case study of absolute tower

7/29/2019 case study of absolute tower

1/9

CTBUH

Technical Paperhttp://technicalpapers.ctbuh.org

Subject: Building Case Study; Architecture/Design; Structural Engineering; Construction

Paper Title: Case Study: Absolute World Towers, Mississauga

Author(s): Lagendijk, Bas1

Pignetti, Anthony & Vacilotto, Sergio2

Affi liation(s): 1MAD Architects

2Dominus Construction Group

Publication Date: 2012

Original Publication: CTBUH Journal 2012 Issue IV

Paper Type: 1. Book chapter/Part chapter

2. Journal paper

3. Conference proceeding

4. Unpublished conference paper

5. Magazine article

6. Unpublished

Council on Tall Buildings and Urban Habitat/Author(s


2/9

Tall buildings: design, construction and operation | 2012 Issue IV

Inside Canadas Marilyn Towers

Creating an Energy-Producing Skyscraper

Fluid-based Aerodynamic Performance

Ice, Snow and Tall Buildings

Assessing Koreas Technology Potential

Talking Tall with Bjarke Ingels

In Numbers: Canada Rising

Reports: Shanghai Congress & 2012 Awards

CTBUH JournalInternational Journal on Tall Buildings and Urban Habitat


3/9

Inside | 3CTBUH Journal | 2012 Issue IV

The challenges associated with the inherentinconsistency of air ow may open a new way ofthinking about tall buildings as highly adaptive,

dynamic systems capable of responding to the

opportunities and challenges associated with

spatially and temporally uctuating resources.

Menicovich et al., page 18

News and Events

This IssueDennis Poon

CTBUH Trustee

CTBUH LatestAntony Wood

CTBUH Executive Director

Debating Tall:Tall Buildings: A Sustainable

Future for Cities?

Global NewsHighlights from the CTBUH

global news archive

02

04

05

06

Case Study

Absolute World Towers,MississaugaBas Lagendijk, Anthony

Pignetti & Sergio Vacilotto

12

Research

A Diferent Approach to theAerodynamic Perormanceo Tall Buildings

David Menicovich; JasonVollen; Michael Amitay; Chris

Letchford; Edward DeMauro;

Ajith Rao & Anna Dyson

Increasing Problems oFalling Ice and Snow onModern Tall BuildingsMichael Carter & Roman

Stangl

A Proposal to Create anEnergy-Producing Megatallor Kunming, China

Thomas Kraubitz

Assessing PotentialDevelopment in SouthKoreas Supertall BuildingTechnologyPayam Bahrami, David Scott,

Eun-Ho Oh & Young-Ho Lee

18

24

30

36

Features

Tall Buildings in NumbersCanada Rising

Talking Tall: Bjarke Ingels hasBIG Plans or Tall BuildingsBjark Ingels

Design ResearchCTBUH International Student

Design Competition 2012

40

42

46

CTBUH

48

52

55

55

56

57

58

59

Inside

48

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48 | CTBUH 9th World Congress Shanghai CTBUH 9th World Congress Shanghai | 49C TB UH J ou rn al | 20 12 I ss ue I V C TB UH J ou rn al | 20 12 I ss ue I V

WhenShanghaiViceMayorShenJuntookthe

stagetooffi ciallyopentheCTBUH 9th World

Congress,hequicklysetthetonefor the

issuesthatwoulddominatethenextthree

daysofdiscussionanddebate.Land

resourcesarenotrenewable,Mr.Junsaid.We

havenochoicebuttobuildhighrises tosave

landeffi ciently.Tallbuildings,heemphasized,

mustserveassolutionstoChinaslong-

standingurbanissuesofpollutionand

over-crowding.Itisan urgentandcriticaltask

tomeetthesechallenges.

World Congress Draws Global IndustryLeaders to Address Key Issues

(Left to right) QingWei Kong,Shanghai Tower;Timothy Johnson,CTBUH Chairman;

Shen Jun,Shanghai ViceMayor;Antony Wood,CTBUH ExecutiveDirector;Guo QingLi,Tongji University.CTBUH

ReportbyKevinBrass, CTBUHPublicAairsManager

CTBUH Report: CTBUH 9th World Congress Shanghai

Working GroupsShanghaiprovidedanopportunityforthe

CTBUHsarrayofworkinggroupstogather

andplotstrategyfornewandon-going

projects.Thesessionswhichtookplacethe

daybeforethecongressincludeda

roundtablemeetingofCTBUHleaders,

whichattractedmorethan30active

representativesfromaroundtheworld.The

rousingdiscourseprimarilyfocusedonthe

fledglingcityrepresentativeprogramand

thebestwaystogrowthe Councils

initiativesonagrassrootslevel.

Twooftheworkinggroupstoutedthe

releaseofnewtechnicalguides Outrigger

TheballroomoftheGrandHyattJin Maowas

packedtocapacityfortheopeningceremo-

nies.TheCongresssoldoutweeksbeforethe

opening,with850registereddelegatesfrom

43countriesinattendance,includingmanyof

thetopdevelopers,architects,engineersand

buildingownersfromChinaandaroundthe

world.Wepurposelybroughttogethera

widerangeofexpertiseandviewpoints,

includingthedevelopersthatareleadingthe

tallbuildingboominAsia,saidCTBUH

ExecutiveDirectorAntonyWood.

TheCTBUH9 th WorldCongressclosedto ravereviews, after threedaysof in-depth presentations, livelypanel

discussionsandnetworkingevents.

Asiawasthecenterpieceofthe event,which

wastitled, AsiaAscending:theAgeofthe

SustainableSkyscraperCity,butdiscussions

inevitablyfocusedonissuesaffectingcities

andbuildersaroundtheworld.Fromthe

outset,CTBUHChairmanTimothyJohnson,a

designpartneratNBBJ,challengedthe

audience.Letsfindnewwaystomake

buildingsmoresustainable,hesaid.Letsbe

innovative.Letsfindwaystochangetheway

wethinkoftall buildings.

