1、Designation: C 1519 04Standard Practice forEvaluating Durability of Building Construction Sealants byLaboratory Accelerated Weathering Procedures1This standard is issued under the fixed designation C 1519; the number immediately following the designation indicates the year oforiginal adoption or, in
2、 the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers the method for the determination ofthe durability of a sealan
3、t based on its ability to function incyclic movement maintaining adhesion and cohesion afterrepeated exposure to laboratory accelerated weathering proce-dures.1.2 This practice describes two laboratory acceleratedweathering procedures for evaluating the durability of asealant.1.3 The RILEM TC139DBS
4、Durability Test Method isrelated to this practice.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 determine the applica-bility of r
5、egulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C 717 Terminology of Building Seals and SealantsC 719 Test Method for Adhesion and Cohesion of Elasto-meric Joint Sealants Under Cyclic Movement (HockmanCycle)C 1442 Practice for Conducting Tests on Sealants UsingArtificia
6、l Weathering ApparatusG 113 Terminology Relating to Natural and ArtificialWeathering Tests of Nonmetallic MaterialsG 141 Guide for Addressing Variability in Exposure Testingon Nonmetallic MaterialsG 151 Practice for Exposing Nonmetallic Materials in Ac-celerated Test Devices That Use Laboratory Ligh
7、t SourcesG 154 Practice for Operating Fluorescent Light ApparatusFor UV Exposure to Nonmetallic MaterialsG 155 Practice for Operating Xenon Arc Light Apparatusfor Exposure of Nonmetallic Materials2.2 RILEM StandardRILEM TC139DBS Durability Test Method Determina-tion of changes in adhesion, cohesion,
8、 and appearance ofelastic weatherproofing sealants for high movement fa-cade joints after exposure to artificial weathering33. Terminology3.1 The definitions given in Terminology C 717 on termsrelating to building seals and sealants and in TerminologyG 113 on terms relating to natural and artificial
9、 weatheringtests are applicable to this practice.4. Significance and Use4.1 This practice describes the procedure to evaluate and/orcompare the durability of sealants when subjected to acceler-ated weathering and cyclic movement in a joint.4.2 Sealant installation procedures, design considerationsan
10、d movement during cure affect the aging processes and arefundamental to the success of any sealant. These factors are notaddressed with this test procedure.4.3 The amount, type and frequency of movement a sealantexperiences during its lifetime strongly depends on the mate-rials used in construction
11、and on the orientation of the jointtoward sunlight and many other factors that are not uniform orconsistent.4.4 Climatic exposures will differ with the orientation of thebuilding and shading as well as with local and regional climaticconditions. Climates in a given location can vary from year toyear
12、 because of differences in solar radiation, temperature,rainfall, and atmospheric conditions. Further, the quality andintensity of solar radiation on the earths surface varies withgeographic location, season, time of day, and cloud cover.4.5 Variations in results may be expected when operatingcondit
13、ions are varied within the accepted limits of this practice.Therefore, all test results using this practice must be accom-panied by a report of the specific operating conditions asrequired in Section 11. Refer to Practice G 151 for detailedinformation on the caveats applicable to use of results obta
14、inedaccording to this practice.1This practice is under the jurisdiction of ASTM Committee C24 on BuildingSeals and Sealants and is the direct responsibility of Subcommittee C24.40 onWeathering.Current edition approved May 1, 2004. Published July 2004. Originally approvedin 2002. Last previous editio
15、n approved in 2002 as C 1519 - 02a.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.3Published in Materials an
16、d Structures (2001), pp. 34, 579588.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.6 The results of laboratory exposure cannot be directlyextrapolated to estimate an absolute rate of deteriorationcaused by natural weathering becau
17、se the acceleration factor ismaterial dependent and can be significantly different for eachmaterial and for different formulations of the same material.However, exposure of a similar material of known outdoorperformance, a control, along with the test specimens allowscomparison of the durability rel
18、ative to that of the controlunder the test conditions. Evaluation in terms of relativedurability also greatly improves the agreement in test resultsamong different laboratories.4.7 Results of this procedure will depend on the care that istaken to operate the equipment according to Practices G 154and
