ASTM C1176 C1176M-2008 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方法》.pdf

《ASTM C1176 C1176M-2008 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方法》.pdf》由会员分享，可在线阅读，更多相关《ASTM C1176 C1176M-2008 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方法》.pdf（4页珍藏版）》请在麦多课文档分享上搜索。

1、Designation: C 1176/C 1176M 08Standard Practice forMaking Roller-Compacted Concrete in Cylinder Molds Usinga Vibrating Table1This standard is issued under the fixed designation C 1176/C 1176M; the number immediately following the designation indicates theyear of original adoption or, in the case of

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

3、ndard procedures ofrodding and internal vibration, as described in Practice C 31,are not practicable. This practice is applicable to freshly mixedconcrete, prepared in the laboratory and the field, having anominal maximum size aggregate of 50 mm 2 in. or less. Ifthe nominal maximum size aggregate is

4、 larger than 50 mm 2in., the practice is applicable only when performed on thefraction passing the 50-mm 2-in. sieve with the largeraggregate being removed in accordance with Practice C 172.This practice, intended for use in testing roller-compactedconcrete, may be applicable to testing other types

5、of concretesuch as cement-treated aggregate and mixtures similar tosoil-cement.1.2 Two methods are provided for making concrete cylin-ders using a vibrating table:1.2.1 Method A is a procedure for making test specimens insteel reusable molds attached to a vibrating table.1.2.2 Method B is a procedur

6、e for making test specimens insingle-use plastic molds that have been inserted into a metalsleeve attached to a vibrating table.1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefo

7、re, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard

8、to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C 31/C 31M Practice for Making and Curing Concrete TestSpecimens in the FieldC 39/C 39M Test Method for Compressive Strength of Cy-

9、lindrical Concrete SpecimensC 172 Practice for Sampling Freshly Mixed ConcreteC 192/C 192M Practice for Making and Curing ConcreteTest Specimens in the LaboratoryC 470/C 470M Specification for Molds for Forming Con-crete Test Cylinders VerticallyC 496/C 496M Test Method for Splitting Tensile Strengt

10、hof Cylindrical Concrete SpecimensC 1170 Test Method for Determining Consistency and Den-sity of Roller-Compacted Concrete Using a VibratingTableE11 Specification for Wire Cloth and Sieves for TestingPurposes3. Summary of Practice3.1 This practice describes methods for making cylindricalconcrete tes

11、t specimens using a vibrating table. Test specimensare made in cylindrical molds that are attached to the vibratingtable under a 9-kg 20-lb surcharge to facilitate consolidation.4. Significance and Use4.1 This practice is intended to be used for stiff to extremelydry concrete mixtures commonly used

12、in roller-compactedconcrete construction. This practice is used instead of roddingor internal vibration, which cannot properly consolidate con-crete of this consistency (Note 1).NOTE 1Further description of this concrete consistency is given in1This practice is under the jurisdiction of ASTM Committ

13、ee C09 on Concreteand ConcreteAggregates and is the direct responsibility of Subcommittee C09.45 onRoller-Compacted Concrete.Current edition approved June 1, 2008. Published July 2008. Originally approvedin 1991. Last previous edition approved in 2005 as C 1176 05.2For referenced ASTM standards, vis

14、it 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 the end of this standard.Copyright ASTM International,

15、 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.ACI 207.5 Roller-Compacted Mass Concrete3and 211.3 Guide for Se-lecting Proportions for No-Slump Concrete3. The consistency of roller-compacted concrete may be determined in accordance with Test MethodC 1170.5. Appa

16、ratus5.1 Molds:5.1.1 Type A MoldA cylindrical mold conforming to therequirements of Specification C 470 for 150-mm 6-in. diam-eter by 300-mm 12-in. high reusable molds. Molds shall bemade of steel or other hard metal not readily attacked by thecement paste. Aluminum molds shall not be used. Molds sh

17、allbe equipped with permanently affixed metal slotted brackets onthe baseplate so the molds can be rigidly clamped to a vibratingtable. The top rim of the mold shall be smooth, plane, andparallel to the bottom of the mold. The bottom of the mold shallprovide a watertight seal.5.1.2 Type B MoldA sing

18、le-use plastic, cylindrical mold150 mm 6 in. in diameter and 300 mm 12 in. in height. Themold specifications shall conform to Specification C 470 forsingle-use plastic molds.5.1.2.1 Mold SleeveA Type B cylindrical mold shall beinserted into a rigid cylindrical sleeve with a bottom baseplatethat is c

