1、Designation: C 474 05Standard Test Methods forJoint Treatment Materials for Gypsum Board Construction1This standard is issued under the fixed designation C 474; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revis
2、ion. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 joi
3、nt compound and paper joint tape.1.1.1 Joint treatment materials are specified in SpecificationC 475/C 475M.1.1.2 The joint treatment material described in this standardare for use with gypsum board installed in accordance withSpecification C 840.1.2 The test methods appear in the following order:Se
4、ctionJoint 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 Compoun
5、d at Tape Edges 14Glass-Mesh Joint Tape TestSkewness 131.3 The values stated in inch-pound units are to be regardedas the standard. The SI (metric) values given in brackets areapproximate and are provided for information purposes only.1.4 The text of this standard references notes and footnotesthat
6、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 theresponsibility of the user of this
7、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 Build-ing Materials and SystemsC 472 Test Methods for Physical Testing of G
8、ypsum, Gyp-sum Plasters, and Gypsum ConcreteC 475/C 475M Specification for Joint Compound and JointTape for Finishing Gypsum BoardC 840 Specification for Application and Finishing of Gyp-sum BoardC 1396/C 1396M Specification for Gypsum BoardD 685 Practice for Conditioning Paper and Paper Productsfor
9、 TestingD 828 Test Method for Tensile Properties of Paper andPaperboard Using Constant-Rate-of-Elongation ApparatusD 3882 Test Method for Bow and Skew in Woven andKnitted FabricsE 100 Specification for ASTM Hydrometers2.2 TAPPI Standard:T 411 Thickness (Caliper) of Paper, Paperboard, and Com-bined B
10、oard33. 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.3.2.1.1 DiscussionA 0 % bond means that no pape
11、r fiberis adhering to the joint compound. A 100 % 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.3.2.3 joint compound, powder, nA drying-type or setting-type cem
12、entitious material to be mixed with water.1These test methods 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
13、edition approved Jan. 1, 2005. Published February 2005. Originallyapproved in 1961. Last previous edition approved in 2002 as C 474 02.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume inf
14、ormation, refer to the standards Document Summary page onthe ASTM website.3Available 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 of this standard.Copyright ASTM International, 100 Ba
15、rr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.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, powder, with approxi-ma
16、tely 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 2F256 1 C byplacing 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
17、 Methods C 472 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 the volume of water
18、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 compound, ready-mi
19、x, to reincorporateany separated ingredients. Adjust the temperature to 77 6 2F25 6 1 C 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 achieve a viscosity
20、 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 Sampling:5.2.1 S
21、ampling shall be in accordance with SpecificationC 475/C 475M.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 height of 212 to 3
22、 in. 65 to 75 mm.5.4.2 Viscometer4, adjusted to operate at 78 6 1 r/min, andwith a 250 cm-g sensitivity cartridge.5.4.3 Viscometer Pin, having dimensions 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.
23、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 from 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 containe
24、r.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 surface.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
25、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 (usually within 1 min). If thetracing remains inconsistent, estimate the average viscosityreading.5.6 Report:5.6.1 Report the viscosity of the joint compoun
26、d specimenin Brabender units.5.7 Precision and Bias:5.7.1 Precision and bias of this test method have not beendetermined.6. Shrinkage6.1 Significance 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 performanc
27、e has not been determined.6.2 Sampling:6.2.1 Sampling shall be in accordance with SpecificationC 475/C 475M.6.3 Specimen Preparation:6.3.1 Specimen 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 f
28、ilm that peels clean from apartially dried patty may be used.56.4.2 Balance, having a sensitivity of 10 mg (Fig. 1 and Fig.2).6.4.3 Beaker, Ring Stand, and Wire Cradle (see Fig. 1).6.4.4 Forced Air Drying Oven, capable of being maintainedat 90 to 120 F 32 to 49 C.6.4.5 Spatula, having a blade approx
29、imately 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. 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 t
30、o 0.8 sp gr, inaccordance with Specification E 100.4The 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
