ASTM C232 C232M-2013 Standard Test Method for Bleeding of Concrete.pdf

《ASTM C232 C232M-2013 Standard Test Method for Bleeding of Concrete.pdf》由会员分享，可在线阅读，更多相关《ASTM C232 C232M-2013 Standard Test Method for Bleeding of Concrete.pdf（4页珍藏版）》请在麦多课文档分享上搜索。

1、Designation: C232/C232M 12C232/C232M 13Standard Test MethodsMethod 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

2、 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 TheseThis test methods covermethod covers the determ

3、ination of the relative quantity of mixing water that will bleed froma sample of freshly mixed concrete. Two test methods, that differ primarily in the degree of vibration to which the concrete sampleis subjected, are included.1.2 The two test methods are not expected to yield the same test results

4、when samples of concrete 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 ei

5、ther SI units or inch-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 tex

6、t of this standard references 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

7、with its use. 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. (WarningFresh hydraulic cementitious mixtures are caustic and may cause chemical burns to skin andtissue upon

8、 prolonged exposure).22. 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 P

9、ractice for Making and 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 compositio

10、n, treatment,environment, 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 A specimen consolidated by rodding only and tested

11、without further disturbance, thus simulatingdisturbance simulates conditions in which the concrete, after placement, concrete is not subjected to intermittent vibration.vibration after placement.3.3 Method BFor a sample consolidated by vibration and tested with further intermittent periods of vibrat

12、ion, thus simulatingconditions in which concrete, after being placed, is subjected to intermittent 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.Curr

13、ent edition approved Nov. 1, 2012June 15, 2013. Published December 2012August 2013. Originally approved in 1949. Last previous edition approved in 20092012as C232/C232M 09.C232/C232M 12. DOI: 10.1520/C0232_C0232M-12.10.1520/C0232_C0232M-13.2 Section on Safety Precautions, Manual of Aggregate and Con

14、crete Testing, Annual Book of ASTM Standards, Vol 04.02.3 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This

15、document 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

16、 as 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 standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. Un

17、ited States1TEST METHOD ASAMPLE CONSOLIDATED BY TAMPING4. Apparatus4.1 ContainerA cylindrical container 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 conform to the requirements of for a me

18、asureinTest Method C29/C29M.The inside shall be smooth and In addition, the inside surface of the container shall be free of corrosion,coatings, or lubricants.4.2 Scale, of sufficient capacity to determine the mass of the load required with an accuracy of 0.5 %. Balances or scales shallbe calibrated

19、 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 from the surface of the test

20、 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, the diameter of which is 16

21、 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 bleedingbleed waterrecovered is one involving weighing, evaporation, and reweighing.4.7 Metal Beaker (Optional)A 1000-mL metal beaker for collecting the decanted supernatant water and slu

22、dge.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, prepare as described in Pr

23、actice 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 50 mm 2 in. Concretec

24、ontaining aggregate larger than 50 mm 2 in. in nominal maximum size shall be wet sieved over a 37.5 mm 112-in. sieve andthe 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/C138M except that the conta

25、iner 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 after troweling thesurface of

26、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 throughout the test, except when

27、 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 the collection of bleeding

28、bleed water, tilt the specimen carefullyby placing a block approximately 50 mm 2 in. thick under one side of the container 2 min prior to each time the water iswithdrawn. After the water is removed, return the container to a level position without jarring. After each withdrawal, transfer thewater to

29、 a 100-mL graduated cylinder. Record the accumulated quantity of water after each transfer. When only the total volumeof bleeding is desired to be determined, the periodic removal procedure shall be omitted and the entire amount removed in a singleoperation. If it is desired to determine the mass of

30、 the bleedingbleed water and to exclude the material present other than the water,carefully decant the contents of the cylinder into a metal beaker. Determine the mass and record the mass of the beaker and itscontents. Dry the beaker and its contents to constant mass and record the final mass. The d

31、ifference between the two masses, D,is equal to the mass of the bleedingbleed water. The mass of the sludge shall also be obtained, if desired, by initially determiningthe tare mass of the beaker.7. Calculation7.1 Calculate the volume of bleedingbleed water per unit area of surface, V, as follows:V

32、5V1/A (1)where:V 1 = volume of bleeding water measured during the selected time interval, mL, andV 1 = volume of bleed water measured during the selected time interval, mL, andA = area of exposed concrete, cm2.C232/C232M 132The comparative rate of bleeding shall be determined as the test progresses

33、by comparing the volume of bleedingbleed waterfor each equal time interval.7.2 Calculate the accumulated bleedingbleed 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 spec

34、imen, g,W = total mass of the batch, kg,w = net mixing water (the total amount of 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.D = mass

35、 of the bleed water, g, or total volume withdrawn from the test specimen in cubic centimeters multiplied by 1 g/cm3.TEST METHOD BSAMPLE CONSOLIDATED BY VIBRATION8. Apparatus8.1 Vibrating PlatformA platform shall be provided upon which the filled container shall be mounted. The platform shall beequip

36、ped 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). Suitable vibration will be provided if there is boltedto the platform a 93W 18-hp electric motor

37、, 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 anddimensions shown in Fig. 2. The hole through the eccentric is 13.5 mm 34/64 in. or an appr

38、opriate 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 Fig. 2.8.2 TimerA timing device, by means of which the periods of vibration provided to the pla

39、tform 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, and 285mm 1118 in. high shall be provided. A steel container cover shall also be provided. The

40、 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.9. Vibrating 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

41、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 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

42、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. Procedure11.1 Consolidation of Test SpecimenConsolidate the sample in the container by means of vibration of only that durationrequired to effect t

43、he desired degree of compaction. Sufficient vibration has been applied as soon as the surface of the concretehas become relatively smooth. Stop the consolidating procedure immediately upon the first appearance of free water segregatingfrom the concrete as indicated by the development of a water shee

44、n 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 container and handling the containerduring the operations of determining the mass and placing it on the platform for test.11.2 Intermittent VibrationP

45、lace 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 the motor. Continue intermittent vibration for 1 h.11.3 Determination of Bleeding WaterThe intermittent periods of vibrations do not permit the

46、determination of bleeding waterat a number of different time intervals. Determine the total volume of bleeding water as described for Method A.C232/C232M 13312. Calculation12.1 Calculate the percentage bleeding water as described for Method A.8. Report8.1 Concrete mixture proportions,8.2 Source and

47、identification of each material used,13.3 Method used for collection of the bleeding data (A or B),8.3 The volume of bleedingbleed water per unit area of surface, and the accumulated bleedingbleed water, expressed as apercentage of the net mixing water contained within the test specimen, and8.4 Elap

48、sed time required for cessation of bleeding.9. Precision and Bias9.1 Precision:9.1.1 Method AData are not available to evaluate the precision of Method A directly. However, there the test method forconcrete consolidated by vibration. There is reason to believe that the precision for Method A of test

49、s for concrete consolidatedby rodding is at least as good as that for Method B. concrete consolidated by vibration. The values given for Method B shall beused as maximum precision limits for Method A.concrete consolidated by rodding.9.1.2 Method BThe single operator-day-multibatch standard 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