Attendeesopenlyexchangedideasandtheir

experiences,providingauniqueopportunity

togobehindthescenesat manyofthe

worldsbiggestandmostinnovativeprojects.

Wehopebysharingourexperienceand

insightintothebuildingsystemwewould

makeacontributiontosustainablesupertall

buildingsintheworld,saidQingWeiKong,

ShanghaiTowerChairman,strikingachord

thatwouldresonatethroughouttheevent.

ShanghaiTowersaspirationsgofarbeyondits

height.Thedeveloperswanttomakeitthe

mostsustainablebuildingintheworld,with

greenareasandadesignthatmakesit a

comfortableandeffi cientpartofShanghais

changinglandscape.

Sustainabilityandtheneedto createeffi cient

andwell-organizedprojectsthatintegrate

andenhancetheurbanenvironmentwere

Richard Tomasetti ofThornton Tomasetti,Vincent TseofParsons Brinckerho;RafaelVinly and Tony LongofCBRichard Ellis engaged in thepanel discussion.CTBUH

Traditional dragon dancetroupeperformanceat theopeningceremony.CTBUH

DesignforHighRisesBuildingsreleasedby

theCTBUHOutriggerWorkingGroup,and

NaturalVentilationinHigh-RiseO ce

Buildings,aproductof theCTBUH

SustainabilityWorkingGroup(see

advertorialonpage51.)Theotherworking

groupsBuildingInformationModeling;

Fire&LifeSafety;Research,Academic&

Postgraduate;SeismicDesignandWind

Engineeringfocuseddiscussionson

developingresearchprojectsandthebest

waystosharethelatestinformationintheir

respectivefields.

consistentthemes.Speakersfocusedonthe

complexitiesofdevelopinglargeprojects,

fromenergycostsandprojectmanagement

tothepoliticalinfluenceoniconicprojects.

Weneedtowork togethertofindabalance

betweeniconicdesignandsustainability,said

MehdiJalayerian,executivevicepresidentof

EnvironmentalSystemsDesign,duringa

rousingpaneldiscussionontheopportunities

andbarrierstosustainability.Theyclashat

somepoint.

Delegatessharedinformationanddesignsfor

thelatestprojects,aswellasthe challenges

projectsarefacingaroundtheworld.Over

andoveragain,speakersemphasizedthattall

buildingsarestillayoungtypologyandthe

industryisstillwrestlingwiththeissuesof

creatingeffi cientprojectsthataddressthe

needsoffast-growingcities.

Thisisahugechallengeforus. Itisstillnota

maturebusinessmodelinChina,saidZhaohui

Jia,generalmanageroftheGreenlandGroup,

oneofthelargestdevelopersoftall buildings

inChina.Wearestilltryingto explorethis

businessmodel.

Tallbuildingsstillplayauniqueroleincities,a

pointbroughthomebytheplenarysession

featuringtheowners/developersbehindthe

past,presentandfutureworldstallest

building.Attendees oftheGlobal Leaders workshop.CTBUH

Attendees ofthesold out Congress listen to theDay 2 plenary session presentations.

CTBUH

CTBUH 2012Student Competition winner Alexis DeBosscher;Johannes deJong,KONE;Chris Wilkinson,Wilkinson Eyre.CTBUH

Timothy Johnson issues research seed fundingcheckto winner Dr.Kristen Day,New York University with LiHongyu from sponsor AECOM.CTBUH

Skyscrapers We

purposely broughttogether a wide range

of expertise and

viewpoints, including

the developers that are

leading the tall

building boom in

Asia.

24 | Climateand Environment Climate and Environment | 25C TB U H J ou rn al | 20 12 I ss ue I V C TB UH J ou rn al | 20 12 I ss ue I V

Background

Troublesomeiceandsnowformationson

buildingsareinnowayanew phenomenon.

Buildingdesignersandownershavelong

struggledwiththevariousaspectsofwinter

precipitation.Thishasledto thedevelopment

ofstandardsandcodestoaddresssuchtopics

aswindloadsandsnowloadsduringbuilding

design.However,theaspectoffalling,sliding

orwindblowniceandsnowfroma buildingis

atopicthathasnotbeen widely

acknowledged,andconsequentlyhas

generatedlittleinthewayof standards,

guidelinesorprescriptivebuildingcode

requirementstoassistdesigners.Inaddressing

concerns,designershavelargelyreliedon

pastexperienceortrialanderrormethodsfor

reducingpotentialrisks.Thelearningprocess

industry-widehasbeenslowornon-existent

duetothereluctantnatureofvariousparties

todiscusserrorsorincidents,forfearof

litigation.Opendiscussionoftheissueswill

acceleratethelearningprocessaroundthe

emergingproblemscreatedbyadvancing

faadeperformanceandtallbuildingdesign.

Modern Towers,New Issues

Thefaadesofsomerecentlycompletedhigh

performancebuildingsareactivelypromoting

hazardousiceandsnowformationsunder

typicalwinterconditions,ratherthanunusual,

severeorinfrequentweatherconditions.This

realizationisunnerving,asmodernhigh

performancebuildingsoftenshowonly

modestorquestionablereductionsinenergy

usage,attimesfallingshortoftheirprediction

models.Furthermore,buildingcodesand

Increasing Problems of Falling Ice and Snowon Modern Tall Buildings

Reportedincidentsof hazardousiceandsnowfalling frombuildingsareon

therise, specificallyfor recentlycompletedtallbuildings. High performance

faadeshaveimprovedinternalthermalperformance, butincreasedthe

conditionsfor formingiceon metalandglassskins. Thispaper shedslighton

theissues, describingthefactorsthat contributeto icingandhazardousice

andsnowformation, andprovidesmethodsto addresstheseissueswithin the

design process.Michael Carter

Table1.BuildingEnvelopeRequirements ASHRAEStandard 90.12004 2010Comparison (Table5.5-4,BuildingEnvelopeRequirements for ClimateZone4-Non-Residential) ASHRAE

