1、Designation: C 478M 07METRICStandard Specification forPrecast Reinforced Concrete Manhole Sections Metric1This standard is issued under the fixed designation C 478M; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.PART IGENERAL1. Scope1.1 This specification covers th
3、e manufacture and purchaserequirements of products used for the assembly and construc-tion of circular precast reinforced concrete manholes used insewer and water works.1.2 Part I, Sections 1-11, of this specification presentsgeneral requirements and requirements which are common toeach precast conc
4、rete product covered by this specification.1.3 Part II of this specification presents specific require-ments for each manhole product in the following sections:Product SectionGrade Rings 12Flat Slab Tops 13Risers and Conical Tops 14Base Sections 15Steps and Ladders 16NOTE 1Future products will be in
5、cluded in Part II in a future revisionof this specification.1.4 This is the metric (SI) companion to SpecificationC 478.NOTE 2This specification is a manufacturing and purchase specifica-tion only, and does not include requirements for backfill, or the relation-ship between field load conditions and
6、 the strength requirements of themanhole products and appurtenances. Experience has shown, however,that the successful performance of this product depends upon the properselection of the product strength, type of foundation and backfill, and carein the field installation of the manhole products and
7、connecting pipes. Theowner of the project for which these products are specified herein iscautioned to require inspection at the construction site.2. Referenced Documents2.1 ASTM Standards:2A 82/A 82M Specification for Steel Wire, Plain, for Con-crete ReinforcementA 185/A 185M Specification for Stee
8、l Welded Wire Rein-forcement, Plain, for ConcreteA 496/A 496M Specification for Steel Wire, Deformed, forConcrete ReinforcementA 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 Reinfo
9、rcementA 706/A 706M Specification for Low-Alloy Steel De-formed and Plain Bars for Concrete ReinforcementC33 Specification for Concrete AggregatesC 39/C 39M Test Method for Compressive Strength of Cy-lindrical Concrete SpecimensC 150 Specification for Portland CementC 260 Specification for Air-Entra
10、ining Admixtures for Con-creteC 309 Specification for Liquid Membrane-Forming Com-pounds for Curing ConcreteC 494/C 494M Specification for Chemical Admixtures forConcreteC 497 Test Methods for Concrete Pipe, Manhole Sections,or TileC 595 Specification for Blended Hydraulic CementsC 618 Specification
11、 for Coal Fly Ash and Raw or CalcinedNatural Pozzolan for Use in ConcreteC 822 Terminology Relating to Concrete Pipe and RelatedProductsC 989 Specification for Ground Granulated Blast-FurnaceSlag for Use in Concrete and MortarsC 1017/C 1017M Specification for Chemical Admixtures1This specification i
12、s under the jurisdiction of ASTM Committee C13 onConcrete Pipe and is the direct responsibility of Subcommittee C13.06 on Manholesand Specials.Current edition approved March 1, 2007. Published March 2007. Originallyapproved in 1980. Last previous edition approved in 2006 as C 478M 06b.2For reference
13、d 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Con
14、shohocken, PA 19428-2959, United States.for Use in Producing Flowing Concrete2.2 ACI Standard:ACI 318 Building Code, Requirements for Reinforced Con-crete33. Terminology3.1 DefinitionsFor definitions of terms relating to con-crete pipe, see Terminology C 822.4. Materials and Manufacture4.1 General m
15、aterial requirements for precast reinforcedconcrete manhole products are presented in 4.1.1-4.1.8. Othermaterials or additional requirements for a product, if any, arecovered in the Part II section for that specific product.4.1.1 Reinforced ConcreteReinforced concrete shall con-sist of cementitious
16、materials, mineral aggregates, and water, inwhich steel reinforcement has been embedded in such amanner so that the steel reinforcement and concrete acttogether.4.1.2 Cementitious Materials:4.1.2.1 CementCement shall conform to the requirementsfor portland cement of Specification C 150, or shall be
17、portlandblast-furnace slag cement or portland-pozzolan cement con-forming to Specification C 595, except that the pozzolanconstituent of the Type IP portland-pozzolan cement shall befly ash.4.1.2.2 Fly AshFly ash shall conform to the requirementsof Class F or Class C of Specification C 618.4.1.2.3 G
18、round Granulated Blast-Furnace Slag (GGBFS)GGBFS shall conform to the requirements of Grade 100 or 120of Specification C 989.4.1.3 Allowable Combinations of Cementitious MaterialsThe combination of cementitious materials used in the concreteshall be one of the following:4.1.3.1 Portland cement only,
