ASTM C793-05(2017)

Standard Test Method for Effects of Laboratory Accelerated Weathering on Elastomeric Joint Sealants

SIGNIFICANCE AND USE
5.1 It is known that solar radiation contributes to the degradation of sealants in exterior building joints. The use of a laboratory accelerated weathering machine with actinic radiation, moisture and heat appears to be a feasible means to give indications of early degradation by the appearance of sealant cracking. However, simulated weather factors in combination with extension may produce more severe degradation than weather factors only. Therefore, the effect of the weathering test is made more sensitive by the addition of the bending of the specimen at cold temperature.
SCOPE
1.1 This test method covers a laboratory procedure for determining the effects of accelerated weathering on cured-in-place elastomeric joint sealants (single- and multicomponent) for use in building construction.  
1.2 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.  
1.3 The committee with jurisdiction over this standard is not aware of any comparable standards published by other ASTM committees or other organizations.  
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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-Jan-2017
• ICS: 83.060 - Rubber
• ICS: 91.100.50 - Binders. Sealing materials
• Technical Committee: C24 - Building Seals and Sealants
• Drafting Committee: C24.40 - Weathering

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: C793 − 05 (Reapproved 2017)
Standard Test Method for
Effects of Laboratory Accelerated Weathering on
1
Elastomeric Joint Sealants
This standard is issued under the fixed designation C793; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope chambers specified in Section 6 and operated in accordance
with specifications in Section 8 and Practice C1442.
1.1 This test method covers a laboratory procedure for
determining the effects of accelerated weathering on cured-in-
4.2 Following this treatment the specimens are exposed for
place elastomeric joint sealants (single- and multicomponent)
24 h in a freezer maintained at −26 6 2°C (−15 6 4°F).
for use in building construction.
4.3 At the end of the cold exposure, the specimens are bent
1.2 The values stated in SI units are to be regarded as the
over a mandrel within 1 s at the specified temperature.
standard. The values in parentheses are for information only.
5. Significance and Use
1.3 The committee with jurisdiction over this standard is not
aware of any comparable standards published by other ASTM
5.1 It is known that solar radiation contributes to the
committees or other organizations.
degradation of sealants in exterior building joints. The use of a
1.4 This standard does not purport to address all of the
laboratory accelerated weathering machine with actinic
safety concerns, if any, associated with its use. It is the
radiation, moisture and heat appears to be a feasible means to
responsibility of the user of this standard to establish appro-
give indications of early degradation by the appearance of
priate safety and health practices and determine the applica-
sealant cracking. However, simulated weather factors in com-
bility of regulatory limitations prior to use.
bination with extension may produce more severe degradation
than weather factors only. Therefore, the effect of the weath-
2. Referenced Documents
ering test is made more sensitive by the addition of the bending
2
2.1 ASTM Standards:
of the specimen at cold temperature.
C717 Terminology of Building Seals and Sealants
C1442 Practice for Conducting Tests on Sealants Using
6. Apparatus
Artificial Weathering Apparatus
6.1 Exposure Apparatus—The exposure apparatus shall be
G151 Practice for Exposing Nonmetallic Materials in Accel-
one of the three types of laboratory accelerated weathering
erated Test Devices that Use Laboratory Light Sources
devices described in Practice C1442 that use either xenon arc,
3. Terminology
fluorescent UV, or open flame carbon arc radiation. Consult
Practice C1442, Section 7 for the differences in test parameters
3.1 Definitions—See Terminology C717 for applicable defi-
among the devices. Because of differences in test conditions,
nitions of the following terms: cure, elastomeric, joint, sealant,
test results may differ with the type of device used. The choice
and substrate.
of device shall be by mutual agreement among the interested
4. Summary of Test Method
parties.
4.1 Three sealant specimens are spread on aluminum plates
6.2 Freezer or Cold Box, having a temperature controlled
and exposed in one of the laboratory accelerated weathering
at −26 6 2°C (−15 6 4°F).
1
6.3 Rectangular Brass Frame, with inside dimensions 130
This test method is under the jurisdiction of ASTM Committee C24 on Building
1 1
Seals and Sealants and is the direct responsibility of Subcommittee C24.40 on
by 40 by 3 mm (5 by 1 ⁄2 by ⁄8 in.).
Weathering.
6.4 Aluminum Plates, three, each 152 by 80 by 0.3 mm (6 by
Current edition approved Feb. 1, 2017. Published March 2017. Originally
approved in 1975. Last previous edition approved in 2010 as C793 – 05(2010). DOI:
3 by 0.01 in.).
10.1520/C0793-05R17.
1
2
6.5 Steel Mandrel, 12.7 mm ( ⁄2 in.) in diameter and about
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
102 mm (4 in.) long.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. 6.6 Thin-Bladed Knife.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
C793 − 05 (2017)
NOTE 2—See Annex A1 in Practice C1442 for determining the xenon
6.7 Straightedge, metal or plastic, about 152 mm (6 in.)
arc exposure time required to obtain the same radiant exposure at other
long.
irradiance levels.
6.8 Spatula, steel, about 152 mm (6 in.)
...

