1、Designation: C961 06 (Reapproved 2011)C961 15Standard Test Method forLap Shear Strength of Sealants1This standard is issued under the fixed designation C961; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision
2、. 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 test method covers a laboratory procedure for determining the lap shear strength of sealants. It also providesinformation on t
3、he adhesive bond of the sealants to the tested substrates.1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is th
4、e responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.1.4 The subcommittee with jurisdiction of this standard is not aware of any similar or equivalent ISO standard.2. Referenced Documen
5、ts2.1 ASTM Standards:2C717 Terminology of Building Seals and Sealants3. Terminology3.1 DefinitionsThe Refer to Terminology C717 for definitions of the following terms used in this test method are found inTerminology method: C717, 4.1: adhesive failure, cohesive failure, sealant, standard conditions,
6、 and substrate.4. Summary of Test Method4.1 The sealant is placed between two glass substrates. The sample is placed in a tensile tester and pulled at a constant rate tofailure. The maximum shear force and mode of failure is noted. Maximum shear stress is calculated and reported.5. Significance and
7、Use5.1 Sealants are generally subjected to longitudinal and lateral shear stresses in end use applications. This test method measuresthe cohesive strength of sealants when subjected to shear stresses, and also provides information regarding the adhesive bond tothe substrates being tested.6. Apparatu
8、s6.1 Sealant Applicator or Oven, capable of maintaining the sealant within 62.8C (65F) of the specified temperature.6.2 Substrates, of annealed glass that are 25.4 mm wide by 76.2 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 pro
9、vide 3.18-mm (18-in.) sealant thickness (Fig. 2).6.4 Hot Knife or Spatula.6.5 Tension Testing Machine, capable of pulling a specimen at a rate of 12.7 mm (0.5 in.)/min.7. Sampling7.1 Sealant shall be free of external surface contaminants such as talc, oil, dust, and moisture. Handling of the sealant
10、 surfacesin contact with the substrate shall be minimized.1 This test method is under the jurisdiction ofASTM Committee C24 on Building Seals and Sealants and is the direct responsibility of Subcommittee C24.30 on Adhesion.Current edition approved Dec. 1, 2011Dec. 1, 2015. Published January 2012Janu
11、ary 2015. Originally approved in 1981. Last previous edition approved in 20062011 asC961C96106(2011).06. DOI: 10.1520/C0961-06R11.10.1520/C0961-15.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standard
12、svolume information, refer to the standards Document 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
13、adequately depict all changes accurately, ASTM 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 Consh
14、ohocken, PA 19428-2959. United States17.2 A 1.0-kg (2.2-lb) representative sample shall be taken from bulk stock for testing.8. Test Specimens8.1 Prepare six test specimens from the bulk sample by using the applicator or the oven method.8.1.1 Applicator Method:8.1.1.1 Clean the substrate surface wit
15、h soap and water followed by a water rinse and solvent wipe with methyl ethyl ketone(MEK).NOTE 1At the request of the sealant manufacturer, an alternative cleaning procedure may be used.8.1.1.2 Using an appropriate die or nozzle, apply a 25.4 by 25.4-mm (1 by 1-in.) layer of sealant onto one end of
16、the substratesurface at a thickness that when compressed will comply with 8.1.1.4. Substrates shall be at a temperature of 2362C, 50610 %relative humidity (73.4 6 3.6F). standard conditions. Apply the sealant at the specified temperature 62.8C (65F) (Fig. 1).8.1.1.3 Immediately after sealant applica
17、tion place a second substrate onto the sealant to form an overlap of 6.45 cm2 (1 in.2)(Fig. 1).8.1.1.4 Using a template (Fig. 2), compress the overlayed sealant to form the 3.18-mm (18-in.) thick overlap (Fig. 3).8.1.1.5 Remove excess sealant from the specimen with a hot knife or spatula.8.1.2 Oven
18、Method:8.1.2.1 Clean the substrate surface with soap and water followed by a water rinse and solvent wipe with MEK (Note 1).8.1.2.2 Place sufficient sealant onto the substrate so that when compressed, a 6.45-cm2 (1-in.2) overlap that will comply with8.1.2.4 is obtained.8.1.2.3 Separately place both
