ASTM C1435 C1435M-2008 Standard Practice for Molding Roller-Compacted Concrete in Cylinder Molds Using a Vibrating Hammer《用振动锤在柱形模子中模压碾实混凝土的标准实施规范》.pdf

《ASTM C1435 C1435M-2008 Standard Practice for Molding Roller-Compacted Concrete in Cylinder Molds Using a Vibrating Hammer《用振动锤在柱形模子中模压碾实混凝土的标准实施规范》.pdf》由会员分享，可在线阅读，更多相关《ASTM C1435 C1435M-2008 Standard Practice for Molding Roller-Compacted Concrete in Cylinder Molds Using a Vibrating Hammer《用振动锤在柱形模子中模压碾实混凝土的标准实施规范》.pdf（5页珍藏版）》请在麦多课文档分享上搜索。

1、Designation: C 1435/C 1435M 08Standard Practice forMolding Roller-Compacted Concrete in Cylinder MoldsUsing a Vibrating Hammer1This standard is issued under the fixed designation C 1435/C 1435M; the number immediately following the designation indicates theyear of original adoption or, in the case o

2、f 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 molding cylindrical test specimensfrom concrete when the standard proced

3、ures of rodding andinternal vibration, as described in Practice C 31/C 31M andPractice C 1176, are not practicable. This practice is applicableto freshly-mixed concrete, prepared in the laboratory and thefield.1.2 Freshly-mixed concrete is molded in cylindrical moldsusing an electric vibrating hamme

4、r equipped with a shaft andcircular plate.1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. Within the text, theinch-pound units are shown in brackets. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be us

5、ed independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.4 The text of this practice references notes and footnotes,which provide explanatory material. These notes and footnotes(excluding those in tables and figures) shall not be considered

6、as requirements of this practice.1.5 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 to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitat

7、ions 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-lindrical Concrete SpecimensC 172 Practice for Sampling Freshly Mixed ConcreteC 470/C 470M Specification for

8、 Molds for Forming Con-crete Test Cylinders VerticallyC 496/C 496M Test Method for Splitting Tensile Strengthof Cylindrical Concrete SpecimensC 1170 Test Method for Determining Consistency and Den-sity of Roller-Compacted Concrete Using a VibratingTableC 1176 Practice for Making Roller-Compacted Con

9、crete inCylinder Molds Using a Vibrating Table2.2 ACI Documents:207.5R Report on Roller-Compacted Concrete3211.3 Practice for Selecting Proportions for No-Slump Con-crete33. Summary of Practice3.1 This practice describes molding cylindrical concrete testspecimens using a vibrating hammer. Test speci

10、mens aremolded vertically in cylindrical molds by compacting the stiffto very dry concrete mixture in four lifts using a vibratinghammer.4. Significance and Use4.1 This practice, intended for use in testing roller-compacted concrete, may be applicable to testing other types ofcementitious material s

11、uch as coarse-grained, soil-cement. Thispractice provides standardized requirements for molding stiffto very dry consistency concrete mixtures commonly used inroller compacted concrete construction. This practice is usedinstead of rodding or internal vibration, which cannot properlyconsolidate concr

12、ete of this consistency (Note 1).NOTE 1Further description of roller compacted concrete consistencyis given in ACI 207.5R and 211.3. The consistency of concrete using avibrating table may be determined in accordance with Test MethodsC 1170.4.2 This practice is used to mold cylindrical test specimens

13、commonly used for testing compressive or tensile strength ofconcrete. Specimens tested for compressive strength and split-ting tensile strength shall be in accordance with Test MethodsC 39/C 39M and C 496/C 496M, respectively. Test specimensalso may be used to determine density of fresh concrete.1Th

14、is practice is under the jurisdiction of Committee C09 on Concrete andConcrete Aggregates and are the direct responsibility of Subcommittee C09.45 onRoller-Compacted Concrete.Current edition approved June 1, 2008. Published July 2008. Originally approvedin 1999. Last previous edition approved in 200

