ASTM C232-2007 Standard Test Methods for Bleeding of Concrete《混凝土泌水性的标准试验方法》.pdf

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1、Designation: C 232 07Standard Test Methods forBleeding of Concrete1This standard is issued under the fixed designation C 232; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indica

2、tes the year of last reapproval. Asuperscript epsilon (e) 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 These test methods cover the determination of therelative quantity of mixing wat

3、er that will bleed from a sampleof freshly mixed concrete. Two test methods, that differprimarily in the degree of vibration to which the concretesample is subjected, are included.1.2 The two test methods are not expected to yield the sametest results when samples of concrete from the same batch are

4、tested by each method. When various concretes are to becompared, all the tests must be conducted using the samemethod, and if the batches are of similar unit weight, thesample masses shall not differ by more than 1 kg (2 lb).1.3 The values stated in SI units are to be regarded asstandard. The values

5、 in parentheses are provided for informa-tion purposes only.1.4 The text of this standard references notes and footnoteswhich 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 n

6、ot purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility 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. (WarningFreshhydraulic cementitious mi

7、xtures are caustic and may causechemical burns to skin and tissue upon prolonged exposure).22. Referenced Documents2.1 ASTM Standards:3C 138/C 138M Test Method for Density (Unit Weight),Yield, and Air Content (Gravimetric) of ConcreteC 172 Practice for Sampling Freshly Mixed ConcreteC 192/C 192M Pra

8、ctice for Making and Curing ConcreteTest Specimens in the LaboratoryC 670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction Materials3. Significance and Use3.1 This test method provides procedures to be used fordetermining the effect of variables of composition, t

9、reatment,environment, or other factors in the bleeding of concrete. It isalso permitted to be used to determine the conformance of aproduct or treatment with a requirement relating to its effect onbleeding of concrete.3.2 Method AFor a sample consolidated by rodding onlyand tested without further di

10、sturbance, thus simulating condi-tions in which the concrete, after placement, is not subjected tointermittent vibration.3.3 Method BFor a sample consolidated by vibration andtested with further intermittent periods of vibration, thussimulating conditions in which concrete, after being placed, issub

11、jected to intermittent vibration.TEST METHOD ASAMPLE CONSOLIDATED BYTAMPING4. Apparatus4.1 ContainerA cylindrical container of approximately14L(12-ft3) capacity, having an inside diameter of 255 6 5mm(10 614 in.) and an inside height of 280 6 5mm(11614 in.).The container shall be made of metal havin

12、g a thickness of2.67 to 3.40 mm (0.105 to 0.134 in.) and shall be externallyreinforced around the top with a 2.67 to 3.40 mm (0.105 to0.134 in.) metal band, 40 mm (112 in.) wide. The inside shallbe smooth and free of corrosion, coatings, or lubricants.4.2 Scale, of sufficient capacity to determine t

13、he mass of theload required with an accuracy of 0.5 %. Balances or scalesshall be calibrated at least annually or whenever there is reasonto question the accuracy of the equipment. Equipment not inoperating condition or out of tolerance shall be marked as suchand taken out of service until corrected

14、.4.3 Pipet, or similar instrument, for drawing off free waterfrom the surface of the test specimen.1These test methods are under the jurisdiction of ASTM Committee C09 onConcrete and ConcreteAggregates and are the direct responsibility of SubcommitteeC09.60 on Testing Fresh Concrete.Current edition

15、approved July 15, 2007. Published August 2007. Originallyapproved in 1949. Last previous edition approved in 2004 as C 232 04.2Section on Safety Precautions, Manual of Aggregate and Concrete Testing,Annual Book of ASTM Standards, Vol 04.02.3For referenced ASTM standards, visit the ASTM website, www.

