1、Designation: C 961 06Standard Test Method forLap Shear Strength of Sealants1This standard is issued under the fixed designation C 961; 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 parenthes
2、es indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers a laboratory procedure fordetermining the lap shear strength of sealants. It also providesinformation on the adhesive bond of the
3、 sealants to the testedsubstrates.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user
4、 of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.4 The subcommittee with jurisdiction of this standard isnot aware of any similar or equivalent ISO standard.2. Referenced Documents2.1 ASTM Standards:C 71
5、7 Terminology of Building Seals and Sealants3. Terminology3.1 Definitions:3.1.1 The definitions of the following terms used in this testmethod are found in Terminology C 717, 4.1: adhesive failure,cohesive failure, sealant, and substrate.4. Summary of Test Method4.1 The sealant is placed between two
6、 glass substrates. Thesample is placed in a tensile tester and pulled at a constant rateto failure. The maximum shear force and mode of failure isnoted. Maximum shear stress is calculated and reported.5. Significance and Use5.1 Sealants are generally subjected to longitudinal andlateral shear stress
7、es in end use applications. This test methodmeasures the cohesive strength of sealants when subjected toshear stresses, and also provides information regarding theadhesive bond to the substrates being tested.6. Apparatus6.1 Sealant Applicator or Oven, capable of maintaining thesealant within 62.8C (
8、65F) of the specified temperature.6.2 Substrates, of annealed glass that are 25.4 mm wide by76.2 mm long and 6.35 mm thick (1 by 3 by 0.25 in.). Othersubstrates may be used when specified (Fig. 1).6.3 Template, to provide 3.18-mm (18-in.) sealant thickness(Fig. 2).6.4 Hot Knife or Spatula.6.5 Tensio
9、n Testing Machine, capable of pulling a specimenat a rate of 12.7 mm (0.5 in.)/min.7. Sampling7.1 Sealant shall be free of external surface contaminantssuch as talc, oil, dust, and moisture. Handling of the sealantsurfaces in contact with the substrate shall be minimized.7.2 A 1.0-kg (2.2-lb) repres
10、entative sample shall be takenfrom bulk stock for testing.8. Test Specimens8.1 Prepare six test specimens from the bulk sample byusing the applicator or the oven method.8.1.1 Applicator Method:8.1.1.1 Clean the substrate surface with soap and waterfollowed by a water rinse and solvent wipe with meth
11、yl ethylketone (MEK).NOTE 1At the request of the sealant manufacturer, an alternativecleaning procedure may be used.8.1.1.2 Using an appropriate die or nozzle, apply a 25.4 by25.4-mm (1 by 1-in.) layer of sealant onto one end of thesubstrate surface at a thickness that when compressed willcomply wit
12、h 8.1.1.4. Substrates shall be at a temperature of 236 2C, 50 6 10 % relative humidity (73.4 6 3.6F). Apply thesealant at the specified temperature 62.8C (65F) (Fig. 1).8.1.1.3 Immediately after sealant application place a secondsubstrate onto the sealant to form an overlap of 6.45 cm2(1 in.2)(Fig.
13、1).8.1.1.4 Using a template (Fig. 2), compress the overlayedsealant to form the 3.18-mm (18-in.) thick overlap (Fig. 3).1This test method is under the jurisdiction ofASTM Committee C24 on BuildingSeals and Sealants and is the direct responsibility of Subcommittee C24.30 onAdhesion.Current edition ap
14、proved Sept. 1, 2006. Published September 2006 Originallyapproved in 1981. Last previous edition approved in 2001 as C 961 01.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.8.1.1.5 Remove excess sealant from the specimen with a hotk
15、nife or spatula.8.1.2 Oven Method:8.1.2.1 Clean the substrate surface with soap and waterfollowed by a water rinse and solvent wipe with MEK (Note1).8.1.2.2 Place sufficient sealant onto the substrate so thatwhen compressed, a 6.45-cm2(1-in.2) overlap that will complywith 8.1.2.4 is obtained.8.1.2.3
16、 Separately place both the substrate with sealant andthe overlapping substrate into an oven and condition for 30 minat the specified temperature.8.1.2.4 Immediately upon removing the substrates from theoven, place the second substrate onto the sealant on the firstsubstrate (Fig. 1). Using the templa
17、te (Fig. 2), compress theoverlayed sealant to form a 3.18-mm (18-in.) thick overlap(Fig. 3).8.1.2.5 Remove excess sealant from the specimen with a hotknife or spatula.9. Conditioning9.1 Condition all test specimens at 23 6 2C (73.4 6 3.6F)for at least 24 h prior to testing.9.2 Additional conditionin