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. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: C793 − 05 (Reapproved 2010) C793 − 05 (Reapproved 2017)
Standard Test Method for
Effects of Laboratory Accelerated Weathering on
1
Elastomeric Joint Sealants
This standard is issued under the fixed designation C793; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope
1.1 This test method covers a laboratory procedure for determining the effects of accelerated weathering on cured-in-place
elastomeric joint sealants (single- and multicomponent) for use in building construction.
1.2 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.
1.3 The committee with jurisdiction over this standard is not aware of any comparable standards published by other ASTM
committees or other organizations.
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 and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2
2.1 ASTM Standards:
C717 Terminology of Building Seals and Sealants
C1442 Practice for Conducting Tests on Sealants Using Artificial Weathering Apparatus
G151 Practice for Exposing Nonmetallic Materials in Accelerated Test Devices that Use Laboratory Light Sources
3. Terminology
3.1 Definitions—See Terminology C717 for applicable definitions of the following terms: cure, elastomeric, joint, sealant, and
substrate.
4. Summary of Test Method
4.1 Three sealant specimens are spread on aluminum plates and exposed in one of the laboratory accelerated weathering
chambers specified in Section 6 and operated in accordance with specifications in Section 8 and Practice C1442.
4.2 Following this treatment the specimens are exposed for 24 h in a freezer maintained at −26 6 2°C (−15 6 4°F).
4.3 At the end of the cold exposure, the specimens are bent over a mandrel within 1 s at the specified temperature.
5. Significance and Use
5.1 It is known that solar radiation contributes to the degradation of sealants in exterior building joints. The use of a laboratory
accelerated weathering machine with actinic radiation, moisture and heat appears to be a feasible means to give indications of early
degradation by the appearance of sealant cracking. However, simulated weather factors in combination with extension may
produce more severe degradation than weather factors only. Therefore, the effect of the weathering test is made more sensitive by
the addition of the bending of the specimen at cold temperature.
1
This test method is under the jurisdiction of ASTM Committee C24 on Building Seals and Sealants and is the direct responsibility of Subcommittee C24.40 on
Weathering.
Current edition approved June 1, 2010Feb. 1, 2017. Published July 2010March 2017. Originally approved in 1975. Last previous edition approved in 20052010 as
C793 – 05.C793 – 05(2010). DOI: 10.1520/C0793-05R10.10.1520/C0793-05R17.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
C793 − 05 (2017)
6. Apparatus
6.1 Exposure Apparatus—The exposure apparatus shall be one of the three types of laboratory accelerated weathering devices
described in Practice C1442 that use either xenon arc, fluorescent UV, or open flame carbon arc radiation. Consult Practice C1442,
Section 7 for the differences in test parameters among the devices. Because of differences in test conditions, test results may differ
with the type of device used. The choice of device shall be by mutual agreement among the interested parties.
6.2 Freezer or Cold Box, having a temperature controlled at −26 6 2°C (−15 6 4°F).
1 1
6.3 Rectangular Brass Frame, with inside dimensions 130 by 40 by 3 mm (5 by 1 ⁄2 by ⁄8 in.).
6.4 Aluminum Plates, three, each 152 by 80 by 0.3 mm (6 by 3 by 0.01 in.).
1
6.5 Steel Mandrel, 12.
...