CONCRETE TANKS...A typical prestressed concrete tank floor consists of the following features: • A cast-in-place, highly reinforced, concrete floor with a slight upward slope to

CONCRETE TANKS

AWWA D110 Type I

DURABILITY

TO COMEFor more than 90 years, DN Tanks has constructed liquid storage tanks to provide you with a reliable water source when you want it, and more importantly, when you need it. It is not just our passion; it's our legacy.

We are a solutions-focused company and back our tanks with employees who are committed from inception through construction and beyond to give you the best solution for your system.

When considering your community's potable water source, fire suppression system, wastewater and recycled water containment and all your system storage needs, think of DN Tanks.

Site Preparation Floor & Footings Wall Construction Roof Options

Vertical Prestressing

Abrasive Blasting Circumferential Prestressing

Advanced Technology

Automated Shotcrete

Appurtenances Tank Rendering DN Tanks Showcase

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Key Attributes of a DN Tanks AWWA D110 Type I Prestressed Concrete Tank

•Tank Capacities —from40,000gallonsto

50milliongallons(MG)andmore.

•Custom Dimensions —waterheightsfrom8’

toover100’anddiametersfrom25’toover400’.

•Siting Options —atgrade,partiallyburied,

differentiallyback-filled(hillsides)andfully

buried(withmulti-usecapabilities).

•Seismic Resilience —provenperformance

throughLomaPrieta,NisquallyandNorthridge

earthquakes,tonameafew.

•Durability —regardlessofweatherextremes,

provenreliabilitythroughextremefireand

freezethawevents.

•Bi-axial Wall Compression —provides

longevity,durabilityandliquidtightness.

•Reinvesting in the Local Economy —useof

materials,laborandequipmentfromwithin

thecommunity.

•Enhanced Water Quality —concreteinherently

insulates,keepingliquidsatamoreconsistent

temperature.

•Best Long-term Value —ourtanksspeak

forthemselves.Nocoatingsrequired,which

eliminatesroutinemaintenancecosts

anddowntime.Requestalifecyclecost

analysistoday.

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SITE PREPARATIONAproperlypreparedsubgradeisessentialtotankconstruction.Beforethestructuraltank

designbegins,alicensedgeotechnicalengineerpreparesasite-specificgeotechnical

report.Thereportprovidesdesignparametersthatincludebearingcapacity,anticipated

settlements,seismiccriteria,andrecommendedsubgradeandfoundationpreparation.

•Subgradepreparationforeachtankis

completedinaccordancewiththecivilsiteplans

andthesite-specificgeotechnicalreport.

•Pipingconnectionsthatpenetratethrough

thefloor(e.g.,inlet,outlet,overflow,etc.)are

encasedinunderslabconcretepipeblocks.

•Awaterstopisincorporatedbetweenthe

floorandpipeblocktoensurealiquid-tight

connection.

•Wallandroofpipepenetrationscanbeeasily

incorporated.

FLOOR & FOOTINGSA typical prestressed concrete tank floor consists

of the following features:

• A cast-in-place, highly reinforced, concrete floor

with a slight upward slope to the center allows

for drainage.

• Monolithic or large section pours limit joints

to improve tank performance and achieve

construction efficiency.

• A thickened perimeter wall footing transmits the

concentrated wall loads to the subgrade beneath.

• A permanent PVC waterstop at all joints for

water tightness.

• Seismic base restraint cables are developed into

the perimeter footing to account for site-specific

seismic loading.

• Experienced field crews place the concrete and

ensure it is vibrated, screeded and finished to

meet the project specifications.

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CAST-IN-PLACE WALL CONSTRUCTIONPrestressedconcreteplacessteelintensionandconcrete

incompression,allowingforbothmaterialstoresistforces

intheiridealstates.Thecorewallisdesignedtoaccountfor

project-specificparametersandloadings.Atypicaltankcorewall

consistsofa10"minimumuniformthickness.Forlargercapacity

tanks,wallsmaybethickerandtaperedontheinsidefaceto

accommodateincreasedloads.

