1、Designation: C 185 08American Association StateHighway and Transportation Officials StandardAASHTO No.: T137Standard Test Method forAir Content of Hydraulic Cement Mortar1This standard is issued under the fixed designation C 185; the number immediately following the designation indicates the year of
2、original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department o
3、f Defense.1. Scope*1.1 This test method covers the determination of the aircontent of hydraulic cement mortar under the conditionshereinafter specified.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 Values in SI shall b
4、e obtained by measurement in SIunits or by appropriate conversion, using the Rules for Con-version and Rounding in IEEE/ASTM SI 10, of measurementsmade in other units.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of
5、the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.5 Warning Fresh hydraulic cementitious mixtures arecaustic and may cause chemical burns to skin and tissue uponprolonged exposure.22. Referenced D
6、ocuments2.1 ASTM Standards:3C91 Specification for Masonry CementC 109/C 109M Test Method for Compressive Strength ofHydraulic Cement Mortars (Using 2-in. or 50-mm CubeSpecimens)C 150 Specification for Portland CementC 183 Practice for Sampling and the Amount of Testing ofHydraulic CementC 230/C 230M
7、 Specification for Flow Table for Use in Testsof Hydraulic CementC 305 Practice for Mechanical Mixing of Hydraulic CementPastes and Mortars of Plastic ConsistencyC 511 Specification for Mixing Rooms, Moist Cabinets,Moist Rooms, and Water Storage Tanks Used in theTesting of Hydraulic Cements and Conc
8、retesC 595 Specification for Blended Hydraulic CementsC 778 Specification for Standard SandC 1005 Specification for Reference Masses and Devices forDetermining Mass and Volume for Use in the PhysicalTesting of Hydraulic CementsC 1157 Performance Specification for Hydraulic CementC 1328 Specification
9、 for Plastic (Stucco) CementC 1329 Specification for Mortar CementE 438 Specification for Glasses in Laboratory ApparatusE 694 Specification for Laboratory Glass Volumetric Appa-ratusIEEE/ASTM SI 10 Standard for Use of the InternationalSystem of Units (SI): The Modern Metric System3. Summary of Test
10、 Method3.1 Prepare a mortar with standard sand and the cement tobe tested, using a water content sufficient to give a requiredflow. Compact the mortar into a measure of known volume anddetermine mass. Calculate the air content from the measureddensity of the mortar, the known densities of the consti
11、tuents,and the mixture proportions.4. Significance and Use4.1 The purpose of this test method is to determine whetheror not the hydraulic cement under test meets the air-entrainingor non-air-entraining requirements of the applicable hydrauliccement specification for which the test is being made. The
12、 aircontent of concrete is influenced by many factors other than thepotential of the cement for air entrainment.5. Apparatus5.1 Flow Table, Flow Mold, and Caliper, shall conform toSpecification C 230/C 230M.5.2 MeasureA cylindrical measure having an inside di-ameter of 76 6 2 mm and a depth (approxi
13、mately 88 mm)adjusted by standardization with water to contain 400 6 1mL1This test method is under the jurisdiction of ASTM Committee C01 on Cementand is the direct responsibility of Subcommittee C01.21 on Air Entrainment.Current edition approved July 1, 2008. Published August 2008. Originallyapprov
14、ed in 1944. Last previous edition approved in 2002 as C 185 02.2Refer to the section on Safety Precautions, “Manual of Cement Testing,”Annual Book of ASTM Standards, Vol 04.01.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. Fo
15、r 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 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.at 2
16、3.0 6 2.0 C (Note 1). For the purposes of this test, thecapacity of the measure in millilitres is the mass of the watercontent of the measure, in grams, divided by 0.9976, nocorrection in mass being made for the buoyant effect of air. Themeasure shall have a uniform wall thickness. The thickness oft
17、he wall and bottom shall not be less than 2.9 mm. The totalmass of the empty measure shall not be more than 900 g. Themeasure shall be made of a metal not attacked by the cementmortar.NOTE 1Calibrate the 400-mL measure by filling with distilled waterat 23.06 2.0 C to a point where the meniscus exten