Research: Climate and Environment

Roman Stangl

Authors

Michael Carter, Director/ConsultantRoman Stangl, Director/Project Manager

Northern MicroclimateInc.(NMI)

33Water Street N.P.O.Box 277CambridgeOntario N1R 5T8Canada

t:+12264440188f:+12264440183e:[email protected];

[email protected]

Michael CarterMichael is a director and thelead technical consultantofNorthern MicroclimateInc.,an architecturalconsultingrm that focuses on theprediction,evaluation and mitigation offallingiceand snow.Hehas contributed to publications with theNational InstituteofBuildingSciences,ConstructionSpecications Canada and theInternationalConferenceon Snow Engineering.Recognized as anexpert in his eld,Michael works with architecturaland engineeringrms,focusingon his ability tovisualizeand interpret thecharacteristics ofabuildingdesign within its local micro-climate.

Roman StanglRoman is a director and thelead project managerofNorthern MicroclimateInc.A CTBUH memberwith international experience,hehas been activelymanagingand consultingwithin thedesign andconstruction eld since2005.Roman has contributedto publications with theNational InstituteofBuildingSciences,Construction Specications Canada and theInternational Conferenceon Snow Engineering.

Figure1.Exampleofsnow and icefreezingon visionglass panel.NMI

High performance

faades have improved

internal thermal

performance, but

increased the

conditions for forming

ice on metal and glass

skins

standardshaveshownatrendtowards

increasingtheperformanceofroof,wall,and

glassassemblies,asevidencedbycomparing

ASHRAEStandard90.1betweenthe2004 and

2010versions(seeTable1). Further

exacerbatingtheissueoficeandsnow

formationsonfaadesistheadditionof

variousexteriorelementsintendedtocontrol

solargain,whichultimatelyserveascold

collectionsurfaces.Asa result,reportsof

fallingiceandsnowincidentsfromhigh

performancebuildingsoverthelasttenyears

haveshownanincreaseinthefrequencyand

severityofhazardousiceandsnowformation.

Althoughformalrecordsoffallingiceand

snowincidentreportsdonotyetexist,this

trendhasbeenidentifiedthrougharecordof

mediaaccountsandprojectexperience.New

reportsinthelasttwoyearshavedetailed

dozensoffalling,slidingorwindblowniceand

snowincidentsinNorthAmericaalone,

includingsuchbuildingsastheDuke Energy

BuildinginCharlotteandtheNewYorkTimes

BuildinginNewYork.

Manyoftheeventsinvestigatedbythe

authorshavenotbeenfoundtobe causedby

asingleinfluencingfactor,butratherbyalist

offactorsthattendtohave acumulative

effect.True,therearesituationswhereasingle

designfeature,suchasawindowsill/mullion

configurationora solarshadedevice,hashad

asignificantimpactontheformationof

hazardousiceandsnow.However,overthe

courseofnumerousbuildinginvestigations,

whichincludesmultiplecoldroomlaboratory

testsconductedincollaborationwiththeU.S.

ArmyColdRegionsResearchandEngineering

Laboratory(CRREL),thisisfoundtobethe

exceptionratherthantherulewhenitcomes

tonewlycompletedhighperformance

buildings.

Inthesimplestofexplanations,thecurrently

achievedreductionsinheatlossfrommany

buildingsinteriorsarepromotinganincrease

inpotentiallydangerousiceandsnow

formations.Asinsulationvalues,glass

technology,andbuildingsystemsprogressin

thefuturetoconserveenergy,the

correspondingfurtherreductionsinheatloss

throughthefaadewillonlyincreasethe

probabilityofhazardousiceandsnow

formationandrelease,creatingsignificant

challengesforbuildingdesigners,ownersand

operators,withfurtherimpactstopublic

safety.Consequently,investigationand

researchintothecausesoftheseissuesis

neededandisongoing.However,atthistime

empiricaldataand/ordetailedcasestudies

havenotbeendevelopeddueto the

reluctanceofbuildingownersanddesigners

todiscusstheirchallengesopenly.

Thefollowingcaseexamplesarebasedon

interviewswithbuildingownersand

operatorsofrecentlycompletedbuildings,

combinedwithreviewsofincidentandcold

roomtestreports.Thecasesrevealinteresting

datathatinitiallyseemedcounterintuitive,

butcanbeexplainedwhenthe individual

designdetailsareinvestigated.

CaseExample1

BuildingType:Tall,HighPerformance

Location:NortheasternUnitedStates

Inthisexample (seeFigure1), observationsof

icesheetswerereportedtoform inthecenter

ofverticalvisionglassofarecentlycompleted

building,andwouldsubsequentlyreleaseand

falltothebusystreetbelow.Thisreport was

takenwithsomeskepticismasheatloss

characteristicsofatraditionalwindowand

framerelationshipcallfortheexteriorskin

temperatureofthecenterofthe windowto

bethewarmestlocation,sinceitis the

furthestfromtheinfluenceofthe framethat

wouldtypicallyhavetheadvantageof

insulationorathermallybrokenprofile.

However,inthisparticularcasethelarge

insulatedglasspanelsofferedanimproved

thermalperformanceovertraditionalglass

andtherewasnospandrelpanel,onlya

minimalisticmetalframe.Thus,theglass

panelswerethemainresistivecomponentof

theassembly,promotingicetoformdirectly

inthecenter(thecoldestlocation)ofvertical

visionglasspanels.Thekeypointtothis

exampleisthefactthat theprofileofthe

assemblyisproducingskintemperaturesthat

alignwithexteriortemperaturesduringmore

typicalwinterprecipitationevents,thereby

promotinganincreaseinfrequencyand

severityoficingovermoretraditionalwall

assemblies.Tobeclear,therelationship

betweenglassandframeisnot thesole

cause,butlikelyatippingpointforthis

particularexample.Otherinfluencingfactors

couldinclude:themovetomoreeffi cient

withunderfloordisplacementventilation

systems,theheatlosscharacteristicsofthe

wholefaadeasasystem,andex ternalfactors

suchaselevation,buildinggeometryand

orientationtoprevailingweather.Overall,this

examplerevealsthatasimprovementsin

buildingperformancearemade,andexterior

skintemperaturesarereducedorata

minimummodified,thereisopportunityfor

hazardousiceandsnowformationstooccur

indifferentmannersandamounts.

