ha12 building with earth in av - auroville green...

BUILDINGWITHEARTHINAUROVILLE

Acasestudy

Auroshilpam, Auroville 605 101, TN INDIA Tel: +91 (0) 413 – 262 3064 / 262 3330 Fax: 262 2886 Email: [email protected] Web site: http://www.earth-auroville.com

BUILDINGWITHEARTHINAUROVILLEAcasestudy

Author:SatpremMaïni

Auroville–November2002RevisedApril2005

33pages

AUROVILLEEARTHINSTITUTE

Ref.:CS.05

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CONTENT

Lessonsfromthepast………………………………………………………Earthasabuildingmaterial…………………………………………………..

Earthtobuildwith……………………………………………………Compressedstabilisedearthblocks(CSEB)…………………………Rammedearth……………………………………………………….Managementofresources……………………………………………..

TheAurovilleexperience…………………………………………………….

Houses……………………………………………………………….Apartments…………………………………………………………..Publicbuildings………………………………………………………Vikascommunity………………………………………..……………

TheAurovilleEarthInstitute………………………………………………….

Trainingcoursesactivities……………………………………………..Auramequipmentforearthconstruction………………………………Appropriateearth‐basedbuildingtechnologies……………………….Vaultedstructures…………………………………………………….Disasterresistantbuildings……………………………………………

Building with earth from head to toe: Training centre of the EarthInstitute……

Earthversusothermaterials…………………………………………………Costeffectiveness……………………………………………………Theenvironmentalcosts………………………………………………ComparisonofbuildingmaterialsinAuroville…………………………

Towardsthefuture………………………………………………………….

122223458912

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“Aurovilleistheattempttowardscollectiverealisation”.TheMother,June1968

Aurovillewantstobethebridgebetweenthepastandthefuture.Takingadvantageofalldiscoveries from without and from within, Auroville will boldly spring towards futurerealisations.

TheMother,AurovilleCharter,28thFebruary1968

LESSONSFROMTHEPAST

Down through the ages, people have been using raw earth for building their livingspaces.ThetraditionhasgrownoutofanattempttobeinharmonywithNature,touseandyet respecther. Every single continent andnearly every countrypossesses a richheritage of earthen buildings. At least 30%of theworld’s population lives in earthenhouses.FromtheroofoftheworldinTibetorintheAndesMountainsinPeru,totheshoresoftheNileinEgyptorinthefertilevalleysofChina,manyaretheexamplesofearthusedasabuildingmaterial.TheoldestonecanstillbeseeninEgypt,near Luxor, which was built around1300BC: thevaults of theRamasseum,inthe“rest”ofThebes.Ithasbeenbuiltwithadobes,thesundriedmudbricks.

Ramasseum,Egypt,~1300BC Indiaalsoshowsveryoldearthenbuildings,liketheSheypalaceinLadakh,whichwasbuiltwith adobe in the XVIIth century. The oldest one haswithstood 1006Himalayanwinters: the Tabomonastery in Spiti Valley, Himachal Pradesh, whichwas built withrammedearthin996AD.

SheyPalace,Ladakh,India–XVIIthCentury

TaboMonastery,Spiti,HP,India–996AD

Raw earth for building has been used worldwide for millennia but, during the 20thcentury,mostof the skillsof earthbuilderswere lostandbuildingwithearthbecamemarginal.We owe a lot to the Egyptian architectHassan Fathy for the renaissance ofearthenarchitectureinthemiddleoftheXXthcentury.Thenewdevelopmentwithearthconstructionreallystartedinthenineteenfifties,withthe technology of compressed stabilised earth blocks (CSEB): a Colombian researchprogramforaffordablehousesproposedthefirstmanualpress,theCinvaram.Thishasledtoarenaissanceofthetraditionofearthenarchitectureandconstruction–arevivalwhichisbenefitingfromtheresultsofscientificresearch.Aurovilleisattemptingtorevivethesetraditionalskillsandtodemonstratethatearthisstill anoblebuildingmaterialwhichcanbeused formanifestingmodern,harmoniousandprogressivearchitecture.

EARTHASABUILDINGMATERIAL

EARTHTOBUILDWITHThe earth used for building is composed of fourmain elements: gravel, sand, silt andclay.Accordingtothequalitiesandproportionsofthesecomponents,thesoilswillhavedifferentbehavioursandcharacteristics.Manysoilscanbeusedforbuilding,butsomemayneedimprovement.TheAurovilleredsoilgotitscolourfromironoxideswhichgiveexcellentpropertiesandmakeremarkablebuildingmaterials.Somemaysay,"Usingsoilsforbuildingwillleadtothedestructionofnature..."True,ifitisdonewithoutknowledgeorwithunconsciousness.Wrong, if one is attentive to themanagement of resources and the balance of nature.First of all, one should plan how to use the excavation afterward. Topsoil should bescrapedaway,soastobere‐usedforagricultureorgardens.

A modern practice is to stabilize the soil by using additives. They increase themechanicalpropertiesandstabilizetheearthagainstwater.Themostcommonadditiveiscement.Lime isalsoused,but toa lesserextent. InAuroville, theearth isstabilisedwithabout5%byweightofcement.ThequalityofthelimearoundAurovilleisnothighenoughtobeused.

