ASTM C825-2006 Standard Specification for Precast Concrete Barriers《预制混凝土栅栏的标准实施规范》.pdf

1、Designation: C 825 06Standard Specification forPrecast Concrete Barriers1This standard is issued under the fixed designation C 825; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses

2、indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers precast concrete barriers, in-tended to be used adjacent to a roadway or as a median, toredirect vehicles unintentionally leaving

3、the roadway.1.2 The values stated in inch-pound units are to be regardedas the standard. The values given in parentheses are forinformation only.2. Referenced Documents2.1 ASTM Standards:2A 82/A 82M Specification for Steel Wire, Plain, for Con-crete ReinforcementA 185/A 185M Specification for Steel

4、Welded Wire Rein-forcement, Plain, for ConcreteA 416/A 416M Specification for Steel Strand, UncoatedSeven-Wire for Prestressed ConcreteA 421/A 421M Specification for Uncoated Stress-RelievedSteel Wire for Prestressed ConcreteA 496/A 496M Specification for Steel Wire, Deformed, forConcrete Reinforcem

5、entA 497/A 497M Specification for Steel Welded Wire Rein-forcement, Deformed, for ConcreteA 615/A 615M Specification for Deformed and PlainCarbon-Steel Bars for Concrete ReinforcementA 616/A 616M Specification for Rail-Steel Deformed andPlain Bars for Concrete Reinforcement3A 617/A 617M Specificatio

6、n for Axle-Steel Deformed andPlain Bars for Concrete Reinforcement3C 31/C 31M Practice for Making and Curing Concrete TestSpecimens in the FieldC33 Specification for Concrete AggregatesC 39/C 39M Test Method for Compressive Strength of Cy-lindrical Concrete SpecimensC 42/C 42M Test Method for Obtain

7、ing and Testing DrilledCores and Sawed Beams of ConcreteC 150 Specification for Portland CementC 173/C 173M Test Method for Air Content of FreshlyMixed Concrete by the Volumetric MethodC 231 Test Method for Air Content of Freshly MixedConcrete by the Pressure MethodC 260 Specification for Air-Entrai

8、ning Admixtures for Con-creteC 330 Specification for Lightweight Aggregates for Struc-tural ConcreteC 494/C 494M Specification for Chemical Admixtures forConcreteC 595 Specification for Blended Hydraulic CementsC 618 Specification for Coal Fly Ash and Raw or CalcinedNatural Pozzolan for Use in Concr

9、ete3. Classification3.1 Precast concrete barriers manufactured in accordancewith this specification shall be as shown in either Fig. 1or Fig.2.4. Basis of Acceptance4.1 Precast barrier shall comply with all of the provisions ofthis specification and shall be tested as prescribed in 8.3 and8.4.4.1.1

10、Acceptance as to Strength PropertiesConcrete bar-rier shall be acceptable under the strength tests when thesections have met the requirements of Section 8.4.1.2 Acceptance as to Dimensional PropertiesConcretebarrier shall meet the dimensional tolerances of Section 9.4.1.3 Acceptance as to End Result

11、The concrete barriersections shall be finally acceptable to the purchaser at thedesignated point of delivery with no significant cracking.Significant cracking is defined as fractures or cracks passingthrough the section or any continuous structural crack extend-ing for a length of 12 in. (305 mm) or

12、 more, regardless ofposition in the section.5. Materials5.1 CementPortland cement shall conform to the require-ments of Specification C 150 or shall be portland blast-furnaceslag cement or portland-pozzolan cement conforming to therequirements of Specification C 595.1This specification is under the

13、jurisdiction of ASTM Committee C-27 onPrecast Concrete Products and is the direct responsibility of Subcommittee C27.20on Architectural and Structural Products.Current edition approved Jan. 1, 2006. Published January 2006. Originallyapproved in 1979 Last previous edition approved in 1997 as C 825 97

14、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.3Withdrawn.1Copyright ASTM International, 100 Barr Harbor Dr

