ASTM C232 C232M-2009 Standard Test Methods for Bleeding of Concrete《混凝土泌水现象的标准试验方法》.pdf

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1、Designation: C 232/C 232M 09Standard Test Methods forBleeding of Concrete1This standard is issued under the fixed designation C 232/C 232M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the year of last revision. A number in pare

2、ntheses 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 These test methods cover the determination of therelative quantity

3、of mixing water 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 s

4、ame batch aretested 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 either SI units or inch-pound unitsare

5、to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.4 The text of this standard references notes and

6、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 not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of th

7、e 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 mixtures are caustic and may causechemical burns to skin and tissue upon prolonged exposure).22. Referenced Docum

8、ents2.1 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 Practice for Making and Curing ConcreteTest Specimens in the LaboratoryC 670 Practice for Preparing Precision and

9、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, treatment,environment, or other factors in the bleeding of concrete. It isalso permitted to be used to determine

10、 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 disturbance, thus simulating condi-tions in which the concrete, after placement, is not subjected tointermittent

11、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, issubjected to intermittent vibration.TEST METHOD ASAMPLE CONSOLIDATED BYTAMPING4. Apparatus4.1 ContainerA cylindric

12、al container of approximately14-L 12-ft3 capacity, having an inside diameter of 255 6 5mm 10 614 in. and an inside height of 280 6 5mm11614 in. The container shall be made of metal having a thicknessof 2.67 to 3.40 mm 0.105 to 0.134 in. and shall be externallyreinforced around the top with a 2.67 to

13、 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 the mass of theload required with an accuracy of 0.5 %. Balances or scalesshall be calibrated at least annually or whenev

14、er 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.1These test methods are under the jurisdiction of ASTM Committee C09 onConcrete and ConcreteAggregates and are the dire

15、ct responsibility of SubcommitteeC09.60 on Testing Fresh Concrete.Current edition approved June 1, 2009. Published July 2009. Originally approvedin 1949. Last previous edition approved in 2007 as C 232 07.2Section on Safety Precautions, Manual of Aggregate and Concrete Testing,Annual Book of ASTM St

16、andards, Vol 04.02.3For referenced ASTM standards, visit the 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

17、the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.3 Pipet, or similar instrument, for drawing off free waterfrom the surface of the test specimen.4.4 Glass Graduate, 100-mL capacity for collecting andmeasuring

18、 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 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 p

19、rocedure 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 forcollecting the decanted supernatant water and sludge.4.8 Balance (Optional)A balance sensitive to1gfordetermining the mass of the d

20、ecanted 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 the laboratory, prepare as de-scribed in Practice C 192/C 192M. For concrete made in thefield, sample the concrete as described in

21、 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 nominal maximum size of 50 mm2 in. Concrete containing aggregate larger than 50 mm 2 in.in nominal maximum size shall be wet sieved

22、 over a 3.75 mm112-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 withTest Method C 138/C 138M except that the container shall befilled to a height of 254 6 3mm10618 in. Level the topsurface of the concr

23、ete 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 and 75 F. Immediately aftertroweling the surface of the specimen, record the time anddetermine the mass of the container and its contents. Plac

24、e 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 the cover in place throughoutthe test, except when drawing off the water. Draw off (withpipet or similar instrument) the water that has accumu

25、lated 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 observation. To facilitate the collection ofbleeding water, tilt the specimen carefully by placing a blockapproximately 50 mm 2 in. thick under o

26、ne 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. After each withdrawal, transfer thewater to a 100-mL graduated cylinder. Record the accumulatedquantity of water after each transfer. When only

27、 the totalvolume of bleeding is desired to be determined, the periodicremoval procedure shall be omitted and the entire amountremoved in a single operation. If it is desired to determine themass of the bleeding water and to exclude the material presentother than the water, carefully decant the conte

28、nts 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 mass 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 al

29、so beobtained, if desired, by initially determining the tare mass ofthe beaker.7. Calculation7.1 Calculate the volume of bleeding water per unit area ofsurface, 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 concre

