1、Designation: C 631 09Standard Specification forBonding Compounds for Interior Gypsum Plastering1This standard is issued under the fixed designation C 631; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A
2、 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 This specification covers minimum requirements forbonding compounds for adhering interior gypsum plaster tostructurally sound surface
3、s.1.2 This specification also covers test methods for determin-ing performance requirements and physical properties.1.3 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlya
4、nd are not considered standard.1.4 The following safety hazards caveat pertains only to thetest methods described in this specification: This standard doesnot purport to address all of the safety concerns, if any,associated with its use. It is the responsibility of the user of thisstandard to establ
5、ish appropriate safety and health practicesand determine the applicability of regulatory limitations priorto use.2. Referenced Documents2.1 ASTM Standards:2C11 Terminology Relating to Gypsum and Related Build-ing Materials and SystemsC 28/C 28M Specification for Gypsum PlastersC 472 Test Methods for
6、 Physical Testing of Gypsum, Gyp-sum Plasters and Gypsum ConcreteC511 Specification for Mixing Rooms, Moist Cabinets,Moist Rooms, and Water Storage Tanks Used in theTesting of Hydraulic Cements and Concretes3. Terminology3.1 DefinitionsFor definitions relating to gypsum andrelated building materials
7、 and systems, see Terminology C11.4. Physical Properties4.1 GeneralThe bonding compound shall be a film form-ing, non-oxidizing, non-toxic, non-flammable compositionsuitable for application by brush, roller, and spray. Thecompound shall be tinted to show, by visual inspection, whereit has been appli
8、ed. The tinting material shall not show throughthe material being bonded. The surfaces to which bondingcompounds are applied shall be relatively smooth, clean, anddry. Surface coatings shall be removed if their nature indicatesan unsatisfactory condition. Surfaces shall be prepared inaccordance with
9、 the manufacturers directions.4.2 ConsistencyThe bonding compound shall be of ahomogeneous nature with no settling of the solids. Thecompound shall be free of foreign matter, and when applied inaccordance with the manufacturers directions, shall coverevenly.4.3 Film CharacteristicsA dry film of the
10、bonding com-pound shall be uniform and smooth and shall remain flexible.The film shall not be noticeably affected by mild acid or alkali.5. Performance Requirements5.1 Bonding CapabilityA dry film of bonding compoundshall be capable of bonding gypsum plaster immediately afterdrying and 10 days after
11、 drying when tested as specified inSection 12.5.2 DegradationBonding compound that separates shallbe able to be re-mixed to a uniform consistency when tested asspecified in Section 10.5.3 High Temperature StabilityThe bond strength shall benot less than 20 psi (138 kPa) when tested as specified inSe
12、ction 9.5.4 Freeze-Thaw StabilityThe bond strength shall be notless than 20 psi (138 kPa) when tested as specified in Section11.5.5 Bond StrengthBond strength of a fresh sample or a 30day old sample shall be not less than 20 psi (138 kPa) whentested as specified in Section 12.6. Sampling6.1 Take a s
13、ample of not less than 1 kg from each shipmentor consignment for analysis and tests. Except in special cases,take the sample from not less than three separate containers,1This specification is under the jurisdiction of ASTM Committee C11 onGypsum and Related Building Materials and Systems and is the
14、 direct responsibilityof Subcommittee C11.02 on Specifications and Test Methods for Accessories andRelated Products.Current edition approved May 1, 2009. Published May 2009. Originallyapproved in 1988. Last previous edition approved in 2004 as C 631 95a(2004).2For referenced ASTM standards, visit th
15、e 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.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100
16、Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.chosen at random. In addition, take samples from containersthat appear to be nonrepresentative, and test separately. Imme-diately place the samples in airtight glass containers andtransport to the testing laboratory in t
17、hese containers. Takeprecautions to reduce evaporation or drying to a minimum.Thoroughly mix the bonding compound in the container ifthere is a tendency for liquid phase separation.7. Apparatus7.1 Moist CabinetSpecification C511.7.2 OvenA forced draft type oven, having a temperaturecontrolled at 140
18、 6 5F(606 3 C) for high temperature testsand 100 6 5F(386 3 C) for drying of the briquets.7.3 FreezerA freezer having a controlled temperatureof106 2 F (-23 6 1 C).7.4 BalanceAbalance capable of weighing at least 2500 gat a precision of 0.1 g.7.5 Timing DeviceA standard clock or watch with secondhan
19、d.7.6 TamperA tamper made up of a nonabsorptive, non-abrasive, non-brittle material and having a cross section of12in. by 1 in. (13 by 25 mm) and approximately 5 to 6 in. (130to 150 mm) long. The tamping face shall be flat and at rightangles to the length of the tamper.7.7 Straight EdgeA steel strai
20、ght edge not less than 4 in.(100 mm) long and not less than116 in. (1.6 mm) nor more than18 in. (3.2 mm) in thickness.7.8 SpatulaAspatula with a metal blade 6 in. (150 mm) inlength and12 in. (13 mm) in width, with straight edges.7.9 Paint BrushA standard 1 in. (25 mm) wide brush,with natural or synt
