ASTM C796 C796M-2012 Standard Test Method for Foaming Agents for Use in Producing Cellular Concrete Using Preformed Foam《使用预成型泡沫生产多孔混凝土用发泡剂的标准试验方法》.pdf

1、Designation:C79604 Designation: C796/C796M 12Standard Test Method forFoaming Agents for Use in Producing Cellular ConcreteUsing Preformed Foam1This standard is issued under the fixed designation C796/C796M; the number immediately following the designation indicates the yearof original adoption or, i

2、n the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon () 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. Scope*1.1

3、This test method furnishes a way of measuring, in the laboratory, the performance of a foaming chemical to be used inproducing foam (air cells) for making cellular concrete.1.2 This test method includes the following:1.2.1 Manufacture of laboratory quantities of cellular concrete.1.2.2 Determination

4、 of the air content of the freshly prepared cellular concrete and of the hardened concrete after handling inconventional machinery.1.2.3 Determination of the following properties of the hardened concrete: compressive strength, tensile splitting strength,density, and water absorption. It may not be n

5、ecessary to study all of the above properties in all cases, depending on the proposeduse of the material.1.3The values stated in inch-pound units are to be regarded as the standard.1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stat

6、ed in eachsystem may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from thetwo systems may result in non-conformance with the standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its u

7、se. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.1.5 The text of this standard references notes and footnotes which provide explanatory material. These notes and footnot

8、es(excluding those in tables and figures) shall not be considered as requirements of the standard.2. Referenced Documents2.1 ASTM Standards:2C88 Test Method for Soundness of Aggregates by Use of Sodium Sulfate or Magnesium SulfateC150 Specification for Portland CementC192/C192M Practice for Making a

9、nd Curing Concrete Test Specimens in the LaboratoryC495 Test Method for Compressive Strength of Lightweight Insulating ConcreteC496/C496M Test Method for Splitting Tensile Strength of Cylindrical Concrete SpecimensC511 Specification for Mixing Rooms, Moist Cabinets, Moist Rooms, and Water Storage Ta

10、nks Used in the Testing ofHydraulic Cements and ConcretesC802 Practice for Conducting an Interlaboratory Test Program to Determine the Precision of Test Methods for ConstructionMaterialsC869 Specification for Foaming Agents Used in Making Preformed Foam for Cellular Concrete3. Terminology3.1 Definit

11、ions:3.1.1 cellular concretea lightweight product consisting of portland cement, cement-silica, cement-pozzolan, lime-pozzolan,or lime-silica pastes, or pastes containing blends of these ingredients and having a homogeneous void or cell structure, attained1This test method is under the jurisdiction

12、of ASTM Committee C09 on Concrete and Concrete Aggregates and is the direct responsibility of Subcommittee C09.23 onChemical Admixtures.Current edition approved Nov.April 1, 2004.2012. Published November 2004.May 2012. Originally approved in 1974. Last previous edition approved in 1997 asC79697.C796

13、04. DOI: 10.1520/C0796-04.10.1520/C0796_C0796M-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.1This doc

14、ument is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as

15、 appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, Unit

16、ed States.with gas-forming chemicals or foaming agents (for cellular concretes containing binder ingredients other than, or in addition toportland cement, autoclave curing is usually employed).3In cellular concrete the density control is achieved by substitutingmacroscopic air cells for all or part

17、of the fine aggregate. Normal-weight coarse aggregate is usually not used but lightweightaggregates, both fine and coarse, are often utilized in cellular concrete.3.2 Symbols:Dex1= experimental density of the concrete before pumping, lb/ftkg/m3(kg/mlb/ft3)Dex2= experimental density of the concrete a

18、fter pumping, lb/ftkg/m3(kg/mlb/ft3)Dth= theoretical density of the plastic mix based on absolute volume, lb/ftkg/m3(kg/mlb/ft3)Dd= design density of the text mixture, lb/ftkg/m3(kg/mlb/ft3)SGC = specific gravity of cement = 3.15T = time required to overfill the container, minT1= time required to ge

19、nerate 1 ftm3(1 m1 ft3) of foam, minV = volume of foam container, ftm3(mft3)Va= volume of air required in the test batch, ftm3(mft3)Vc= volume of test specimen (cylinder), ftm3(mft3)Vf= volume of foam in the test batch, ftm3(mft3)Vw= volume of water absorbed by test specimen in 24 h, ftm3(mft3)W1= n

20、et weightmass of foam in overfilled container before striking off, lb (kg) kg lbW2= net weightmass of foam in container after striking off, lb (kg) kg lbWc= weight of cement in the test batch, lb (kg) mass of cement in the test batch, kg lbWf= weight of foam in the test batch, lb (kg) mass of foam i

