ASTM C1176 C1176M-2013 Standard Practice for Making Roller-Compacted Concrete in Cylinder Molds Using a Vibrating Table《使用振动台在筒模中制作碾压混凝土的标准操作规程》.pdf

1、Designation: C1176/C1176M 08C1176/C1176M 13Standard Practice forMaking Roller-Compacted Concrete in Cylinder Molds Usinga Vibrating Table1This standard is issued under the fixed designation C1176/C1176M; the number immediately following the designation indicates the yearof original adoption or, in t

2、he case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This practice covers procedures for making cylindrical test specimens from concrete

3、when the standard procedures ofrodding and internal vibration, as described in Practice C31/C31M, are not practicable. This practice is applicable to freshly mixedconcrete, prepared in the laboratory and the field, having a nominal maximum size aggregate of 50 mm 2 in. or less. If thenominal maximum

4、 size aggregate is larger than 50 mm 2 in., the practice is applicable only when performed on the fractionpassing the 50-mm 2-in. sieve with the larger aggregate being removed in accordance with Practice C172. This practice, intendedfor use in testing roller-compacted concrete, may be applicable to

5、testing other types of concrete such as cement-treated aggregateand mixtures similar to soil-cement.1.2 Two methods are provided for making concrete cylinders using a vibrating table:1.2.1 Method A is a procedure for making test specimens in steel reusable molds attached to a vibrating table.1.2.2 M

6、ethod B is a procedure for making test specimens in single-use plastic molds that have been inserted into a metal sleeveattached to a vibrating table.1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in eachsystem may not be exa

7、ct 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 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof

8、the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C31/C31M Practice for Making and Curing Concrete Test Specimens in the FieldC39/C39M Test Method for Compres

9、sive Strength of Cylindrical Concrete SpecimensC172 Practice for Sampling Freshly Mixed ConcreteC192/C192M Practice for Making and Curing Concrete Test Specimens in the LaboratoryC470/C470M Specification for Molds for Forming Concrete Test Cylinders VerticallyC496/C496M Test Method for Splitting Ten

10、sile Strength of Cylindrical Concrete SpecimensC1170C1170/C1170M Test Method for Determining Consistency and Density of Roller-Compacted Concrete Using a VibratingTableE11 Specification for Woven Wire Test Sieve Cloth and Test Sieves3. Summary of Practice3.1 This practice describes methods for makin

11、g cylindrical concrete test specimens using a vibrating table. Test specimens aremade in cylindrical molds that are attached to the vibrating table under a 9-kg 20-lb surcharge to facilitate consolidation.1 This practice is under the jurisdiction of ASTM Committee C09 on Concrete and Concrete Aggreg

12、ates and is the direct responsibility of Subcommittee C09.45 onRoller-Compacted Concrete.Current edition approved June 1, 2008Dec. 15, 2013. Published July 2008February 2014. Originally approved in 1991. Last previous edition approved in 20052008 asC1176 05.C1176 08. DOI: 10.1520/C1176_C1176M-08.10.

13、1520/C1176_C1176M-13.2 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 document is not an ASTM standard an

14、d 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 as appropriate. In all cases only

15、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. United States14. Significance and Use

16、4.1 This practice is intended to be used for stiff to extremely dry concrete mixtures commonly used in roller-compacted concreteconstruction. This practice is used instead of rodding or internal vibration, which cannot properly consolidate concrete of thisconsistency (Note 1).NOTE 1Further descripti

17、on of this concrete consistency is given in ACI 207.5 Roller-Compacted Mass Concrete3 and 211.3 Guide for SelectingProportions for No-Slump Concrete3. The consistency of roller-compacted concrete may be determined in accordance with Test Method C1170C1170/C1170M.5. Apparatus5.1 Molds:5.1.1 Type A Mo

18、ldA cylindrical mold conforming to the requirements of Specification C470/C470M for 150-mm 6-in.diameter by 300-mm 12-in. high reusable molds. Molds shall be made of steel or other hard metal not readily attacked by thecement paste. Aluminum molds shall not be used. Molds shall be equipped with perm

19、anently affixed metal slotted brackets on thebaseplate so the molds can be rigidly clamped to a vibrating table. The top rim of the mold shall be smooth, plane, and parallelto the bottom of the mold. The bottom of the mold shall provide a watertight seal.5.1.2 Type B MoldA single-use plastic, cylind