18、g may be done as specified bymutual agreement between the purchaser and sealant manufac-turer.10. Procedure10.1 Attach each specimen to the jaws of the tension testingmachine and separate at a crosshead speed of 12.7 mm (0.5in.)/min to failure (separation) (Fig. 4). Align the testingmachine jaws to
19、prevent cocking of test assembly.10.2 Visually inspect and record the mode of bond failure(cohesive or adhesive) and the approximate percentage of each.10.3 Observe and record the maximum shear force innewtons (or pounds-force).11. Calculation11.1 Calculate the maximum shear stress, S, as follows:S
20、5 F/Awhere:S = maximum shear stress, Pa (or lbf/in.2),F = maximum shear force, N (or lbf), andA = contact area of the specimen with one substrate, m2(orin.2).11.2 Average the results of the six specimens tested.12. Report12.1 Report the following information:12.1.1 Equipment used to apply the sealan
21、t,12.1.2 Average maximum lap shear stress and range ofvalues in Pa (or psi),12.1.3 Any substrate deformation during testing and degreeof deformation,12.1.4 Type of failure, adhesive, or cohesive, and percent-age of each,12.1.5 Sealant application temperature,12.1.6 Oven temperature and time of condi
22、tioning, if differ-ent from 8.1.2.3,12.1.7 Substrates tested,12.1.8 Substrate cleaning procedure if different from 8.1.1.1and 8.1.2.1, and12.1.9 Any additional conditioning as allowed by 9.2.13. Precision and Bias213.1 The precision and bias of this test method are based ondata obtained from results
23、 from six laboratories using sixreplicate specimens, glass substrates, and a high-modulussealant. Both applicator and oven methods were used and themode of failure on all samples was cohesive.13.2 Applicator MethodIn the laboratory study using thismethod the within-laboratory coefficient of variatio
24、n was foundto be 9.11 % of the mean and the between-laboratory coeffi-cient of variation was found to be 11.8 % of the mean.13.2.1 RepeatabilityTwo results, each the mean of tripli-cate determinations, obtained by the same operator on differentdays, should be considered suspect if they differ by mor
25、e than14.6 % relative.13.2.2 ReproducibilityTwo results, each the mean of trip-licate determinations, obtained by operators in different labo-ratories, should be considered suspect if they differ by morethan 34.0 % relative.13.3 Oven MethodIn the interlaboratory study using thismethod, the within-la
26、boratory coefficient of variation wasfound to be 8.11 % of the mean and the between-laboratorycoefficient of variation was found to be 10.37 % of the mean.2Supporting data have been filed at ASTM Headquarters. Request RR: C24-1041.LengthDimension mm in.G, J 76.2 6 0.25 (3.006 0.01)H, K, M 25.4 6 0.2
27、5 (1.00 6 0.01)I, L 6.35 6 0.10 (0.2506 0.004)FIG. 1 Assembly of Test Sealant on SubstratesC96106213.3.1 RepeatabilityTwo results, each the mean of tripli-cate determinations, obtained by the same operator on differentdays, should be considered suspect if they differ by more than13.0 % of the mean.1
28、3.3.2 ReproducibilityTwo results, each the mean of trip-licate determinations, obtained by operators in different labo-ratories should be considered suspect if they differ by morethan 31.5 % of the mean.LengthDimension mm in.A 76.2 6 5 (3.006 0.20)B over 12.7 (over 0.50)C 6.35 6 0.25 (0.256 0.01)D 5
29、0.8 6 0.25 (2.006 0.01)E 9.525 6 0.10 (0.375 6 0.004)F over 76.2 (over 3.00)NOTE 1The template shall be made of a material of low thermal conductivity, such as wood or fiberglass.FIG. 2 TemplateFIG. 3 Test Assembly on Template After CompressionC96106313.4 No statement can be made on the bias of this
30、 testmethod since no referee method is available for determiningthese properties. When the test method is conducted asdescribed herein, the method is believed to be without bias.14. Keywords14.1 lap shear; lap shear strength; sealant; shear strengthASTM International takes no position respecting the
31、 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 standard is
32、 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 International Hea
33、dquarters. 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 below.This st
34、andard 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).FIG. 4 Test Assembly Installed in Testing MachineC961064