CaseExample2BuildingType:Tall,HighPerformance

Location:MidwestUnitedStates

Thesecondexample (seeFigure2) alsodeals

withtherelationshipbetweenglassand

frame.Howeverinthiscasethefocusis onice

andsnowformationsthataccumulateon

windowsillsormullioncapsatthebaseof

visionpanels.Inthisexample,significantice

formationswereconsistentlyformingatthe

edgeofmullioncapsandfalling.Historically,

sillsormullioncapsofarelativelysmall

dimensionwerenotpronetohazardousice

formations,asheatlossthroughthecurtain

wallsystemwouldcreatesuffi cientmeltingto

avoidsignificanticeformations.However,

2004 2010 % Change

O p aq u e El e m en t s I n su l at i o nM i n. R - Va l ue I n su l at i o n Mi n . R - Va l ue

Ro of (I nsulatio n entirel y above deck) R-15 R-20 33%

Wall above grade (mass) R-5.7 R-9.5 67%

Steel-framed walls R-13 R-13 +R-7.5 Cont. 58%

F ene st ra ti on A ss em bl y M ax . U A ss em bl y M ax. U

Vert ical gl azing 0%40% of wall U-0.57 U-0.50 14%

30 | Energy Energy | 31C TB UH J ou rn al | 20 12 I ss ue I V C TB UH J ou rn al | 20 12 I ss ue I V

TheConcept

CurrentenergyprovisionsystemsinChinaareheavilybasedonexhaustiblefuelssuchas

coal,hydrocarbons,anduranium.TofulfillChinascommitmenttoreducecarbondioxideemissionsperunitofGDPby 40to50%by2020, newsystemstoreducethe

influenceontheenvironmentmustbeconsidered.Citiesareturningtotallbuildingstoaddresstheneedforspacein urbansettings,wherelittlenewlandisavailable,but

skyscrapersaretypicallybigenergyconsumers.Theyalsotendtobeineffi cient,duetothespaceneeded forvertical

circulation.Thehigherthebuilding,themoreliftsandverticalinfrastructureneeded,limiting

theamountofusablefloorspace.

TheKrafthauscansimultaneouslyaddressChinasneedformorespaceandcleanenergy(seeFigure1).Theconceptcombinesa750-meter-tallsolarupdrafttowersome-

timescalledasolarchimneyorsimplyasolartowerandaclimateresponsivetallbuilding.Attheheartof theKrafthausisasolarthermal

powerplantutilizingacombinationofasolaraircollectorandthecentralupdrafttubetogenerateasolarinducedconvectiveflow,whichdrivespressurestagedturbinesto

produceelectricity.

Thissolarfacilityislinkedwithamulti-programmaticverticaltowerreachingup215

floors.Thetowercanoffergardens,shopping,leisure,entertainment,andculturalfacilities,inadditiontooffi cesandapartmentsa

completeverticalcity.The70-meter-widesolartubeatthecoreof theKrafthausallows

Chinasfast-growingurban population andneedfor sustainableenergysourcesrequire alternativedevelopment ideas. TheKrafthaus, whichcombinesan energy-producing solar tower with an environmentally-responsive, 215-storybuilding, isoneid ea under consideration to addresstheissuesfacingChinascities. Thebuilding hasinstalled power capacityabout30

MWof electricity. With onlya portion usedbythe building, thebulkof theenergywouldbefedinto thelocalgrid.ThomasKraubitz

Author

ThomasKraubitz,Senior Consultant

Happold Ingenieurbro GmbH (Buro Happold)Pfalzburger Str.43-4410717 BerlinGermany

t:+49308609063146f:+493086090666e:[email protected]

ThomasKraubitzThomas has been workingin theeld ofsustainableplanningand design for over ten years and hasdeveloped a holistic view ofbuildings and theurbancontext.Hehasworkedin dierent climatic zones inconsulting,project management,urban planning,urban design and architecturefor Stefan Behnisch,Ken Yeang,and Rem Koolhaas,amongst others.Asa Fulbright Scholar hewas a Teaching and ResearchAssistant at Harvard University from 20072009.Since2012heis also a studio critic at theTechnicalUniversity Berlin.

Figure1.TheKrafthaus,Kunming.Thomas Kraubitz

Research: Energy

A Proposal to Create an Energy-ProducingMegatall for Kunming, China

liftsandinfrastructuretobeplacedinsidethe

concretetube.Oneachfloor thereisahorizontalinstallmentareaforbuildingservicesandtechnicalequipment150meters

longwhichallowsanopenspaceanda veryflexiblefloorplan.aswellaseasyaccess formaintenanceorreplacementwithouttakingupvaluablerentablespace.

TheKrafthausformofgeneratingenergyissimple,reliable,accessible,andbasedon

renewablematerials.TheprincipleofthesystemwasfirstdescribedbyIsidoroCabanyesin1903andwasrevisitedinthe late1970sbyMichaelSimonandJoerg Schlaich.

Theysuccessfullydemonstratedtheconceptin1982ina smalltestinginstallationinManzanares,Spain.Combiningthesystemwithatallbuildingis,however,anew

approach.

Inordertorealizethepotentialofthe

Krafthauslinkedwithatallbuilding,itisessentialtofirststudyacommercialsolarupdrafttowerinoperationtogaintechnicalandfinancialinputfortheproject.Thesolar

towertestingfacilityinManzanaresprovidedvaluableinformation;howeveritwaslimitedbyitsheightof only195metersandmaximumpoweroutputof50kW. The

researchoperationwastoosmalltocollectdataoncommercialenergyproduction.Withalargerchimneyheightthepressure

differencesincreasethestackeffectandahigherpoweroutputispossible.

