1、Designation: C474 13Standard Test Methods forJoint Treatment Materials for Gypsum Board Construction1This standard is issued under the fixed designation C474; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisio
2、n. 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 These test methods cover the physical testing of jointcompound, paper joint tape, glass-mesh joint tape, and anassembly of joint c
3、ompound and paper joint tape.1.1.1 Joint treatment materials are specified in SpecificationC475/C475M.1.1.2 The joint treatment material described in this standardare for use with gypsum board installed in accordance withSpecification C840.1.2 The test methods appear in the following order:SectionJo
4、int Compound Tests:Viscosity 5Shrinkage 6Check Cracking 7Putrefaction 8Joint Tape Tests:Tensile Strength 9Width 10Thickness 11Paper Joint Tape TestsDimensional Stability 12Assemblages of Paper Joint Tape and Joint Compound:Bond of Paper Joint Tape to Joint Compound 15Cracking of Joint Compound at Ta
5、pe Edges 14Glass-Mesh Joint Tape TestSkewness 131.3 The values stated in inch-pound units are to be regardedas standard. The values given in brackets are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.4 The text of this standard references
6、 notes and footnotesthat provide explanatory material. These notes and footnotes(excluding those in tables and figures) shall not be consideredas requirements of the standard.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibi
7、lity of the user of this standard 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:2C11 Terminology Relating to Gypsum and Related BuildingMaterials and SystemsC472 Test Methods for
8、 Physical Testing of Gypsum, Gyp-sum Plasters and Gypsum ConcreteC475/C475M Specification for Joint Compound and JointTape for Finishing Gypsum BoardC840 Specification forApplication and Finishing of GypsumBoardC1396/C1396M Specification for Gypsum BoardD685 Practice for Conditioning Paper and Paper
9、 Productsfor TestingD828 Test Method for Tensile Properties of Paper andPaperboard Using Constant-Rate-of-ElongationApparatus(Withdrawn 2009)3D3699 Specification for KerosineD3882 Test Method for Bow and Skew in Woven andKnitted FabricsE100 Specification for ASTM HydrometersE177 Practice for Use of
10、the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 TAPPI Standard:T411 Thickness (Caliper) of Paper, Paperboard, and Com-bined Board43. Terminology3.1 DefinitionsFor definitions of terms relating togypsu
11、m, see Terminology C11.3.2 Definitions of Terms Specific to This Standard:3.2.1 bond, nin joint systems, the quality of adhesionbetween the paper joint tape and joint compound.3.2.1.1 Discussion % bond means that no paper fiber is1These test methods are under the jurisdiction of ASTM Committee C11 o
12、nGypsum and Related Building Materials and Systems and are the direct responsi-bility of Subcommittee C11.02 on Specifications and Test Methods for Accessoriesand Related Products.Current edition approved May 1, 2013. Published July 2013. Originally approvedin 1961. Last previous edition approved in
13、 2012 as C474 12. DOI: 10.1520/C0474-13.2For 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.3The last approved ve
14、rsion of this historical standard is referenced onwww.astm.org.4Available from Technical Association of the Pulp and Paper Industry, Technol-ogy Park, P.O. Box 105113, Atlanta, GA 30348.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Dri
15、ve, PO Box C700, West Conshohocken, PA 19428-2959. United States1adhering to the joint compound. A100 % bond means that thereis cohesive failure of the paper joint tape.3.2.2 check cracking, nin joint systems, short, narrowcracks randomly oriented in the surface of the dried jointcompound.3.2.3 join
16、t compound, powder, nA drying-type or setting-type cementitious material to be mixed with water.3.2.4 joint compound, ready-mix, nA drying-type cemen-titious material that is factory mixed in ready-to-use form.4. Specimen Preparation4.1 Joint Compound, Powder:4.1.1 Mix 300 g of joint compound, powde
17、r, with approxi-mately 150 to 160 mL of water.4.1.2 Allow the specimen to stand for 30 min (Note 1),remix and adjust the temperature to 77 6 2F 25 6 1C byplacing the container holding the specimen in warm or coolwater.NOTE 1Allow setting type compounds to stand for one half of theirsetting times, as
18、 determined by Test Methods C472 but not more than 30min, prior to remixing.4.1.3 Measure the viscosity in accordance with Section 5.4.1.4 If the measured viscosity is not between 480 and 520Brabender units, repeat 4.1.1-4.1.3 through with an increase ordecrease in water as necessary.4.1.5 Record th
19、e volume of water used to adjust the viscos-ity to 500 6 20 Brabender units (see Note 2).NOTE 2Making note of the volumes of water, in millilitres per 100 gof material, used to adjust the viscosity, will facilitate specimen prepara-tion in other tests.4.2 Joint Compound, Ready-Mix:4.2.1 Remix joint
20、compound, ready-mix, to reincorporateany separated ingredients. Adjust the temperature to 77 6 2F25 6 1C by placing the container holding the specimen inwarm or cool water.4.2.2 Measure the viscosity in accordance with Section 5.4.2.3 If the viscosity is more than 520 Brabender units, addwater to ac
