1、Designation: C478M 12aStandard Specification forPrecast 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 last revis
2、ion. 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 Department of Defense.PART IGENERAL1. Scope1.1 This specification covers the manu
3、facture 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 1-11, of this specification presentsgeneral requirements and requirements which a
4、re 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 Ladders 16NOT
5、E 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 between field
6、 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 installation of the m
7、anhole 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 Reinforceme
8、ntA706/A706M Specification for Low-Alloy Steel Deformedand Plain Bars for Concrete ReinforcementA1064/A1064M Specification for Steel Wire and WeldedWire Reinforcement, Plain and Deformed, for ConcreteC33 Specification for Concrete AggregatesC39/C39M Test Method for Compressive Strength of Cylin-dric
9、al Concrete SpecimensC150 Specification for Portland CementC260 Specification for Air-Entraining Admixtures for Con-creteC309 Specification for Liquid Membrane-Forming Com-pounds for Curing ConcreteC494/C494M Specification for Chemical Admixtures forConcreteC497 Test Methods for Concrete Pipe, Manho
10、le Sections, orTileC595 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 Specification for Slag Cement for Use in Concrete andMortarsC1017/C1017M Sp
11、ecification for Chemical Admixtures forUse in Producing Flowing Concrete2.2 ACI Standard:ACI 318 Building Code, Requirements for Reinforced Con-crete33. Terminology3.1 DefinitionsFor definitions of terms relating to concretepipe, see Terminology C822.4. Materials and Manufacture4.1 General material
12、requirements for precast reinforcedconcrete manhole products are presented in 4.1.1-4.1.8. Other1This 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 Oct. 1, 2012. P
13、ublished October 2012. Originallyapproved in 1980. Last previous edition approved in 2012 as C478M 12 DOI:10.1520/C0478M-12A.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,
14、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, PO Box C700, West Conshohocken, PA 19428-2959. United States1ma
15、terials 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 materials, mineral aggregates, and water, inwhich steel reinforcement has been embedded in such amanner so
16、 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 C150, or shall be portlandblast-furnace slag cement or portland-pozzolan cement con-forming to Specification C595, except tha
17、t 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 C618.4.1.2.3 Slag CementSlag cement shall conform to therequirements of Grade 100 or 120 of Specification C989.4.1.3 Allowa
18、ble Combinations 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 A combination of Portland cement and slag c
19、ement,4.1.3.5 A combination of Portland cement and fly ash, or4.1.3.6 A combination of Portland cement, slag cement (notto exceed 25 % of the total cementitious weight) and fly ash(not to exceed 25 % of the total cementitious weight).4.1.4 AggregatesAggregates shall conform to Specifica-tion C33, ex
20、cept 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 C260;4.1.5.2 Chemical admixture conforming to SpecificationC494/C494M;4.1.5.3 Chemical admixture for use i
21、n 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 Specification A1064/A1064M; or of bars conforming to Specification A615/A615M, Grade
22、 280 or 420, or Specification A706/A706M,Grade 420.4.1.7 Secondary Synthetic FiberCollated fibrillated poly-propylene virgin fibers shall not be prohibited when used insteel reinforced concrete manholes as a non-structural manu-facturing enhancement. Only fibers designed and manufacturedspecifically
23、 for use in concrete and so certified by the manu-facturer 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 requirements for a product are prescribed in thes
24、pecific 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 Manufacturers are not prohibited from submitti
25、ng 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 with the appropriate sections on manufac
26、ture 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 reinforcementcover, continuity, laps, welds and splice
27、s. 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 duringplacement of the concrete shall not be c
28、ause 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 Splices:6.4.1 If splices are not welded, the re
29、inforcement 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 splices are welded and are not lapped to the
30、minimum requirements in 6.4.1, pull tests of representativespecimens shall develop at least 50 % of the minimum speci-fied strength 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
31、speci-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 50 mm. For butt welded spli
32、ces, the represen-tative 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,proportioned, and mixed with such proportions of cementitiousmaterials and water as will produce a thor
33、oughly-mixedC478M 12a2concrete 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 bymass. Cementitious materials shall be as specified in 4.1.2 andshall be added to the mix in a
34、 proportion not less than 280kg/m3, 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
35、.1-7.2.4 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 tempe
36、ratures as may be needed to enable the productsto meet the strength requirements. The curing chamber shall beso constructed as to allow 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
37、ofperforated pipes, 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 C309 is applied and shallbe left intact until the required concrete
38、 strength requirementsare met. The concrete at the time of application of themembrane shall be within 6C of the atmospheric temperature.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 proh
39、ibited from combiningmethods prescribed in 7.2.1-7.2.3 provided the required con-crete 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 concre
40、te 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 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 Accep
41、tance of a 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 Specime
42、nCompression 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 M
43、ethods C497, and shall betested in accordance with Test Method C39/C39M. For man-hole products, 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 ea
44、ch days production. 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 % o
45、f 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 Test Methods C497, except that the requirements formoisture conditioning shall not apply. One core shall be takenfrom a manhole product select
46、ed at random from 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 concr
47、ete 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 d
48、oes 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
49、equal to or greater than80 % of the specified strength of the concrete with no corebelow 75 % of the specified strength of the concrete, theconcrete strength of the days production run shall be accept-able.8.2.1.5 If the concrete strength of the two cores does notmeet the preceding concrete strength requirement, then theremainder of the days production run shall be either rejected,or, at the option of the manufacturer, each manhole product ofthe remainder of the days production run is not prohibitedfrom being cored and accepted individually.8.2.1.6 P
