1、Designation: C474 11Standard 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. Scope*1.1 These test methods cover the physical testing of jointcompound, paper joint tape, glass-mesh joint tape, and anassembly of joint
3、compound 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:SectionJ
4、oint 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 T
5、ape 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 reference
6、s 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 theresponsib
7、ility 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 fo
8、r Physical Testing of Gypsum, Gyp-sum Plasters and Gypsum ConcreteC475/C475M Specification for Joint Compound and JointTape for Finishing Gypsum BoardC840 Specification for Application and Finishing of Gyp-sum BoardC1396/C1396M Specification for Gypsum BoardD685 Practice for Conditioning Paper and P
9、aper Productsfor Testing3D828 Test Method for Tensile Properties of Paper andPaperboard Using Constant-Rate-of-Elongation Appara-tus3D3699 Specification for KerosineD3882 Test Method for Bow and Skew in Woven andKnitted FabricsE100 Specification for ASTM Hydrometers2.2 TAPPI Standard:T411 Thickness
10、(Caliper) of Paper, Paperboard, and Com-bined Board43. Terminology3.1 DefinitionsFor definitions of terms relating to gyp-sum, 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.
11、3.2.1.1 DiscussionA0 % bond means that no paper fiberis adhering to the joint compound. A100 % bond means thatthere is 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.1These test methods
12、 are under the jurisdiction of ASTM Committee C11 onGypsum 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 March 1, 2011. Published March 2011. Origina
13、llyapproved in 1961. Last previous edition approved in 2005 as C474 05. DOI:10.1520/C0474-11.2For 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
14、Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.4Available from Technical Association of the Pulp and Paper Industry, Technol-ogy Park, P.O. Box 105113, Atlanta, GA 30348.1*A Summary of Changes section appears at the end
15、of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.3 joint 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 m
16、aterial 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, powder, 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 byplaci
17、ng the container holding the specimen in warm or coolwater.NOTE 1Allow setting type compounds to stand for one half of theirsetting times, as 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 visc
18、osity 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 the 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
19、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 compound, ready-mix, to reincorporateany separated ingredients. Adjust the temperature to 77 6 2F25 6 1C by placing the container holding the specimen inwarm o
20、r 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 achieve 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 COMP
21、OUND5. Joint Compound Viscosity5.1 Significance and Use:5.1.1 This test method provides a procedure for measuringjoint compound viscosity.5.2 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
22、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 height of 212 to 3 in. 65 to 75 mm.5.4.2 Viscometer5, adjusted to operate at 78 6 1 r/min, andwith a 250 cm-g sensitivity cartridge.5.4.3 Viscometer Pin, having d
23、imensions as follows:in. mmShaft diameter 0.187 6 0.015 4.75 6 0.38Pin diameter 0.094 6 0.015 2.39 6 0.38Immersion depth (from bottom of spindle) 1.625 6 0.015 41.3 6 0.38Length of pin projecting from shaft 0.750 6 0.015 19.1 6 0.38Upper pin from bottom of shaft 0.313 6 0.015 7.95 6 0.38Lower pin fr
24、om bottom of shaft 0.125 6 0.015 3.28 6 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 puddling the samplecontainer with a spatula and sharply rapping the bottom of thecontainer on a hard flat su
25、rface.5.5.2 Lock the filled container in the center of the viscom-eter spindle platform. Raise the platform until the level of thespecimen reaches the mark on the viscometer pin and lock theplatform in place.5.5.3 Start the viscometer. Read the viscosity after the penstarts to trace a straight line
26、(usually within 1 min). If thetracing remains inconsistent, estimate the average viscosityreading.5.6 Report:5.6.1 Report the viscosity of the joint compound specimenin Brabender units.5.7 Precision and Bias:5.7.1 Precision and bias of this test method have not beendetermined.6. Shrinkage6.1 Signifi
27、cance and Use:6.1.1 This test is used 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 Specime
28、n preparation shall be in accordance 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 S
29、tand, and Wire Cradle (see Fig. 1).6.4.4 Forced Air Drying Oven, capable of being maintainedat 90 to 120F 32 to 49C.6.4.5 Spatula, having a blade approximately 4 in. by12 in.100 by 13 mm.6.4.6 Steel-Reinforced Broad Knife,a5to8in.130 by 200mm drywall broad knife reinforced by a steel bar, 1 in. 255T
30、he sole source of supply of the apparatus known to the committee at this timeis the Brabender “Visco-Corder” Model VC-3, manufactured by C.W. BrabenderInstruments Inc., South Hackensack, NJ. If you are aware of alternative suppliers,please provide this information to ASTM International Headquarters.