30、te, 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 Calculate the accumulated bleeding water, expressed asa percentage of the net mixing water contained within the testspecimen, as follows:C 5 w/

31、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 of water minus thewater absorbed by the aggregates), kg,S = mass of the sample, g, andD = mass of the bleeding water, g, or total volumewithdra

32、wn from the test specimen in cubic centime-ters multiplied by 1 g/cm3.TEST METHOD BSAMPLE CONSOLIDATED BYVIBRATION8. Apparatus8.1 Vibrating PlatformA platform shall be provided uponwhich the filled container shall be mounted. The platform shallbe equipped with a suitable device so that intermittent

33、periodsof vibration of reproducible duration, frequency, and ampli-tudes will be imparted to the specimen container as prescribedby Section 8 (see Fig. 1). 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 m

34、ass is approxi-mately 110 g 0.24 lb is attached by means of a setscrew. Theeccentric shall be fabricated from cold-rolled stock in accor-dance with the details and dimensions shown in Fig. 2. Thehole through the eccentric is 13.5 mm 34/64 in. or anappropriate size to accommodate the motor shaft. The

35、 platformshall be supported on rubber supports resting on a concreteslab. The concrete slab shall be separated from the floor by alayer of cork as shown in Fig. 2.C 232/C 232M 0928.2 TimerA timing device, by means of which the periodsof vibration provided to the platform and specimen in accor-dance

36、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 bottom,and 285 mm 1118 in. high shall be provided.Asteel containercover shall also be provided. The container and cover shallconform wit

37、h 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 follows: Power on for 3s, power off 30 s. However, due to the coasting of the motorafter the power is turned off, the period of perceptibl

38、e 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 depthequal to approximately one half the average diameter of thecontainer. The size of the test sample can best be regulated bymass; a sam

39、ple 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 SpecimenConsolidate thesample in the container by means of vibration of only thatduration required to effect the desired degree of compaction.Sufficient v

40、ibration has been applied as soon as the surface ofthe concrete has become relatively smooth. Stop the consoli-dating procedure immediately upon the first appearance of freewater segregating from the concrete as indicated by thedevelopment of a water sheen on its surface. For someunusually wet or pl

41、astic mixtures, no consolidating effort willbe needed beyond that supplied by placing the sample in thecontainer and handling the container during the operations ofdetermining the mass and placing it on the platform for test.11.2 Intermittent VibrationPlace the cover on the con-tainer and the contai

42、ner 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.11.3 Determination of Bleeding WaterThe intermittentperiods of vibrations do not permit the determination ofbleeding water at a number of di

43、fferent time intervals. Deter-mine the total volume of bleeding water as described forMethod A.12. Calculation12.1 Calculate the percentage bleeding water as describedfor Method A.13. Report13.1 Concrete mixture proportions,13.2 Source and identification of each material used,13.3 Method used for co

44、llection 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 the net mixing water contained within the test specimen, and13.5 Elapsed time required for cessation of bleeding.14. Precision and Bias14.1

45、 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 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 Metho

46、d 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 to20 %, and 1.77 % for more than 20 %. Therefore, results of twoproperly conducted tests by the same operator on the same dayon different

47、 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 % for morethan 20 %. (See Note 1.)NOTE 1These numbers represent, respectively, the (1s) and (d2s)limits as described in Practice C 670.14.2 B

48、iasThe test methods have no bias because thevalues determined can be defined only in terms of the testmethods.15. Keywords15.1 bleeding; concrete, bleeding ofFIG. 1 Vibrating Platform and TimerC 232/C 232M 093FIG. 2 Detail of Vibrating Platform ApparatusC 232/C 232M 094SUMMARY OF CHANGESCommittee C0

49、9 has identified the location of selected changes to these test methods since the last issue,C 232 07, that may impact the use of these test methods. (Approved June 1, 2009)(1) Revised the standard as dual-units test methods.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 infri