16、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 Barr Harbor Drive, P

17、O Box C700, West Conshohocken, PA 19428-2959, United States.4.4 Glass Graduate, 100-mL capacity for collecting andmeasuring the quantity of water withdrawn.4.5 Tamping RodA round, straight steel rod, 16 mm (58in.) in diameter and approximately 610 mm (24 in.) in length,having the tamping end rounded

18、 to a hemispherical tip, thediameter of which is 16 mm (58 in.).4.6 The apparatus listed in 4.7, 4.8, and 4.9 are required ifthe procedure of measuring the amount of bleeding waterrecovered is one involving weighing, evaporation, and re-weighing.4.7 Metal Beaker (Optional)A 1000-mL metal beaker forc

19、ollecting the decanted supernatant water and sludge.4.8 Balance (Optional)A balance sensitive to1gfordetermining the mass of the decanted water and sludge.4.9 Hot Plate (Optional)Asmall electric hot plate or othersource of heat for evaporating decanted water.5. Test Specimen5.1 For concrete made in

20、the laboratory, prepare as de-scribed in Practice C 192/C 192M. For concrete made in thefield, sample the concrete as described in Practice C 172. Theapparatus described in this test method is permitted to be usedwith samples of concrete containing any size of aggregategraded up to and including a n

21、ominal maximum size of 50 mm(2 in.). Concrete containing aggregate larger than 50 mm (2 in.)in nominal maximum size shall be wet sieved over a 3.75 mm(112-in.) sieve and the test performed on a portion of thesample that passes through the sieve.5.2 Fill the container with the concrete in accordance

22、withTest Method C 138/C 138M except that the container shall befilled to a height of 254 6 3mm(10618 in.). Level the topsurface of the concrete to a reasonably smooth surface by aminimum amount of troweling.6. Procedure6.1 During the test, maintain the ambient temperature be-tween 18 and 24 C (65 an

23、d 75 F). Immediately aftertroweling the surface of the specimen, record the time anddetermine the mass of the container and its contents. Place thespecimen and container on a level platform or floor free ofnoticeable vibration and cover the container to prevent evapo-ration of the bleed water. Keep

24、the cover in place throughoutthe test, except when drawing off the water. Draw off (withpipet or similar instrument) the water that has accumulated onthe surface at 10-min intervals during the first 40 min and at30-min intervals thereafter until cessation of bleeding, record-ing the time of last obs

25、ervation. To facilitate the collection ofbleeding water, tilt the specimen carefully by placing a blockapproximately 50 mm (2 in.) thick under one side of thecontainer 2 min prior to each time the water is withdrawn.After the water is removed, return the container to a levelposition without jarring.

26、 After each withdrawal, transfer thewater to a 100-mL graduated cylinder. Record the accumulatedquantity of water after each transfer. When only the totalvolume of bleeding is desired to be determined, the periodicremoval procedure shall be omitted and the entire amountremoved in a single operation.

27、 If it is desired to determine themass of the bleeding water and to exclude the material presentother than the water, carefully decant the contents of thecylinder into a metal beaker. Determine the mass and recordthe mass of the beaker and its contents. Dry the beaker and itscontents to constant mas

28、s and record the final mass. Thedifference between the two masses, D, is equal to the mass ofthe bleeding water. The mass of the sludge shall also beobtained, if desired, by initially determining the tare mass ofthe beaker.7. Calculation7.1 Calculate the volume of bleeding water per unit area ofsurf

29、ace, V, as follows:V 5 V1/A (1)where:V1= volume of bleeding water measured during the se-lected time interval, mL, andA = area of exposed concrete, cm2.The comparative rate of bleeding shall be determined as thetest progresses by comparing the volume of bleeding water foreach equal time interval.7.2

30、 Calculate the accumulated bleeding water, expressed asa percentage of the net mixing water contained within the testspecimen, as follows:C 5 w/W! 3 S (2)Bleeding, % 5 D/C! 3 100where:C = mass of the water in the test specimen, g,W = total mass of the batch, kg,w = net mixing water (the total amount

31、 of water minus thewater absorbed by the aggregates), kg,S = mass of the sample, g, andD = mass of the bleeding water, g, or total volumewithdrawn from the test specimen in cubic centime-ters multiplied by 1 g/cm3.TEST METHOD BSAMPLE CONSOLIDATED BYVIBRATION8. Apparatus8.1 Vibrating PlatformA platfo

32、rm shall be provided uponwhich the filled container shall be mounted. The platform shallbe equipped with a suitable device so that intermittent periodsof vibration of reproducible duration, frequency, and ampli-tudes will be imparted to the specimen container as prescribedby Section 8 (see Fig. 1).