In2010,a solarchimneyplantstarted

operationinJinshawan,WuhaiCity,InnerMongolia,China.The200-kilowattpowergeneratingunitcansupply400,000kWhofelectricityperyear,savingtheequivalentof

100tonsofcoal and900tonsofwater,

Kunming

Jinshawan,Wuhai

Figure2.Kunmingannual averageglobal radiation overlay.Schlaich Bergermann Solar

Aconventional solar

updraft power station

consumes several

hundred hectares of

land, if it is designed to

generate as much

electricity produced by

modern power stations

using conventional

technology

comparedwiththermalpowergeneration.TheRMB1.38billion(US$208million)projectcallsforafullfacilitycovering277 hectarestoproduceacomparableoutputof27.5MW by

2013.Butonlydatafrom prolongedoperationwillallowforajudgementontheperfor-manceofthepowerplantand itspotentialasrealestateproperty.Sofaronlylimited

informationonitsexistenceandoperationisavailableandstillhastobeverified.

FindingtheIdeal Location

Aconventionalsolarupdraftpowerstation

consumesseveralhundredhectaresofland,ifitisdesignedtogenerateasmuchelectricityproducedbymodernpowerstationsusingconventionaltechnology,suchasfossilfuels

ornuclearenergy.Untilrecently,mostdiscussionsofKrafthaushavefocusedonhotareaswherelargeamountsofverylow-value

landisavailable,suchasdeserts.Butthelimitednumberofconsumersandhighinfrastructureandtransportcostsinthoseperiodshavemadeiteconomically

impractical.

Oneofthemost importantaspectsforplanningandrunningasolarpowerplantis

globalradiation.Atfirst itmayseemthat areas

withahighairtemperaturearemostsuitable

butradiationweakeningcomponentsoftheatmosphere-suchasclouds,aerosolsandwatervapourneedtobeconsideredaswell

fortherightlocationforasolarupdrafttower.OnlybyevaluatingMeteotest/Meteonormsatellitedata,whichincludesthesolarweakeningcomponentsthatreducetheW/

mheatgainonsurface,an informeddecisionforthemosteffectivelocationbemade.Veryimportantisalsoahighpossibletemperaturedifferencebetweendayandnighttoallowa

steadyoperationoftheupdrafttowerthatcansafeheatduringtheday inwaterpacksandreleasesitatnight.

InChina,theYunnanProvinceoffersmanyele-

mentsnecessaryforthesolarupdrafttower

withupto220240W/m 2 ofAnnualAverageGlobalRadiation.ThesiteofthechimneyplantinJinshawan,WuhaiCity,hasavalueof

just180220W/m2 andamuchsmaller

population(400,000people),whichmeanshigherinfrastructurecostsdueto thedistancetoconsumers.

Afteroverlayingsolarradiationmapsandthestudyofpopulationmaps (seeFigure2), theCityofKunming,YunnanProvince,was

identifiedasanidealsiteforthisconceptandpreliminarydiscussionshavetakenplaceontheconceptwithlocalplanningauthorities.Solarradiationalreadyplaysa largerolein

Kunming,with60to70% ofitswarmwaterprovidedbysolar-thermalenergy.ThepopulationofKunmingprefecturestoodat6.4millionin2010andit isexpectedtogrow

tobecomethelargestmetropolisoftheregion.ThestrongeconomyoftheGreatKunmingArea(GKA)largelydependson

tourismandagriculture,withlimitedspaceduetoitshillsandmountains.Thecity,oftencalledSpringCity,hasalsoreceivedattentionforitsproximitytotheemergingbusiness

opportunitieswithAssociationofSoutheastAsianNations(ASEAN)members,especiallyVietnam.Thespecificclimaticconditionsallowseveralharvestsayearandits

picturesquesettingmakesitanationalandinternationaltouristdestination.Atthesametimethemostsuitableareasfordevelopment

aretheprimefarmlandsonthelakeshoreofferingvaluableviewsfornewhousing

9thWorld Congress ShanghaiReport

Kevin Brass

CTBUH 2012 Awards OverviewKevin Brass

CTBUH on the RoadCTBUH events around the

world

DiaryUpcoming tall building events

ReviewsReview of new books in the

CTBUH Library

CommentsFeedback on past journal

issues

Meet the CTBUHJavier Quintana de Ua

CTBUH OrganizationalStructure & Member Listings


4/9

12 | Absolute World Towers, Mississauga CTBUH Journal | 2012 Issue IV

Shapely Pair of Towers Challenges the Status Quo

Anthony Pignetti

Case Study: Absolute World Towers, Mississauga

Dubbed the Marilyn Monroe towers, the CTBUH 2012 Best Tall Building

Americas award-winning project is the result o a unique public-private

partnership and an international design competition, which chose a new

Chinese irm doing its irst work in North America. The innovative design,

however, created an array o issues or the builders.

Like other suburbs in North America, the

Toronto satellite community o Mississauga is

quickly developing into an interdependent,

urbanized area. Canadas sixth largest and

astest-growing major city, Mississauga has a

diverse economy and multicultural character,

as well as a new-ound status as an important

city center in the Greater Toronto area (GTA).

However, its rapid development into an

urbanized center has been at the expense o a

unique cityscape character.

The redevelopment o a major downtown

intersection was seen as an opportunity to

redene Mississaugas urban landscape

through an innovative public-private

partnership and internationally recognized

architectural design. The project had to add

something naturalistic and human to contrast

with the existing backdrop o listless boxy

buildings.

