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ACI304.2R-96Thisreportdescribespumpsfortransportingandplacingconcrete.Rigidandflexiblepipelinesarediscussedandcouplingsandotheraccessoriesdescribed.Recommendationsforproportioningpumpableconcretesuggestoptimumgradationofaggregates;outlinewater,cement,andadmixturerequirements;andemphasizetheneedforevaluationoftrialmixesforpumpability.Theimportanceofsaturatinglightweightaggregatesisstressed.Suggestionsaregivenforlayoutoflines;formaintaininguniformdeliveryrate,aswellasuniformqualityofconcreteattheendoftheline;andforcleaningoutpipelines.Thisreportdoesnotcovershotcretingorpumpingofnonstructuralinsu-latingorcellularconcrete.Keywords:admixtures;aggregategradation;aggregates;cementcontent;coarseaggregates;concreteconstruction;concretes;conveying;couplings;fineaggregates;finenessmodulus;lightweightaggregateconcrete;light-weightaggregates;mixproportioning;pipeline;placing;placingboom;pozzolans;pumpedconcrete;pumps;qualitycontrol;watercontent.CONTENTSChapter1—Introduction,p.304.2R-2Chapter2—Pumpingequipment,p.304.2R-22.1—Pistonpumps2.2—Typesofvalves2.3—Trailerpumps2.4—Truck-mountedconcretepumps2.5—Placingbooms2.6—Specializedequipment2.7—SafetyChapter3—Pipelineandaccessories,p.304.2R-53.1—Generaldescription3.2—Systempressurecapacity3.3—Rigidplacingline—Straightsections,bends,andelbows3.4—Systemconnection3.5—Flexiblesystem—Hosetypesandapplications3.6—ConcreteplacingsystemaccessoriesChapter4—Proportioningpumpableconcrete,p.304.2R-104.1—Basicconsiderations4.2—Normalweightaggregate4.3—Lightweightaggregateconcrete4.4—Waterandslump4.5—Cementitiousmaterials4.6—Admixtures4.7—Fiberreinforcement4.8—Trialmixes4.9—TestingforpumpabilityChapter5—Fieldpractices,p.304.2R-205.1—General5.2—Pipelineconcreteplacement5.3—PoweredboomplacementPlacingConcretebyPumpingMethodsReportedbyACICommittee304NeilR.Guptill,ChairmanDavidJ.AkersRobertA.Kelsey*JamesS.PierceCasimirBognacki*JohnC.KingPaulE.ReinhartJamesL.Cope†WilliamC.KrellRoyceJ.Rhoads*MichaelGardnerGaryR.MassKennethL.SaucierDanielJ.Green*PatrickMcDowellPaulR.StodolaTerenceC.HollandDipakT.ParekhWilliamX.Sypher*ThomasA.Johnson*RogerJ.Phares*RobertE.Tobin*SamuelA.KalatKevinWolf*Memberofsubcommitteethatpreparedthisreport.†Chairmanofsubcommitteethatpreparedthisreport.ACI304.2R-96supersedesACI304.2R-91andbecameeffectiveJanuary1,1996.Copyright©1996,AmericanConcreteInstitute.Allrightsreservedincludingrightsofreproductionanduseinanyformorbyanymeans,includingthemakingofcopiesbyanyphotoprocess,orbyanyelectronicormechanicaldevice,printedorwrittenororal,orrecordingforsoundorvisualrepro-ductionorforuseinanyknowledgeorretrievalsystemordevice,unlesspermissioninwritingisobtainedforthecopyrightproprietors.304.2R-1ACICommitteeReports,Guides,StandardPractices,DesignHandbooks,andCommentariesareintendedforguidanceinplanning,designing,executing,andinspectingconstruction.Thisdocumentisintendedfortheuseofindividualswhoarecompetenttoevaluatethesignificanceandlimitationsofitscon-tentandrecommendationsandwhowillacceptresponsibilityfortheapplicationofthematerialitcontains.TheAmericanCon-creteInstitutedisclaimsanyandallresponsibilityfortheappli-cationofthestatedprinciples.TheInstituteshallnotbeliableforanylossordamagearisingtherefrom.Referencetothisdocumentshallnotbemadeincontractdocu-ments.IfitemsfoundinthisdocumentaredesiredbytheArchi-tect/Engineertobeapartofthecontractdocuments,theyshallberestatedinmandatorylanguageforincorporationbytheAr-chitect/Engineer.304.2R-2ACICOMMITTEEREPORTFig.1—PistonpumpandpoweredvalvepumpingtrainChapter6—Fieldcontrol,p.304.2R-24Chapter7—References,p.304.2R-247.1—Recommendedreferences7.2—Citedreferences7.3—OtherreferencesAppendix1—Metric(SI)systemadaptation,p.304.2R-25CHAPTER1—INTRODUCTIONACIdefinespumpedconcreteasconcretethatistransport-edthroughhoseorpipebymeansofapump.Pumpingcon-cretethroughmetalpipelinesbypistonpumpswasintroducedintheUnitedStatesinMilwaukeein1933.Thisconcretepumpusedmechanicallinkagestooperatethepumpandusuallypumpedthroughpipelines6in.orlargerindiameter.Manynewdevelopmentshavesincebeenmadeinthecon-cretepumpingfield.Theseincludenewandimprovedpumps,truck-mountedandstationaryplacingbooms,andpipelineandhosethatwithstandhigherpumpingpressures.Asaresultoftheseinnovations,concreteplacementbypumpshasbecomeoneofthemostwidelyusedpracticesoftheconstructionindustry.Pumpingmaybeusedformostconcreteconstruction,butisespeciallyusefulwherespaceforconstructionequipmentislimited.Concretepumpingfreeshoistsandcranestode-livertheothermaterialsofconstructionconcurrentlywithconcreteplacing.Also,othercraftscanworkunhamperedbyconcreteoperations.Asteadysupplyofpumpableconcreteisnecessaryforsat-isfactorypumping.1Apumpableconcrete,likeconventionalconcrete,requiresgoodqualitycontrol,i.e.,uniform,proper-lygradedaggregate,materialsuniformlybatchedandmixedthoroughly.2Concretepumpsareavailablewithmaximumoutputcapacitiesrangingfrom15to250yd3/hr.Maximumvolumeoutputandmaximumpressureontheconcretecannotbeachievedsimultaneouslyfrommostcon-cretepumpsbecausethiscombinationrequirestoomuchpower.Eachfootofvertic
本文标题:ACI 304.2R-96 Placing Concrete by Pumping Methods
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