19、4.1.3.2 Portland blast-furnace slag cement only,4.1.3.3 Slag modified Portland cement only,4.1.3.4 Portland pozzolan cement only,4.1.3.5 A combination of Portland cement and groundgranulated blast-furnace slag,4.1.3.6 A combination of Portland cement and fly ash, or4.1.3.7 A combination of Portland
20、cement, ground granu-lated blast-furnace slag (not to exceed 25 % of the totalcementitious weight) and fly ash (not to exceed 25 % of thetotal cementitious weight).4.1.4 AggregatesAggregates shall conform to Specifica-tion C33, except that the requirements for gradation shall notapply.4.1.5 Admixtur
21、es and BlendsThe following admixturesand blends are allowable:4.1.5.1 Air-entraining admixture conforming to Specifica-tion C 260;4.1.5.2 Chemical admixture conforming to SpecificationC 494/C 494M;4.1.5.3 Chemical admixture for use in producing flowingconcrete conforming to Specification C 1017/C 10
22、17M;4.1.5.4 Chemical admixture or blend approved by theowner.4.1.6 Steel ReinforcementReinforcement shall consist ofwire conforming to Specification A 82/A 82M or SpecificationA 496/A 496M, of wire fabric conforming to SpecificationA 185/A 185M or Specification A 497/A 497M, or of bars ofGrade 40 st
23、eel conforming to Specification A 615/A 615M orof bars conforming to Specification A 706/A 706M.4.1.7 Secondary Synthetic FiberCollated fibrillatedpolypropylene virgin fibers shall not be prohibited when usedin steel reinforced concrete manholes as a non-structuralmanufacturing enhancement. Only fib
24、ers designed and manu-factured specifically for use in concrete and so certified by themanufacturer shall be accepted.4.1.8 Other MaterialsOther materials required for a prod-uct and not covered in Section 4 will be covered in the Part IIsection for that specific product.5. Design5.1 Design requirem
25、ents for a product are prescribed in thespecific Part II section for that product.5.1.1 The minimum compressive strength of concrete man-hole products covered by this specification shall be 27.6 MPaunless specified otherwise in Part II of this specification.5.2 Modified or Special Design:5.2.1 Manuf
26、acturers are not prohibited from submitting tothe owner, for approval prior to manufacture, designs otherthan those prescribed in the specific section for a product. Ifsuch approval is obtained, then the product shall meet all thetests and performance requirements specified by the owner inaccordance
27、 with the appropriate sections on manufacture andphysical requirements.5.2.2 If permitted by the owner, the manufacturer is notprohibited from requesting approval of designs of specialsections, such as reducers, tees, and bases.6. Reinforcement6.1 This section presents requirements for reinforcement
28、cover, continuity, laps, welds and splices. Other reinforcementrequirements are presented in Section 4 and any additionalrequirements are given in the Part II section for a specificproduct.6.2 CoverThe exposure of the ends of reinforcement,stirrups or spacers used to position the reinforcement durin
29、gplacement of the concrete shall not be cause for rejection.6.3 ContinuityThe continuity of the circumferential rein-forcement shall not be destroyed during the manufacture of theproduct, except when lift holes or pipe openings are providedin the product.6.4 Welded Steel Cage Laps, Welds, and Splice
30、s:6.4.1 If splices are not welded, the reinforcement shall belapped not less than 20 diameters for deformed bars, and 40diameters for plain bars and cold-drawn wire. In addition,where lapped cages of welded wire fabric are used withoutwelding, the lap shall contain a longitudinal wire.6.4.2 When spl
31、ices are welded and are not lapped to theminimum requirements in 6.4.1, pull tests of representative3Available from American Concrete Institute (ACI), P.O. Box 9094, FarmingtonHills, MI 48333-9094, http:/www.aci-int.org.C478M072specimens shall develop at least 50 % of the minimum speci-fied strength
32、 of the steel, and there shall be a minimum lap of50 mm. For butt welded splices in bars or wire, permitted onlywith helically wound cages, pull tests of representative speci-mens shall develop at least 75 % of the minimum specifiedstrength of the steel.6.5 Steel Hoop SplicesA representative sample
33、steel hoopwith welded splices shall develop at least 50 % of the mini-mum specified strength of the steel, and there shall be aminimum lap of 50 mm. For butt welded splices, the represen-tative steel hoop sample shall develop at least 75 % of theminimum specified strength of the steel.7. Precast Con
34、crete Manufacture7.1 MixtureThe aggregates shall be sized, graded, propor-tioned, and mixed with such proportions of cementitiousmaterials and water as will produce a homogeneous concretemixture of such quality that the products will conform to thetest and design requirements of this specification.