19、 G 155. Significant factors include regulation of the linevoltage, freedom from salt or other deposits from water,temperature control, humidity control, where applicable, con-dition and age of the burners and filters in xenon arc equip-ment, and age of lamps in fluorescent UV equipment.NOTE 1Additio
20、nal information on sources of variability and onstrategies for addressing variability in the design, execution and dataanalysis of laboratory accelerated exposure tests is found in Guide G 141.5. Summary5.1 For this procedure, specimens are prepared in which thesealant to be tested adheres to two pa
21、rallel contact surfaces.This procedure uses the same type of specimens, in the samedimensions, and the same preparation and cure as described inTest Method C 719. While any substrates can be specified andused, this procedure was developed with anodized aluminumsubstrates. Following cure, the specime
22、ns are placed in anartificial weathering chamber for 4 weeks. On removal fromthe weathering chamber, they are placed in a cyclic movementmachine and subjected to 6 cyclic movements of extension andcompression at room temperature according to the method ofC 719. Any degree of extension and compressio
23、n can be used.After the movement cycles the sealant is blocked open at therecommended extension and examined for flaws. The cycle ofweathering followed by movement testing and examination isrepeated as often as specified. After each cycle, the number ofcycles is recorded as well as the mode of failu
24、re, that is,cohesive or adhesive, amount of failure, the depth of anycracks or breaks and other pertinent observations, such assealant deformation and bubble formation.6. Apparatus6.1 Aluminum Supports, for the preparation of test speci-mens (two supports for each specimen). Anodized aluminum isthe
25、standard substrate, but this method can be used with othersubstrates as well. Substrates should be compatible with thesealant, should not degrade under weathering, and should fitinto the joint movement apparatus. If primer is recommendedby the sealant manufacturer, it should be used in accordancewit
26、h the manufacturers recommendations.6.2 Spacers, for the preparation of the specimens should beof a non-adherent material and of a shape to produce a sealantjoint as depicted in Test Method C 719.NOTE 2If the spacers are made of a material to which the sealantadheres, their surfaces should be made n
27、on-adherent, for example, by athin wax coating.6.3 Non-Adherent Substance, for the preparation of testspecimens, for example, polytetrafluoroethylene (PTFE) filmor vellum paper, preferably on the advice of the sealantmanufacturer.6.4 Ventilated Convection-Type Oven, capable of beingmaintained at 50
28、6 2C.6.5 Artificial Weathering DeviceChoice of type of appa-ratus and duration of exposure shall be by mutual agreementamong the interested parties. Because of differences in testconditions, test results may differ with the type of apparatusused. Consult Practices G 154 and G 155 for differences in
29、thespectral power distributions of the exposure sources andPractice C 1442 for the differences in test parameters in the twotypes of apparatus specified.6.5.1 Fluorescent UV/Condensation ApparatusOperatethe device in accordance with Practice C 1442, Section 7.3.6.5.2 Xenon Arc Light ApparatusOperate
30、 the device inaccordance with Practice C 1442, Section 7.2.NOTE 3The xenon arc ruggedness test was run at 70 % RH using anexposure cycle of 2 h light followed by 2 h light plus water spray for morethorough wetting. The test results compared well with those of outdoorexposures. Therefore, these condi
31、tions are considered an alternate to thedefault parameters.7. Preparation of Test Specimens7.1 Adhere the sealant to be tested to two parallel contactsurfaces as described in Test Method C 719. The user is tospecify the number of specimens.7.2 Unless specified otherwise, use anodized aluminumsubstra
32、tes.7.3 For each specimen, assemble two supports and twospacers as shown in Test Method C 719 and set up on thenon-adherent substrate.7.4 Follow the instructions of the sealant manufacturer, forinstance, whether a primer is to be used.7.5 Fill the hollow space formed by supports and spacersshall be
33、with sealant previously conditioned for 24 h at 23 62C. The following precautions shall be taken:(a) avoid the formation of air bubbles;(b) discard the first5gofsealant out of the tube, cartridgeor dispenser;(c) press the sealant towards the contact surface of thesupports; and(d) trim the sealant su
34、rfaces so that they are flush with theface of the supports and spacers.7.6 Backing materials and other joint formation aids shouldbe removed as soon as possible, consistent with no deformationof the sealant, to assist in the curing process.8. Conditioning8.1 The specimens shall be conditioned or cur
