1、Designation: C661 15Standard Test Method forIndentation Hardness of Elastomeric-Type Sealants byMeans of a Durometer1This standard is issued under the fixed designation C661; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、 of last revision. A number in parentheses 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 test method describes a
3、 laboratory procedure fordetermining indentation hardness of joint sealing compounds,(single- and multicomponent), intended for use in buildingconstruction.1.2 The values stated in SI units are to be regarded as thestandard. The values in parentheses are for information only.1.3 The committee with j
4、urisdiction over this standard is notaware of any comparable standards published by other orga-nizations.1.4 This standard does not purport to address the safetyconcerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety andhealth p
5、ractices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C717 Terminology of Building Seals and SealantsD2240 Test Method for Rubber PropertyDurometer Hard-ness3. Terminology3.1 DefinitionsSee Terminology C717 for applicable defi-nitio
6、ns of the following terms: compound; elastomeric; hard-ness; joint; sealant, non-sag; sealant, self-leveling, and stan-dard conditions.4. Significance and Use4.1 The results obtained by this test method are simply ameasure of the indentation into the sealant material of theindentor under load; they
7、are not generally considered ameasure of abrasion or wear resistance of the sealant.5. Apparatus5.1 Durometer, Type A-2, with a dial graduated in units from0 to 100. (See Test Method D2240 for a description of theindentor and a method of calibration of the durometer.)5.2 Rectangular Brass Frame, wit
8、h inside dimensions 130by 40 by 6 mm (approximately 5 by 112 by14 in.).5.3 Aluminum Plates, two 16 to 24 gage, 80 by 150 mm(approximately 3 by 6 in.).5.4 Thin-Bladed Knife.5.5 Chamber, capable of maintaining 38 6 2C (100 63.5F) and 95 % relative humidity.5.6 Metal Straightedge.6. Standard Test Condi
9、tions6.1 Unless otherwise specified by those authorizing thetests, testing is conducted under standard conditions as definedin Terminology C717.7. Procedure7.1 Test for Hardness of Multicomponent Sealants:7.1.1 Condition at least 250 g of base compound andappropriate amounts of curing agent for at l
10、east 24 h atstandard conditions; then mix the components thoroughly for 5min.7.1.2 Fill the brass frame, after centering it on the aluminumplate, with a portion of the conditioned compound and strike itoff flat with a metal straightedge. Lift the frame from thesealant after separating it by running
11、a thin-bladed knife alongthe inside of the frame. Prepare two such specimens and curethem for 14 days at standard conditions.NOTE 1In the case of a self-leveling sealant or compound, do not liftthe brass frame until the sealant is sufficiently cured so that it will notspread on the plate.7.1.3 At th
12、e end of the curing period, take three hardnessreadings on each specimen at standard conditions. Hold thedurometer on the surface of the specimen and press it firmly1This test method is under the jurisdiction ofASTM Committee C24 on BuildingSeals and Sealants and is the direct responsibility of Subc
13、ommittee C24.20 onGeneral Test Methods.Current edition approved June 1, 2015. Published July 2014. Originally approvedin 1970. Last previous edition approved in 2011 as C661 06(2011). DOI:10.1520/C0661-15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer S
14、ervice at serviceastm.org. For Annual Book of ASTMStandards volume information, refer 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 States1against the surface using a force of about
15、 1.3 kgf (3 lbf). Keepthe pressure foot parallel to the surface of the specimen. Takethe instantaneous indentation reading immediately after mak-ing firm contact between the pressure foot and the specimen.After taking the first reading, shift the durometer (or specimen)to a new position in order to
16、avoid errors due to fatigue andsurface effects from the previous indentation. Take readings onsmooth portions of the surface no closer than 13 mm (12 in.)from the edges of the sealant pat and also no closer than 25 mm(1 in.) from each other. Note the individual values, eachrounded off to the nearest
17、 unit on the scale.NOTE 2The highest precision in this test can be obtained when thedurometer is supported by a rigid stand and a dead weight is fasteneddirectly to the instrument with the center of gravity of the weight actingin line of the indentor point. A freely acting total deadweight load ofap
18、proximately 1.3 kgf (3 lbf) has been found satisfactory for the testing ofvarious sealants (Fig. 1).NOTE 3The values obtained in the test method described in 7.1.3 areknown as “instantaneous” values. Occasionally a purchaser may request“delayed” values such as these taken aftera5or10-s delay. To obt
19、ain adelayed value the same procedure is followed, except that the pressurefoot is allowed to rest on the surface of the sealant under the fixed load forthe additional time requested and a reading is taken at the specified time,for example, after 5 s, 10 s, or other specified period. Delayed reading
20、s aretaken in addition to the instantaneous reading. An instrument with amaximum reading hand is helpful in making such determinations.7.2 Test for Hardness of Single-Component Sealants:7.2.1 Condition at least 250 g of compound for a minimumof 24 h at standard conditions before starting the test.7.
