1、Designation: C1756 11Standard 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. A numb
2、er 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 sealantbehavior terms that have been defined by Committee C24.1.2 When available, photograp
3、hs 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 with jurisdiction over this standar
4、d 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 safety and health practices and determi
5、ne the applica-bility of regulatory limitations 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 TerminologyC717.4. Significance and Use4.1 This guide is intended to be used in evaluat
6、ing 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 illustrate terms defined byCommittee C24.4.2 Not all of the terms illustrated here
7、 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. Reference Photographs5.1 Figs. 1-9 present a standard reference photograph
8、 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; sag1This guide is under the jurisdiction ofASTM Committee C24 on Buildin
9、g Sealsand Sealants and is the direct responsibility of Subcommittee C24.10 onSpecifica-tions, Guides and Practices.Current edition approved June 15, 2011. Published August 2011. DOI: 10.1520/C1756-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Servi
10、ce at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.adhesion failure, nin building construction,
11、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 common and may appear to beinerfacia
12、l 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, nin building construction, failure c
13、haracterized 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 112dirt pick-up, nin building construction, soiling caused by a forei
14、gn 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 Migrationreversion, nin building construction in joi
15、nt 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 specific seal or sealant formula-tio
16、n, high heat, ultraviolet radiation, or moisture (as a liquid or vapor) may causereversion acting either alone or in combination. The seal and sealant industry is notin agreement on reversion causes.FIG. 7 Reversionrundown, nin building construction, bloom or fluid migration from a sealant thatdue t
17、o natural forces is carried down and accumulates on vertical and slopingsurfaces.DiscussionSimilar patterns of discoloration can be caused by other thanblooming and fluid migration.FIG. 8 RundownC1756 113APPENDIXX1. TRANSMITTAL FORM SEALANT FAILURE PHOTO(S) FOR C1756INTRODUCTIONPlease submit photogr
18、aphs 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 least1200 3 960 pix
19、els, grayscale. (Selected photos will beconverted 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 conditions. Howev
20、er, 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 main-tains the e
21、xclusive 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 114X1.2 Transmittal FormX1.2.1 Complete as much of this form as possible (leaveb
22、lanks 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 views of the s
23、ame 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 sealant was ins
24、talled, 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 position respe
25、cting 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 responsibility.This st
26、andard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM Internat
27、ional 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 address shown belo
28、w.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,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 ASTM website (www.astm.org/COPYRIGHT/).C1756 115