21、hieve a viscosity of 500 6 20 Brabender units (seeNote 2).4.2.3.1 If the original sample viscosity is less than 480Brabender units, test as received.JOINT COMPOUND5. Joint Compound Viscosity5.1 Significance and Use:5.1.1 This test method provides a procedure for measuringjoint compound viscosity.5.2
22、 Sampling:5.2.1 Sampling shall be in accordance with SpecificationC475/C475M.5.3 Specimen Preparation:5.3.1 Prepare specimens in accordance with Section 4.5.4 Apparatus:5.4.1 Viscosity Specimen Container, metal or plastic with anopen top having an inside diameter of 212 to 3 in. 65 to 75mm and a hei
23、ght of 212 to 3 in. 65 to 75 mm.5.4.2 Viscometer5, adjusted to operate at 78 6 1 r/min.5.4.3 Viscometer Pin (Spindle), having dimensions as fol-lows:in. mmShaft diameter 0.187 0.015 4.75 0.38Pin diameter 0.094 0.015 2.39 0.38Immersion depth (from bottom of spindle) 1.625 0.015 41.3 0.38Length of pin
24、 projecting from shaft 0.750 0.015 19.1 0.38Upper pin from bottom of shaft 0.313 0.015 7.95 0.38Lower pin from bottom of shaft 0.125 0.015 3.28 0.385.5 Procedure:5.5.1 Fill the viscosity container with the mixed specimenuntil level with the top of the container.5.5.1.1 Remove all air bubbles by pudd
25、ling the samplecontainer with a spatula and sharply rapping the bottom of thecontainer on a hard flat surface.5.5.2 Secure the filled container in the center of the viscom-eter spindle platform. Position the spindle so that the samplecomes up to the immersion mark on the pin (spindle).5.5.3 Start th
26、e viscometer and record the viscosity readingon the digital display after 30 s. If the viscometer readout goesto a strip chart recorder, read the viscosity after the pen startsto trace a straight line (usually within 1 min); if the tracingremains inconsistent, estimate the average viscosity reading.
27、5.6 Report:5.6.1 Report the viscosity of the joint compound specimenin Brabender units.5.7 Precision and Bias:5.7.1 The precision of this test method is based on aninterlaboratory study conducted in 2011. Seven laboratoriesusing Brookfield equipment and eight laboratories using Bra-bender equipment
28、tested two different materials, by alternativemethods. Every test result represents an individualdetermination, and each lab was asked to report five replicateresults for each material / instrument combination. Except forthe limited amount of data reported for several of the material/ instrument com
29、binations, Practice E691 was followed for thedesign and analysis of the data.5.7.1.1 Repeatability Limit (r) Two test results obtainedwithin one laboratory shall be judged not equivalent if theydiffer by more than the “r” value for that material; “r” is theinterval representing the critical differen
30、ce between two testresults for the same material, obtained by the same operatorusing the same equipment on the same day in the samelaboratory. Repeatability limits are listed in Table 1 and Table2 below.5.7.1.2 Reproducibility limit (R)Two test results shall bejudged not equivalent if they differ by
31、 more than the “R” valuefor that material; “R” is the interval representing the critical5The sources of supply of the apparatus known to the committee at this time arethe Brabender “Visco-Corder” Model VC-E, manufactured by C.W. BrabenderInstruments Inc., South Hackensack, NJ. and the Brookfield R/S
32、-SST Rheometer,manufactured by Brookfield Engineering Laboraties Inc., Middleboro, MA. If youare aware of alternative suppliers, please provide this information to ASTMInternational Headquarters. Your comments will receive careful consideration at ameeting of the responsible technical committee1, wh
33、ich you may attend.C474 132difference between two test results for the same material,obtained by different operators using different equipment indifferent laboratories. Reproducibility limits are listed in Table1 and Table 2 below.5.7.1.3 The above terms (repeatability limit and reproduc-ibility lim
34、it) are used as specified in Practice E177.5.7.1.4 Any judgment in accordance with statements 9.1.1and 9.2 would have an approximate 95 % probability of beingcorrect.5.7.2 BiasAt the time of the study, there was no acceptedreference material suitable for determining the bias for this testmethod, the
35、refore no statement on bias is being made.5.7.3 The precision statement was determined through sta-tistical examination of 296 results, by alternative methods, ontwo materials (described below).5.7.3.1 Sample A: A representative conventional weightready-mixed all-purpose joint compound prepared spec
36、ificallyfor the round-robin test and distributed to all testing laborato-ries.5.7.3.2 Sample B: A representative low-viscosity wall tex-ture compound prepared specifically for the round-robin testand distributed to all testing laboratories.6. Shrinkage6.1 Significance and Use:6.1.1 This test is used
37、 to measure the amount of shrinkage injoint compound. The degree of correlation between this testand service performance has not been determined.6.2 Sampling:6.2.1 Sampling shall be in accordance with SpecificationC475/C475M.6.3 Specimen Preparation:6.3.1 Specimen preparation shall be in accordance
38、withSection 4.6.4 Apparatus:6.4.1 Plastic or Rubber Film, approximately 5 by 5 in. 130by 130 mm. Any thin, flexible film that peels clean from apartially dried patty may be used.66.4.2 Balance, having a sensitivity of 10 mg (Fig. 1 and Fig.2).6.4.3 Beaker, Ring Stand, and Wire Cradle (see Fig. 1).6.