18、ds appreciably abovethe top of the measure, placing a clean piece of plate glass on the top ofthe measure, and allowing the excess water to be squeezed out. Theabsence of air bubbles as seen through the glass ensures that the measureis completely full. Care shall be taken that the excess water is wi
19、ped fromthe sides of the container before weighing.5.3 Mixer, Bowl, and Paddle, shall conform to the apparatussection of Practice C 305.5.4 StraightedgeA steel straightedge not less than 200mm long and not less than 1.5 mm nor more than 3.5 mm inthickness.5.5 Weights and Weighing Devices, shall conf
20、orm to Speci-fication C 1005. Evaluate the weighing device for precisionand accuracy at a total load of 2 kg.5.6 Glass GraduatesGlass graduates of 250-mL capacity,conforming to the requirements of Specifications E 438 andE 694.5.7 Tamper, conforming to the requirements of Test MethodC 109/C 109M. Th
21、e tamping face of the tamper shall be flatand at right angles to the length of the tamper.5.8 Tapping Stick, a piece of hard wood having a diameterof approximately 16 mm and a length of approximately 152mm.5.9 SpoonA metal restaurant-type serving spoon not lessthan 230 mm in length and with a bowl a
22、pproximately 100 mmin length.6. Temperature and Humidity6.1 Maintain the temperature of the room and dry materialsat 23.0 6 4.0 C.6.2 Condition the mixing water and the measure, if it isbeing calibrated at 23 6 2 C.6.3 Maintain the relative humidity of the laboratory at notless than 50 %.7. Standard
23、 Sand7.1 Use sand conforming to the requirements of Specifica-tion C 778 for 2030 sand.8. Sampling8.1 Sample the cement in accordance with Practice C 183.NOTE 2Polyvinyl chloride (PVC) sample containers, upon occasion,have been found to affect the air-entraining potential of a cement sample.The same
24、 problem might be experienced with containers made from otherplastics.9. Procedure9.1 BatchProportion the standard mortar using 350 gcement to 1400 g 2030 standard sand and sufficient water togive a flow of 8712 6 712 % when determined in accordancewith 9.3.NOTE 3Test Method C 185 refers to hydrauli
25、c cements that complyunder Specification C 150, Specification C 595, and Performance Speci-fication C 1157. Masonry cements (see Specification C91), mortar ce-ments (see Specification C 1329), and plastic cements (see SpecificationC 1328) require different sand, mass, and flow. Refer to the applicab
26、lespecification.9.2 Mixing of MortarMix the mortar in accordance withPractice C 305.9.3 Flow DeterminationCarefully wipe dry the flow-tabletop and place the flow mold at the center of it. Using the spoon,place a layer of mortar about 25 mm in thickness in the moldand tamp 20 times with the tamper. T
27、he tamping pressure shallbe just sufficient to ensure uniform filling of the mold. Overfillthe top of the mold approximately 20 mm with mortar andtamp as specified for the first layer. Then cut off the mortar toa plane surface, flush with the top of the mold, by drawing thestraightedge with a sawing
28、 motion across the top of the mold.Wipe the flow table top clean and dry, being especially carefulto remove any water from around the edge of the mold. Lift themold away from the mortar 1 min after completing the mixingoperation. Immediately drop the table 10 times in accordancewith Specification C
29、230/C 230M. The flow is the resultingincrease in average diameter of the mortar mass, as determinedwith the calipers, measured on at least four diameters atapproximately equispaced intervals, expressed as a percentageof the original diameter. Make trial mortars with varyingpercentages of water until
30、 the specified flow is obtained. Makeeach trial with fresh mortar.9.4 Mass per 400 mL of MortarWhen the quantity ofmixing water has been found that produces a flow of 8712 6712 %, immediately determine the mass per 400 mL of mortar,using the mortar remaining in the mixing bowl after the flowhas been
31、 determined. In the determination of the mass per 400mL, do not use the portion of the mortar used in the flowdetermination. Using the spoon, place the mortar gently intothe 400ml measure in three equal layers. Tamp each layer 20times around the inner surface of the measure. For the finallayer of mo
32、rtar, overfill the 400ml measure approximately 20mm. The position of the tamper shall be that: the broad side ofthe tamper is parallel to the radius and is perpendicular to theinner surface of the measure. Each layer is tamped in onecomplete revolution (rotation) with only sufficient pressure toadeq
