1、Designation: C920 14aStandard Specification forElastomeric Joint Sealants1This standard is issued under the fixed designation C920; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses
2、indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 This ASTM specification covers the properties of acured single- or mult
3、icomponent cold-applied elastomeric jointsealant for sealing, caulking, or glazing operations onbuildings, plazas, and decks for vehicular or pedestrian use,and types of construction other than highway and airfieldpavements and bridges.1.2 A sealant meeting the requirements of this specificationshal
4、l be designated by the manufacturer to be one or more ofthe types, classes, grades, and uses defined in Section 7.1.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 This standard is similar, but not identical, to ISO 11600
5、.2. Referenced Documents2.1 ASTM Standards:2C510 Test Method for Staining and Color Change of Single-or Multicomponent Joint SealantsC639 Test Method for Rheological (Flow) Properties ofElastomeric SealantsC661 Test Method for Indentation Hardness of Elastomeric-Type Sealants by Means of a Durometer
6、C679 Test Method for Tack-Free Time of Elastomeric Seal-antsC717 Terminology of Building Seals and SealantsC719 Test Method for Adhesion and Cohesion of Elasto-meric Joint Sealants Under Cyclic Movement (HockmanCycle)C793 Test Method for Effects of Laboratory AcceleratedWeathering on Elastomeric Joi
7、nt SealantsC794 Test Method forAdhesion-in-Peel of Elastomeric JointSealantsC1183 Test Method for Extrusion Rate of Elastomeric Seal-antsC1193 Guide for Use of Joint SealantsC1246 Test Method for Effects of Heat Aging on WeightLoss, Cracking, and Chalking of Elastomeric SealantsAfter CureC1247 Test
8、Method for Durability of Sealants Exposed toContinuous Immersion in LiquidsC1442 Practice for Conducting Tests on Sealants UsingArtificial Weathering Apparatus3. Terminology3.1 DefinitionsRefer to Terminology C717 for definitionsof the following terms used in this specification: adhesivefailure, cau
9、lking, chemically curing sealant, cohesive failure,cure, cured, elastomeric, glazing, joint, primer, seal, sealant,and standard conditions.4. Classification of Sealants4.1 A sealant qualifying under this specification shall beclassified as to type, grade, class, and use as follows:4.1.1 Type SA sing
10、le-component sealant.4.1.2 Type MA multicomponent sealant.4.1.3 Grade PA pourable or selfleveling sealant that hassufficient flow to form a smooth, level surface when applied ina horizontal joint at 4.4C (40F).4.1.4 Grade NSA nonsag or gunnable sealant that permitsapplication in joints on vertical s
11、urfaces without sagging orslumping when applied at temperatures between 4.4 and 50C(40 and 122F).4.1.5 Class 100/50A sealant that when tested for adhesionand cohesion under cyclic movement (8.8) shall withstand anincrease of at least 100 % and a decrease of at least 50 % of thejoint width as measure
12、d at the time of application, and, inaddition, meet all the requirements of this specification.4.1.6 Class 50A sealant that when tested for adhesion andcohesion under cyclic movement (8.8) shall withstand anincrease and decrease of at least 50 % of the joint width asmeasured at the time of applicati
13、on, and, in addition, meet allthe requirements of this specification.1This specification is under the jurisdiction of ASTM Committee C24 onBuilding Seals and Sealants and is the direct responsibility of Subcommittee C24.10on Specifications, Guides and Practices.Current edition approved June 1, 2014.