31、 this information to ASTM International Headquarters. Your com-ments will receive careful consideration at a meeting of the responsible technicalcommittee1, which you may attend.5Rubber dental dam dusted with talc, polyethylene, or PTFE films have beenfound satisfactory for this use.C4740526.4.8 Vol
32、umetric 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, odorless.6.5.1.2 Kerosine.6.6 Preparation of Apparatus:6.6.1 Support PlatesCover three plastic or glass plateswith plastic or rubber film.6.6.2 Obtain
33、 and record the tare weight 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 M.6.8 Determination o
34、f Wet Volume:6.8.1 Prepare a specimen to determine the wet specificgravity by weighing the specimen in the volumetric container.6.8.1.1 Adjust the temperature to 77 6 2F256 1 C byplacing the container holding the specimen in warm or coolwater.6.8.1.2 Puddle the specimen with the spatula to removeent
35、rapped air bubbles.6.8.1.3 Fill the container completely and strike off thesurface flush with the top using the steel-reinforced broadknife.6.8.1.4 Weigh the filled container to the nearest 0.01 g.Record the weight of the filled container.6.9 Preparation of Specimen to Determine Dry Volume:6.9.1 Pla
36、ce approximately 30 g of specimen onto eachprepared support plate.6.9.1.1 Spread the specimen into an elongated patty316to14 in. 5.0 to 6.5 mm thick with a spatula.6.9.1.2 Remove any specimen remaining on the spatula andadd to the patty.NOTE 3The patty may be scored across its narrowest width tofaci
37、litate breaking the patty after it is dry.6.9.1.3 Weigh and record the total weight of each patty, filmand plate.FIG. 1 Wire Cradle in KerosineFIG. 2 Patty Immersed in KerosineC4740536.9.1.4 When testing setting type joint compounds, placethe patties in the drying oven one h after the setting time h
38、asbeen reached as determined by Test Methods C 472.6.9.1.5 When testing drying type joint compounds, place thepatties in the drying oven immediately after weighing.6.9.2 Dry patties at a temperature between 100 and 120 F32 to 49 C for 16 to 24 h.6.9.3 Strip off the plastic or rubber film, and contin
39、ue to dryuntil constant weight is reached.6.10 Determination of Dry Volume:6.10.1 Immerse each patty in a beaker of the displacementfluid, such that they do not touch the sides of the beaker, untilconstant weight is reached.NOTE 4Each patty may be broken into two or three pieces to fit in thebeaker
40、without touching the sides.6.10.2 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.6.10.3 With the wire cradle suspended in the beaker ofdisplacement fluid, weigh each patty in air on the pan of th
41、ebalance (Fig. 1), and record as its air weight.6.10.4 Next, weigh each patty in the wire cradle, makingsure that the patty is completely immersed in the liquid and thatit does not touch the sides of the beaker (Fig. 2). Record theseweights as the immersed weight.6.11 Calculation of Shrinkage:6.11.1
42、 Determine the net weight of the compound in thevolumetric container by subtracting the weight obtained in6.8.1.4 from the weight obtained in 6.7.1.6.11.2 Divide the net weight obtained in 6.11.1 by thevolume of the container obtained in 6.7.1. Record the result asG, grams per millilitre.G 5Total we
43、ight 2 Container tare weightVolume of Container(1)6.11.3 Determine the net weight of each specimen bysubtracting the tare weight of its support plate weight and itsweight obtained in 6.9.1.3.6.11.4 Divide the net weight obtained in 6.11.3 by G.Record as V, volume of patty.V 5Dry weight 2 Support pla
44、te tare weightG(2)6.11.5 Subtract the immersed patty weight obtained in6.10.4 from the air patty weight obtained in 6.10.3. Record asD, the weight difference.6.11.6 Calculate the percent shrinkage as follows:% Shrinkage 5 DX/V!, (3)where:D = the difference in air and immersed weight,X = 100/displace
45、ment fluids specific gravity, andV = weight of wet patty/specific gravity of the compound.6.12 Report:6.12.1 Take the average 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
46、take the average of the six.6.13 Precision and Bias:6.13.1 Precision and bias of this test method have not beendetermined.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
47、 correlation between this test and service performance hasnot been determined.7.2 Sampling:7.2.1 Sampling shall be in accordance with SpecificationC 475/C 475M.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
48、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 C 1396/C 1396M.7.4.3.1 To determine compliance to Specification C 475/C 475M, Specification C 1396/C 1396M gypsum wallboardshall be used.67.4.4 El
49、ectric Fan, capable of forcing a continuous currentof air at a velocity of 350 to 450 ft/min 1.8 to 2.3 m/s at adistance of approximately 3 ft 1 m.7.5 Procedure:7.5.1 Place the rod on a piece of gypsum wallboard andplace some of the specimen next to the rod.7.5.2 Form a 312 to 4 in. 90 to 100 mm wide wedge of thespecimen with the steel-reinforced broad knife, with the rod onone side and the wallboard on the other side to guide the knife.7.5.2.1 Hold the broad knife at an angle less than 45 withresp
