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1、FabricatingaWatertightPrecastConcreteSepticTank DanWagner MilanVault Inc SEPTICTANKQUALITIES Whatqualitiesdowewantinaseptictank COST BENEFIT DEPENDABLE ECONOMICAL Barneybuysaconcreteseptictank ComponentsofWatertightness EngineeringandDesignManufacturingQualityAssuranceandTestingInstallation Thesepti
2、ctankmust WithstandallloadingconditionsSurfaceSurchargeConcentratedwheelloadsLateralLoadsSoilBearingCapacity DesignConsiderations NOTRAFFIC NOLOADS ASTMC1227LOADS LIGHTTRUCKTRAFFIC Theseptictankmustnotbebuoyant itmustnotfloat DesignConsiderations DesignSpecifications Tanksshouldbedesignedatleastto A
3、STMC1227StdandardSpecificationforPrecastConcreteSepticTanksASTMC890StandardPracticeforMinimumStructuralDesignLoadingforMonolithicorSectionalPrecastConcreteWaterandWastewaterStructuresLocalCodes CSAB66 IAPMO ANSI ManufacturingandInstallation NPCADesignRecommendations Minimumconcretethicknessforcondit
4、ionsCleanformsingoodconditionsProperreinforcementplacementPrepourandpostpourinspectionsAwelldesignedconcretemixProperfinishingandcuringLiftinginsertsdesignedwithS F 4min ProperlySealedjointsandfittings TheManufacturingProcess RawMaterialsMixDesignReinforcementProductionPractices Seals Fittings andJo
5、ints Post PourOperations RawMaterials Usequality certifiedmaterialsAggregatesCementWaterAdmixtures MixDesignforWatertightness LowWater CementitiousRatio Amaximumof0 45 weightofwater weightofcementandpozzolans Minimum4 000psistrengthat28daysMinimumstrengthwhenshipped Qualitymaterials wellgradedaggreg
6、atesVolumetricproportioning ACI211 Airentrainment WATER STRENGTH POROSITY Aggregates Compriseofabout70 ofthetotalvolumeConformtoASTMC33CleanandwellgradedFreefromdeleterioussubstancesMoisturecontentcheckeddailyProperlyhandledandstored EntrainedAir DesirableImprovesfreeze thawresistance ASRresistance
7、sulfateresistanceImprovesworkabilityEntrappedAir Non desirableBugholesReleasedthroughadequatevibration AirContent PurposeofReinforcement ConcreteisstrongincompressionbutweakintensionReinforcementsuppliesstrengthtowithstandtensileandshearforcesexperiencedbyconcreteSometimestanksexperiencegreatestforc
8、esduringstripping handling andtransporting Non reinforcedConcreteBehavior ReinforcedConcreteBehavior ReinforcementRequirements MeetASTMrequirements A615orA706 DesignedtowithstandallloadingconditionsProvideadequatecovertoprotectfromcorrosion 1 min ASTMC1227 Spacedproperly nottouchingformwork REBARSHO
9、WING Visibleproblems RebarTouchingForm Whatitshouldlooklike Pre PourOperations Pre Pouractivitiesinclude SettingofformworkFormsmustbecleanedandinspectedaftereachusePositioningofsteelreinforcementPositioningofBlockoutsPositioningofembeddeditems i e liftingapparatus CastingConcrete Placementofconcrete
10、isimportantConsolidatingConcreteInsufficientvibrationleadstopoorconsolidation excessivevibrationcausessegregationPropervibrationtechniquesleadtosmooth densesurfacesthatpromoteimpermeability Curing Propercuringisimportantindevelopingstrength durability andwatertightnessTwocriticalelementsincuringMain
11、tainingCorrectMoistureMaintainingConcreteTemperatureNote ACI305HotWeatherConcretingACI306ColdWeatherConcreting PostPourPractices SufficientStrengthforstrippingHandletoreduceoreliminatedamagePerformapostpoorinspectionMarkthecastingwithallrequiredinformationStoreproducttopreventdamageinstorage TANKSEA
12、M JOINTSEAL 3 8 maximumgapbetweentwomatingjointsurfacesBEFOREsealantisapplied ASTMC1227 05Section10 3 PROOFTESTING ASTMC1227 10a9 1Prooftestingisusedtodemonstratethestrengthofthetanktoresistanticipatedexternalandinternalloads 9 1 1Prooftesting whenrequiredbythepurchaser shallbeperformedinsuchawayast
13、osimulatetheactualanticipatedloads PROOFTESTING CalculateforanticipatedactualloadsInternalandexternalSoilloads lateralearthloadsWeightoftankUseliveloadatthesurfaceof300lb ft2unlessheavierloadsareanticipated Prooftestto150 oftheanticipatedactualloads ProofTesting Vacuum With300psfLiveLoadfromASTMC 12
14、27 ProofTesting Vacuum TopLoads 540psf x150 810psfFloorLoads 715psf x150 1 073psfWallLoads 180psf x150 270psf Sincethefloorloadisthehighestloadforce itcanbeusedforvacuumtesting 1 073psf 14 9 Mercury With300psfLiveLoadfromASTMC 1227 AlternativeLoads Typicalloadsforaseptictankare SoilsInternalfluidsEx
15、ternalsoil saturatedsoilsWeightoftankIncidentalloadsfromavehicle ProofTesting Vacuum Withaconcentratedwheelloadof2 250pounds ProofTesting Vacuum TopLoads 325psf x150 488psfFloorLoads 500psf x150 750psfWallLoads 220psf x150 330psf Sincethefloorloadisthehighestloadforce itcanbeusedforvacuumtesting 750
16、psf 10 4 Mercury Better Withaconcentratedwheelloadof2 250pounds ProofTesting Alternative Placetankonabedofsand about3 4 Vacuumtestforthewallloads330psfor4 6 ofmercuryAddweighttothetoptosimulatetheadditionalliveandsoilloads 750psf 330psf 420lbs ft2Add1 680lbs 4ft2x420lbs ft2 ona2 x2 areaincenterVoluntaryprooftestinginOhio approvedbyODH4 mercury 2 000lbs ona2 x2 area AreaforAdditionalWeight 2 x2 Footprint TestinginAction Vacuum TestinginAction WatertightTesting VacuumTesting4 ofMercury Hg for5minu
