifying authority shall provide a test protocol
servo-valves.
consisting of the test load (positive or negative), number of
6.2.4 Air Pressure Measuring Apparatus—Equipment to
samples to test for each glazing type, glass edge bite, and
measure pressure differentials across the test specimen with an
loading sequence.
accuracy of 62 % of its maximum rated capacity, or 6100 Pa
(2 psf), whichever is less, and with a response time less than 10.2 The specifying authority shall state whether the glass
50 ms.Acceptable apparatus includes manometers, mechanical specimens shall be dry glazed in a standard test frame or in a
pressure gages and electronic pressure transducers. test frame designed to simulate a specific glazing system. If the
E998−19
test frame is to simulate a specific glazing system, complete before testing another specimen. Remove glass fragments from
glazing details and support conditions shall be provided by the test assembly prior to testing another specimen.
specifying authority.
12. Report
10.3 The specifying authority shall provide locations for
12.1 The report shall include the following information:
strain gage installation and deflection measuring devices, as
12.1.1 Date of the test, the date of the report, the ambient
well as a schedule of recording strain gage readings and
temperature, and the barometric pressure.
deflections.
12.1.2 Identification of the glass specimens (manufacturer,
11. Procedure
source of supply, dimensions, both nominal and measured,
manufacturer’s designation, materials, and other pertinent in-
11.1 Measure and record ambient temperature and baromet-
formation).
ric pressure.
12.1.3 Detailed drawings of the glass specimen, test frame,
11.2 Install strain gages to the glass specimen according to
testchamber,acompletedescriptionofallinstrumentation,and
procedures in Annex A2. Refer to Appendix X1 for example
a statement that the test was conducted using a standard test
strain gage locations.
frame or a test frame specified by the specifying authority.
11.3 Install glass specimens in the test frame in accordance 12.1.4 A detailed description of the specified test protocol.
12.1.5 Records of measured chamber pressures, deflections,
with recommendations in Annex A1 for standard support
conditions or as specified by the specifying authority. and strain gage readings according to the test protocol, with
each specimen being properly identified.
11.4 Install deflection gages at locations specified by the
12.1.6 A summary of test observations, including unex-
specifying authority. Refer to Appendix X1 for example
pected behavior or failures of test specimens and time of
deflection gage locations.
occurrence.
11.5 Record reference strain and deflection readings at
12.1.7 Identification or description of any applicable speci-
no-load conditions.
fication. Documentation of each glass specimen inspection
results (including culled specimens) in accordance with appli-
11.6 Load specimen to low level pressure, 20 % of test load
cable specifications.
for 1 min. Release load.Allow 3 to 5 min gage and restoration
12.1.8 A statement that the tests were conducted in accor-
time.
dance with the specified test method, or a full description of
11.7 If air leakage around the test specimen is excessive,
any deviations.
tape or alternate soft, flexible material shall be permitted to be
used to cover any cracks and joints through which the leakage
13. Precision and Bias
is occurring. Such material shall not be used when there is a
13.1 No statement is made about either the precision or the
probability that it may significantly restr
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