14、 Published July 2014. Originally approvedin 1979. Last previous edition approved in 2014 as C920 14. DOI: 10.1520/C0920-14A.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, r
15、efer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14.1.7 Class 35A sealant that when tested for adhesion andcohesion under cyclic movement (8.8) shall withstand anincrease an
16、d decrease of at least 35 % of the joint width asmeasured at the time of application, and, in addition, meet allthe requirements of this specification.4.1.8 Class 25A sealant that when tested for adhesion andcohesion under cyclic movement (8.8) shall withstand anincrease and decrease of at least 25
17、% of the joint width asmeasured at the time of application, and, in addition, meet allthe requirements of this specification.4.1.9 Class 1212 A sealant that when tested for adhesionand cohesion under cyclic movement (8.8) shall withstand anincrease and decrease of at least 1212 % of the joint width
18、asmeasured at the time of application, and, in addition, meet allthe requirements of this specification.4.1.10 Use T1A sealant designed for use in joints inpedestrian and vehicular traffic areas such as walkways, plazas,decks and parking garages where a higher durometer sealant isdesired.4.1.11 Use
19、T2A sealant designed for use in joints inpedestrian and vehicular traffic areas such as walkways, plazas,decks and parking garages where a lower durometer sealant isdesired.NOTE 1Hardness alone does not correlate with joint performance. Thejoints in pedestrian and vehicular traffic areas such as wal
20、kways, plazas,decks, and parking garages require appropriate design considerationsincluding material selection, total joint design, manufacturer involvementand field testing.4.1.12 Use NTA sealant designed for use in joints innontraffic areas.4.1.13 Use IA sealant designed for use in joints which ar
21、esubmerged continuously in a liquid.4.1.14 Use MA sealant that meets the requirements of thisspecification when tested on mortar specimens in accordancewith 9.9 and 9.10.4.1.15 Use GA sealant that meets the requirements of thisspecification when tested on glass specimens in accordancewith 9.9 9.11.4
22、.1.16 Use AA sealant that meets this specification whentested on aluminum specimens in accordance with 9.9 and9.10.4.1.17 Use OA sealant that meets this specification whentested on substrates other than the standard substrates inaccordance with 9.9 and 9.10.5. Materials and Manufacture5.1 A single-c
23、omponent sealant shall be a uniform mixtureof a consistency suitable for immediate application by hand orpressure caulking gun or by hand tool. The sealant whencompletely cured shall form an elastomeric solid capable ofmaintaining a seal.5.2 A multicomponent chemically curing sealant shall befurnish
24、ed in two or more components. The resulting mixtureshall be uniform and of a consistency suitable for immediateapplication by hand or pressure caulking gun, or by hand tool.The sealant when completely cured shall form an elastomericsolid capable of maintaining a seal.6. General Requirements6.1 Stabi
25、lity:6.1.1 A single-component sealant, when stored in the origi-nal unopened container at temperatures of not more than 27C(80F) shall be capable of meeting the requirements of thisspecification for at least 6 months after date of delivery.6.1.2 A multicomponent sealant, when stored in the originalu
26、nopened container at temperatures of not more than 27C(80F) shall be capable of meeting the requirements of thisspecification for at least 6 months after date of delivery.6.2 ColorThe color of the sealant, after curing 14 days ina laboratory controlled at standard conditions, shall be thatcolor whic
27、h has been agreed upon between the purchaser andthe supplier.6.3 The sealant shall be intended for use only on clean, drysurfaces. Where a primer is recommended by a manufacturerfor a specific surface, all tests on that surface shall include theprimer.NOTE 2The proper use of primers (or surface cond
28、itioners) inconnection with the application of sealants is described in detail in GuideC1193. This guide also describes proper methods for joint design, back-upmaterials, surface preparation, tooling of sealant, and other importantprocedures in sealant application in buildings.6.4 The same condition
29、s of time, temperature, and humidityshall be used for cure of test specimens for Test Methods C661,C719, C794, and C1247.7. Significance and Use7.1 This specification covers several classifications of seal-ants as described in Section 4 for various applications. Itshould be recognized by the purchas
30、er or design professionalthat not all sealants meeting this specification are suitable forall applications and all substrates. It is essential, therefore, thatthe applicable type, grade, class, and use be specified so thatthe proper classification of sealant is provided for the intendeduse. Test met
31、hods relate to special standard specimen sub-strates of mortar, glass, and aluminum. If tests are requiredusing substrates in addition to or other than the standard, theyshould be so specified for testing.8. Physical Requirements8.1 Rheological Properties:8.1.1 Grade P (pourable or selfleveling) sea
32、lant shall haveflow characteristics such that when tested in accordance withTest Method C639 it shall exhibit a smooth, level surface.(Refer to Types I and III in the test.)8.1.2 Grade NS (nonsag) or gunnable sealant shall haveflow characteristics such that when tested in accordance withTest Method
