1、Designation: C 794 06Standard Test Method forAdhesion-in-Peel of Elastomeric Joint Sealants1This standard is issued under the fixed designation C 794; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A num
2、ber in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This test method covers a laboratory procedure fordeterm
3、ining the strength and characteristics of the peel prop-erties of a cured-in-place elastomeric joint sealant, single- ormulticomponent, for use in building construction.1.2 The values stated in metric (SI) units are to be regardedas the standard. The values given in parentheses are providedfor infor
4、mation only.1.3 The committee with jurisdiction over this standard is notaware of any comparable standards published by other orga-nizations.1.4 This standard does not purport to address all of thesafety problems, if any, associated with its use. It is theresponsibility of the user of this standard
5、to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C33 Specification for Concrete AggregatesC 109/C 109M Test Method for Compressive Strength ofHydraulic Cement Mortars(Using 2-in. o
6、r 50-mm CubeSpecimens)C 150 Specification for Portland CementC 717 Terminology of Building Seals and SealantsC 1442 Practice for Conducting Tests on Sealants UsingArtificial Weathering ApparatusG113 Terminology Relating to Natural and ArtificialWeathering Tests of Nonmetallic Materials3. Terminology
7、3.1 The definitions given in Terminology C 717 on termsrelating to building seals and sealants and in TerminologyG113 on terms relating to natural and artificial weatheringtests are applicable to this test method.4. Summary of Test Method4.1 This test method consists of preparing test specimens byem
8、bedding a strip of cloth in a thin layer of the sealant beingtested, on several substrate materials, curing these specimensfor a certain length of time under specified conditions, thenplacing them in a tension-testing machine in such a way thatthe embedded cloth is peeled back from the substrate at
9、180,and measuring the force exerted as well as the nature of theseparation of the sealant from the substrate.5. Significance and Use5.1 There are differences in opinion among those concernedwith sealant technology whether or not this adhesion-in-peeltest is intended to simulate the conditions encoun
10、tered by asealant in normal use. Nevertheless, since it represents a test todestruction, the value of the test denotes the ability of the curedsealant to maintain a bond to the substrate under severeconditions.5.2 Many sealant manufacturers utilize the adhesion-in-peeltest for determining the adhesi
11、ve characteristics of sealant/primer combinations with unusual or proprietary substrates.6. Apparatus and Materials6.1 Testing Machine with tension grips capable of pulling atthe rate of separation of 51 mm (2 in.)/min, and having a chartindicator calibrated in 0.45-kg (1-lb) units.6.2 Standard Subs
12、trates:6.2.1 Aluminum Alloy, Type 6063-T5 or 6061-T6, with aclear anodized finish of not less than 0.0075-mm (0.3-mil)thickness over a scale-free finish; 2 pieces, 152 by 76 by 6.3mm (6 by 3 by14 in.).6.2.2 Mortar Slabs, prepare two cement mortar slabs, each152 by 76 by 9.5 mm (6 by 3 by38 in.) in s
13、ize, using one partof high early strength Portland cement conforming to Type IIIof Specification C 150 for Portland Cement, to two parts byweight of clean, uniformly graded, concrete fine aggregate(sand) conforming to Specification C33, for Concrete Aggre-gates. Use sufficient water to produce a flo
14、w of 100 6 5 whentested in accordance with the procedure for the determination1This 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 approved Sept. 15, 2006. Published September
15、 2006. Originallyapproved in 1975. Last previous edition approved in 2001 as C 794 01.2For 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
16、 page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.of consistency of cement mortar described in Test MethodC 109. After curing 1 day in moist air and 6 days in saturatedlime water at 23 6 2C (73 6 3F), prepare t
17、he surface of 152by 76 mm (6 by 3 in.) of each slab by wet grinding either sidewith a belt sander using No. 60 aluminum carbide sanding beltor using an iron lap with No. 60 silicon carbide (or aluminumoxide) grain until the aggregate is uniformly exposed. Returnthe slabs to saturated lime water stor