The winning design obeys many o the rules

o the typical North-American high-rise: a

central core, a straightorward and economic

Authors

Bas Lagendijk, Strategy Executive

MAD Architects3rd Fl. West Tower7 Banqiao Nanxiang, BeixinqiaoBeijing 100007, China

t: +86 10 6402 6632, : +86 10 6402 3940e: [email protected], www.i-mad.com

Anthony Pignetti, Vice Presidento ConstructionSergio Vacilotto, Director o Site Operations

Dominus Construction Group

7777 Keele Street, Suite 216Concord, Ontario L4K 1Y7, Canada

t: +1 905 669 2200, : +1 905 669 [email protected], www.dominus.ca

Bas Lagendijk

Bas Lagendijk deals with communication inArchitecture at MAD. As a strategic thinker he inormson the potential o Architecture and communicatesbetween clients, collaborators, governments,constructors and the general public.

Educated in Interior Architecture, Inormation Tech-nology and Graphic Design, he previously worked atOMA, where he was involved in many contemporaryissues ranging rom buildings to large scale sustain-ability issues such as Zeekracht, Roadmap 2050, WestKowloon Cultural District and the Venice Biennale.

Anthony Pignetti & Sergio Vacilotto

Dominus Construction Group is a ull serviceconstruction rm in the Greater Toronto Area. Draw-ing on the extensive industry expertise o seniormanagement team members, Anthony Pignetti andSergio Vacilotto, Dominus has distinguished itselwithin the industry as a new brand o builder ocusedon innovation and unique orms o partnership.

Dominus has earned a reputation or deliveringprojects unprecedented in engineering and technicalcomplexity such as L-Tower, constructed atop oTorontos renowned Sony Centre or the PerormingArts, in addition to the Absolute World Towers CTBUH 2012 Best Tall Building or the Americas.

Sergio Vacilotto

Bas Lagendijk structure and a glass aade. However, the

outcome is undamentally dierent in the

perception o the people. By the time o

completion the result was recognized by the

public and news accounts as an inspiring

place to live, something more than a place

that strives or simple eciency. The buildings

hope to provide residents with an emotional

connection to their hometown and neigh-

bors, and a local landmark to dene the city.

A Risky Development Plan

The developers o the site, Fernbrook Homes

and Cityzen Development Group, were

determined to tackle the lack o a unique

character when they set out to redevelop the

intersection in Mississaugas downtown core.

It was determined that the best use or this

important property would be a residential

development. The entire project includes a

master-planned community o ve towers

with more than 158,000 square meters, 1,850

residential units, a three-story 3,252-square

meter recreation area, and retail acilities.


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Absolute World Towers, Mississauga | 13CTBUH Journal | 2012 Issue IV

Figure 1. The Towers created a new skyline or the City. Tom Arban Figure 2. Absolute World Towers, Mississauga. Tom

Arban

In a break rom industry tradition, Fernbrook

and Cityzen sponsored an international

competition to nd an iconic design that

would realize their vision. This was the rst

such design competition that the GTA hadseen in more than 40 years and the Mayor

and City embraced the opportunity with

great enthusiasm.

Due to the prominence o the location, the

City had a special interest in the

redevelopment initiative. They were an active

partner in shaping and realizing the

development vision. In a unique spirit o

partnership, the City was invited to participate

on the judging panel or the project. The City

and its residents were part o the decision-

making process and helped identiy the

winning proposal. The City also worked

closely with the developer throughout the

construction process to manage many o the

unique challenges associated with

implementing the unprecedented eatures o

the successul design. The public sense o

ownership that dened this undertaking rom

its inception helped bring the project to

realization.

The response to the competition ar exceeded

expectations. More than 600 expressions o

interest were registered and 92 submissions

received, producing an array o unique and

inspiring architectural designs rom a global

pool o talent.

The winning design rom Ma Yansong o MAD

Architects clearly captured the publics

imagination. The design helped create a

strong partnership between the City and the

developers, the architects, the contractor and

the engineers. MADs design stood out or its

ability to oer a sharp contrast to the existinglandscape o traditional rectangular buildings

that had come to dene Mississauga (see

Figure 1), addressing one o the primary goals

o the City and the developer.

A Distinct Shape

Winning the competition generated

enormous public interest internationally, but

was particularly noteworthy in China, where

MAD became the rst Chinese architecture

oce to build a signicant high-rise project

abroad. Suddenly a young architect rom

mainland China was given an international

platorm to showcase new ideas and design

philosophy. This also oered Chinese

developers a new appreciation or the

potential o their domestic talent.

Fondly dubbed the Marilyn by local residents

in homage to the curvaceous appeal o

Marilyn Monroe, the Absolute World Towers

parallel the twisting fuidity o natural lines

ound in lie (see Figure 2). The fowing orm

oers an organic punctuation in the

landscape and challenges the prevalence o

commonplace development in the area.

The architects ambition to provide each

resident a unique experience o the city

resulted in two towers that have continuous

The towers fowing

form offers an organicpunctuation in the

landscape and

challenges the

prevalence of

commonplace

development in the

area.

balconies which widen individual viewing

angles and promote community at the micro

scale o a single foor. At the macro level, the

cadence o the foors rising into the sky echo

the modular rhythms o the human

experience, while suggesting the movement

o an adoring gure. Critics have praised the

designs ability to create a structure that

constantly seems to change, depending on

the vantage point. The design illustrates that

the human spirit eels more connected to a

building that oers privacy while still

promoting human interaction.

The design brie presented or the

competition calling or a single tower was


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Figure 3. Typical oor plans o the Absolute World 56. MAD

Figure 4. The towers rotation diference. PERI Figure 5. Typical structural conguration. MAD

straightorward, with restrictions limited only

to the amount and size o units. This allowed

the competing designers ull expression andfexibility.

Eschewing the tradition o accentuated

verticality in high-rises, MADs design or the

Absolute World Towers chose not to

emphasize vertical lines. Instead, the design

eatures smooth, unbroken balconies that

wrap each foor o the building. In addition, at

each successive level, the foor plate rotates in

a range o one to eight degrees aording

panoramas o the Mississauga skyline (see

Figure 3). By maximizing the viewing

potentials both inside and outside the

buildings, the design created a medium or

social interaction throughout the balconies

and connected the city dwellers with

naturalistic design principles.