31、 Your com-ments will receive careful consideration at a meeting of the responsible technicalcommittee1, which you may attend.6Rubber dental dam dusted with talc, polyethylene, or PTFE films have beenfound satisfactory for this use.C474 112mm wide by18 in. 3 mm thick, by the knife width, attachedto t
32、he 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 volumebetween 25 and 300 cm3.6.5 Reagents and Materials:6.5.1 Displacement Fluids.6.5.1.1 Mineral Spirits
33、, 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 weight of each assembly.6.7 Calibration:6.7.1 Volumetric ContainerDetermine the container vol-ume in
34、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 of Wet Compound:6.8.1 Prepare a specimen to determine the density of wetcompound by weighing the sp
35、ecimen 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 with thespatula to remove entrapped air bubbles.6.8.1.3 Finish filling the container and strike off
36、 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 of the compound in thevolumetric container by subtracting the weight obtained in6.8.1.4 from the w
37、eight 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.FIG. 1 Wire Cradle in KerosineFIG. 2 Patty Immersed in KerosineC474 113G 5total weight container tare weightvolume of container(
38、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 specimen remaining on the spatula a
39、ndadd 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 wei
40、ght 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 support plate tare weightG(2)6.10 Determination of Dry Volume:6.10.1 Dry patties at a temperature between 100 and 120F32 to 49C for 16 to 24 h.6.10.1.1
41、 When testing setting type joint compounds, placethe patties in the drying oven 1 h after the setting time has beenreached as determined by Test Methods C472.6.10.1.2 When testing drying type joint compounds, placethe patties in the drying oven immediately after weighing.6.10.2 Strip off the plastic
42、 or rubber film, and continue todry under the conditions specified in 6.10.1 until constantweight is reached.6.10.3 Immerse each patty in a beaker of the displacementfluid, such that they do not touch the sides of the beaker, for aminimum of 4 h, until constant weight is reached.NOTE 4Each patty may
43、 be broken into two or three pieces to fit in thebeaker without touching the sides.6.10.4 Remove each patty from the displacement fluid.Using a cloth moistened in the same fluid, lightly blot off theexcess fluid from the surface of the patty.6.10.5 With the wire cradle suspended in the beaker ofdisp
44、lacement fluid, weigh each patty in air on the pan of thebalance (Fig. 1), and record as its air weight.6.10.6 Next, weigh each patty in the wire cradle, ensuringthat the patty is completely immersed in the liquid and that itdoes not touch the sides of the beaker (Fig. 2). Record theseweights as the
45、 immersed weight.6.10.7 Subtract the immersed patty weight obtained in6.10.6 from the air patty weight obtained in 6.10.5. Record asD, the weight difference, which is the weight of fluid displacedby the dried and then saturated patty.6.10.8 Divide D, the weight difference, by M, the density ofthe di
46、splacement fluid determined in 6.7.2, and record as dryvolume of patty, R, mL.R 5 D/M (3)6.11 Calculation of Shrinkage:6.11.1 Calculate the percent shrinkage as follows:% shrinkage 5 1 R / V!# 3 100 (4)where:R = volume of the dry patty, andV = volume of the wet patty.6.12 Report:6.12.1 Take the aver
47、age of the three patties tested. If there isa difference between the percent shrinkage of the three pattiesof more than 1.5 %, completely retest an additional threespecimens and take the average of the six.6.13 Precision and Bias:6.13.1 Precision and bias of this test method have not beendetermined.
48、7. Check Cracking of Joint Compound7.1 Significance and Use7.1.1 This test method is used to measure the degree andtype of field and edge cracking of joint compound. The degreeof correlation between this test and service performance hasnot been determined.7.2 Sampling:7.2.1 Sampling shall be in acco
49、rdance with SpecificationC475/C475M.7.3 Specimen Preparation:7.3.1 Prepare specimens in accordance with Section 4,except use a quantity of 100 g.7.4 Apparatus:7.4.1 Rod, metal or glass,18 in. 3.2 mm in diameter by 7in. 180 mm in length.7.4.2 Steel-Reinforced Broad Knife, as defined in 6.4.6.7.4.3 Gypsum Wallboard, Specification C1396/C1396M.7.4.3.1 To determine compliance to Specification C475/C475M, Specification C1396/C1396M gypsum wallboard shallbe used.77.4.4 Electric Fan, capable of forcing a
