ASTM C232 C232M-2012 Standard Test Methods for Bleeding of Concrete《混凝土泌水的标准试验方法》.pdf

1、Designation: C232/C232M 09 C232/C232M 12Standard Test Methods forBleeding of Concrete1This standard is issued under the fixed designation C232/C232M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the year of last revision. A numb

2、er 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 These test methods cover the determination of the relativ

3、e quantity of mixing water that will bleed from a sample of freshlymixed concrete. Two test methods, that differ primarily in the degree of vibration to which the concrete sample is subjected, areincluded.1.2 The two test methods are not expected to yield the same test results when samples of concre

4、te from the same batch are testedby each method. When various concretes are to be compared, all the tests must be conducted using the same method, and if thebatches are of similar unit weight, the sample masses shall not differ by more than 1 kg 2 lb.1.3 The values stated in either SI units or inch-

5、pound units are to be regarded separately as standard. The values stated 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 The text of this standard ref

6、erences notes and footnotes which provide explanatory material. These notes and footnotes(excluding those in tables and figures) shall not be considered as requirements of the standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is th

7、e responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use. (WarningFresh hydraulic cementitious mixtures are caustic and may cause chemical burns to skin andtissue upon prolonged exposure).2

8、2. Referenced Documents2.1 ASTM Standards:3C29/C29M Test Method for Bulk Density (“Unit Weight”) and Voids in AggregateC138/C138M Test Method for Density (Unit Weight), Yield, and Air Content (Gravimetric) of ConcreteC172 Practice for Sampling Freshly Mixed ConcreteC192/C192M Practice for Making and

9、 Curing Concrete Test Specimens in the LaboratoryC670 Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials3. Significance and Use3.1 This test method provides procedures to be used for determining the effect of variables of composition, treatment,environme

10、nt, or other factors in the bleeding of concrete. It is also permitted to be used to determine the conformance of a productor treatment with a requirement relating to its effect on bleeding of concrete.3.2 Method AFor a sample consolidated by rodding only and tested without further disturbance, thus

11、 simulating conditionsin which the concrete, after placement, is not subjected to intermittent vibration.3.3 Method BFor a sample consolidated by vibration and tested with further intermittent periods of vibration, thus simulatingconditions in which concrete, after being placed, is subjected to inte

12、rmittent vibration.1 These test methods are under the jurisdiction of ASTM Committee C09 on Concrete and Concrete Aggregatesand are the direct responsibility of Subcommittee C09.60on Testing Fresh Concrete.Current edition approved June 1, 2009Nov. 1, 2012. Published July 2009December 2012. Originall

13、y approved in 1949. Last previous edition approved in 20072009 asC232 07.C232/C232M 09. DOI: 10.1520/C0232_C0232M-09.10.1520/C0232_C0232M-12.2 Section on Safety Precautions, Manual of Aggregate and Concrete Testing, Annual Book of ASTM Standards, Vol 04.02.3 For referenced ASTM standards, visit the

14、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.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an

15、 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 appropriate. In all cases only the current versionof the standard as published by ASTM is to

16、 be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1TEST METHOD ASAMPLE CONSOLIDATED BY TAMPING4. Apparatus4.1 ContainerA cylindrical co

17、ntainer of approximately 14-L 12-ft3 capacity, having an inside diameter of 255 6 5 mm 106 14 in. and an inside height of 280 6 5 mm 11 6 14 in. The container shall be made of metal having a thickness of 2.67 to3.40 mm 0.105 to 0.134 in. and shall be externally reinforced around the top with a 2.67c

18、onform to the requirements of TestMethod C29/C29Mto 3.40 mm 0.105 to 0.134 in. metal band, 40 mm 1. 12 in. wide. The inside shall be smooth and free ofcorrosion, coatings, or lubricants.4.2 Scale, of sufficient capacity to determine the mass of the load required with an accuracy of 0.5 %. Balances o

19、r scales shallbe calibrated at least annually or whenever there is reason to question the accuracy of the equipment. Equipment not in operatingcondition or out of tolerance shall be marked as such and taken out of service until corrected.4.3 Pipet, or similar instrument, for drawing off free water f