35、ed followingthe procedures of Test Method C 719, Section 8.9. Test Procedure9.1 After completion of the above curing process, place thetest specimens in an artificial weathering device so that thesealant surface (top of the joint) faces the exposure source. TheC1519042face of the samples are positio
36、ned at the specified distancefrom the exposure source.9.1.1 If the specimens do not completely fill the racks, fillthe empty spaces with blank metal panels to maintain the testconditions within the chamber.9.1.2 Specimens should be confined to an exposure areawhere the irradiance is at least 90 % of
37、 that measured at thecenter of the exposure area. Unless it is shown that irradianceuniformity meets the requirements of Practice G 151, section5.1.3 for no repositioning, use one of the procedures describedin section 5.1.4 to insure that all specimens receive radiantexposures that are as similar as
38、 possible. Irradiance uniformitycan be determined in accordance with Practice G 151, SectionA1.9.1.3 Operate the artificial weathering device according tothe specifications in 6.5 for 4 weeks.NOTE 4If the irradiance level of the xenon arc apparatus is set at 0.35rather than 0.51 W/m2.nm) at 340 nm,
39、operate it for 5.8 weeks instead of4 weeks. (See Annex A1.2.1 in C 1442 for determination of exposure timeat other irradiance levels.9.2 At the end of the 4 weeks in the artificial weatheringmachine, test the sealant to 6 movement cycles as described inTest Method C 719, section 9.4 and 9.5 (room te
40、mperaturemovement), at the prescribed movement amplitude.9.2.1 Extend the specimen to the prescribed maximumextension and block open with appropriate spacers. Examinethe sealants for any flaws. Flaws include any cracks, breaks,adhesive or cohesive loss. Measure and record the depth of anycrack or fl
41、aw and any pertinent observations. Remove theblocks and allow the samples to recover to the dimensions ofthe sealant at initial cure.9.3 Other measurements such as hardness, tensile strength,elongation and modulus can also be made, if specified.9.4 The artificial weathering exposure, the movement te
42、st,the examination and measurements of any flaws represent onecycle of this durability procedure.9.5 The cycle is to be repeated as often as is specified.Observations and measurements are to be made and recorded atthe end of each cycle.10. Periods of Exposure and Evaluation of Results10.1 In most ca
43、ses, periodic evaluation of materials isnecessary to determine when significant changes occur.10.2 The time of radiant exposure necessary to produce adefined change in a material property can be used to evaluateor rank the stability of materials. This method is more reliablethan evaluating materials
44、 after an arbitrary exposure time orradiant exposure.10.2.1 Exposure to an arbitrary time or radiant exposuremay be used for the purpose of a specific test if agreed upon bythe parties concerned or if required for conformance to aparticular specification. When a single exposure period is used,select
45、 a time or radiant exposure that will produce the largestperformance differences between the test materials.10.2.2 In the development of a specification, the minimumexposure time shall be that necessary to produce a substantialchange in the property of interest for the least stable materialbeing eva
46、luated. An exposure time that produces a significantchange in one type of material cannot be assumed to beapplicable to other types of materials.11. Report11.1 The report shall make reference to this practice andshall include the following information:11.1.1 The name and type of sealant;11.1.2 The b
47、atch of sealant from which the specimens wereproduced, if possible;11.1.3 The type of support material if different than thestandard of anodized aluminum;11.1.4 The primer used, if applicable;11.1.5 Weathering information to conform to the Reportsection of Practice G 151 plus the following:11.1.5.1
48、Type, manufacturer and model of artificial weath-ering apparatus used,11.1.5.2 Irradiance level and actual time (number of hours)in weathering apparatus.11.1.6 The amplitude of extension/compression used for themovement cycles;11.1.7 Whether or not flaws occurred, and, if the affirmative,the cycle a
49、t which they occurred, types of flaws (adhesion orcohesion or other types), and depth of any flaws; and11.1.8 Any deviations from the specified procedures andconditions.12. Keywords12.1 artificial aging; artificial weathering; building sealants;durability; joint movement; sealants; weatheringASTM International takes no 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 su