39、4.4 Forced Air Drying Oven, capable of being maintainedat 90 to 120F 32 to 49C.6Rubber dental dam dusted with talc, polyethylene, or PTFE films have beenfound satisfactory for this use.TABLE 1 Brookfield R/S SST (Brabender units)Material ID AverageAxRepeatabil-ityStandardDeviationSrReproduc-ibilityS
40、tandardDeviationSRRepeatabil-ityLimitrReproduc-ibilityLimitRSample A 660.0 7.6 23.6 21.2 66.0Sample B 133.6 1.8 5.7 5.2 15.9TABLE 2 Brabender VC-E (Brabender units)Material ID AverageAxRepeatabil-ityStandardDeviationSrReproduc-ibilityStandardDeviationSRRepeatabil-ityLimitrReproduc-ibilityLimitRSampl
41、e A 602.7 7.2 28.3 20.1 79.3Sample B 123.1 1.9 8.0 5.4 22.4AThe average of the laboratories calculated averages.FIG. 1 Wire Cradle in KerosineC474 1336.4.5 Spatula, having a blade approximately 4 in. by12 in.100 by 13 mm.6.4.6 Steel-Reinforced Broad Knife, a 5 to 8 in. 130 by 200mm drywall broad kni
42、fe reinforced by a steel bar, 1 in. 25mm wide by18 in. 3 mm thick, by the knife width, attachedto the back of the knife blade14 in. 6 mm from the edge.6.4.7 Hydrometer, having a range of 0.7 to 0.8 sp gr, inaccordance with Specification E100.6.4.8 Volumetric Container, a container which has a volume
43、between 25 and 300 cm3.6.5 Reagents and Materials:6.5.1 Displacement Fluids.6.5.1.1 Mineral Spirits, odorless.6.5.1.2 Kerosine (see Specification D3699).6.6 Preparation of Apparatus:6.6.1 Support PlatesCover three plastic or glass plateswith plastic or rubber film.6.6.2 Obtain and record the tare we
44、ight of each assembly.6.7 Calibration:6.7.1 Volumetric ContainerDetermine the container vol-ume in cubic centimetres and its tare weight in grams.6.7.2 Mineral Spirits, KerosineUsing the hydrometer, de-termine the specific gravity and record the result as density M,g/mL.6.8 Determination of Density
45、of Wet Compound:6.8.1 Prepare a specimen to determine the density of wetcompound by weighing the specimen in the volumetric con-tainer.6.8.1.1 Adjust the temperature to 70 6 2F 21 6 1C byplacing the container holding the specimen in warm or coolwater.6.8.1.2 Puddle the specimen within the container
46、with thespatula to remove entrapped air bubbles.6.8.1.3 Finish filling the container and strike off the surfaceflush with the top using the steel-reinforced broad knife.6.8.1.4 Weigh the filled container to the nearest 0.01 g.Record the weight of the filled container.6.8.1.5 Determine the net weight
47、 of the compound in thevolumetric container by subtracting the weight obtained in6.8.1.4 from the weight obtained in 6.7.1.6.8.1.6 Divide the net weight obtained in 6.8.1.5 by thevolume of the container obtained in 6.7.1. Record the result aswet compound density G, g/mL.G 5total weight 2 container t
48、are weightvolume of container(1)6.9 Preparation of Specimen to Determine Wet and DryVolume:6.9.1 Place approximately 30 g of specimen onto eachprepared support plate (see 6.6.1).6.9.1.1 Spread the specimen into an elongated patty316 to14in. 5.0 to 6.5 mm thick with a spatula.6.9.1.2 Remove any speci
49、men remaining on the spatula andadd to the patty.NOTE 3The patty may be scored across its narrowest width tofacilitate breaking the patty after it is dry.6.9.1.3 Weigh and record the total weight of each patty, film,and plate.6.9.1.4 Determine the net weight of each specimen bysubtracting the tare weight of its support plate weight and theweight obtained in 6.9.1.3.6.9.1.5 Divide the net weight obtained in 6.9.1.4 by G.Record as wet volume of patty V, mL.V 5wet patty weight 2 support pla