21、hetic bristles.7.10 Testing MachineAny type that is of sufficient capac-ity and that is capable of applying the load continuously andwithout shock at the rate of 0.05 in. (1.27 mm)/min, withprovision for adjustment of the rate of loading.7.11 Briquet MoldsThe molds for making test specimensshall be
22、made of metal not attacked by the plaster mortar andshall have sufficient material in the sides to prevent spreadingduring molding. Gang molds, when used, shall be of the typeshown in Fig. 1. The dimensions of the briquet molds shallconform to the following requirements: width of mold, be-tween insi
23、de faces, at waist line of the briquet, 1 in. (25.4 mm)with permissible variations of 60.01 in. (0.25 mm) for moldsin use and 60.005 in. (0.13 mm) for new molds; thickness ofmolds measured at the point of greatest thickness on either sideof the mold at the waist line, 1 in. (25.4 mm) with permissibl
24、evariations of + 0.004 in. (0.10 mm) and 0.002 in. (0.05 mm)for new molds and 0.02 in. (0.5 mm) for molds in use. Theinside faces at the waist line shall have a vertical slot 0.03 in.(0.75 mm) wide by 0.06 in. (1.5 mm) deep to accept thedivider. The briquet specimens shall conform to the dimen-siona
25、l requirements shown in Fig. 2.7.12 DividerSheet brass 0.02 in. (0.05 mm) thick, 1.1 in.(27.8 mm) wide by 1 in. (25.4 mm) high.7.13 Clips for Briquet Testing Machine The clips forholding the tension test specimen shall be in accordance withFig. 3.8. Conditioning8.1 Room Temperature and Humidity Main
26、tain the airtemperature in the vicinity of the mixing and testing area, 70 65F(216 3 C). Maintain the relative humidity at 50 6 2%.8.2 Temperature of the Mixing Water726 2F(226 1C).9. High Temperature Test9.1 Significance and UseThis test method provides pro-cedures for evaluating the bond strength
27、of adhesives afterbeing exposed to accelerated aging at high temperature.9.2 Specimen PreparationFor each test specimen, transferthe bonding compound, taken from the sample obtained, into astandard 1 pt (400 mL) glass container.9.3 ProcedurePlace the specimen in the oven for 30 days.Remove the conta
28、iner, allow the compound to cool to roomtemperature, mix the compound to a uniform consistency, andtest as specified in Section 12.9.4 Test and RetestsTest six briquets and report theaverage of the test results. If the result of any one of the sixtests varied more than 15 % from the average, reject
29、it andreport the average of the other five tests. If the results frommore than two tests vary more than 15 % from the average,reject the series and retest.9.5 Precision and BiasThe precision and bias of the HighTemperature Test for determining bond strength after exposureto high temperature is essen
30、tially the same as specified in thetest method for bond strength, 12.7.10. Degradation Test10.1 Significance and UseThis test method simulates theeffects of high temperature storage on the physical propertiesof bonding compound.10.2 Specimen PreparationFor each test, transfer thebonding compound, fr
31、om the sample obtained, into a standard1 pt (400 mL) glass container.10.3 ProcedurePlace the specimen in the oven for 15days. Remove the container from the oven and examine theFIG. 1 Briquet Gang MoldC631092contents for settling and separation. Place the container back inthe oven for an additional 1
32、5 days. Remove the container andexamine the contents again for settling and separation. Allowthe compound to come to room temperature, and mix to auniform consistency. Mix by hand, stirring with a wood, metal,or plastic paddle for not more than 5 min.10.4 Tests and RetestsBonding compound that fails
33、 to beremixed to a uniform consistency shall be considered to havefailed the test.10.5 ReportDetermine the extent of settling and separa-tion by measuring, and report as a percentage of the height ofthe specimen in the clear glass container, represented by thelocation of the liquid/solid interface.1
34、0.6 Precision and BiasNo information is presentedabout either the precision or bias of the degradation test formeasuring settling, separation, or the ability to be mixed to auniform consistency since the test result is nonquantitative.11. Freeze-Thaw Cycle Test11.1 Significance and UseThis test meth
35、od provides pro-cedures for determining the bond strength of bonding com-pounds after being exposed to accelerated storage conditions ofalternate freezing and thawing.11.2 Specimen PreparationFor each test specimen, trans-fer the bonding compound, taken from the sample obtained,into a standard 1 pt
36、(400 mL) glass container having a screw onor friction fit cover.11.3 ProcedurePlace a covered specimen in the freezerfor 16 h. Remove the specimen and allow to thaw at roomtemperature for 8 h. Repeat this procedure for 5 cycles. Afterthe fifth cycle, allow the compound to come to room tempera-ture,
37、and then test as specified in Section 12.11.4 Tests and RetestsTest six briquets and report theaverage of the test results. If the result of any one of the sixtests varies more than 15 % from the average, reject it andreport the average of the other five tests. If the results frommore than two tests
38、 vary more than 15 % from the average,reject the series and retest.11.5 Precision and BiasThe precision and bias of thefreeze-thaw cycle test for determining bond strength afterexposure to alternate freezing and thawing are essentially thesame as specified in the test method for bond strength, 12.7.