20、rical mold 150 mm 6 in. in diameter and 300 mm 12 in. in height. The moldspecifications shall conform to Specification C470/C470M for single-use plastic molds.5.1.2.1 Mold SleeveA Type B cylindrical mold shall be inserted into a rigid cylindrical sleeve with a bottom baseplate thatis clamped to the

21、vibrating table. The mold sleeve shall be made of steel or other hard metal that does not react with concretecontaining portland or other hydraulic cement. The sleeve shall be capable of firmly and vertically holding hold firmly the plasticmold in place without deformation without deforming it so th

22、at it is vertical and shall be slotted vertically with adjustable clampsfor tightening around the mold. The sleeve shall be hinged so that it can be opened to remove the mold (Fig. 1) and shall also havepermanently affixed slotted metal brackets so the sleeve may be rigidly clamped to the vibrating

23、table. The mold sleeve shall havea minimum wall thickness of 3 mm 18 in., and a minimum baseplate thickness of 6 mm 14 in. The inside diameter of the moldsleeve shall be 3 6 1.5 mm 18 6 116 in. larger than the outside diameter of the Type B mold and have a height 6 to 13 mm 14to 12 in. less than the

24、 height of the Type B mold.5.2 Vebe Vibrating TableA vibrating table with a 20-mm 34-in. thick steel deck with dimensions of approximately 380 mm15 in. in length, 260250 mm 10 10 in.14 in. in width, and 300 mm 12 in. in height. The vibrating table shall be constructedin such a manner as to prevent f

25、lexing of the table during operation. The table deck shall be activated by an electromechanicalvibrator. The total mass of the vibrator and table shall be approximately 9590 kg 210200 lb. The table shall be level and clampedto a concrete floor or base slab that has sufficient mass to prevent displac

26、ement of the apparatus during specimen preparation (Note2).NOTE 2The recommended vibrating table for these procedures is the Vebe vibrating table. Testing to date has been performed using this apparatus.An alternative vibrating table may be substituted for the Vebe apparatus provided it meets the sp

27、ecifications for the sinusoidal vibration given in 7.1.5.3 Swivel Arm and Guide SleeveA metal guide sleeve with a clamp assembly or other suitable holding device mounted ona swivel arm. The swivel arm and guide sleeve must be capable of holding a metal shaft attached to a 9-kg 20-lb cylindrical mass

28、in a position perpendicular to the vibrating surface and allowing the shaft to slide freely when the clamp is released. The swivelarm must be capable of maintaining the guide sleeve in a locked position directly over the center of the specimens to be vibrated.The swivel arm shall also be capable of

29、being rotated away from the center of the table (Note 3).NOTE 3The Vebe vibrating table comes equipped with the swivel arm and guide sleeve.5.4 SurchargeA cylindrical steel mass with a metal shaft at least 460 mm 18 in. in length and 16 6 2 mm 58 6 116 in.in diameter attached perpendicularly to and

30、embedded in the center of the mass. The shaft shall slide through the guide sleevewithout binding. The surcharge shall have a diameter of 145 6 3 mm 534 6 18 in. The surcharge assembly shall have a massof 9.0 6 0.25 kg 20 6 0.5 lb including the mass of the metal shaft (Fig. 1). If the surcharge is t

31、o be hand held, the length of theshaft may be reduced to about 300 mm 12 in. and fabricated with a “T” or “D” handle for gripping the surcharge shaft to avoidslipping.5.5 SieveA 50-mm 2-in. sieve conforming to Specification E11.5.6 Small ToolsTrowels, square-ended shovel and hand scoops, steel trowe

32、l, wooden float, wrench, tamping rod, and flashlightas required.6. Sampling6.1 Samples of fresh concrete shall be obtained in accordance with Practice C172.3 ACI Manual of Concrete Practice, Part 1, Materials and General Properties of Concrete, 2005, American Concrete Institute (ACI), P.O. Box 9094,

33、 Farmington Hills,MI 48333.C1176/C1176M 1326.2 Concrete samples shall have a nominal maximum size aggregate of 50 mm 2 in. or less. If the concrete has aggregate largerthan 50 mm 2 in., samples shall be obtained by wet sieving over a 50-mm 2-in. sieve in accordance with Practice C172.6.3 Concrete te