15、ive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.2 AggregatesAggregates shall conform to SpecificationC33orC330.5.3 AdmixturesAdmixtures may be used with the ap-proval of the purchaser. Air-entraining admixtures shall con-form to Specification C 260. Chemical admixtures shall con-

16、form to Specification C 494. Fly ash or other pozzolanicadmixtures shall conform to Specification C 618. Admixturescontaining chlorides shall not be used in the manufacture ofprestressed barrier sections.5.4 Steel ReinforcementSteel reinforcement shall consistof wire fabric conforming to Specificati

17、ons A 185 or A 497, orof wire conforming to Specifications A 82, A 421, or A 496, orof strand conforming to Specification A 416, or of barsconforming to Specifications A 615/A 615M, A616/A 616M,or A617/A 617M.6. Design6.1 Precast concrete barrier shall be as defined in Section 3.6.2 Concrete Strengt

18、hConcrete for barrier sections shallhave a design compressive strength of 4000 psi (28 MPa) in 28days.6.3 Air EntrainmentUnless otherwise specified by thepurchaser, all concrete shall have an air content of 512 6 1%as measured by Test Methods C 173 or C 231.6.4 DimensionsCross-sectional dimensions o

19、f the barriershall be as shown in Fig. 1. Unless otherwise specified by thepurchaser, the length of each barrier section shall be aminimum of 10 ft (3 m).6.5 Steel ReinforcementUnless designated by the pur-chaser, steel reinforcement shall be designed by the producerand shall be sufficient to permit

20、 handling, delivery, andplacement of the sections without damage. The producer shallprovide steel reinforcement details to the purchaser. The designcover of concrete over reinforcing steel shall be a minimum of2 in. (50 mm). Unless prestressing is used, reinforcement shallbe assembled as a cage util

21、izing any combination of single ormultiple layers and mats containing sufficient longitudinal barsor wire extending through the section to maintain the shape andposition of reinforcement within the form during placement ofthe concrete. The exposure of the ends of longitudinal rein-forcement in the b

22、arrier shall not be a cause for rejection.NOTE 1The purchaser or producer, or both, of the precast concretebarrier specified herein is cautioned that he should design reinforcing forthe ends of barrier sections in accordance with the publication “ConcreteMedian Barrier Research,” Vol, 2, Research Re

23、port, prepared by theSouthwest Research Institute for the Federal Highway Administration, toprevent fracture at the joints.6.6 Reinforcement Laps, Welds, and SplicingAll splicesshall be acceptable to the purchaser and shall develop the fullstrength of the reinforcing.6.7 Concrete FinishConcrete fini

24、shing shall be at theoption of the producer and shall produce a finish comparable toa steel form finish. The concrete finish and curing of all medianbarrier sections shall be uniform for all sections included in thecontract lot.6.8 Lifting DevicesShould the producer cast lifting de-vices into the ba

25、rrier sections, they shall not be on the sidesurfaces.6.9 AnchorageAnchorage to prevent lateral movement ofthe barrier shall consist of dowels, keyway joints, or interlock-ing devices as may be specified by the purchaser.7. Manufacture7.1 MixtureThe constituent materials shall be propor-tioned and t

26、horoughly mixed to produce a uniform concretemixture of such quality so as to conform to the strengthrequirements of this specification.7.2 CuringThe barrier section shall be subjected to anyone of the following methods of curing, or combinationthereof. The sections shall be cured for a length of ti

27、mesufficient to develop the specified concrete compressivestrength as determined in accordance with Section 8.7.2.1 Accelerated CuringThe sections may be cured witheither low-pressure steam or radiant heat in a moist atmo-sphere.7.2.2 Water CuringThe sections may be water-cured bycovering with water

28、saturated material or by a system ofFIG. 1 New Jersey BarrierFIG. 2 Type-F BarrierC825062perforated pipes, mechanical sprinklers, porous hose, or by anyother method that will keep the section moist.7.2.3 Membrane CuringA sealing membrane may beapplied at a rate which will restrict the loss of water

