1、Designation: C478M 15aStandard Specification forCircular Precast Reinforced Concrete Manhole Sections(Metric)1This standard is issued under the fixed designation C478M; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of la
2、st revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.PART IGENERAL1. Scope1.1 This specification co
3、vers the manufacture and purchaserequirements of products used for the assembly and construc-tion of circular vertical precast reinforced concrete manholesand structures used in sewer, drainage, and water works.1.2 Part I, Sections 111, of this specification presentsgeneral requirements and requirem
4、ents which are common toeach precast 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 L
5、adders 16NOTE 1Future products will be included in Part II in a future revisionof this specification.1.4 This specification is the SI companion to C478.NOTE 2This specification is a manufacturing and purchase specifica-tion only, and does not include requirements for backfill, or the relation-ship b
6、etween 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 product strength, type of foundation and backfill, and carein the field installat
7、ion 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 Standards:2A615/A615M Specification for Deformed and Plain Carbon-Steel Bars for Concrete
8、 ReinforcementA706/A706M Specification for Deformed and Plain Low-Alloy Steel Bars for Concrete ReinforcementA1064/A1064M Specification for Carbon-Steel Wire andWelded Wire Reinforcement, Plain and Deformed, forConcreteC33/C33M Specification for Concrete AggregatesC39/C39M Test Method for Compressiv
9、e Strength of Cylin-drical Concrete SpecimensC150/C150M Specification for Portland CementC260/C260M Specification for Air-Entraining Admixturesfor ConcreteC309 Specification for Liquid Membrane-Forming Com-pounds for Curing ConcreteC494/C494M Specification for Chemical Admixtures forConcreteC497M Te
10、st Methods for Concrete Pipe, Manhole Sections,or Tile (Metric)C595/C595M Specification for Blended Hydraulic CementsC618 Specification for Coal Fly Ash and Raw or CalcinedNatural Pozzolan for Use in ConcreteC822 Terminology Relating to Concrete Pipe and RelatedProductsC989/C989M Specification for S
11、lag Cement for Use inConcrete and MortarsC1017/C1017M Specification for Chemical Admixtures forUse in Producing Flowing ConcreteC1116/C1116M Specification for Fiber-Reinforced ConcreteC1602/C1602M Specification for Mixing Water Used in theProduction of Hydraulic Cement Concrete2.2 ACI Standard:ACI 3
12、18 Building Code, Requirements for Reinforced Con-crete33. Terminology3.1 DefinitionsFor definitions of terms relating to concretepipe, see Terminology C822.1This specification is under the jurisdiction of ASTM Committee C13 onConcrete Pipe and is the direct responsibility of Subcommittee C13.06 on
13、Manholesand Specials.Current edition approved Oct. 15, 2015. Published November 2015. Originallyapproved in 1980. Last previous edition approved in 2015 as C478M 15. DOI:10.1520/C0478M-15A.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at servic
14、eastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American Concrete Institute (ACI), P.O. Box 9094, FarmingtonHills, MI 48333-9094, http:/www.aci-int.org.Copyright ASTM International, 100 Barr Harbor Drive,
15、 PO Box C700, West Conshohocken, PA 19428-2959. United States14. Materials and Manufacture4.1 General material requirements for precast reinforcedconcrete manhole products are presented in 4.1.1 4.1.9. Othermaterials or additional requirements for a product, if any, arecovered in the Part II section
16、 for that specific product.4.1.1 Reinforced ConcreteReinforced concrete shall con-sist of cementitious materials, mineral aggregates, admixtures,if used, and water, in which steel reinforcement has beenembedded in such a manner so that the steel reinforcement andconcrete act together.4.1.2 Cementiti
17、ous Materials:4.1.2.1 CementCement shall conform to the requirementsfor portland cement of Specification C150/C150M, or shall beportland blast-furnace slag cement, portland-limestone cement,or portland-pozzolan cement conforming to the requirementsof Specification C595/C595M, except that the pozzola
18、n con-stituent of the Type IP portland-pozzolan cement shall be flyash.4.1.2.2 Fly AshFly ash shall conform to the requirementsof Class F or Class C of Specification C618.4.1.2.3 Slag CementSlag cement shall conform to therequirements of Grade 100 or 120 of Specification C989/C989M.4.1.3 Allowable C
19、ombinations of Cementitious MaterialsThe 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 Portland-pozzolan cement only,4.1.3.4 Portland-limestone cement only,4.1.3.5 A combina
20、tion of portland cement or portland-limestone cement and slag cement,4.1.3.6 A combination of portland cement or portland-limestone cement and fly ash,4.1.3.7 A combination of portland cement or portland-limestone cement, slag cement, and fly ash, or4.1.3.8 A combination of portland-pozzolan cement