18、age until needed.6.2.2.1 Slabs may be prepared and shipped to other loca-tions for use. The slabs may be shipped dry and shall bereturned to saturated lime water storage on arrival until needed.6.2.2.2 Prior to use, wet grind the previously ground surfaceto remove any laitance, rinse thoroughly unde
19、r running tapwater, and dry the slabs overnight at 105 to 110C (220 to230F). Clean the slabs by vigorous brushing with a stiff-bristled fiber brush to remove any film or powder. Conditionthe slabs at standard conditions for not less than 1 day and notmore than 7 days.6.2.3 Plate Glass, polished, cle
20、ar, 152 by 76 by 6.3 mm (6by3by14 in.).NOTE 1Because of the fact that adhesive properties of a joint sealantare related to the nature of the substrate, it is strongly recommended thatwhenever possible the peel test be made with the substrates that are to beused in the building under consideration in
21、 addition to or in place of thespecified substrates described in 6.2.1, 6.2.2, and 6.2.3. Such substratesinclude brick, marble, limestone, granite, stainless steel, plastic, quarrytile, and others. For practical reasons the specimen dimensions may bechanged from the standard sizes provided the thick
22、ness of the sealantremains as specified.6.3 Spacer Strips, four, of hard wood, metal, or glass asfollows: two 152 by 76 by 6.3 mm (6 by 3 by14 in.) forpreparing the test specimens on aluminum and glass, and twoof the same length and width but 9.3 mm (38 in.) thick forpreparing the test specimens on
23、mortar.6.4 Glass Rod, about 12.7 mm (12 in.) in diameter and about305 mm (12 in.) long.6.5 Stainless Steel or Brass Rods, two, 1.6 mm (116 in.) indiameter, about 305 mm (12 in.) long.6.6 Masking Tape, paper, roll, 25.4 mm (1 in.) wide.6.7 Airplane3/Wire4Cloth Grade A, desized, 4.28 oz/yd,80/84 count
24、, 6 pieces at least 178 mm (7 in.) long and 76 mm(3 in.) wide, or suitable wire cloth,430-mesh, 0.254-mm(10-mil) thickness.6.8 Putty Knife, stiff, about 38 mm (112 in.) wide.6.9 Knife, with sharp razor-type blade.6.10 Exposure ApparatusThe exposure apparatus shall beone of the three types of laborat
25、ory accelerated weatheringdevices described in Practice C 1442, that use either xenon arc,fluorescent UV or open flame carbon arc radiation. ConsultPractice C 1442 for the differences in test parameters amongthe devices. Because of differences in test conditions, testresults may differ with the type
26、 of device used. The choice ofdevice shall be by mutual agreement among the interestedparties.7. Test Specimens and Cure Procedures7.1 Two test specimens shall be prepared on aluminum, twoon cement mortar, two on glass, and two on each of any othersubstrate materials specified, using the following p
27、rocedures:7.1.1 Condition not less than 250 g of sealant (and sufficientportion of other components, if a multicomponent) in a closedcontainer for 24 h at 23 6 2C (73.4 6 3.6F) and 50 6 5%relative humidity.7.1.2 Clean the test surfaces of all metal and glass substrateswith methyl ethyl ketone or sim
28、ilar solvent followed by athorough cleaning with a detergent solution (Note 3), a finalrinse with distilled or deionized water, and air dry. Cleanmasonry surfaces with a dry stiff fiber bristle brush.7.1.3 Apply primer to the clean dry test surfaces only whenspecified and supplied by the sealant man
29、ufacturer and agreedupon by the purchaser.7.1.4 Place a strip of masking tape 25 mm (1 in.) wideacross the test surface of the substrate so that the lower edge ofthe tape is parallel and at least 76.2 mm (3 in.) from the lowershort edge of the substrate (Fig. 1A).7.1.5 Spread a portion of the condit
30、ioned compound, afterbeing mixed thoroughly for 5 min (if multicomponent), overthe 102 by 76-mm (4 by 3-in.) area, which includes themasking tape, to a depth slightly more than 1.6 mm (116 in.), asshown in Fig. 1B.7.1.6 Smear one piece of cloth with the compound at oneend over an area of 102 by 76 m
31、m (4 by 3 in.), forcing it intoboth sides of the cloth with a putty knife until the sealant hasthoroughly penetrated the cloth.7.1.7 Lay the impregnated cloth over the layer of compoundand place the spacer bars of proper thickness (see 6.3) on eachside of the specimen.7.1.8 Place a 1.6-mm (116-in.)
