1、Designation: C 478 08Standard Specification forPrecast Reinforced Concrete Manhole Sections1This standard is issued under the fixed designation C 478; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A num
2、ber 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 the manufacture a
3、nd purchaserequirements of products used for the assembly and construc-tion of circular vertical precast reinforced concrete manholesand structures used in sewer and water works.1.2 Part I, Sections 1-11, of this specification presentsgeneral requirements and requirements that are common toeach prec
4、ast concrete 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 wi
5、ll to be included in Part II in a futurerevision of this specification.1.4 A complete metric companion to this specification hasbeen developed, Specification C 478M; therefore, no metricequivalents are presented in this specification.NOTE 2This specification is a manufacturing and purchase specifica
6、-tion only and does not include requirements for backfill, or the relation-ship between field load conditions and 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
7、product strength, type of foundation and backfill, and carein the field installation of the manhole products and 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 Standard
8、s:2A 82/A 82M Specification for Steel Wire, Plain, for Con-crete ReinforcementA 185/A 185M Specification for Steel 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-forcem
9、ent, Deformed, for ConcreteA 615/A 615M Specification for Deformed and PlainCarbon-Steel Bars for Concrete ReinforcementA 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 St
10、rength of Cy-lindrical Concrete SpecimensC 150 Specification for Portland CementC 260 Specification for Air-Entraining 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 Method
11、s for Concrete Pipe, Manhole Sections,or TileC 595 Specification for Blended Hydraulic CementsC 618 Specification 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-Fur
12、nace1This specification is 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 15, 2008. Published March 2008. Originallyapproved in 1961. Last previous edition approved in 2007 as
13、 C 478 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.1Copyright ASTM International, 100 Barr Harbor Driv
14、e, PO Box C700, West Conshohocken, PA 19428-2959, United States.Slag for Use in Concrete and MortarsC 1017/C 1017M Specification for Chemical Admixturesfor Use in Producing Flowing Concrete2.2 ACI Standard:3318 Building Code, Requirements for Reinforced Concrete3. Terminology3.1 DefinitionsFor defin
15、itions of terms relating to precastreinforced concrete manholes, see Terminology C 822.4. Materials and Manufacture4.1 General material requirements for precast reinforcedconcrete manhole products are presented in 4.1.1-4.1.8. Othermaterials or additional requirements for a product, if any, arecover
16、ed in the Part II section for that specific product.4.1.1 Reinforced ConcreteReinforced concrete shall con-sist of cementitious 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 Cemen
17、titious Materials:4.1.2.1 CementCement shall conform to the requirementsfor portland cement of Specification C 150, or shall be portlandblast-furnace slag cement or portland-pozzolan cement con-forming to Specification C 595, except that the pozzolanconstituent of the Type IP portland-pozzolan cemen
18、t 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 Ground 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 Ma
19、terialsThe combination of cementitious materials used in the concreteshall be one of the following:4.1.3.1 Portland cement only,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 an
20、d groundgranulated blast-furnace slag,4.1.3.6 A combination of Portland cement and fly ash, or4.1.3.7 A combination of Portland 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 Ag
21、gregatesAggregates shall conform to Specifica-tion C33, except that the requirements for gradation shall notapply.4.1.5 Admixtures 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 S
22、pecificationC 494/C 494M;4.1.5.3 Chemical admixture for use in producing flowingconcrete conforming to Specification C 1017/C 1017M;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 Specifica
23、tionA 496/A 496M, of wire fabric conforming to SpecificationA 185/A 185M or Specification A 497/A 497M, or of bars ofGrade 40 steel conforming to Specification A 615/A 615M orof bars conforming to Specification A 706/A 706M.4.1.7 Secondary Synthetic FiberCollated fibrillatedpolypropylene virgin fibe
24、rs shall not be prohibited when usedin steel reinforced concrete manholes as a non-structuralmanufacturing enhancement. Only fibers 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 pr
25、od-uct and not covered in Section 4 will be covered in the Part IIsection for that specific product.5. Design5.1 Design requirements 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 speci
26、fication shall be 4000 psiunless specified otherwise in Part II of this specification.5.2 Modified or Special Design5.2.1 Manufacturers are not prohibited from submitting tothe owner, for approval prior to manufacture, designs otherthan those prescribed in the specific section for a product. Ifsuch
