1、Designation: C1756 14C1756 17Standard 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 r
2、evision. 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 avai
3、lable, 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 o
4、ver this 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 safety, health an
5、d healthenvironmental practices and determine theapplicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of Internationa
6、l Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers 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 Terminology C717.4. Signif
7、icance and Use4.1 This guide is intended to be used in 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 defi
8、ned by Committee C24.4.2 Not all of the terms illustrated 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
9、Photographs5.1 Figs. 1-9 present a standard reference photograph 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 T
10、his guide is under the jurisdiction of ASTM Committee C24 on Building Seals and Sealants and is the direct responsibility of Subcommittee C24.10 onSpecifications,Guides and Practices.Current edition approved Jan. 1, 2014Sept. 1, 2017. Published January 2014September 2017. Originally approved in 2011
11、 Last previous edition approved in 20112014as C1756-11.-14. DOI: 10.1520/C1756-14.10.1520/C1756-17.2 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 Doc
12、ument Summary page on the ASTM website.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. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM
13、recommends that users consult prior editions as appropriate. In all 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
14、failure, nin building construction, failure of the bond between asealant 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
15、common and may appear to beinterfacial without the use of magnification.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,
16、 nin building construction, failure characterized by rupturewithin 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 172dirt pick-up, nin building co
17、nstruction, 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 migration, nin building construction, accumulation of a fluid from a sealanton or in an adjacent material.FIG. 6 Fluid Migrationrevers
18、ion, nin building construction in joint sealing, a loss of elastomericproperties 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
19、 specific seal or sealantformulation, high heat, ultraviolet radiation, 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, discoloration
20、of a buildings surfaces bymovement of a contaminant due to natural forces.DiscussionNatural forces include wind, snow-melt, rain movement by surfacetension, gravity, capillary action, kinetic energy, and air currents.Typical movementof contaminants includes fluid migration and blooming from a sealan
21、t, deposit ofatmospheric pollutants, and chemical staining.FIG. 8 RundownC1756 173APPENDIXX1. TRANSMITTAL FORM SEALANT FAILURE PHOTO(S) FOR C1756INTRODUCTIONPlease submit photographs of sealant failures with this transmittal from by email to thesubcommittee C24.10 on Specifications, Guides and Pract
22、ices, 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 1200 960 pixels, grayscale. (Selected photos will be converted toTIFFs for publication.)X1.1.2 Do not show brand names or other identif
23、iable proprietary information in the photos (or state them on the form).X1.1.3 Photographs of sealant failures in service are preferred to laboratory or mock-up conditions. However, staged or laboratoryphotographs will be considered.X1.1.4 The person submitting these photos represents to ASTM that,
24、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 acknowledges that ASTM maintains theexclusive right to publish these phtotos.sagnin building construction, the gravity-induced downward flow of asealant or gl
25、azing compund, resulting in an uneven thickness, when applied on avertical surface.FIG. 9 SagC1756 174X1.2 Transmittal FormX1.2.1 Complete as much of 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 fro
26、m 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; forexample, multiple views of the same detail will allow the subcommittee to understand the condition and select the bestrepresentation.Condition illustra
27、ted (i.e., adhesion failure): _Generic sealant chemistry, if known (i.e., 2-part urethane): _Substrates (i.e., brick masonry and anodized aluminum): _Approximate date sealant was installed, if known: _Data photo taken: _Location (city, state): _Weather exposure (i.e., north face under roof eave): _O
28、bservations and comments to be considered by subcommittee: _Form completed and photo(s) submitted by (printed name): _Submitted on (date): _ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this
29、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 responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years
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32、959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 175