15、7 as C 1435/C 1435M 07.2For 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.3ACI Manual of Concrete Practice, Part

16、 1, Materials and General Properties ofConcrete, American Concrete Institute, Farmington Hills, MI.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Specimens tested for

17、 density of fresh concrete shall be inaccordance with Test Methods C 1170.NOTE 2For some extremely dry mixtures; (those with a consistencygreater than 45 s when tested in accordance with Test Methods C 1170)4the density of specimens made in accordance with this practice may begreater than the in-pla

18、ce density of roller-compacted concrete due to thegreater potential for voids at the bottom of the lifts in the field.5. Apparatus5.1 Molds:5.1.1 Type A Reusable MoldA cylindrical mold conform-ing to the requirements of Specification C 470/C 470M for150-mm 6-in. diameter by 300-mm 12-in. high reusab

19、lemolds.5.1.2 Type B Single-Use MoldA single-use plastic, cylin-drical mold 150-mm 6-in. diameter and 300-mm 12-in. inheight. The mold specifications shall conform to SpecificationC 470/C 470M for single-use, plastic molds.5.1.2.1 Mold SleeveA Type B cylindrical mold shall beinserted into a rigid cy

20、lindrical sleeve. The cylindrical sleeveshall be made of steel or other hard metal resistant to cementpaste corrosion. The sleeve shall be capable of firmly holdingthe plastic mold upright without deformation of the mold. Thesleeve shall be split and hinged on one side so that it can beopened to rem

21、ove the plastic mold; adjustable clamps shall beprovided on the other side for tightening the sleeve around themold. A metal base plate with brackets shall be provided inwhich to insert the bottom portion of the sleeve to hold thesleeve during compaction. The sleeve shall have a minimumwall thicknes

22、s of 3 mm 18 in., and a minimum base platethickness of 6 mm 14 in. The inside diameter of the moldsleeve shall be 3 6 1mm18 6116 in. larger than the outsidediameter of the Type B mold and have a height 13 6 6mm12614 in. less than the height of the Type B mold.5.2 Vibrating HammerA vibrating compacti

23、on hammerhaving a mass (without tamping plate and shaft) of 10 6 1.5 kg22 6 3.3 lb. It also shall have a minimum power input of 900W and be capable of providing 2000 6 200 impacts/min.NOTE 3The vibrating hammer used to compact the specimens, suchas shown in Fig. 1, is of the type used typically for

24、breaking up concreteand masonry. It provides oscillatory motion in the axial direction thatmakes the hammer an effective vibratory compactor.5.3 Tamping PlateA circular steel plate attached to a steelshaft, which is inserted into the vibrating hammer chuck. Theplate diameter shall be 140 6 3mm512 61

25、8 in. and themass of the plate and shaft assembly shall be 3 6 1 kg 6.6 62.2 lb (See Fig. 2).5.4 Small ToolsA square-ended shovel, a hand scoop, atamping rod, and a stopwatch.6. Sampling6.1 Samples of freshly-mixed concrete shall be obtained inaccordance with Practice C 172.6.2 Concrete samples shal

26、l have a maximum size aggregateof 50 mm 2 in. or less. If the concrete has aggregate largerthan 50 mm 2 in. samples shall be obtained by wet sievingover a 50-mm 2-in. sieve in accordance with Practice C 172.6.3 Concrete test specimens shall be molded within 45 minafter the completion of mixing unles

27、s otherwise specified.6.4 Technical Precautions:6.4.1 When obtaining samples, ensure that the samples arerepresentative of the bulk production.6.4.2 Concrete with stiff to very dry consistency is highlysusceptible to segregation during handling. To minimize seg-regation, use care in obtaining sample

28、s and during transporting,remixing, and preparation of the specimens.7. Calibration7.1 Calibrate the vibrating hammer after any event, includ-ing repairs, that might affect its operation, after 300 h ofservice, or at least one time per year.8. Molding Specimens8.1 Method A, Type A Molds:8.1.1 Coat T

