1、Designation: C478 14Standard 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 U.S. Department of Defense.PART IGENERAL1. Scope1.1 This specification covers the manufacture
3、 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 requirements that are common
4、 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 16NOTE 1Future
5、 products 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 a
6、nd 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 product stre
7、ngth, 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:2A615/A615
8、M Specification for Deformed and Plain Carbon-Steel Bars for Concrete 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 Specific
9、ation for Concrete AggregatesC39/C39M Test Method for Compressive Strength of Cylin-drical 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 Spe
10、cification for Chemical Admixtures forConcreteC497 Test Methods for Concrete Pipe, Manhole 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 Related
11、ProductsC989 Specification for Slag Cement for Use in Concrete andMortarsC1017/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 p
12、recastreinforced concrete manholes, 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 Manholesand Specials.Current edition approved Sept. 15, 2014. Published October 2014. Originallyappr
13、oved in 1961. Last previous edition approved in 2013 as C478 13. DOI:10.1520/C0478-14.2For 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
14、 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 States14. 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 C150, or shall be p
17、ortlandblast-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 conform to the requirementsof Class F or Class C of Specification C618.4.1.2.3 Slag
18、 CementSlag cement shall conform to therequirements of Grade 100 or 120 of Specification C989.4.1.3 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,4.1.3.2 Portland blast-furnace
19、slag cement only,4.1.3.3 Portland pozzolan cement only,4.1.3.4 A combination of Portland cement and slag cement,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
20、 25 % of the total cementitious weight).4.1.4 AggregatesAggregates 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
21、C260;4.1.5.2 Chemical admixture 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 weld
22、ed wire conforming to Specification A1064/A1064M or of bars conforming to Specification A615/A615M,Grade 40 or 60, or Specification A706/A706M, Grade 60.4.1.7 Secondary Synthetic FiberCollated fibrillated poly-propylene virgin fibers shall not be prohibited when used insteel reinforced concrete manh
23、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
24、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
25、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
26、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
27、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
28、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
29、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
30、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 representativespecimens shall develop at least 50 % of the minimum speci-fied ultimate tensile strength of the steel, and there shall be aminimum lap of
31、 2 in. For butt welded splices in bars or wire,permitted only with helically wound cages, pull tests ofrepresentative specimens shall develop at least 75 % of theminimum specified ultimate tensile strength of the steel.6.5 Steel Hoop SplicesA representative sample steel hoopwith welded splices shall
32、 develop at least 50 % of the mini-mum specified ultimate tensile strength of the steel, and thereshall be a minimum lap of 2 in. For butt welded splices, therepresentative steel hoop sample shall develop at least 75 % ofthe minimum specified ultimate tensile strength of the steel.7. Precast Concret
33、e Manufacture7.1 MixtureThe aggregates shall be sized, graded,proportioned, and mixed with such proportions of cementitiousmaterials and water as will produce a thoroughly-mixedC478 142concrete of such quality that the products will conform to thetest and design requirements of this specification. A
34、ll 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 cementitious materialscontent demonstrate that the quality and per
35、formance 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 toany other method or combination of methods approved by theowner that will give satisfactory results.7.2.1 Steam CuringCo
36、ncrete 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. The curing chamber shall be soconstructed as to allow full
37、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 method that will keep the products moist duringthe curing per
38、iod.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 themembrane shall be within 10F of the atmospheric tempera-ture. Al
39、l 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 requiredconcrete compressive strength is attained.8. Acceptance8.1 A
40、cceptance 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 on
41、e 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 conforma
42、nce 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 the
43、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 man-hole products, an owner shall not be prohibited from requ
44、iringconcrete 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
45、 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 CoresCores shall be cutfrom the concrete manhole product and teste
46、d 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 the concretecompressive strength of the core is equal to or
47、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 taken and tested.8.2.1.4 If the concrete compressive strength
48、 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
49、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 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