20、rom the surface of the test specimen.4.4 Glass Graduate, 100-mL capacity for collecting and measuring the quantity of water withdrawn.4.5 Tamping RodA round, straight steel rod, 16 mm 58 in. in diameter and approximately 610 mm 24 in. in length, havingthe tamping end rounded to a hemispherical tip,

21、the diameter of which is 16 mm 58 in.4.6 The apparatus listed in 4.7, 4.8, and 4.9 are required if the procedure of measuring the amount of bleeding water recoveredis one involving weighing, evaporation, and reweighing.4.7 Metal Beaker (Optional)A 1000-mL metal beaker for collecting the decanted sup

22、ernatant water and sludge.4.8 Balance (Optional)A balance sensitive to 1 g for determining the mass of the decanted water and sludge.4.9 Hot Plate (Optional)A small electric hot plate or other source of heat for evaporating decanted water.5. Test Specimen5.1 For concrete made in the laboratory, prep

23、are as described in Practice C192/C192M. For concrete made in the field, samplethe concrete as described in Practice C172. The apparatus described in this test method is permitted to be used with samples ofconcrete containing any size of aggregate graded up to and including a nominal maximum size of

24、 50 mm 2 in. Concretecontaining aggregate larger than 50 mm 2 in. in nominal maximum size shall be wet sieved over a 3.7537.5 mm 112-in. sieveand the test performed on a portion of the sample that passes through the sieve.5.2 Fill the container with the concrete in accordance with Test Method C138/C

25、138M except that the container shall be filledto a height of 254 6 3 mm 10 6 18 in. Level the top surface of the concrete to a reasonably smooth surface by a minimumamount of troweling.6. Procedure6.1 During the test, maintain the ambient temperature between 18 and 24 C 65 and 75 F. Immediately afte

26、r troweling thesurface of the specimen, record the time and determine the mass of the container and its contents. Place the specimen and containeron a level platform or floor free of noticeable vibration and cover the container to prevent evaporation of the bleed water. Keepthe cover in place throug

27、hout the test, except when drawing off the water. Draw off (with pipet or similar instrument) the waterthat has accumulated on the surface at 10-min intervals during the first 40 min and at 30-min intervals thereafter until cessationof bleeding, recording the time of last observation. To facilitate

28、the collection of bleeding water, tilt the specimen carefully byplacing a block approximately 50 mm 2 in. thick under one side of the container 2 min prior to each time the water is withdrawn.After the water is removed, return the container to a level position without jarring. After each withdrawal,

29、 transfer the water toa 100-mL graduated cylinder. Record the accumulated quantity of water after each transfer. When only the total volume of bleedingis desired to be determined, the periodic removal procedure shall be omitted and the entire amount removed in a single operation.If it is desired to

30、determine the mass of the bleeding water and to exclude the material present other than the water, carefully decantthe contents of the cylinder into a metal beaker. Determine the mass and record the mass of the beaker and its contents. Dry thebeaker and its contents to constant mass and record the f

31、inal mass. The difference between the two masses, D, is equal to the massof the bleeding water. The mass of the sludge shall also be obtained, if desired, by initially determining the tare mass of the beaker.7. Calculation7.1 Calculate the volume of bleeding water per unit area of surface, V, as fol

32、lows:V 5V1/A (1)where:V 1 = volume of bleeding water measured during the selected time interval, mL, andA = area of exposed concrete, cm2.C232/C232M 122The comparative rate of bleeding shall be determined as the test progresses by comparing the volume of bleeding water for eachequal time interval.7.