29、ype A molds with a suitable lubricant or bondbreaker prior to casting the test specimens to facilitate removalfrom the mold.8.1.2 Hold the mold stationary either by clamping to a rigid,flat base or standing on the foot brackets and center thevibrating hammer so that the edges of the tamping plate do

30、 nottouch the walls of the mold. Lower the vibrating hammer intothe mold to check for proper clearance.8.1.3 Place enough concrete in the mold so that the moldwill be filled to one-fourth of its volume after consolidation,approximately 3.4 kg 7.5 lb. Use a tamping rod to distributethe loose concrete

31、 as it is added. During filling, use square-ended shovels and scoops to obtain representative samples andhandle the concrete in such a manner that larger sized coarseaggregates do not separate from the mortar.8.1.4 Place the vibrating hammer with tamping plate ontothe concrete (Fig. 1).8.1.5 Start t

32、he vibrating hammer and allow the concrete toconsolidate under the tamping plate. Observe the concrete inthe annular space between the edge of the tamping plate andthe inside wall of the mold. As the concrete consolidates,mortar should fill in the annular space between the outer edgeof the tamping p

33、late and the inside mold wall. Observe themortar until it forms a ring around the total perimeter of thetamping plate. When the mortar ring forms completely aroundthe tamping plate, stop the vibrating hammer.8.1.6 If a rock pocket prevents the mortar ring from formingat one small location, even thou

34、gh it has formed in all otherlocations, the vibrating hammer can be stopped and the nextlayer of concrete added.8.1.7 If a significant portion of the mortar ring does not formafter 20 s, the vibrating hammer shall be stopped and the nextlayer of concrete added. This situation may be a result ofinsuf

35、ficient mortar due to either improper sampling, segrega-tion, or improper mixture proportioning. In these instances, theconcrete should be inspected visually after stripping from themold to determine if there is adequate mortar distribution anda decision made whether to accept or reject the specimen

36、.8.1.8 Repeat the procedure in 8.1.3-8.1.7 for the second andthird lifts of concrete, filling the mold to approximately4Hansen, K. and Kahler, C., “RCC Tests, Testing, and Test Sections LessonsLearned,” The Journal of Dam Safety, Volume 2, Issue 1 (Winter 2004), p.14C 1435/C 1435M 082one-half and th

37、ree-fourths of its volume, respectively. For thefourth lift, overfill the mold by mounding the concrete abovethe top of the mold.Again, place the tamping plate on the looseconcrete and consolidate. If the tamping plate consolidatesconcrete below the top level of the mold, turn off the vibratinghamme

38、r. Place additional concrete in the mold so that, whenconsolidated, the concrete can be finished smooth and levelwith the top of the mold.8.1.9 Finally, strike off the top of the concrete with thevibrating hammer and tamping plate. With the hammer inoperation and the plate in contact with the rim of

39、 the cylindermold, move the plate back and forth across the top of thecylinder to force excess material beyond the rim. Continueworking the surface until it is smooth and level with the top ofthe cylinder mold. Avoid tearing the surface of the concrete.9. Keywords9.1 compressive; consolidate; cylind

40、er; molds; roller com-pacted concrete; soil cement; specimen; strength; tensile;vibrating hammerFIG. 1 Vibrating Hammer for Molding RCC SpecimensC 1435/C 1435M 083FIG. 2 Circular Steel Tamping Plate and Metal ShaftC 1435/C 1435M 084SUMMARY OF CHANGESCommittee C09 has identified the location of selec

41、ted changes to this practice since the last issue,C 1435/C 1435M 07, that may impact the use of this practice. (Approved June 1, 2008)(1) Revised Fig. 2.Committee C09 has identified the location of selected changes to this practice since the last issue,C 1435/C 1435M 06, that may impact the use of t

42、his practice. (Approved November 1, 2007)(1) Revised Fig. 2.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 pa

43、tent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited ei

44、ther for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair

45、 hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).C 1435/C 1435M 085