1、Designation: C1756 11C1756 14Standard Guide forComparing Sealant Behavior to Reference Photographs1This 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 sealant behavior terms that have been defined by Committee C24.1.2 When available,
3、photographs that better illustrate these terms, or that illustrate additional terms defined by Committee C24,will be included in future editions of this standard. Photographs for consideration may be submitted to the committee using theform in Appendix X1.1.3 The committee with jurisdiction over thi
4、s standard is not aware of any comparable standards published by otherorganizations.1.4 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
5、 determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C717 Terminology of Building Seals and Sealants3. Terminology3.1 The terms used in this guide are defined in Terminology C717.4. Significance and Use4.1 This guide is intended to be used in
6、evaluating sealant conditions that occur in service, along with other diagnostictechniques in failure analysis. These standard reference photographs have been selected and approved throughASTMs consensusballoting process to illustrate terms defined by Committee C24.4.2 Not all of the terms illustrat
7、ed here are failures, and there are other failure mechanisms that affect sealants that are notdiscussed in this guide. This guide is intended to be one of a number of sources of information used in the evaluation of sealantbehavior.5. Reference Photographs5.1 Figs. 1-9 present a standard reference p
8、hotograph for each of the terms defined in Terminology C717, reprinted with theirdefinitions.6. Keywords6.1 adhesion failure; chalking; cohesion failure; crazed; dirt pick-up; elastomeric joint sealant; fluid migration; reversion;rundown; sag1 This guide is under the jurisdiction of ASTM Committee C
9、24 on Building Seals and Sealants and is the direct responsibility of Subcommittee C24.10 onSpecifications,Guides and Practices.Current edition approved June 15, 2011Jan. 1, 2014. Published August 2011January 2014. Originally approved in 2011. Last previous edition approved in 2011 asC1756-11. DOI:
10、10.1520/C1756-11.10.1520/C1756-14.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an AST
11、M 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 possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In al
12、l 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 C700, West Conshohocken, PA 19428-2959. United States1adhesion failure, nin building construction, failure of the bond between as
13、ealant and a substrate.DiscussionThis definition pertains to interfacial adhesion failure, a lack ofbond at the interface between the materials. Interphasal adhesion failure, withinthe sealant or substrate near the interface, is less common and may appear to beinerfacial without the use of magnifica
14、tion.FIG. 1 Adhesion Failurechalking, vin building construction, formation of a powder on the surface 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
15、the sealant.FIG. 3 Cohesive Failurecrazed, adjin building construction, having a random network of cracks in asealant surface which do not penetrate through the body of the material.FIG. 4 CrazedC1756 142dirt pick-up, nin building construction, soiling caused by a foreign materialother than micro-or
16、ganism growth that is deposited on, adhered to, or embeddedinto a sealant.FIG. 5 Dirt Pick-upfluid 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 elastome
17、ricproperties and a decrease in durometer hardness of a seal or cured sealantfollowing environmental exposure.DiscussionSoftening and the ability to permanently reshape a seal or sealantusually characterizes reversion. Depending on a specific seal or sealantformulation, high heat, ultraviolet radiat
18、ion, or moisture (as a liquid or vapor) maycause reversion acting either alone or in combination. The seal and sealantindustry is not in agreement on reversion causes.FIG. 7 Reversionrundown, nin building construction, bloom or fluid migration from a sealant thatdiscoloration of a buildings surfaces
19、 by movement of a contaminant due to naturalforces is carried down and accumulates on vertical and sloping surfaces.forces.DiscussionSimilar patterns of discoloration can be caused by other thanblooming and fluid migration.DiscussionNatural forces include wind, snow-melt,rain movement by surface ten
20、sion, gravity, capillary action, kinetic energy, and aircurrents. Typical movement of contaminants includes fluid migration and bloomingfrom a sealant, deposit of atmospheric pollutants, and chemical staining.FIG. 8 RundownC1756 143APPENDIXX1. TRANSMITTAL FORM SEALANT FAILURE PHOTO(S) FOR C1756INTRO
21、DUCTIONPlease 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 resoluti
22、on of at least 1200 960 pixels, grayscale. (Selected photos will be converted toTIFFs for publication.)X1.1.2 Do not show brand names or other identifiable proprietary information in the photos (or state them on the form).X1.1.3 Photographs of sealant failures in service are preferred to laboratory
23、or mock-up conditions. However, staged or laboratoryphotographs will be considered.X1.1.4 The person submitting these photos represents to ASTM that, to the best of his/her knowledge, information, and belief,there is not copyright or other limitation on ASTMs use of these photos, and he/she acknowle
24、dges that ASTM maintains theexclusive 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 144X1.2 Transmittal FormX1.2.1 Complete as much of
25、this form as possible (leave blanks if necessary), and submit it as an attachment to the same emailmessage with the photos.X1.2.2 Submit completed from in TIFF or PDF format.X1.2.3 Multiple photographs may be submitted with the same transmittal form so long as they relate to the same condition; fore
26、xample, multiple views of the same detail will allow the subcommittee to understand the condition and select the bestrepresentation.Condition illustrated (i.e., adhesion failure): _Generic sealant chemistry, if known (i.e., 2-part urethane): _Substrates (i.e., brick masonry and anodized aluminum): _
27、Approximate date 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 Inter
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