Building an Idea

Many observers questioned whether the MAD

design could actually be built. The unique

eatures o this type o rotating structure had

never beore been subjected to Ontario

building code requirements and there was no

precedent or the construction challenges.

From the outset, local architectural and

engineering rms were engaged to rene the

design and ensure it would meet all local

standards without compromising the initial

design intent. While the lead time or most

projects was normally three to our months

beore excavation was scheduled to

commence, in the case o Absolute World, thepreparatory period was extended to 12

months. This type o extensive pre-planning

ensured the project was kept on schedule by

anticipating potential issues.

While consultants always play a major role in

the construction o any project, in this case

their role was even more signicant. The

rotating design meant that every foor was

unique. Meeting these challenges required

extensive collaboration among all the

construction disciplines throughout the

process.

In addition, there was some initial concern

that the unique layouts would limit the ability

to market and sell residential units in the

tower. However, the interest generated by the

competition and the publics participation in

the nal selection helped the developers

easily sell out the apartments in a ew days.

The developer had taken a signicant gamble

in committing to deliver a design developed

out o a competition, but the results provided

evidence that design does matter in the

Ground Level, -10 Level 40, 159Level 24, 42


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marketplace and a unique design can sell at a

premium.

Given the initial response, the developer

requested that the architect produce a designor a second tower. Ma Yansong was adamant

that a second tower should be

complimentary, but not a duplicate o the rst

tower. The second buildings design used the

same technique o rotating foor plates, but

eatured dierent angles to create a dierent,

but related orm (see Figure 4).

The rst and tallest tower starts to twist rom

below and increases its rotation initially by 1

degree to a maximum o 8 degrees rotation

per foor or a total cumulative foor plate

rotation o 209 degrees. The buildings vertical

middle section, or its hip, represents the

maximum eight degree rotation. For the

second tower, the rotation was 4 degrees or

every foor or a total cumulative foor plate

rotation o 200 degrees.

While the two towers look similar, they are

very dierent. In addition to dierent angle

rotations, the buildings also have dierent

aade treatments. While the rst tower is

more transparent, the second tower is more

opaque. This distinguishes the two towers

and allows them to seem to interact with

each other.

The addition o a second building actually

strengthened the original concept. As the

architect observed, a single tower could have

been viewed as a sculptural piece, but the

addition o a second tower transormed the

development into a true urban space.

An Economy o Structure

The torsional orm o the towers is

underpinned with a surprisingly simple and

inexpensive structural solution. The tworesidential towers are supported by a grid o

concrete load-bearing walls. The bearing walls

extend and contract in response to the

sectional fuctuation created by the rotation

o the foors (see Figure 5), while the balconies

consist o cantilevered concrete slabs. In order

to ensure the elegant edge proles are as thin

as possible, there is a thermal break in the

slabs at the exterior glazing, so that the

insulation need not wrap the entirety o the

balconies. Meanwhile, the dynamically fuid

shaping o the towers, naturally aerodynamic,

adeptly handles wind loading and ensures

comort throughout all the balconies. In

addition to providing every resident with a

livable exterior place to enjoy views o

Mississauga, the balconies also naturally

shade the interior rom the higher angle

summer sun while soaking in the lower angle

winter sun, reducing air conditioning costs

(see Figure 6).

For the construction team, Absolute Worlds

creative architectural design resulted in a

number o construction challenges and

opportunities or innovation. The design

presented complex issues involving thermal

transer, orming and concrete usage.

Innovative construction solutions and

engineering design were required to realize

the vision and achieve results within budget

and on schedule.

A key eature o the buildings design is the

presence o continuous wrapping balconies

on every foor (see Figure 7). The balconies are

also an integrated part o the curved and

rotating design o the overall structure. Thisgroundbreaking design presented unique

challenges relating to the transer o cold and

heat, both horizontally and vertically. While

balconies can create thermal challenges in

traditionally shaped structures, in the

Absolute World the curved and rotating

design o the building compounded the

challenges.

The horizontal thermal transer concerns

required a break in the concrete slabs that

would still accommodate the unique design

eatures. The rotating foor plates also caused

additional vertical thermal transer issues. As

the foor plates rotated, the window lines did

not align as in traditional building structuresand this created another set o transer issues.

A number o potential solutions were

considered but dismissed or being

excessively costly or risking construction

delays. The team was also not prepared to

consider a solution that would compromise

the balcony eature or any o the suites.

The solution was eventually ound in an

innovative two-pronged approach: thermal

breaks were utilized to minimize the

horizontal thermal transer, and an internal

bulkhead, along with an external insulated

sot, was utilized to minimize the vertical

thermal transer. The thermal breaks were

ormed in such a way that it allowed or

sections in the slab up to 50 millimeters in

width and varying lengths up to 1,200

millimeters. The void that resulted rom this

approach was later nished with re stopping

smoke seal and waterproong.

In implementing these solutions, The

construction company, Dominus, developed a

new and innovative proprietary process. Not

Figure 6. Typical balcony conguration. MAD

Winter Sun

Summer Sun

Wonderful Views

Cool Breeze

Figure 7. The continuous wrapping balconies with

rotating oor plates. Tom Arban


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Figure 8. Rail climbing system (RCS) on Absolute World

56. PERI

The solution was

eventually found in aninnovative two-

pronged approach:

thermal breaks were

utilized to minimize

the horizontal thermal

transfer and an internal

bulkhead, along withan external insulated

soft, was utilized to

minimize the vertical

thermal transfer.

only were transer issues minimized to within

acceptable levels, but the integrity o the

original design was protected.

The unique design properties o the building

also required an innovative concrete orming

method. Traditional fy tables were not

appropriate or this construction because they

would have resulted in large unsupported

panels when the rotation o the foor plate

was more than two degrees. The ormwork

partner, Premorm, needed to develop a new

orming method that would allow or

conguration changes, while maintaining

structural integrity. This had to be

accomplished without compromising saety.

