1、Designation: C 478 07Standard 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 precast reinforced concrete manholes used insewer and water works.1.2 Part I, Sections 1-11, of this specification presentsgeneral requirements and requirements that are common toeach precast concrete product cov
4、ered 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 will to be included in Par
5、t 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-tion only and does not
6、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, type o
7、f 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:2A 82/A 82M Specificat
8、ion 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-forcement, Deformed, for Concr
9、eteA 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 Strength of Cy-lindrical C
10、oncrete 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 Methods for Concrete Pipe, Man
11、hole 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-Furnace1This specification
12、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 1, 2007. Published March 2007. Originallyapproved in 1961. Last previous edition approved in 2006 as C 478 06b.2For reference
13、d 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 C700, West Con
14、shohocken, 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 definitions of terms relating
15、 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, arecovered in the Part II sectio
16、n 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 Cementitious Materials:4.1.2.
17、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 cement shall befly ash.4.1.2.
18、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 MaterialsThe combination o
19、f 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 and groundgranulated blast
20、-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 AggregatesAggregates shall
21、 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 SpecificationC 494/C 494M
22、;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 SpecificationA 496/A 496M, of wir
23、e 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 fibers shall not be prohibit
24、ed 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 prod-uct and not covered i
25、n 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 specification shall be 4000 p
26、siunless 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 approval is obtained, th
27、en 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 of specialsections, suc
28、h 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 a specificproduct.6.2 Co
29、verThe 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 manufacture of theproduct, except
30、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 addition,where lapped cage
31、s 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, FarmingtonHills, MI 48333-909
32、4, http:/www.aci-int.org.C478072specimens 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
33、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, the representa-tive stee
34、l 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 homogeneous concretemixture of
35、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 proportion not less than 470lb/
36、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 7.2.1-7.2.4 or to anyother method
37、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 as needed to enable the
38、 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 pipes, mechanical sprinkl
39、ers, 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 requirementsare met. The co
40、ncrete 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 combiningthe methods pre
41、scribed 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 products shall be asspe
42、cified 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 product on the basis of
43、 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 SpecimenCompression tests for satisfyingt
44、he 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 497, and shall betested i
45、n 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 production. Theaverage compress
46、ive 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 strength of the concret
47、e.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 from each daysproduction
48、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 requirement, anothercore
49、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 strength of the two cores