21、n the test batch, kg lbWTW= total weightmass of water in the test batch, including weight of foam, lb (kg) kg lbWuf= density of foam, lb/ftkg/m3(kg/mlb/ft3)Ww= weightmass of water added to test batch at mixer, lb (kg)kg lb4. Summary of Test Method4.1 This test method includes the following:4.1.1 Man

22、ufacture of laboratory quantities of cellular concrete.4.1.2 Determination of the air content of freshly prepared cellular concrete and of hardened concrete after handling inconventional machinery.4.1.3 Determination of the following properties of hardened concrete: compressive strength, tensile spl

23、itting strength, density,and water absorption. It may not be necessary to study all of the above properties in all cases, depending on the proposed use ofthe material.5. Significance and Use5.1 This test method is used to develop data for comparison or compliance with the requirements of Specificati

24、on C869.6. Apparatus6.1 MixerThe mixer shall be a power-driven paddle-type mixer with a capacity of at least 4 ft0.10 m3(0.12 m4 ft3), anoperating speed of 40 to 50 r/min (4.2 to 5.2 rad/s), and equipped with rubber wiper blades. , an operating speed of 4 to 5 rad/s40 to 50 r/min, and equipped with

25、rubber wiper blades.6.2 Foam GeneratorThe foam generator shall be a laboratory-sized generator approved by the manufacturer of the foambeing used and shall be similar to the type used in the field.6.3 PumpThe pump shall be an open or closed throat-type pump and shall be run at 26027 to 630 r/min (27

26、.266 rad/s 260to 66.0 rad/s).630 r/min. The pump shall be equipped with a 4.5-ft0.15-m3(0.13-m4.5-ft3)“ feed” “feed” reservoir and 50 ft (15m)15 m 50 ft of open-end 1-in. (25-mm)25-mm 1-in. inside diameter rubber hose on the pump discharge, the exit end of thehose being at the same height as the pum

27、p.6.4 Curing CabinetThe curing cabinet shall be as described in Specification C511.6.5 MoldsThe cylindrical molds for compression test specimens shall be as described in theApparatus section of Test MethodC495. The molds for all other test specimens shall conform to the cylinder molds in the Apparat

28、us section of PracticeC192/C192M.6.6 Strike-Off Plate for MoldsA14-in. (6-mm) thick, flat steel plate at least 8 in. (200 mm) longer and 2 in. (50 mm) widerthan the diameter of the mold. A 6-mm 14-in. thick, flat steel plate at least 200 mm 8 in. longer and 50 mm 2 in. widerthan the diameter of the

29、mold.6.7 ScalesScales and weightsmass shall be accurate to within 0.1 % of the weight of the material being measured.3ACI Committee 116, “Cement and Concrete Terminology,” American Concrete Institute, Publication SP-19, 1967, p. 144.C796/C796M 1226.8 Compression MachinesCompression testing machines

30、used for compressive strength tests and tensile-splitting strengthtests shall conform to the requirements of Test Methods C495 and C496/C496M, respectively.6.9 Drying OvenThe drying oven shall be as described in Test Method C88.6.10 Compressed AirA source of compressed air capable of maintaining pre

31、ssures in the range of 60 to 100 psi (0.4 to 0.7MPa) to 61 psi (60.007 MPa). A source of compressed air capable of maintaining pressures at a selected pressure in the rangeof 400 to 700 kPa 60 to 100 psi. The pressure selected shall be held in a tolerance of 635 kPa 65 psi.6.11 Weighing Container fo

32、r Concrete A machined-steel container of 0.5 ft0.015 m3(0.014 m0.5 ft3) volume with a flatsmooth rim.6.12 Strike-Off Plate for Weighing ContainerA14-in. (6-mm) thick, flat steel plate, at least 8 in. (200 mm) longer and 2 in.(50 mm) wider than the diameter of the rim of the weighing container. A 6-m

33、m 14-in. thick, flat steel plate, at least 200 mm8 in. longer and 50 mm 2 in. wider than the diameter of the rim of the weighing container.6.13 Stop WatchA stop watch graduated in seconds and minutes.6.14 CalipersCalipers to span 3, 6, and 12 in. (76, 152, and 305 mm). Calipers to span 75, 150, and

34、300 mm 3, 6, and12 in.6.15 Foam Weighing ContainerA lightweight vessel of approximately 2 ft0.06 m3(0.06 m2 ft3) capacity, with a smooth rimfor striking off.6.16 Strike-Off Plate for Foam Weighing Container A14-in. (6-mm) thick, flat steel plate at least 8 in. (200 mm) longer and2 in. (50 mm) wider