34、st specimens shall be made within 45 min after the completion of mixing concrete unless otherwise stipulated.7. Calibration and Standardization7.1 The vibrating table shall produce a sinusoidal vibratory motion with a frequency of at least 60 6 2 Hz 3600 6 100vibrations per min and a double amplitud

35、e of vibration of 0.45 6 0.10.43 6 0.008 mm 0.0170 6 0.0030 in. when a27.0 6 1.0-kg 60.0 6 2.5-lb surcharge is rigidly bolted to the center of the table.FIG. 1 Vibrating TableCylinder Preparation (Type B Mold)C1176/C1176M 1337.1.1 Determine the frequency and double amplitude4 of the vibrating table

36、under simulated test conditions prior to initial useand annually thereafter. A vibrating reed tachometer should be used to check the frequency of vibration.7.2 Recalibrate the vibrating table after any event (including repairs) that might affect its operation, or whenever test results arequestionabl

37、e.8. Technical Precautions8.1 When obtaining samples, ensure that the samples are representative of the material being sampled.8.2 Concrete with stiff to extremely dry consistency is highly susceptible to segregation during handling. To minimizesegregation, use care in obtaining samples and during t

38、ransporting, remixing, and testing of the concrete.8.3 After at least every three months of continued use, inspect and clean the underside of the vibrating table top of any hardenedconcrete or cement paste which may interfere with free movement of the table top.9. Procedure9.1 Method AType A Molds:9

39、.1.1 Coat Type A molds with a suitable lubricant or bond breaker prior to casting the test specimens to facilitate removal fromthe mold.9.1.2 Place the mold on the vibrating table, and center the surcharge so that the edges of the plastic plate do not touch the wallsof the mold. Lower the surcharge

40、into the mold to check for proper clearance. Attach the mold to the vibrating table, and firmlytighten the wing nuts. Move the surcharge away from the mold.9.1.3 Place enough concrete in the mold so that the mold will be filled to one-third of its volume after consolidation(approximately 4.5 kg 9.5

41、lb). A tamping rod may be used to distribute the loose concrete as it is added. During filling, usesquare-ended shovels and scoops to obtain representative samples, and handle the concrete in such a manner that larger sizedcoarse aggregate particles do not separate from the mortar.9.1.4 Move the sur

42、charge over the center of the mold, release the guide sleeve clamp, and place the surcharge gently on the looseconcrete. The surcharge shall be able to vertically slide free without binding on the guide sleeve.9.1.5 If the surcharge cannot be centered in the mold without binding on the inside wall o

43、f the mold, place the surcharge directlyonto the specimen in the mold without use of the guide sleeve, and hold the surcharge shaft perpendicular to the top of the table.Hold the surcharge shaft manually while vibrating the specimen. Do not apply any additional hand pressure to the surcharge whenman

44、ually holding the surcharge.9.1.6 Start the vibrator table, and allow the concrete to consolidate under the surcharge. Using a flashlight, observe the concretein the annular space between the edge of the surcharge and the inside wall of the mold. As the concrete consolidates, mortar willfill in the

45、annular space between the outer edge of the surcharge and the inside mold wall. Observe the mortar until it forms a ringaround the total perimeter of the surcharge. When the mortar ring forms completely around the surcharge, stop the vibrator. If thewing nuts loosen while casting the specimen, retig

46、hten the wing nuts, then continue vibrating to ensure complete consolidation ofthe specimen.9.1.7 If a rock pocket prevents the mortar ring from forming at one small location, even though it has formed in all otherlocations, the vibrator can be stopped and another layer of concrete added. If a signi

47、ficant portion of the mortar ring does not form,this indicates the concrete may have insufficient mortar due to either improper sampling, segregation, or improper mixtureproportioning. In these instances, the concrete specimen should be visually inspected after stripping from the mold, and a decisio

48、nthen made whether to accept or reject the specimen.9.1.8 Repeat the procedure in 9.1.3 through 9.1.7 for the second lift of concrete, filling the mold to approximately two-thirdsof its volume. For the third lift, overfill the mold by mounding the concrete above the top of the mold. Again, place the

49、 surchargeon the loose concrete and consolidate. If the surcharge consolidates concrete below the top level of the mold, turn off the vibratingtable. Place additional concrete in the mold so that, when consolidated, the concrete will be about 3 mm 18 in. above the topof the mold. Continue vibrating, and slide the surcharge back and forth across the top of the mold until the compacted concreteis level with the top of the mold. This replaces strikeoff with a float since stiff concrete