PERI had never beore designed a system that

was required to climb and also move in

relation to a varying rotation.

Premorms solution teamed two main

eatures an EFCO climbing elevator

ormwork system and a modied Peris

SKYDECK drop head system with a modied

rail climbing system (RCS) (see Figures 8 and

9). The climbing elevator ormwork system

contributed to project eciency and allowed

or aster turnaround on the main central core

o the building, avoiding schedule delays. The

modied SKYDECK provided the ability to

orm the constantly changing foor plate by

allowing panels to be carried out immediately

ater the slab concrete reached the required

strength (see Figure 10). This revolving process

permitted panels to be used immediately or

the next cycle and created eciencies.

Since the SKYDECK system is not traditionally

used above grade, a specialized enclosure

system was required around the ormwork to

ensure saety. A modied RCS system worked

in conjunction with the SKYDECK system. The

enclosure simplied the heating requirements

or the concrete slabs during winter pours as

it enclosed two foors below the deck

currently under construction. The result was

Figure 10. SKYDECK slab ormwork. PERI

Figure 9. Trapezoidal RCS panels on Absolute World

50 are installed on an inclined angle o 21 26.

The mobile hydraulic system moves RCS panels

independent o crane. PERI

Figure 11. Heavy structural reinorcement at tower base. Dominus


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Absolute World Towers Project Data

Location:Hurontario St. & Burnhamthorpe Rd

Building Function: Residential

Absolute World 56

Height to Architectural Top: 176m

Stories: 56

TotalArea: 45,000 m2

Total Cumulative Floor Plate Rotation: 209

min. 1 to a max. o 8 rotation per foor

Absolute World 50

Height to Architectural Top: 158 m

Stories: 50

TotalArea: 40,000 m2

Total Cumulative Floor Plate Rotation: 200

(consistent 4 rotation per foor)

Owners/Developers:

Fernbrook Homes & Cityzen Development

Group

DesignArchitect: MAD

Architect o Record: Burka Architects

Structural Engineer:

Sigmund Soudack & Associates Ltd.

MEP Engineer: ECE Group Ltd.; Stantec

Concrete Engineer: Coey Geotechnics

Contractor: Dominus Construction Group

Forming Contractor: Premorm

Material Suppliers: Innocon; Gilbert Steel Ltd

Landscape Architect: NAK Design

Interior Designer: ESQAPE Design

greater eciency and ewer lost days due to

weather constraints.

Through these innovations, the construction

team was able to achieve a cycle time romfoor to foor that could match those o

traditional systems or conventional building

designs.

Concrete Considerations

The last major innovation in the construction

o this building related to the use o the

concrete. Although the building was unique

in its design, it was still required to meet all

structural requirements or a residential

condominium, creating another set o

challenges.

First, the traditional concentric loading o

columns was not appropriate or the unique

design o the building. The structural

engineer, Sigmund Soudack and Associates,

was presented with the challenge o nding

an alternative that utilized sucient rebar and

concrete while still allowing or livable spaces.

The nal structural design included heavy

reinorcement at the bottom o the tower (see

Figure 11) using 35M bars. However, this

design did not allow or use o traditional

methods to consolidate the concrete. The

nal concrete specication called or 70 Mpa

columns, walls and beams; and 50 Mpa slabs.

While this addressed some o the structural

concerns, the concrete was still required to

meet unctionality considerations and ensure

ormability and nal nish o the fooring. This

represented the second major challenge. The

concrete supplier, Innocon, had to identiy a

product that could meet the need or high

volume, accurate consistency,accommodation o a tight construction

schedule, reliability in a ull cycle o seasons,

and unctional workability on foor slabs. The

concrete supplier recommended the use o

sel-consolidating concrete. This product was

capable o meeting all the requirements or

the columns and walls and could be used in a

special mix or the slabs. The product also

oered the added benet o increased

eciency by requiring ewer workers and

minimizing the risk o worker crowding. The

construction schedule spanned over a ull

cycle o seasons and special methods were

utilized to ensure sucient heating in thewinter and cooling in the summer to allow

the concrete to properly cure.

For the columns and walls the sel-

consolidating concrete perormed

exceptionally well. The specied mix designs

called or an ultimate strength o 70 MPa in 90

days. Testing demonstrated that these levels

were achieved in only 28 days. The concrete

perormed at rates much higher than

expected. The products perormance

required the concrete nishers to adapt to an

accelerated schedule because the concrete

reached a nished state more rapidly than

traditionally expected.

Dominus opted or the use o concrete

pumps to alleviate unnecessary crane usage

and hoisted concrete with the traditional

bucket method. For the columns, builders

preabricated many o the column supports in

a staging area and then hoisted them into

place. These techniques contributed to speed

and eciency in the construction cycle.

A New Urbanism

The end result o the process created a new

orm o urbanism based on partnership and

innovation. All aspects o the Absolute World

Towers project challenged the boundaries o

conventional industry norms and practices.

The initial design competition allowed

dynamic new ideas and design philosophies

to come orward. The engagement o the City

contributed to shaping and realizing the

developments vision, consistent with theCitys own aspirations. The resulting

architectural design broke ree rom

conventional thinking and introduced a

natural orm back into the citys (sub)urban

experience, made possible by a series o

design and construction innovations. The

result is a distinct type o urbanism and a

curvy new shape or uture cities.

The Absolute Towers

stretch the limits of paired

sculptural form to create a

marker on the skyline for a

regional center.

Richard Cook, CTBUH 2012 Awards Chair /

Cook+Fox Architects.

THEY SAID

Note: More detailed information on Absolute

World Towers as the CTBUH Best Tall Building

Americas 2012 can be found in Best Tall

Buildings 2012, which can be purchased online

at CTBUH Webshop: https://store.ctbuh.org

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