1、Designation: C478 11Standard Specification forPrecast Reinforced Concrete Manhole Sections1This standard is issued under the fixed designation C478; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A numbe
2、r 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 manufacture and
3、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 that are common toe
4、ach 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 16NOTE 1Future pro
5、ducts will to be included in Part II in a futurerevision of this specification.1.4 This specification is the inch-pound companion toSpecification C478M; therefore, no SI equivalents are pre-sented in the specification.NOTE 2This specification is a manufacturing and purchase specifica-tion only and d
6、oes 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 product strength
7、, 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 Standards:2A82/A82M Spec
8、ification for Steel Wire, Plain, for ConcreteReinforcementA185/A185M Specification for Steel Welded Wire Rein-forcement, Plain, for ConcreteA496/A496M Specification for Steel Wire, Deformed, forConcrete ReinforcementA497/A497M Specification for Steel Welded Wire Rein-forcement, Deformed, for Concret
9、eA615/A615M Specification for Deformed and PlainCarbon-Steel Bars for Concrete ReinforcementA706/A706M Specification for Low-Alloy Steel Deformedand Plain Bars for Concrete ReinforcementC33 Specification for Concrete AggregatesC39/C39M Test Method for Compressive Strength of Cy-lindrical Concrete Sp
10、ecimensC150 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, Manhole Sections, o
11、rTileC595 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 Concreteand Mortars1This specification is under
12、the jurisdiction of ASTM Committee C13 onConcrete Pipe and is the direct responsibility of Subcommittee C13.06 on Manholesand Specials.Current edition approved Nov. 1, 2011. Published November 2011. Originallyapproved in 1961. Last previous edition approved in 2009 as C478 09. DOI:10.1520/C0478-11.2
13、For 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 Drive, PO Box C
14、700, West Conshohocken, PA 19428-2959, United States.C1017/C1017M Specification for Chemical Admixtures forUse in Producing Flowing Concrete2.2 ACI Standard:3318 Building Code, Requirements for Reinforced Concrete3. Terminology3.1 DefinitionsFor definitions of terms relating to precastreinforced con
15、crete manholes, see Terminology C822.4. 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, arecovered in the Part II section for that specific produc
16、t.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 Cementitious Materials:4.1.2.1 CementCement shall confo
17、rm 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 that the pozzolanconstituent of the Type IP portland-pozzolan cement shall befly ash.4.1.2.2 Fly AshFly ash shall confo
18、rm to the requirementsof Class F or Class C of Specification C618.4.1.2.3 Ground Granulated Blast-Furnace Slag (GGBFS)GGBFS shall conform to the requirements of Grade 100 or 120of Specification C989.4.1.3 Allowable Combinations of Cementitious MaterialsThe combination of cementitious materials used
19、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 and groundgranulated blast-furnace slag,4.1.3.6 A combin
20、ation 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 AggregatesAggregates shall conform to Specifica-tion C33
21、, 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 C260;4.1.5.2 Chemical admixture conforming to SpecificationC494/C494M;4.1.5.3 Chemical admixture for u
22、se 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 conforming to Specification A82/A82M or SpecificationA496/A496M, of wire fabric conforming to SpecificationA18
23、5/A185M or Specification A497/A497M, or of bars ofGrade 40 steel conforming to Specification A615/A615M or ofbars conforming to Specification A706/A706M.4.1.7 Secondary Synthetic FiberCollated fibrillated poly-propylene virgin fibers shall not be prohibited when used insteel reinforced concrete manh
24、oles as a non-structural manu-facturing enhancement. Only fibers designed and manufacturedspecifically 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 IIs
25、ection 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 specification shall be 4000 psiunless specified otherwise in Part II of
26、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 approval is obtained, then the product shall meet all thetests and
27、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 of specialsections, such as reducers, tees, and bases.6. Reinforce
28、ment6.1 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 a specificproduct.6.2 CoverThe exposure of the ends of reinforcemen
29、t,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 manufacture of theproduct, except when lift holes or pipe openings are provid
30、edin 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 addition,where lapped cages of welded wire fabric are used withoutwel
31、ding, 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, FarmingtonHills, MI 48333-9094, http:/www.aci-int.org.C478 112specimens
32、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 speci-mens shall develop at least 75 % of the minimum specifiedstrengt
33、h 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, the representa-tive steel hoop sample shall develop at least 75 %
34、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 homogeneous concretemixture of such quality that the products will confor
35、m 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 proportion not less than 470lb/yd3, unless mix designs with a lower cemen
36、titious 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 7.2.1-7.2.4 or to anyother method or combination of methods approved by theo
37、wner 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 as needed to enable the products to meetthe strength requirements
38、. 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 pipes, mechanical sprinklers, porous hose, or by anyother approved
39、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 strength requirementsare met. The concrete at the time of application of themem
40、brane 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 combiningthe methods prescribed in 7.2.1-7.2.3 provided the require
41、dconcrete 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 products shall be asspecified in the Part II section for a particu
42、lar 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 product on the basis of inspection ofthe finished product, includi
43、ng 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 SpecimenCompression tests for satisfyingthe minimum specified concrete strength requ
44、irement 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 C497, and shall betested in accordance with Test Method C39/C39M. For
45、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 each days production. Theaverage compressive strength of all cylinders tested s
46、hall 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 strength of the concrete.8.2.1.3 Compression Testing of Cores
47、Cores 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 selected at random from each daysproduction run of a single concrete strength. When
48、 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 requirement, anothercore from the same manhole product shall be
49、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 strength of the two cores is equal to or greater than80 % of th