33、2 Calculate the accumulated bleeding water, expressed as a percentage of the net mixing water contained within the testspecimen, as follows:C 5w/W! 3S (2)Bleeding,%5D/C! 3100where: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

34、water minus the water absorbed by the aggregates), kg,S = mass of the sample, g, andD = mass of the bleeding water, g, or total volume withdrawn from the test specimen in cubic centimeters multiplied by 1g/cm3.TEST METHOD BSAMPLE CONSOLIDATED BY VIBRATION8. Apparatus8.1 Vibrating PlatformA platform

35、shall be provided upon which the filled container shall be mounted. The platform shall beequipped with a suitable device so that intermittent periods of vibration of reproducible duration, frequency, and amplitudes willbe imparted to the specimen container as prescribed by Section 8 (see Fig. 1). Su

36、itable vibration will be provided if there is boltedto the platform a 93W 18-hp electric motor, to the shaft of which a small eccentric whose mass is approximately 110 g 0.24 lbis attached by means of a setscrew. The eccentric shall be fabricated from cold-rolled stock in accordance with the details

37、 anddimensions shown in Fig. 2. The hole through the eccentric is 13.5 mm 34/64 in. or an appropriate size to accommodate the motorshaft. The platform shall be supported on rubber supports resting on a concrete slab. The concrete slab shall be separated from thefloor by a layer of cork as shown in F

38、ig. 2.8.2 TimerA timing device, by means of which the periods of vibration provided to the platform and specimen in accordancewith the provisions of Section 8 is permitted to be regulated.8.3 ContainerA steel container 290 mm 1112 in. in diameter at the top, 280 mm 11 in. in diameter at the bottom,

39、and 285mm 1118 in. high shall be provided. A steel container cover shall also be provided. The container and cover shall conform withthe details given in Fig. 3.8.3.1 The remainder of the apparatus is identical with that given for Method A.FIG. 1 Vibrating Platform and TimerC232/C232M 1239. Vibratin

40、g Cycle9.1 The vibrating cycle shall be as follows: Power on for 3 s, power off 30 s. However, due to the coasting of the motor afterthe power is turned off, the period of perceptible vibration is approximately 7 s.10. Test Specimen10.1 The sample shall be prepared as described for Method A.10.2 The

41、 sample shall be placed in the container to a depth equal to approximately one half the average diameter of thecontainer. The size of the test sample can best be regulated by mass; a sample with a mass of 20 6 0.5 kg 45 6 1 lb usuallymeets the requirements for the apparatus described herein.11. Proc

42、edure11.1 Consolidation of Test SpecimenConsolidate the sample in the container by means of vibration of only that durationrequired to effect the desired degree of compaction. Sufficient vibration has been applied as soon as the surface of the concretehas become relatively smooth. Stop the consolida

43、ting procedure immediately upon the first appearance of free water segregatingfrom the concrete as indicated by the development of a water sheen on its surface. For some unusually wet or plastic mixtures,no consolidating effort will be needed beyond that supplied by placing the sample in the contain

44、er and handling the containerduring the operations of determining the mass and placing it on the platform for test.11.2 Intermittent VibrationPlace the cover on the container and the container on the vibrating platform. Clamp the containerand cover down tightly. Note and record the time, and start t

45、he motor. Continue intermittent vibration for 1 h.FIG. 2 Detail of Vibrating Platform ApparatusC232/C232M 12411.3 Determination of Bleeding WaterThe intermittent periods of vibrations do not permit the determination of bleeding waterat a number of different time intervals. Determine the total volume

46、 of bleeding water as described for Method A.12. Calculation12.1 Calculate the percentage bleeding water as described for 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 or B),13.4 The v

47、olume of bleeding water per unit area of surface, and the accumulated bleeding water, expressed as a percentage ofthe 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 availabl

48、e to evaluate the precision of Method A directly. However, there is reason to believe thatthe precision for Method A is at least as good as that for Method B. The values given for Method B shall be used as maximumprecision limits for Method A.14.1.2 Method BThe single operator-day-multibatch standar

49、d deviation (1s) has been found to be 0.71 % for a bleeding rangefrom 0 to 10 %, 1.06 % for a bleeding range from 10 to 20 %, and 1.77 % for more than 20 %. Therefore, results of two properlyconducted tests by the same operator on the same day on different batches of the same mixture are not expected to differ by morethan 2.0 % (d2s) for a bleeding range from 0 to 10 %, 3.0 % for a range from 10 to 20 %, and 5.0 % for more than 20 %. (SeeNote 1.)NOTE 1These numbers represent, respectively, th