27、approval is obtained, then the product shall meet all thetests and performance requirements specified by the owner inaccordance 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
28、 of specialsections, such as reducers, tees, and bases.6. Reinforcement6.1 This section presents requirements for reinforcementcover, continuity, laps, welds, and splices. Other reinforcementrequirements are presented in Section 4, and any additionalrequirements are given in the Part II section for
29、a specificproduct.6.2 CoverThe exposure of the ends of reinforcement,stirrups or spacers used to position the reinforcement duringplacement of the concrete shall not be cause for rejection.6.3 ContinuityThe continuity of the circumferential rein-forcement shall not be destroyed during the manufactur
30、e of theproduct, except when lift holes or pipe openings are providedin the product.6.4 Welded Steel Cage Laps, Welds, and Splices: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 ad
31、dition,where lapped cages of welded wire fabric are used withoutwelding, the lap shall contain a longitudinal wire.6.4.2 When splices 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, Farmi
32、ngtonHills, MI 48333-9094, http:/www.aci-int.org.C478082specimens shall develop at least 50 % of the minimum speci-fied strength of the steel, and there shall be a minimum lap of2 in. For butt welded splices in bars or wire, permitted onlywith helically wound cages, pull tests of representative spec
33、i-mens shall develop at least 75 % of the minimum specifiedstrength of the steel.6.5 Steel Hoop SplicesA representative sample 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 2 in. For butt welded splices,
34、the representa-tive steel hoop sample shall develop at least 75 % of theminimum specified strength of the steel.7. Precast Concrete Manufacture7.1 MixtureThe aggregates shall be sized, graded, propor-tioned, and mixed with such proportions of cementitiousmaterials and water as will produce a homogen
35、eous concretemixture of such quality that the products will conform to thetest and design requirements of this specification. All concreteshall have a water-cementitious ratio not exceeding 0.53 byweight. Cementitious materials shall be as specified in 4.1.2and shall be added to the mix in a proport
36、ion not less than 470lb/yd3, unless mix designs with a lower cementitious materialscontent demonstrate that the quality and performance 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.
37、4 or to anyother method or combination of methods approved by theowner that will give satisfactory results.7.2.1 Steam CuringConcrete 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
38、 as needed to enable the products to meetthe strength requirements. The curing chamber shall be soconstructed as to allow full circulation of the steam around theentire product.7.2.2 Water CuringConcrete products are water-cured bycovering with water-saturated material, or by a system ofperforated p
39、ipes, mechanical sprinklers, porous hose, or by anyother approved method that will keep the products moist duringthe curing 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 req
40、uirementsare met. The concrete at the time of application of themembrane shall be within 10F of the atmospheric tempera-ture. All concrete surfaces shall be kept moist prior to theapplication of the membrane and shall be damp when themembrane is applied.7.2.4 The manufacturer is not prohibited from
41、combiningthe methods prescribed in 7.2.1-7.2.3 provided the requiredconcrete compressive strength is attained.8. Acceptance8.1 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
42、 products shall be asspecified in the Part II section for a particular product, and shallnot be prohibited from consisting of 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
43、 product on the basis of inspection ofthe finished product, including amount and placement ofreinforcement to determine conformance 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 SpecimenCompressi
44、on tests for satisfyingthe minimum specified concrete strength requirement shall bemade on either concrete cylinders or, at the 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 4
45、97, and shall betested in accordance with Test Method C 39. For manholeproducts, an owner shall not be prohibited from requiringconcrete 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 product
46、ion. Theaverage compressive strength of all cylinders tested shall beequal to or greater than the specified strength of the concrete.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
47、 strength of the concrete.8.2.1.3 Compression Testing of CoresCores shall be cutfrom the concrete manhole product and tested 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 f
48、rom each daysproduction run of a single concrete strength. When the concretecompressive strength of the core is equal to or greater 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 r
49、equirement, anothercore from the same manhole product shall be taken and tested.8.2.1.4 If the concrete compressive strength of 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 st