19、lamped to the vibrating table. The mold sleeve shall bemade of steel or other hard metal that does not react withconcrete containing portland or other hydraulic cement. Thesleeve shall be capable of firmly and vertically holding theplastic mold in place without deformation and shall be slottedvertic

20、ally with adjustable clamps for tightening around themold. The sleeve shall be hinged so that it can be opened toremove the mold (Fig. 1) and shall also have permanentlyaffixed slotted metal brackets so the sleeve may be rigidlyclamped to the vibrating table. The mold sleeve shall have aminimum wall

21、 thickness of 3 mm 18 in., and a minimumbaseplate thickness of 6 mm 14 in. The inside diameter ofthe mold sleeve shall be 3 6 1.5 mm 18 6116 in. larger thanthe outside diameter of the Type B mold and have a height 6 to13 mm 12 to14 in. less than the height of the Type B mold.5.2 Vebe Vibrating Table

22、A vibrating table with a 20-mm34-in. thick steel deck with dimensions of approximately 380mm 15 in. in length, 260 mm 1014 in. in width, and 300mm 12 in. in height. The vibrating table shall be constructedin such a manner as to prevent flexing of the table duringoperation. The table deck shall be ac

23、tivated by an electrome-chanical vibrator. The total mass of the vibrator and table shallbe approximately 95 kg 210 lb. The table shall be level andclamped to a concrete floor or base slab that has sufficient massto prevent displacement of the apparatus during specimenpreparation (Note 2).NOTE 2The

24、recommended vibrating table for these procedures is theVebe vibrating table. Testing to date has been performed using thisapparatus. An alternative vibrating table may be substituted for the Vebeapparatus provided it meets the specifications for the sinusoidal vibrationgiven in 7.1.5.3 Swivel Arm an

25、d Guide SleeveA metal guide sleevewith a clamp assembly or other suitable holding devicemounted on a swivel arm. The swivel arm and guide sleevemust be capable of holding a metal shaft attached to a 9-kg20-lb cylindrical mass in a position perpendicular to thevibrating surface and allowing the shaft

26、 to slide freely when theclamp is released. The swivel arm must be capable of main-taining the guide sleeve in a locked position directly over thecenter of the specimens to be vibrated. The swivel arm shallalso be capable of being rotated away from the center of thetable (Note 3).NOTE 3The Vebe vibr

27、ating table comes equipped with the swivel armand guide sleeve.5.4 SurchargeA cylindrical steel mass with a metal shaftat least 460 mm 18 in. in length and 16 6 2mm58 6116in. in diameter attached perpendicularly to and embedded inthe center of the mass. The shaft shall slide through the guidesleeve

28、without binding. The surcharge shall have a diameter of145 6 3mm534 618 in. The surcharge assembly shallhave a mass of 9.0 6 0.25 kg 20 6 0.5 lb including the massof the metal shaft (Fig. 1). If the surcharge is to be hand held,the length of the shaft may be reduced to about 300 mm 12 in.and fabrica

29、ted with a “T” or “D” handle for gripping thesurcharge shaft to avoid slipping.5.5 SieveA 50-mm 2-in. sieve conforming to Specifica-tion E11.5.6 Small ToolsTrowels, square-ended shovel and handscoops, steel trowel, wooden float, wrench, tamping rod, andflashlight as required.3ACI Manual of Concrete

30、Practice, Part 1, Materials and General Properties ofConcrete, 2005, American Concrete Institute (ACI), P.O. Box 9094, FarmingtonHills, MI 48333.FIG. 1 Vibrating TableCylinder Preparation (Type B Mold)C 1176/C 1176M 0826. Sampling6.1 Samples of fresh concrete shall be obtained in accor-dance with Pr

31、actice C 172.6.2 Concrete samples shall have a nominal maximum sizeaggregate of 50 mm 2 in. or less. If the concrete has aggregatelarger than 50 mm 2 in., samples shall be obtained by wetsieving over a 50-mm 2-in. sieve in accordance with PracticeC 172.6.3 Concrete test specimens shall be made withi

32、n 45 minafter the completion of mixing concrete unless otherwisestipulated.7. Calibration and Standardization7.1 The vibrating table shall produce a sinusoidal vibratorymotion with a frequency of at least 60 6 2 Hz 3600 6 100vibrations per min and a double amplitude of vibration of0.45 6 0.1 mm 0.01

33、70 6 0.0030 in. when a 27.0 6 1.0-kg60.0 6 2.5-lb surcharge is rigidly bolted to the center of thetable.7.1.1 Determine the frequency and double amplitude4of thevibrating table under simulated test conditions prior to initialuse and annually thereafter.Avibrating reed tachometer shouldbe used to che