33、Suitable vibration will be provided ifthere is bolted to the platform a 93W (18-hp) electric motor, tothe shaft of which a small eccentric whose mass is approxi-mately 110 g is attached by means of a setscrew. The eccentricshall be fabricated from cold-rolled stock in accordance withthe details and

34、dimensions shown in Fig. 2. The hole throughthe eccentric is 13.5 mm (34/64 in.) or an appropriate size toaccommodate the motor shaft. The platform shall be supportedon rubber supports resting on a concrete slab. The concrete slabshall be separated from the floor by a layer of cork as shown inFig. 2

35、.C2320728.2 TimerA timing device, by means of which the periodsof vibration provided to the platform and specimen in accor-dance with the provisions of Section 8 is permitted to beregulated.8.3 ContainerA steel container 290 mm (1112 in.) indiameter at the top, 280 mm (11 in.) in diameter at the bot

36、tom,and 285 mm (1118 in.) high shall be provided.Asteel containercover shall also be provided. The container and cover shallconform with the details given in Fig. 3.8.3.1 The remainder of the apparatus is identical with thatgiven for Method A.9. Vibrating Cycle9.1 The vibrating cycle shall be as fol

37、lows: Power on for 3s, power off 30 s. However, due to the coasting of the motorafter the power is turned off, the period of perceptible vibrationis approximately 7 s.10. Test Specimen10.1 The sample shall be prepared as described for MethodA.10.2 The sample shall be placed in the container to a dep

38、thequal to approximately one half the average diameter of thecontainer. The size of the test sample can best be regulated bymass; a sample with a mass of 20 6 0.5 kg (45 6 1 lb) usuallymeets the requirements for the apparatus described herein.11. Procedure11.1 Consolidation of Test SpecimenConsolida

39、te thesample in the container by means of vibration of only thatduration required to effect the desired degree of compaction.Sufficient vibration has been applied as soon as the surface ofthe concrete has become relatively smooth. Stop the consoli-dating procedure immediately upon the first appearan

40、ce of freewater segregating from the concrete as indicated by thedevelopment of a water sheen on its surface. For someunusually wet or plastic mixtures, no consolidating effort willbe needed beyond that supplied by placing the sample in thecontainer and handling the container during the operations o

41、fdetermining the mass and placing it on the platform for test.11.2 Intermittent VibrationPlace the cover on the con-tainer and the container on the vibrating platform. Clamp thecontainer and cover down tightly. Note and record the time,and start the motor. Continue intermittent vibration for 1 h.11.

42、3 Determination of Bleeding WaterThe intermittentperiods of vibrations do not permit the determination ofbleeding water at a number of different time intervals. Deter-mine the total volume of bleeding water as described forMethod A.12. Calculation12.1 Calculate the percentage bleeding water as descr

43、ibedfor Method A.13. Report13.1 Concrete mixture proportions,13.2 Source and identification of each material used,13.3 Method used for collection of the bleeding data (A orB),13.4 The volume of bleeding water per unit area of surface,and the accumulated bleeding water, expressed as a percentageof th

44、e net mixing water contained within the test specimen, and13.5 Elapsed time required for cessation of bleeding.14. Precision and Bias14.1 Precision:14.1.1 Method AData are not available to evaluate theprecision of Method A directly. However, there is reason tobelieve that the precision for Method A

45、is at least as good asthat for Method B. The values given for Method B shall beused as maximum precision limits for Method A.14.1.2 Method BThe single operator-day-multibatch stan-dard deviation (1s) has been found to be 0.71 % for a bleedingrange from 0 to 10 %, 1.06 % for a bleeding range from 10

46、to20 %, and 1.77 % for more than 20 %. Therefore, results of twoproperly conducted tests by the same operator on the same dayon different batches of the same mixture are not expected todiffer by more than 2.0 % (d2s) for a bleeding range from 0 to10 %, 3.0 % for a range from 10 to 20 %, and 5.0 % fo

47、r morethan 20 %. (See Note 1.)NOTE 1These numbers represent, respectively, the (1s) and (d2s)limits as described in Practice C 670.14.2 BiasThe test methods have no bias because thevalues determined can be defined only in terms of the testmethods.15. Keywords15.1 bleeding; concrete, bleeding ofFIG.

48、1 Vibrating Platform and TimerC232073FIG. 2 Detail of Vibrating Platform ApparatusC232074SUMMARY OF CHANGESCommittee C09 has identified the location of selected changes to these test methods since the last issue,C 232 04, that may impact the use of these test methods. (Approved July 15, 2007)(1) Rev

49、ised 4.2.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited eithe