ASTM C1756-11

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: C1756 − 11
StandardGuide for
1
Comparing Sealant Behavior to Reference Photographs
This standard is issued under the fixed designation C1756; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
1.1 This guide provides photographs that illustrate sealant
3.1 The terms used in this guide are defined inTerminology
behavior terms that have been defined by Committee C24.
C717.
1.2 When available, photographs that better illustrate these
terms, or that illustrate additional terms defined by Committee
4. Significance and Use
C24, will be included in future editions of this standard.
4.1 This guide is intended to be used in evaluating sealant
Photographs for consideration may be submitted to the com-
conditions that occur in service, along with other diagnostic
mittee using the form in Appendix X1.
techniques in failure analysis. These standard reference photo-
1.3 Thecommitteewithjurisdictionoverthisstandardisnot
graphs have been selected and approved through ASTM’s
aware of any comparable standards published by other orga-
consensus balloting process to illustrate terms defined by
nizations.
Committee C24.
1.4 This standard does not purport to address all of the
4.2 Not all of the terms illustrated here are failures, and
safety concerns, if any, associated with its use. It is the
there are other failure mechanisms that affect sealants that are
responsibility of the user of this standard to establish appro-
not discussed in this guide. This guide is intended to be one of
priate safety and health practices and determine the applica-
a number of sources of information used in the evaluation of
bility of regulatory limitations prior to use.
sealant behavior.
2. Referenced Documents
2
2.1 ASTM Standards:
5. Reference Photographs
C717Terminology of Building Seals and Sealants
5.1 Figs. 1-9 present a standard reference photograph for
each of the terms defined in Terminology C717, reprinted with
1
ThisguideisunderthejurisdictionofASTMCommitteeC24onBuildingSeals
and Sealants and is the direct responsibility of Subcommittee C24.10 their definitions.
onSpecifications, Guides and Practices.
Current edition approved June 15, 2011. Published August 2011. DOI: 10.1520/
6. Keywords
C1756-11.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
6.1 adhesion failure; chalking; cohesion failure; crazed; dirt
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
pick-up; elastomeric joint sealant; fluid migration; reversion;
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. rundown; sag
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C1756 − 11
adhesion failure, n—in building construction, failure of the bond between a
sealant and a substrate.
Discussion—This definition pertains to interfacial adhesion failure, a lack of
bond at the interface between the materials. Interphasal adhesion failure, within
the sealant or substrate near the interface, is less common and may appear to be
cohesive failure, n—in building construction, failure characterized by rupture
inerfacial without the use of magnification.
within the sealant.
FIG. 1 Adhesion Failure
FIG. 3 Cohesive Failure
chalking, v—in building construction, formation of a powder on the surface of a
crazed, adj—in building construction, having a random network of cracks in a
sealant that is caused by the disintegration of the polymer or binding medium due
sealant surface which do not penetrate through the body of the material.
to weathering.
FIG. 4 Crazed
FIG. 2 Chalking
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C1756 − 11
dirt pick-up, n—in building construction, soiling caused by a foreign material
other than micro-organism growth that is deposited on, adhered to, or embedded
into a sealant.
reversion, n—in building construction in joint sealing, a loss of elastomeric
FIG. 5 Dirt Pick-up
properties and a decrease in durometer hardness of a seal or cured sealant
following environmental exposure.
Discussion—Softening and the ability to permanently reshape a seal or sealant
usually characterizes reversion. Depending on a specific seal or sealant
formulation, high heat, ultraviolet radiation, or moisture (as a liquid or vapor) may
cause reversion acting either alone or in combination. The seal and sealant
industry is not in agreement on reversion causes.
FIG. 7 Reversion
fluid migration,n—inbuildingconstruction, accumulation of a
...