21、and flyash.4.1.4 AggregatesAggregates shall conform to Specifica-tion C33/C33M, except that the requirements for gradationshall not apply.4.1.5 AdmixturesThe following admixtures and blends areallowable:4.1.5.1 Air-entraining admixture conforming to Specifica-tion C260/C260M;4.1.5.2 Chemical admixtu
22、re conforming to SpecificationC494/C494M;4.1.5.3 Chemical admixture for use in producing flowingconcrete conforming to Specification C1017/C1017M;4.1.5.4 Chemical admixture or blend approved by theowner.4.1.6 Steel ReinforcementReinforcement shall consist ofwire and welded wire conforming to Specifi
23、cation A1064/A1064M; or of bars conforming to Specification A615/A615M, Grade 280 or 420, or Specification A706/A706M,Grade 420.4.1.7 WaterWater used in the production of concrete shallbe potable or non-potable water that meets the requirements ofSpecification C1602/C1602M.4.1.8 FiberSynthetic fiber
24、s and nonsynthetic fibers shallbe allowed to be used, at the manufacturers option, in concretemanholes as a nonstructural manufacturing material. Syntheticfibers (Type II and Type III) and nonsynthetic fiber (Type 1)designed and manufactured specifically for use in concrete andconforming to the requ
25、irements of Specification C1116/C1116M shall be accepted.4.1.9 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 requirements for a product are prescribed in thespecific Part II sect
26、ion 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 Manufacturers are not prohibited from submitting tothe owner, for
27、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 with the appropriate sections on manufacture andphysical req
28、uirements.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 reinforcementcover, continuity, laps, welds and splices. Other reinforceme
29、ntrequirements 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 duringplacement of the concrete shall not be cause for rejection.6
30、.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 Splices:6.4.1 If splices are not welded, the reinforcement shall be
31、lapped 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 splices are welded and are not lapped to theminimum requirements
32、 in 6.4.1, there shall be a minimum lapof 50 mm and a weld of sufficient length such that pull tests ofrepresentative specimens shall develop at least 50 % of theminimum specified tensile strength of the steel. For buttwelded splices in bars or wire, permitted only with helicallyC478M 15a2wound cage
33、s, pull tests of representative specimens shalldevelop at least 75 % of the minimum specified tensile strengthof the steel.6.5 Steel Hoop SplicesWhen splices are welded and notlapped to the minimum requirements in 6.4.1, there shall be aminimum lap of 50 mm and a weld of sufficient length suchthat p
34、ull tests from representative specimens shall develop atleast 50 % of the minimum specified tensile strength of thesteel. For butt welded splices, pull tests from representativespecimens shall develop at least 75 % of the minimum speci-fied tensile strength of the steel.7. Precast Concrete Manufactu
35、re7.1 MixtureThe aggregates shall be sized, graded,proportioned, and mixed with such proportions of cementitiousmaterials and water as will produce a thoroughly-mixedconcrete of such quality that the products will conform to thetest and design requirements of this specification. All concreteshall ha
36、ve 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 performance of theproduct
37、 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 toany other method or combination of methods approved by theowner that will give satisfactory results.7.2.1 Steam CuringConcrete products are pl
38、aced 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 full circulation of
39、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 curing period.7.2.3 Seali
40、ng MembraneA sealing membrane conformingto the requirements of Specification C309 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.All concrete surface
41、s 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 requiredconcrete compressive strength is attained.8. Acceptance8.1 Acceptance Procedures
42、: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 one or more of thefoll
43、owing: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 conformance with the designp
44、rescribed 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 the option of themanufac
45、turer, on cores cut from the concrete manhole product.8.2.1.2 Compression Testing of CylindersCylinders shallbe made in accordance with Test Methods C497M, and shall betested in accordance with Test Method C39/C39M. For man-hole products, an owner shall not be prohibited from requiringconcrete compr
46、essive 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 concrete.Not more
47、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 in accordancewith
48、 Test Methods C497M, 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 greater than80 % o
49、f 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 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