39、12. Bond Strength Test12.1 Significance and UseThis test method provides amethod for determining the relative ability of bonding com-pound, after being subject to various simulated conditions ofaging and exposure to temperature extremes, to adhere cemen-titious materials to a properly prepared subst
40、rate.12.2 Materials:12.2.1 Gauging PlasterSpecification C 28/C 28M, at nor-mal consistency (Test Methods C 472).12.2.2 RetarderSodium citrate.12.3 Preparation of Briquets:12.3.1 Prepare not less than six briquets for each series oftests.12.3.2 Partition the briquet molds by placing the divider inthe
41、 slots formed at the waist of the mold.12.3.3 Add the plaster to the required amount of water andallow to soak for 30 s. Add approximately 0.1 g of retarder per100 g of plaster to achievea2to3hplaster set.12.3.4 Prepare the molds by coating them with a thin film ofmineral oil. Support the molds on a
42、 lightly oiled glass or metalplate. Protect the divider from contamination with oil (wrap inplastic food wrap) and carefully insert into the mold slots.12.3.5 Cast the briquets immediately after completely mix-ing the mortar; half fill the molds and puddle the mortaruniformly with the tamper, taking
43、 care not to displace thedivider. Slightly over fill the molds with additional mortar andrepeat the puddling. After the mortar has set, cut off the excessto a plane surface flush with the top of the mold, using a broadknife or similar implement.12.3.6 Immediately after molding, place the molds, on t
44、hebase plate, into the moist cabinet for not less than 16 h.12.3.7 Remove the briquets from the mold and store them atroom temperature and humidity for not less than 48 h.12.3.8 Examine the specimens, and discard any that have airholes or excessively rough surfaces.12.4 Procedure:12.4.1 Apply the bo
45、nding compound, in accordance withthe producers directions, to the flat waist surface of the briquetby means of a paint brush.12.4.2 Remove the divider from the mold. Place the halfbriquet, coated with bonding compound, into the mold. Fill theremaining space in the mold with gypsum plaster, mixed an
46、dmolded as specified in 12.2.NOTE 11 in. = 25.4 mmFIG. 2 Briquet Specimen for Tensile Strength TestC63109312.4.3 The time between coating the briquet with compoundand casting the plaster against it shall be immediately after thecompound has dried, or as recommended by the manufacturer,except when ot
47、herwise specified for a ten day waiting period.12.4.4 Place the filled briquet mold in the moist cabinet fornot less than 16 h. Remove the briquets from the molds as soonas they are thoroughly hardened, but retain them in the moistcabinet for not less than 16 h.12.4.5 The briquets are then dried to
48、constant weight in aforced draft oven maintained at 100 6 5F(386 3 C) and arelative humidity not more than 50 %.12.5 Test MethodTest the briquets immediately after re-moving them from the oven. Remove any loose particles orflash from the surfaces that will be in contact with the clips ofthe testing
49、machine. Make sure the bearing surfaces of the clipsare clean and free of sand, and the roller bearings are lubricatedand maintained to ensure freedom of turning. Keep the stirrupssupporting the clips free of accumulations. Keep the pivots inproper adjustment so that the clips swing freely on the pivotswithout binding the stirrups. Carefully center the briquets inthe clips and apply the load continuously at the rate of 0.05 in.(1.27 mm)/min.12.6 Tests and RetestsTest six briquets and report theaverage of the test