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FeaturesofanAWWAD110TypeIWall

Enhanced Operational and Seismic Performance•“Anchoredflexiblebase”connectionbetweenthefloorand

wallenhancesductilityandreducesbendingmomentsfrom

hydrostatic,thermalandseismicforces,allowingthese

structuralelementstoactindependently.

•Seismicbaserestraintcablesanchoredintothefootingextend

intothecorewall,providingloadtransferduringaseismicevent.

Quality Control•Circumferentialwallformscurvedtothespecifictankradius

areequippedwithequallyspacedpourwindowstoenhance

qualitycontrol,reduceoveralldropheight,andalloweaseof

accessforconcreteplacementandvibration.

•50'widecircumferentialsectionsarepouredatfullheight.

•Rebarcongestionissignificantlyreduced,promotingmore

efficientinspectionandconcreteplacement.

Liquid Tightness and Durability•Verticalprestressingthreadbarscastinthewallprovide

verticalcompressionandminimizeverticalbendingmoments

causedbydifferentialtemperatureanddrynessconditions.

•Horizontaljointsareeliminatedandverticaljointsare

minimizedtoprovidesuperiorwatertightness.

•AllconstructionjointsincorporatepermanentPVCwaterstops.

ROOF OPTIONSPrestressed concrete tanks can be designed with a variety of roof options.

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Flat Roof Features•Low-profile,cast-in-place,two-wayflatslabroofminimizesvisibility.

•Optiontoburyoraccommodatemulti-usestructuressuchasparks,recreationfacilities,pumpstations,etc.onthetankroof.

•Ananchoredflexiblewall/roofconnectionallowsforthermalexpansionoftheroofslabwhilealsoprovidingseismicrestraint.

•Evenlyspacedconcretecolumns,designedwithdroppanelsandfootings,supporttheroofandtransferthecorrespondingloads.

•Aslightupwardslopetothecenter,matchingthefloor,providesdrainage.

Dome Roof Features•Aclear-spanningconcretedomewithnointeriorsupportsorobstructionscaneasilyaccomodatevariousequipmentneeds.

•Typicaldomeheightis10%ofthetankdiameter.

•Continuousreinforcementisincorporatedinbothradialandcircumferentialdirections.

•Circumferentialprestressingappliedatthedomeringplacesthedomeinpermanentcompression.

AWWAD110TypeItanksincorporatevertical

prestressingthreadbarswithinthewalltoprovide

verticalcompressionandcounteractbending.

Features include:•High-strengthsteelthreadbarsareeither1¼"or1¾"

diameter,dependingoncorewallthickness.

•Threadbarsareequippedwithascrewed-onnutanchor

atthetopandbottomtoeliminatestressconcentrations.

•EachthreadbarishousedinsideofarigidPVCpipeto

allowforproperinstallation.

•Ahydraulicramisusedtotensionthethreadbarsafter

theconcretewallsarepoured.

•Threadbarsaretensionedto137or173kipsforthe

respectivediameter,withatightforcetoleranceof1.5%.

•Forceandelongationrecordingsareelectronicallyand

instantaneouslyproducedforeachverticalthreadbar,

documentingtheappliedstress.

•Aftertensioning,threadbarsarepressure-groutedfrom

thebottomupwithatwo-partepoxytoachieveafully

bondedsystemandcorrosionprotection.

VERTICAL PRESTRESSING

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ABRASIVE BLASTINGPriortostartingcircumferentialprestressingandshotcreteoperations,DNTanksuses

anadvancedabrasiveblastingsystemtoroughentheexteriorcorewallsurface.

System features include:•Automatedhydroblastingapplieswaterata

highpressureofupto40,000psitoetchthe

walltoapreciseroughenedfinish,providing

asuperiorbondingsurface.