33、C639 it does not sag more than 4.8 mm (316 in.)in vertical displacement. Also the sealant shall show nodeformation in horizontal displacement. (Refer to Types II andIV in the test.)8.2 Extrusion Rate:8.2.1 Type S (single component), Grade P (pourable orselfleveling) sealant shall have an extrusion r
34、ate of not less than10mL/min when tested in accordance with Test Method C1183,Procedure A.C920 14a28.2.2 Type S (single component), Grade NS (nonsag orgunnable sealant) shall have an extrusion rate of not less than10 mL/min when tested in accordance with Test MethodC1183, Procedure A.8.3 Application
35、 Life:8.3.1 Type M (multicomponent), Grade P (pourable orselfleveling) sealant, when tested in accordance with TestMethod C1183, Procedure A shall be extrudable at a rate of notless than 10 mL/min 3 h after mixing.8.4 Hardness:8.4.1 Use T1(traffic) sealant shall have a hardness reading,after being p
36、roperly cured, of not less than 25 when tested inaccordance with Test Method C661.8.4.2 Use T2(traffic) sealant shall have a hardness reading,after being properly cured, of less than 25 when tested inaccordance with Test Method C661.8.4.3 Use NT (nontraffic) sealant shall have a hardnessreading, aft
37、er being properly cured, of less than 60 when testedin accordance with Test Method C661.8.5 Effects of Heat AgingThe sealant shall not lose morethan 7 % of its original weight or show any cracking orchalking when tested in accordance with Test Method C1246.8.6 Tack-Free TimeThere shall be no transfe
38、r of thesealant to the polyethylene film when tested at 72 h inaccordance with Test Method C679.8.7 Stain and Color ChangeThe sealant shall not causeany visible stain on the top surface of a white cement mortarbase when tested in accordance with Test Method C510.8.8 Adhesion and Cohesion Under Cycli
39、c MovementThetotal loss in bond and cohesion areas among the three speci-mens tested for each surface shall be no more than 9 cm2(112in.2) when tested in accordance with Test Method C719 withstandard mortar, glass, and aluminum or any other specifiedsubstrates.8.9 Adhesion-in-PeelThe peel strength f
40、or each individualtest shall not be less than 22.2 N (5 lbf) when tested inaccordance with Test Method C794 with standard mortar,glass, and aluminum or any other specified substrate. Inaddition, the sealant shall show no more than 25 % adhesivebond loss for each individual test.NOTE 3Curing conditio
41、ns are specified by all of the test methodscited. The manufacturer may request other conditions than those specifiedfor the curing period provided they meet the following requirements: (1)the curing period shall extend for 21 days; (2) the temperature during thecuring period shall not exceed 50C (12
42、2F); and (3) the amended curingconditions recommended by the manufacturer shall also be applied to thedurability, adhesion in peel, and ultraviolet radiation exposure tests.8.10 Adhesion-in-Peel for Use G Exposed to UltravioletExposure Through GlassThe peel strength for each indi-vidual test shall n
43、ot have less than 22.2 N (5 lbf) and thecompound shall be no more than 25 % adhesive bond loss foreach individual test when tested in accordance with TestMethod C794 modified to include 200 h in an acceleratedweathering device followed by 7 days immersion in distilledwater.8.10.1 Exposure ApparatusT
44、he exposure apparatus shallbe one of the three types of laboratory accelerated weatheringdevices described in Practice C1442, that use either xenon arc,fluorescent UV or open flame carbon arc radiation. ConsultPractice C1442 for the differences in test parameters among thedevices. Because of differe
45、nces in test conditions, test resultsmay differ with the type of device used. The choice of deviceshall be by mutual agreement among the interested parties.8.10.1.1 When peel adhesion is to be tested on glasssubstrate specimens after ultraviolet exposure through glass,place the specimens in the weat
46、hering device with the sealantsurface facing away from the light source after 21 days of cureat laboratory conditions. Test conditions in each type of deviceare in accordance with the procedures in C1442, Section 7 onApparatus, except that the xenon arc and open flame carbon arcdevices shall be oper
47、ated without the water spray. Expose thespecimens for 200 h and then continue with 7 days of waterimmersion.NOTE 4Although the xenon arc irradiance setting of 0.35 W/(m2nm)at 340 mm is acceptable, Practice C1442 specifies 0.51 W/(m2nm) at 340mm as the preferred setting. To accommodate testing in xen
48、on arcweathering devices that cannot use the higher irradiance setting, 0.35W/(m2nm) at 340 nm may be used if the length of the total exposure timeis increased to provide the equivalent radiant exposure received at 0.51W/(m2nm) at 340 nm for 200 h exposure. See Annex A1 in PracticeC1442 for determin
49、ing the exposure time.8.10.2 Immediately following the weathering cycle, com-pletely immerse the specimen in distilled or deionized waterfor 7 days. Mortar specimens are placed in a separate containerfrom the glass and aluminum specimens, because the highlyalkali conditions generated could have an effect on the glassand aluminum.8.11 Effects of Accelerated Weathering The sealant shallshow no cracks greater than those shown in Example #2 of Fig.1 in Test Method C793 after the specified ultraviolet exposureand shall show no cracks gre