35、than the diameter of the rim of the container. A 6-mm 14-in. thick, flat steel plate at least 200 mm 8 in.longer and 50 mm 2 in. wider than the diameter of the rim of the container.6.17 Small ToolsSmall tools such as a rubber-headed hammer and a trowel shall be provided.7. Materials and Proportions7

36、.1 CementThe cement used shall be Type I or Type III portland cement meeting the requirements of Specification C150.7.2 Water-Cement RatioThe water requirement will vary with the type and source of cement. For the purpose of these tests,w/c = 0.58 for Type I cement and w/c = 0.64 for Type III cement

37、 shall be used. However, if a particular cement or foaming agentused with these values of w/c does not produce a satisfactory mix, a trial mix or mixes may be made using a different water-cementratio.7.3 Batch QuantitiesThe cement quantity shall be sufficient to allow molding all the test specimens

38、from one test batch. Themixture water-cement ratio determined from 7.2 shall be used to make the test batch.7.3.1 The foaming solution in the foam shall be considered as part of the total mixing water. Foam volume shall be adjustedfor the batch to produce a density after pumping of 640 6 3 lb/ft50 k

39、g/m3(641 6 48 kg/m40 6 3 lb/ft3). .8. Procedure8.1 Make an aqueous solution of the foaming agent in the dilution specified by the manufacturer. If the dilution is not specified,preliminary tests are necessary to determine the required dilution. A suggested starting point for such tests is 40 parts w

40、ater to 1part foaming agent, by volume.8.2 Charge the foam generator with the amount of foaming solution suggested by the manufacturer of the generator.8.3 Connect the generator with the source of compressed air, adjusting the pressure to that recommended by the manufacturerof the foaming agent bein

41、g tested.8.4 Using the stop watch, calibrate the generator as follows. Weigh the empty foam container and determine its volume. Overfillthe container with foam, measuring the time required using a stop watch then weigh. Strike off the excess foam, holding thestrike-off plate in a horizontal position

42、 (plane of the plate horizontal) and moving it across the top of the container with a sawingaction. Again weigh. Calculate the time required per cubic foot (ormetre or cubic metre)foot of foam using the followingequation:T15TW2W1(1)T15TW2W1(1)8.4.1Calculate also the unit weight of the foam as follow

43、s: V C0796_C0796M-12_18.4.1 Calculate also the density of the foam as follows:Wuf(2)Wuf(2)5 W2V C0796_C0796M-12_28.4.2 Calculate the length of time required to generate the required volume of foam, VfT1, as follows: , as follows:SI Units:VfT1562.4VaT1/62.42Wuf!V (3)C796/C796M 123VfT151000 VaT11000 2

44、 WufC0796_C0796M-12_3 (3)Inch-Pound Units:VfT1562.4 VaT (4)VfT1562.4 VaT (4)8.4.3Calculate the weight, 162.4 2 W uf C0796_C0796M-12_48.4.3 Calculate the mass, Wf, of the required volume of foam, VfWuf.NOTE 1The weightdensity of the foam will usually range from 230 to 4 lb/ft65 kg/m3(32 to 64 kg/m2 t

45、o 4 lb/ft3) depending on the foam chemicalused. Adjust the unit weightdensity of foam, Wuf, to the manufacturers recommendation if the foam generator is adjustable.8.4.3.1 If Type I cement is used, weigh out 58.026.0 Wflb (26.31 kg 58.0 Wfkg) of water, lb of water, Ww, and 100.0lb (45.36 kg)45.0 kg

46、100.0 lb of Type I cement.8.4.3.2 If Type III cement is used, weigh out 64.029.0 Wflb (29.03 kg 64.0 Wfkg) of water, lb of water, Ww, and 100.0lb (45.36 kg) of Type III cement. , and 45.0 kg 100.0 lb of Type III cement.8.5 Wet the mixer with water and drain. Add the water, Ww, and start the mixer. G

47、radually add the cement (over a period of12 min). With a trowel, break up any lumps of undispersed cement. Mix for 5 min.8.6 While still mixing, add Vfftm3(mft3) of foam. The required foam time is VfT1. Mix for 2 min after all the foam has beenadded. Discharge the mixer into the pump feed reservoir.

48、 Immediately, proceed to 8.7.8.7 WeighingFill a tared weighing container with a representative sample of the concrete in the reservoir. Before taking thesample, carefully mix the concrete in the reservoir to assure better uniformity without entrapping large air bubbles in the mix. Usea paddle of pro

49、per size to reach the bottom of the reservoir. Use a scoop to transfer the concrete to the container and tap the sidesof the container briskly with the rubber hammer during the filling operation. Overfill the container and strike off the excessconcrete, holding the strike-off plate in a horizontal position (plane of plate horizontal) and moving it across the top of the containerwith a sawing motion. Wipe the surface of the container free of