34、ck the frequency of vibration.7.2 Recalibrate the vibrating table after any event (includingrepairs) that might affect its operation, or whenever test resultsare questionable.8. Technical Precautions8.1 When obtaining samples, ensure that the samples arerepresentative of the material being sampled.8

35、.2 Concrete with stiff to extremely dry consistency ishighly susceptible to segregation during handling. To minimizesegregation, use care in obtaining samples and during trans-porting, remixing, and testing of the concrete.8.3 After at least every three months of continued use,inspect and clean the

36、underside of the vibrating table top of anyhardened concrete or cement paste which may interfere withfree movement of the table top.9. Procedure9.1 Method AType A Molds:9.1.1 Coat Type A molds with a suitable lubricant or bondbreaker prior to casting the test specimens to facilitate removalfrom the

37、mold.9.1.2 Place the mold on the vibrating table, and center thesurcharge so that the edges of the plastic plate do not touch thewalls of the mold. Lower the surcharge into the mold to checkfor proper clearance.Attach the mold to the vibrating table, andfirmly tighten the wing nuts. Move the surchar

38、ge away fromthe mold.9.1.3 Place enough concrete in the mold so that the moldwill be filled to one-third of its volume after consolidation(approximately 4.5 kg 9.5 lb). A tamping rod may be used todistribute the loose concrete as it is added. During filling, usesquare-ended shovels and scoops to obt

39、ain representativesamples, and handle the concrete in such a manner that largersized coarse aggregate particles do not separate from themortar.9.1.4 Move the surcharge over the center of the mold,release the guide sleeve clamp, and place the surcharge gentlyon the loose concrete. The surcharge shall

40、 be able to verticallyslide free without binding on the guide sleeve.9.1.5 If the surcharge cannot be centered in the moldwithout binding on the inside wall of the mold, place thesurcharge directly onto the specimen in the mold without use ofthe guide sleeve, and hold the surcharge shaft perpendicul

41、ar tothe top of the table. Hold the surcharge shaft manually whilevibrating the specimen. Do not apply any additional handpressure to the surcharge when manually holding the sur-charge.9.1.6 Start the vibrator table, and allow the concrete toconsolidate under the surcharge. Using a flashlight, obser

42、ve theconcrete in the annular space between the edge of the surchargeand the inside wall of the mold. As the concrete consolidates,mortar will fill in the annular space between the outer edge ofthe surcharge and the inside mold wall. Observe the mortaruntil it forms a ring around the total perimeter

43、 of the surcharge.When the mortar ring forms completely around the surcharge,stop the vibrator. If the wing nuts loosen while casting thespecimen, retighten the wing nuts, then continue vibrating toensure complete consolidation of the specimen.9.1.7 If a rock pocket prevents the mortar ring from for

44、mingat one small location, even though it has formed in all otherlocations, the vibrator can be stopped and another layer ofconcrete added. If a significant portion of the mortar ring doesnot form, this indicates the concrete may have insufficientmortar due to either improper sampling, segregation,

45、or im-proper mixture proportioning. In these instances, the concretespecimen should be visually inspected after stripping from themold, and a decision then made whether to accept or reject thespecimen.9.1.8 Repeat the procedure in 9.1.3 through 9.1.7 for thesecond lift of concrete, filling the mold

46、to approximatelytwo-thirds of its volume. For the third lift, overfill the mold bymounding the concrete above the top of the mold. Again, placethe surcharge on the loose concrete and consolidate. If thesurcharge consolidates concrete below the top level of themold, turn off the vibrating table. Plac

47、e additional concrete inthe mold so that, when consolidated, the concrete will be about3mm18 in. above the top of the mold. Continue vibrating,and slide the surcharge back and forth across the top of themold until the compacted concrete is level with the top of themold. This replaces strikeoff with

48、a float since stiff concretecannot be easily floated. Do not allow the surcharge to remainin one position when the concrete is being finished because thiscan cause aggregates to be forced down and mortar to be forcedout of the mold resulting in a nonrepresentative test specimen.After the surface has

49、 been screeded with the surcharge, vibratethe specimen for 4 6 1 s without the surcharge to fill in minorsurface tears unless damage to the specimen by large-amplitude oscillations of the vibrator is anticipated.4Kaufman, L.P., Strickland, E.A., and Benavidez, A.A. “Suggested Method forthe Calibration of Vibrating Tables for Maximum Index Density Testing,” Geotech-nical Testing Journal, GTJODJ, Vol 2, No. 3, September 1979, pp. 152157.C 1176/C 1176M 0839.1.8.1 When making test specimens us