32、metal rod lengthwise on topof each spacer strip and squeegee the compound to 1.6 mm (116in.) thick by rolling the glass rod over the metal rods (startingfrom the taped end), and simultaneously pressing on the clothand sealant beneath it. Trim off the excess amount that issqueezed out (Fig. 1C).7.1.9
33、 Cure the specimens containing multicomponent com-pounds 14 days at 23 6 2C (73.4 6 3.6F). Cure thosecontaining single component compounds 21 days as follows(Note 4): 7 days at 23 6 2C (73 6 3.6F), 50 6 5 % relativehumidity; 7 days at 37.8 6 2C (100 6 3.6F) and 95 6 5%relative humidity; and finally
34、7 days at 23 6 2C (73 6 3.6F)and 50 6 5 % relative humidity.7.1.10 After the specimen has cured for about 7 days, coatthe cloth with a layer of the compound about 1.6 mm (116 in.)thick to help minimize cloth failure (Fig. 1D).7.1.11 Immediately following the full curing period (see7.1.9 and Note 4),
35、 make four cuts with a sharp blade length-wise of the specimen, cutting completely through to thesubstrate surface, and remove excess material so as to leavetwo 25.4-mm (1-in.) wide strips of cloth-covered sealantseparated by a space about 9.5 mm (38 in.) wide (Fig. 1E)3Available from Reeves Brother
36、s, Inc., 1271 Ave. of Americas, New York, NY10020.4Available from Tetko Inc., 333 South Highland Ave., Briarcliff Manor, NY10510. Also available from McMaster Carr Supply Co., P.O. Box 4355, Chicago, IL60680.C794062(7.1.12). CautionExtreme caution should be taken in remov-ing the excess material so
37、that the sealant/substrate bond in thetest strips is not disturbed.7.1.12 If peel adhesion is to be tested on glass substratespecimens after ultraviolet exposure through glass, after com-pleting step 7.1.11 and before proceeding with 7.1.13, place thespecimens in the weathering device with the seala
38、nt surfacefacing away from the light source. Test conditions in each typeof device are in accordance with the procedures in C 1442,Section 7 on Apparatus, except that the xenon arc and openflame carbon arc devices shall be operated without the waterspray. Expose the specimens for 200 h and then cont
39、inue asstated in 7.1.13.NOTE 2Although the xenon arc irradiance setting of 0.35 W/(m2 nm)at 340 nm is acceptable, Practice C 1442 specifies 0.51 W/(m2 nm) at 340nm as the preferred setting. To accommodate testing in xenon arcweathering devices that cannot use the higher irradiance setting, 0.35W/(m2
40、 nm) at 340 nm may be used if the length of total exposure time isincreased to provide the equivalent radiant exposure received at 0.51W/(m2 nm) at 340 nm for 200 h exposure. See Annex A1 in PracticeC 1442 for determining the exposure time.7.1.13 Immediately following step 7.1.11 (except as ex-plain
41、ed in 7.1.12), completely immerse the specimen in dis-tilled or deionized water for 7 days. Mortar specimens areplaced in a separate container from the glass and aluminumspecimens, because the highly alkali conditions generatedcould have an effect on the glass and aluminum.NOTE 3At the request of th
42、e sealant manufacturer the detergentcleaning step shall be omitted from the specified cleaning procedure.NOTE 4The manufacturer can suggest other curing conditions for thesingle-component sealants that may be used provided: (a) the curing timedoes not exceed 21 days, and (b) the temperature does not
43、 exceed 50C(122F).8. Test Procedure8.1 Immediately following the 7 days immersion, preparethe specimen for testing by wiping it dry, releasing the sealantfrom the tape by undercutting the sealant 12.7 mm (12 in.) andleaving a 63.5-mm (212-in.) length adhered to the substrate.8.2 Place the specimen i
44、n the testing machine and peel thecloth back at an angle of 180 at a rate of separation of 50.8mm (2 in.)/min (Fig. 2). Peel the sealant for about 1 min andrecord the average force in newtons (or pounds-force) indi-cated by the dial or recording chart of the machine. If the clothpeels clean from the
45、 sealant, disregard the values. In suchinstances, undercut the compound with a sharp blade toproduce separation at the interface to the test surface andcontinue the test.8.3 Test four strips for each of the substrate materialsspecified.FIG. 1 Stages in the Preparation of the Adhesion-in-Peel Test Sp
46、ecimenC7940639. Report9.1 Report the following information for each sampletested:9.1.1 Identification of sample,9.1.2 Identification of the type of sealant, such as single- ormulticomponent, color, etc.,9.1.3 Type and description of accelerated weathering de-vice, test cycle and duration used for ex
47、posure of specimens,9.1.4 Average peel strength in newtons (or pounds-force)for the four strips tested on each substrate,9.1.5 The percentage loss in bond and cohesion for eachstrip tested,9.1.6 Any indication of cloth failure, and9.1.7 Variation, if any, from the specified test procedure.10. Precis
48、ion and Bias10.1 Round-robin studies of the peel test conducted bymembers of ASTM Committee C-24 as well as by individualmembers of the sealant industry indicate that peel tests madeon one sealant sample with a specified substrate by a singleoperator in a single laboratory may yield a range of value
49、s thatvary by 610 to 620 % from the mean value.10.2 The range of values that can be encountered when peeltests are performed by several laboratories on the same sealantsample with the same substrate is commonly 660 % from themean value and is often 6100 %. The reason for this inter-laboratory variation has not yet been determined.11. Keywords11.1 adhesion-in-peel; elastomeric joint sealant; ultravioletexposure; water immersionASTM International takes no position respecting the validity of any patent rights asserted in connection with any
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