•Anautomatedsystemreducesjobsitehazards,

optimizesconstructionscheduleandprovides

aconsistentfinish.

•Hydroblastingisenvironmentallyfriendly,

asitrequiresverylowwaterusageand

eliminatesdust.

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CIRCUMFERENTIAL PRESTRESSINGCircumferentialprestressingistheheartofthetankstructure,counteractingtheliquidloadand

placingthetankwallin200psiresidualcompression.DNTanksprovidessignificantindustry

advancements,includingtheautomatedmachineapplicationoftensioned,hot-dipgalvanized,

⅜"diameter7-wirestrand.

Byplacingthestrandintension,andtherebytheconcretewallincompression,theprestressed

concretetankincorporatesbothmaterialsintheiridealstates.

DN Tanks Automated Strand-wrapping

• Improved accuracy and efficiency

• Tighter force tolerance

• Electronic spacing and recording

• Fewer splices

• Increased shotcrete bond

• Greater safety factor

• First and only company to design and apply

strand to exceed the AWWA requirement

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ADVANCED

Ourstate-of-the-artcircumferentialprestressingequipment

isabletoperformmultiplesophisticatedtaskswithone

simple,automated,quality-controlledunit.

ELECTRONIC MONITORING & CONTINUOUS RECORDINGContinuouselectronicrecordingandinstantaneous

self-correctingforceapplicationareessentialto

ensuretheproperstressisappliedtotheprestressed

steel.Theprestressedsteelplacestheconcreteinto

permanentcompressionandresistsallhydrostatic

loads.Itisimperativethatthestressisapplied

accurately.Theautomatedsystemoffers:

•Computerized,continuouselectronicforcereadings

forthehighestqualitycontrol

•In-linecalibration,allowingforinstantaneouscontrol

oftheforceapplied

•Arecordoftheforcereadingssubmittedtotheowner,

providingconfidencethatthemostcriticalpartofthe

hydrostaticresistancehascorrectlybeenapplied

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AUTOMATED SHOTCRETEThe advanced technology of the automated shotcrete process

is proven to preserve the integrity of a DN Tanks structure by

providing corrosion protection and a permanent bond.

Features of Automated Shotcrete• Control of numerous variables such as uniform distance, angle, and

applied thickness on large surface areas ensures complete encapsulation

of the prestressing strand as well as a proper bond to the corewall.

• Wet-mix shotcrete applied from a nozzle mounted on a mechanized tower

travels at a controlled uniform speed and path.

• A minimum final shotcrete cover of 1.5 inches is applied and built up

in multiple layers.

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APPURTENANCESPrestressedconcretetankscanaccommodatea

varietyofaccessories,suchasroofandwallaccess

hatches,interiorandexteriorladders,vents,safety

railings,level-sensingequipment,orspecialized

securityhardware.Ourexperiencedteamcanhelp

recommendandinstallappurtenancestomeet

specificprojectrequirements.

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PVC Waterstop

Elastomeric Wall-base Bearing Pad

Tank Foundation

Vertical Prestressing Threadbars Housed in PVC Pipe

Cast-in-Place Concrete Corewall

Seismic Base Restraint Cables

Continuous Circumferential Reinforcing

3/8" Ø 7-Wire Galvanized Circumferential Prestressing Strand

Shotcrete Encasement

Roof Shear Can

Wall Shear Can

Elastomeric Wall-top Bearing Pad

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Center Pin

Base Unit and Engine

7-Wire Galvanized Strand Reel

Automated Shotcrete Arm and Nozzle

Adjustable Tower

Stressing Head

Operations Cabin

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DN TANKS SHOWCASE

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STRONG

855.368.2657 | DNTANKS.COM

DNTankshas10regionalofficesand3operationsfacilitieslocatedinGreaterBoston,MA•Dallas,TX•SanDiego,CA

May 2019.©2019DNTanks.Allrightsreserved.DNTanksisaregisteredtrademarkofDNTanks.