29、 to not morethan 0.055 g/cm2of surface in 72 h. The concrete at the timeof application shall be within 10F (6C) of the atmospherictemperature. All surfaces shall be kept moist prior to theapplication of the compounds and shall be damp when thecompound is applied.7.2.4 Curing OptionsOther methods of

30、curing may beused, if approved by the purchaser.7.3 FormsThe forms used in the manufacture of barriersections shall be sufficiently rigid to maintain productionwithin the permissible tolerances given in Section 9. Allcasting surfaces shall be of smooth nonporous material.8. Physical Requirements8.1

31、Compression Test SpecimensThe specimens requiredfor the tests shall be furnished by the producer and shall bemade at random from different batches. Test specimens shall beidentified with barrier sections. Two cylinders will be requiredfor each 25 yd3(19 m3) with a minimum of 2 cylinders for eachday

32、of production. Compression test specimens for satisfyingthe minimum specified concrete strength requirement shall bemade in accordance with Practice C 31 except that curing shallbe in accordance with 8.2.8.2 Curing Compression Test SpecimensTest specimensshall be cured in a similar manner to barrier

33、 sections if they aresteam cured. If barrier sections are cured at normal ambienttemperatures, the specimens shall be cured in accordance withPractice C 31.8.3 Compression TestsCylinders shall be tested in accor-dance with Test Method C 39. The average compressivestrength of all cylinders tested for

34、 each days production shallbe equal to or greater than the specified design strength of theconcrete. In no case shall any cylinder tested fall below 80 %of design strength.8.4 Core Compression TestsIf the criteria of 8.3 are notmet or as an alternative, the producer or purchaser may agreeto use core

35、s taken from the barrier sections in accordance withTest Method C 42. The number of tests required shall be asspecified in 8.1. Test results shall conform to 8.3 except that ifcores are used the average compressive ot1 strength of the testspecimens shall be equal to or greater than 3400 psi (23 MPa)

36、No single core shall have a compressive strength less than 3000psi (21 MPa). If the core tests fail on the daily production run,each barrier section may be individually cored for acceptance.9. Permissible Dimensional Tolerances9.1 Cross-Sectional DimensionsCross-sectional dimen-sions shall not vary

37、 from design dimensions by more than14 in.(6 mm). The vertical center line shall not be out of plumb bymore than14 in. (6 mm).9.2 Longitudinal DimensionsLongitudinal dimensionsshall not vary from the design dimensions by more than14 in.(6 mm) per 10 ft (3 m) of barrier section and shall not exceed34

38、 in. (19 mm) per section.9.3 Location of Anchoring DevicesLocation of anchoringholes shall be as specified by the purchaser.9.4 Surface StraightnessWhen checked with a 10-ft (3-m)straight edge, irregularities measuring more than14 in. (6 mm)shall be corrected as the purchaser may order or approve.9.

39、5 Position of ReinforcementCover over reinforcementshall be not less than 2 in. (50 mm), except for longitudinalreinforcement at the end face of barrier sections.10. Inspection10.1 The quality of materials, the process of manufacturing,and the finished median barrier shall be available for inspectio

40、nby an inspector employed by the purchaser. If the manufactureris required to obtain the services of an independent testingagency, the costs shall be the purchasers responsibility.11. Repairs11.1 Barrier sections may be repaired, if necessary, becauseof occasional imperfections in manufacture or dam

41、age duringhandling. They shall be acceptable if, in the opinion of thepurchaser, the repairs are sound, properly finished, and cured.The repaired sections shall conform to the requirements of thisspecification. Repairs to correct imperfections in manufactureor damage during handling may be made only

42、 after authoriza-tion by the purchaser.12. Rejection12.1 Barrier sections shall be subject to rejection for failureto conform to any of the specification requirements. In addi-tion, individual sections may be rejected due to defects thatindicate inadequate proportioning, mixing, or molding.ASTM Inte

43、rnational 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 patent rights, and the riskof infringement of such rights, are entirely

44、 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 either for revision of this standard or for additional standardsand sho

45、uld 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 hearing you shouldmake your views known to the ASTM Committee on Sta

46、ndards, 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).C825063