21、2.2 Center the brass frame on the aluminum plate and fillthe opening with a portion of the conditioned compound,striking the compound off flat with a straightedge. Lift theframe from the sealant after separating it by running athin-bladed knife along the inside edge of the frame. Two suchspecimens s
22、hall be prepared.7.2.3 Cure the test specimens for a total of 21 days asfollows: 7 days at standard conditions; 7 days in a chambercontrolled at 38 6 2C (100 6 3.5F) and 95 % relativehumidity; and 7 days at standard conditions.NOTE 4The manufacturer may request combinations of temperatureand relativ
23、e humidity for curing purposes other than those specified,provided that (1) the curing period is not longer than 21 days and (2) thetemperature does not exceed 50C (122F).7.2.4 At the end of the 21-day curing period, proceed asdescribed in 7.1.3. (See Notes 2 and 3.)8. Report8.1 Report the following
24、 information for each specimentested:8.1.1 Tradename or other identification of the sealant.8.1.2 Description of the type of compound, such as whethernon-sag, self-leveling sealant, single- or multi-component,color, etc.8.1.3 Description of the curing conditions used in test.8.1.4 Name and descripti
25、on of the durometer.8.1.5 The six individual hardness values and the meanvalue.8.1.5.1 To determine the mean value, individual readingswith a variation of 15 % from the average value of the sixreadings shall be discarded. If more than two readings are thusdiscarded, a completely new set of six readi
26、ngs shall be taken.8.1.6 The delayed reading values, if they are specified bythe purchaser.9. Precision and Bias39.1 The precision and bias calculations for this test methodare based on the results of four laboratories testing five sealantsperforming the test five times for each sealant. The results
27、 aregiven in Table 1.9.2 In another series, ten laboratories tested three well-curedsealants. All were cured by one laboratory and distributed andtested on the same day by all ten laboratories. Two testingdevices were used on all three sealants (one hand held, onefixed to a stand); all were calibrat
28、ed. The results are given inTable 2.NOTE 5The key to the reproducibility between laboratories improvingin 9.2 over 9.1 is the elimination of the variability of the cure cycle fromlaboratory to laboratory. The data in 9.2 indicates the test can be relativelyprecise if the cure cycle is identically re
29、peated in each laboratory. Theusual case between laboratories may more closely be represented by thestatistics in 9.1.3Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:C24-1015.FIG. 1 Type of Durometer Used to Measure Indentation
30、Hardnessof Joint SealantsC661 1529.3 The data using four test machines (two hand held, twoon a stand), all on the same cure sealant in each at tenlaboratories, is given in Table 3.10. Keywords10.1 elastomeric sealant; hardnessASTM International takes no position respecting the validity of any patent
31、 rights asserted in connection with any item mentioned inthis 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
32、 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 Headquarters. Your comment
33、s 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 standard is copyrighted b
34、y 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
35、); 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:/ 1 Precision and Bias Data from Four Laboratories for Five SealantsAMaterial AverageEsti
36、mated StandardDeviation Within aLaboratoryEstimated StandardDeviation BetweenLaboratoriesRepeatability(Internal)Reproducibility(Internal)G1 12.8 1.4 2.4 4.4 18.1G2 36.2 3.5 4.0 6.2 16.0G3 43.8 1.6 6.4 4.0 6.8G4 25.7 3.6 7.8 10.1 22.0G5 38.2 2.2 5.6 9.9 11.2AAt 95 % confidence, the durometer as measu
37、red by this test method can vary 10 points within a laboratory and 22 points between laboratories.TABLE 2 Precision and Bias Data from Ten Laboratories forThree Cured SealantsAMaterial AverageEstimated StandardDeviation Within aLaboratoryEstimated StandardDeviation BetweenLaboratoriesG2 40 2.3 2.6G1
38、 41 2.3 2.8G3 71 1.4 2.0AAt 95 % confidence a durometer can vary 6 points within a laboratory and 8points between laboratories.TABLE 3 Precision and Bias Data from Ten Laboratories withOne Cured Sealant and Two Testing InstrumentsAMaterial AverageEstimated StandardDeviation BetweenLaboratoriesG4 67 1.1G2 70 2.1G3 71 0.6G1 71 1.6AAt 95 % confidence, a durometer can vary 6 points between laboratories whendifferent test machines are used.C661 153
