1、Designation: C1756 17aStandard Guide forComparing Seal or Sealant Behavior to ReferencePhotographs1This standard is issued under the fixed designation C1756; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision
2、. 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 guide provides photographs that illustrate seal andsealant behavior consistent with the scope and areas of interestof Committe
3、e C24.1.2 When available, photographs that better illustrate theseterms, or that illustrate additional terms defined by CommitteeC24, will be included in future editions of this standard.Photographs for consideration may be submitted to the com-mittee using the form in Appendix X1.1.3 The committee
4、with jurisdiction over this standard is notaware of any comparable standards published by other orga-nizations.1.4 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 safe
5、ty, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of
6、International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C717 Terminology of Building Seals and Sealants3. Terminology3.1 The terms used in this guide are defined in TerminologyC7
7、17.4. Significance and Use4.1 This guide is intended to be used in evaluating sealantconditions that occur in service, along with other diagnostictechniques in failure analysis. These standard reference photo-graphs have been selected and approved through ASTMsconsensus balloting process to illustra
8、te terms defined byCommittee C24.4.2 Not all of the terms illustrated here are failures, andthere are other failure mechanisms that affect sealants that arenot discussed in this guide. This guide is intended to be one ofa number of sources of information used in the evaluation ofsealant behavior.5.
9、Reference Photographs5.1 Figs. 1-9 present a standard reference photograph foreach of the terms defined in Terminology C717, reprinted withtheir definitions.6. Keywords6.1 adhesion failure; chalking; cohesion failure; crazed; dirtpick-up; elastomeric joint sealant; fluid migration; reversion;rundown
10、; sag1This guide is under the jurisdiction ofASTM Committee C24 on Building Sealsand Sealants and is the direct responsibility of Subcommittee C24.10onSpecifications, Guides and Practices.Current edition approved Nov. 1, 2017. Published November 2017. Originallyapproved in 2011. Last previous editio
11、n approved in 2017 as C1756-17. DOI:10.1520/C1756-17A.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.Copyrig
12、ht ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of Internationa
13、l Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1adhesion failure, nin building construction, failure of the bond between asealant and a substrate.DiscussionThis definition pertains to interfacial adhesion failure, a lack ofb
14、ond at the interface between the materials. Interphasal adhesion failure, withinthe sealant or substrate near the interface, is less common and may appear to beinterfacial without the use of magnification.FIG. 1 Adhesion Failurechalking, vin building construction, formation of a powder on the surfac
15、e of asealant that is caused by the disintegration of the polymer or binding medium dueto weathering.FIG. 2 Chalkingcohesive failure, nin building construction, failure characterized by rupturewithin the sealant.FIG. 3 Cohesive Failurecrazed, adjin building construction, having a random network of c
16、racks in asealant surface which do not penetrate through the body of the material.FIG. 4 CrazedC1756 17a2dirt pick-up, nin building construction, soiling caused by a foreign materialother than micro-organism growth that is deposited on, adhered to, or embeddedinto a sealant.FIG. 5 Dirt Pick-upfluid
17、migration, nin building construction, accumulation of a fluid from a sealanton or in an adjacent material.FIG. 6 Fluid Migrationreversion, nin building construction in joint sealing, a loss of elastomericproperties and a decrease in durometer hardness of a seal or cured sealantfollowing environmenta
18、l exposure.DiscussionSoftening and the ability to permanently reshape a seal or sealantusually characterizes reversion. Depending on a specific seal or sealantformulation, high heat, ultraviolet radiation, or moisture (as a liquid or vapor) maycause reversion acting either alone or in combination. T
19、he seal and sealantindustry is not in agreement on reversion causes.FIG. 7 Reversionrundown, nin building construction, discoloration of a buildings surfaces bymovement of a contaminant due to natural forces.DiscussionNatural forces include wind, snow-melt, rain movement by surfacetension, gravity,
20、capillary action, kinetic energy, and air currents. Typical movementof contaminants includes fluid migration and blooming from a sealant, deposit ofatmospheric pollutants, and chemical staining.FIG. 8 RundownC1756 17a3APPENDIXX1. TRANSMITTAL FORM SEALANT FAILURE PHOTO(S) FOR C1756INTRODUCTIONPlease
21、submit photographs of sealant failures with this transmittal from by email to thesubcommittee C24.10 on Specifications, Guides and Practices, chairperson. Current email addressesare available on the roster on ASTMs web site.X1.1 PhotographsX1.1.1 Submit JPEG or TIFF files with resolution of at least
22、1200 960 pixels, grayscale. (Selected photos will be con-verted to TIFFs for publication.)X1.1.2 Do not show brand names or other identifiableproprietary information in the photos (or state them on theform).X1.1.3 Photographs of sealant failures in service are pre-ferred to laboratory or mock-up con
23、ditions. However, staged orlaboratory photographs will be considered.X1.1.4 The person submitting these photos represents toASTM that, to the best of his/her knowledge, information, andbelief, there is not copyright or other limitation onASTMs useof these photos, and he/she acknowledges that ASTM ma
24、in-tains the exclusive right to publish these phtotos.sagnin building construction, the gravity-induced downward flow of asealant or glazing compund, resulting in an uneven thickness, when applied on avertical surface.FIG. 9 SagC1756 17a4X1.2 Transmittal FormX1.2.1 Complete as much of this form as p
25、ossible (leaveblanks if necessary), and submit it as an attachment to the sameemail message with the photos.X1.2.2 Submit completed from in TIFF or PDF format.X1.2.3 Multiple photographs may be submitted with thesame transmittal form so long as they relate to the samecondition; for example, multiple
26、 views of the same detail willallow the subcommittee to understand the condition and selectthe best representation.Condition illustrated (i.e., adhesion failure): _Generic sealant chemistry, if known (i.e., 2-part urethane): _Substrates (i.e., brick masonry and anodized aluminum): _Approximate date
27、sealant was installed, if known: _Data photo taken: _Location (city, state): _Weather exposure (i.e., north face under roof eave): _Observations and comments to be considered by subcommittee: _Form completed and photo(s) submitted by (printed name): _Submitted on (date): _ASTM International takes no
28、 position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own respons
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30、o ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the add
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