19、the substrate with sealant and the overlapping substrate into an oven and condition for 30 min atthe specified temperature.8.1.2.4 Immediately upon removing the substrates from the oven, place the second substrate onto the sealant on the firstsubstrate (Fig. 1). Using the template (Fig. 2), compress
20、 the overlayed 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 hot knife or spatula.9. Conditioning9.1 Condition all test specimens at 23 6 2C (73.4 6 3.6F) standard conditions for at least 24 h prior to testing.9.2 Additional conditio
21、ning may be done as specified by mutual agreement between the purchaser and sealant manufacturer.LengthDimension mm in.G, J 76.2 0.25 (3.00 0.01)H, K, M 25.4 0.25 (1.00 0.01)I, L 6.35 0.10 (0.250 0.004)FIG. 1 Assembly of Test Sealant on SubstratesC961 15210. Procedure10.1 Attach each specimen to the
22、 jaws of the tension testing machine and separate at a crosshead speed of 12.7 mm (0.5 in.)/minto failure (separation) (Fig. 4). Align the testing machine jaws to prevent cocking of test assembly.10.2 Visually inspect and record the mode of bond failure (cohesive or adhesive) and the approximate per
23、centage of each.LengthDimension mm in.A 76.2 5 (3.00 0.20)B over 12.7 (over 0.50)C 6.35 0.25 (0.25 0.01)D 50.8 0.25 (2.00 0.01)E 9.525 0.10 (0.375 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
24、 Test Assembly on Template After CompressionC961 15310.3 Observe and record the maximum shear force in newtons (or pounds-force).11. Calculation11.1 Calculate the maximum shear stress, S, as follows:S 5F/A (1)where:S = maximum shear stress, Pa (or lbf/in.2),F = maximum shear force, N (or lbf), andA
25、= contact area of the specimen with one substrate, m2 (or in.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 sealant,12.1.2 Average maximum lap shear stress and range of values in Pa (or psi),12.1.3 Any substr
26、ate deformation during testing and degree of deformation,12.1.4 Type of failure, adhesive, or cohesive, and percentage of each,12.1.5 Sealant application temperature,12.1.6 Oven temperature and time of conditioning, if different from 8.1.2.3,12.1.7 Substrates tested,12.1.8 Substrate cleaning procedu
27、re if different from 8.1.1.1 and 8.1.2.1, and12.1.9 Any additional conditioning as allowed by 9.2.FIG. 4 Test Assembly Installed in Testing MachineC961 15413. Precision and Bias313.1 The precision and bias of this test method are based on data obtained from results from six laboratories using six re
28、plicatespecimens, glass substrates, and a high-modulus sealant. Both applicator and oven methods were used and the mode of failure onall samples was cohesive.13.2 Applicator MethodIn the laboratory study using this method the within-laboratory coefficient of variation was found tobe 9.11 % of the me
29、an and the between-laboratory coefficient of variation was found to be 11.8 % of the mean.13.2.1 RepeatabilityTwo results, each the mean of triplicate determinations, obtained by the same operator on different days,should be considered suspect if they differ by more than 14.6 % relative.13.2.2 Repro
30、ducibilityTwo results, each the mean of triplicate determinations, obtained by operators in different laboratories,should be considered suspect if they differ by more than 34.0 % relative.13.3 Oven MethodIn the interlaboratory study using this method, the within-laboratory coefficient of variation w
31、as found tobe 8.11 % of the mean and the between-laboratory coefficient of variation was found to be 10.37 % of the mean.13.3.1 RepeatabilityTwo results, each the mean of triplicate determinations, obtained by the same operator on different days,should be considered suspect if they differ by more th
32、an 13.0 % of the mean.13.3.2 ReproducibilityTwo results, each the mean of triplicate determinations, obtained by operators in different laboratoriesshould be considered suspect if they differ by more than 31.5 % of the mean.13.4 No statement can be made on the bias of this test method since no refer
33、ee method is available for determining theseproperties. When the test method is conducted as described 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 validity of any patent r
34、ights 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 subject to revision at a
35、ny 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 Headquarters. Your comments w
36、ill 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 standard is copyrighted by A
37、STM 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);
38、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:/ Supporting data have been filed at ASTM International Headquarters and may be obtained by requesting Research Report RR:C24-1041.C961 155