35、All concreteshall have a water-cementitious ratio not exceeding 0.53 bymass. Cementitious materials shall be as specified in 4.1.2 andshall be added to the mix in a proportion not less than 280kg/m3, unless mix designs with a lower cementitious materialscontent demonstrate that the quality and perfo
36、rmance of theproduct meet the requirements of this specification.7.2 CuringConcrete products shall be subjected to anyone of the methods of curing prescribed in 7.2.1-7.2.4 or to anyother method or combination of methods approved by theowner that will give satisfactory results.7.2.1 Steam CuringConc
37、rete products are placed in acuring chamber, free of outside drafts, and cured in a moistatmosphere maintained by the injection of steam for such timeand such temperatures as may be needed to enable the productsto meet the strength requirements. The curing chamber shall beso constructed as to allow
38、full circulation of the steam aroundthe entire product.7.2.2 Water CuringConcrete products are water-cured bycovering with water-saturated material, or by a system ofperforated pipes, mechanical sprinklers, porous hose, or by anyother approved method that will keep the products moist duringthe curin
39、g period.7.2.3 Sealing MembraneA sealing membrane conformingto the requirements of Specification C 309 is applied and shallbe left intact until the required concrete strength requirementsare met. The concrete at the time of application of themembrane shall be within 6C of the atmospheric temperature
40、.All concrete surfaces shall be kept moist prior to the applica-tion of the membrane and shall be damp when the membraneis applied.7.2.4 The manufacturer is not prohibited from combiningmethods prescribed in 7.2.1-7.2.3 provided the required con-crete compressive strength is attained.8. Acceptance8.
41、1 Acceptance Procedures:8.1.1 Unless otherwise designated by the owner at the timeof, or before, placing an order, acceptance procedures forprecast reinforced concrete manhole products shall be asspecified in the Part II section for a particular product, and shallnot be prohibited from consisting of
42、 one or more of thefollowing:8.1.1.1 Acceptance of a product on the basis of tests ofmaterials, including concrete compressive strength and absorp-tion.8.1.1.2 Acceptance of a product on the basis of inspection ofthe finished product, including amount and placement ofreinforcement to determine confo
43、rmance with the designprescribed under this specification, and freedom from defects.8.2 Test Methods:8.2.1 Concrete Compressive Strength Test:8.2.1.1 Type of SpecimenCompression tests for satisfyingthe minimum specified concrete strength requirement shall bemade on either concrete cylinders or, at t
44、he option of themanufacturer, on cores cut from the concrete manhole product.8.2.1.2 Compression Testing of CylindersCylinders shallbe made in accordance with Test Methods C 497, and shall betested in accordance with Test Method C 39. For manholeproducts, an owner shall not be prohibited from requir
45、ingconcrete compressive tests on cylinder specimens numberingin the amount of 5 % of the total order of a manhole product,but not to exceed two cylinders for each days production. Theaverage compressive strength of all cylinders tested shall beequal to or greater than the specified strength of the c
46、oncrete.Not more than 10 % of the cylinders tested shall fall below thespecified strength of the concrete. In no case shall any cylindertested fall below 80 % of the specified strength of the concrete.8.2.1.3 Compression Testing of CoresCores shall be cutfrom the concrete manhole product and tested
47、in accordancewith Test Methods C 497, except that the requirements formoisture conditioning shall not apply. One core shall be takenfrom a manhole product selected at random from each daysproduction run of a single concrete strength. When the concretecompressive strength of the core is equal to or g
48、reater than80 % of the specified strength of the concrete, the concretestrength of the production run is acceptable. If the core doesnot meet the preceding concrete strength requirement, anothercore from the same manhole product may be taken and tested.8.2.1.4 If the concrete compressive strength of
49、 the recore isequal to or greater than 80 % of the specified strength of theconcrete, the concrete strength of the production run is accept-able. If the recore does not meet the preceding concretestrength requirement, that manhole product shall be rejected.Two manhole products from the remainder of the daysproduction run shall be selected at random and one core takenfrom each manhole product and tested. When the averageconcrete strength of the two cores is equal to or greater than80 % of the specified strength of the concrete with no corebelow 75 % of t