33、uately fill the measure and eliminate voids within themortar. After the measure has been filled and tamped in theabove prescribed manner, tap the sides of the measure lightlywith the side of the tapping stick, one each at five differentpoints at approximately equal spacing around the outside of them
34、easure, in order to preclude entrapment of extraneous air(Note 4). No obvious space shall be left between the mortarand the inner surface of the measure as a result of the tampingoperation. Then cut the mortar off to a plane surface, flush withthe top of the measure, by drawing the straightedge with
35、 asawing motion across the top of the measure, making twoC185082passes over the entire surface, the second pass being made atright angles to the first. If, in the striking-off operation, loosesand grains cause the straightedge to ride above the top surfaceof the measure, these grains shall be remove
36、d, and theoperation repeated. Complete the entire operation of filling andstriking off the measure within 112 min. Wipe off all mortar andwater adhering to the outside of the measure. Determine themass of the measure and its contents. Subtract the mass of thecontainer, and record the mass of the mor
37、tar in grams.NOTE 4This operation may be facilitated by placing the measure ona steady flat-surfaced support of lesser diameter than the measure whilefilling and wiping.10. Calculation10.1 Calculate the air content of the mortar from thefollowing formula which is based on the batch proportionsgiven
38、in 9.1, taking the specific gravity of portland cement as3.15 and of 2030 standard sand as 2.65. When the hydrauliccement is other than portland, the appropriate value for itsspecific gravity shall be substituted for the value of 3.15 andthe formula rederived accordingly:Air content, volume % 5 100
39、2 W182.7 1 P!/2000 1 4P!# (1)where:W = mass of 400 mL of mortar, g, andP = percentage of mixing water, based on mass of cementused.NOTE 5This formula is derived as follows:Air content, volume % 5 1001 2 Wa/Wc!# (2)where:Wa= actual mass per unit of volume as determined by thistest method.= W/400 g/mL
40、, where W is the mass in grams of thespecified 400 mL of mortar (9.4),Wc= theoretical mass per unit of volume, calculated on anair-free basis as follows and using the values forquantities of materials and specific gravities as givenin 9.1 and 10.1,= 350 1 1400 1 350 3 P 3 0.013503.15114002.651350 3
41、P 3 0.011= 5 1 0.01P!1.827 1 0.01P!, andP = percentage of mixing water, based on mass of ce-ment.Substituting for Waand Wcwe have:Air content, volume % 5 100S1 2W40031.827 1 0.01P5 1 0.01PDAir content, volume % 5 100 2W431.827 1 0.01P!5 1 0.01P!Air content, volume % 5 100 2 2.5W182.7 1 P!5000 1 10P!
42、Air content, volume % 5 100 2 W182.7 1 P!2000 1 4P!10.2 Make only one determination of air content on a batch.NOTE 6Difficulty has occasionally been experienced with this testmethod by some persons. These difficulties usually have taken the form ofvalues for air content that are abnormally high and
43、that may be greaterthan the specified maxima in specifications for hydraulic cement. Theair-entraining potential of the sand may be reduced by washing in thelaboratory with potable water by decantation until a clear, colorlesssupernatant liquid is obtained. In case of dispute, such freshly washedsan
44、d shall be used.11. Report11.1 When this test method is used for specific action incompliance testing, report the value for the air content to thenearest 1 %.12. Precision and Bias12.1 The single-operator, within-laboratory, standard devia-tion has been found to be 0.56 % air content throughout ther
45、ange of 8 to 19 % air. Therefore, results of two properlyconducted tests by the same operator on similar batches shouldnot differ by more than 1.6 % air.12.2 The multilaboratory standard deviation has been foundto be 1.0 % air content throughout the range from 8 to 19 % air.Therefore, results of two
46、 different laboratories on similarbatches should not differ from each other by more than 2.8 %air.13. Keywords13.1 air content; hydraulic cement mortarC185083For additional useful information on details of cement tests methods, references may be made to the “Manual ofCement Testing,” which appears i
47、n the Annual Book of ASTM Standards, Vol 04.01.SUMMARY OF CHANGESCommittee C01 has identified the location of selected changes to this test method since the last issue,C 185 02, that may impact the use of this test method. (Approved July 1, 2008)(1) Added new Note 2 and renumbered subsequent notes.A
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