COMPRESSEDSTABILISEDEARTHBLOCK(CSEB)

CSEB is nowadays the most widely used earth technology worldwide, as well as inAuroville, because it represents a synthesisbetween traditionalpractices andmoderntechnology.Itbenefitsfromscientificinputs.The stabilized soil is mixed with a little water to become just humid, and then iscompressedintoamanualoramotorizedpress.Incementstabilization,theblocksmustbecuredforfourweeksaftermanufacturing.Afterthis,theycandryfreelyandbeusedlikecommonbrickswithastabilizedsoilcementmortar.InAuroville,CSEBwith5%cementhaveanaveragedrycompressivecrushingstrengthof50kg/cm2(5Mpa)andawetcompressivecrushingstrengthof25kg/cm2.Thewaterabsorption is around 10%. Country fired bricks have around 35 kg/cm² for the drycompressivestrengthanda12%waterabsorptionrate.The Auroville Earth Institute has designed manual presses for CSEB, which aremanufacturedinAurovillebyAureka,oneofitssteelworkshops.Todaythisequipmentissoldworldwide.

RAMMEDEARTH

Thistechnologyhastraditionallybeenusedinmanycountries.France,MoroccoandtheHimalayan countries show a wonderful heritage. Today, rammed earth is used withstabilizers in the USA and Australia where the process has been mechanized. InAuroville,theearthisrammedbyhand.Until 1994, Auroville had only one house made of raw rammed earth. The AurovilleEarth Institute designed new forms andwith the construction of Mirramukhi School,peoplediscoveredtheexceptionalpotentialbeautyandversatilityofstabilisedrammedearth.

MANAGEMENTOFRESOURCES

Building with earth today, we benefit from the countless customs and discoveries ofhumanitydownthroughtheages.Butinthehistoryofearthbuilding,onethingcapturesourattention:allovertheworldand down through the centuries, one is amazed by the balance and harmony thesebuildingsachievewiththelandscapeandthesurroundingphysicalenvironment.Withnewdevelopments(i.e.CSEBonasemi‐industrialscale)oneshouldnotforgettheriskofcreatingecologicaldisastersthroughthemismanagementofresources.On the other hand, propermanagement of the earth resources can create a new andharmonious balance between nature and the buildings, where each enriches andcompletestheother.Firstofall,oneshouldplanhowtheexcavationwillbeusedafterward.Topsoilshouldbescrapedaway,soastobere‐usedforagricultureorgardens.Aurovilleshowsvariouspossibilitiesfortheuseofquarries:aswaterharvestingponds,wastewatertreatmentponds,pools,basementfloorsorshallowdepressionswhichareusedforlandscapedesign,workorplayareas,gardens,etc.

Pondforabiologicalwastewatertreatment,

atVikascommunity

Shallowpercolationpitandlandscaping,

atVikascommunity

Deeppercolationpit,atVikascommunity

Excavationforabasementfloor,

atVikascommunity3

THEAUROVILLEEXPERIENCETheinternationalcityofAuroville isunderconstructioninTamilNadu, inthesouthofIndia. One of its aims is to harmonizematerial and spiritual research to give a livingembodimenttoanactualhumanunity.MirraAlfassa,TheMother,whotogetherwithSriAurobindo worked for nearly half a century on the evolution of humanity, foundedAurovillein1968.From the early days, different experiments have been made with earth building inAuroville,withmixedresults.ThecreationoftheAurovilleEarthInstitutein1989,andtheconstructionoftheVisitors’Centre,startedanewerainearthenarchitecture.ThisVisitors’Centreof1200m²wasgrantedthe“HassanFathyAwardforArchitecturefor thePoor” in1992.Builtofcompressedstabilisedearthblocks, itdemonstrated thepotentialofstabilisedearthasaqualitybuildingmaterial.Since then, the value of earth as a building material has been acknowledged for itseconomicadvantage,aswellasitscomfortandquality,whichpromotesindigenousandsustainabledevelopment.Today,Aurovillecanshowawidevarietyofearthenprojects:publicbuildings,schools,apartmentsandindividualhouses.Most of the projects are builtwith compressed stabilised earth blocks (CSEB), as thistechnology benefits of half a century of research and development worldwide. InAuroville,theseblockspresentmanyadvantagescomparedtofiredbricks: WallsmadeofCSEBarealwayscheaperthanfiredbricks. Theembodiedenergyis15timeslessthanthebricksfiredinthevillage. Thestrengthoftheseblocksismostofthetimehigherthanthelocalfiredbricks.Stabilised rammed earth used for walls is slowly getting known and a few projectsalreadyimplementedthistechnique.TherearealsothreeotherearthtechniquesusedinAuroville.Thesetechniquesareverymarginallyusedasonly8buildingshavebeenbuiltwiththem: Rawrammedearth,foronlytwobuildings. Adobeblocks,thetraditionalsundriedmudbrick,fortwobuildings. Wattleanddaubwhichismudplasteredonawattlemadeofsplitbambooorpalmyratree,for4buildings.

Note for thephotos of the followingpages:when the technique is notmentioned, thebuildingsaremadeorcompressedstabilisedearthblocks.

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HOUSES

Revelationcommunity

Housebuiltwithrawrammedearth

Newlandcommunity

Housebuiltwithwattle&daub

Samasticommunity

Housebuiltwithadobes

SamasticommunityHousebuiltwithCSEB

Samasticommunity

Danacommunity

Auromodelecommunity

NewCreationfield

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Aurobrindavancommunity

Aurobrindavancommunity

Utilitycommunity

HousebuiltwithCSEBandstrawbale

Utilitycommunity

AurovilleEarthInstitutecampus

AurovilleEarthInstitutecampus

VikascommunityCosteffectivehouse


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VikascommunityMoveablehouse

Greenbelt

Greenbelt

Danacommunity

Véritécommunity

Costeffectivehouseinavillage

Experimentalhouseinavillage

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APARTMENTS

Prarthnacommunity

Prarthnacommunity

ClustersatPrayatnacommunity

ClustersatPrayatnacommunity

StaffquarteroftheHealthCentre

Djaimacommunity

KailashYouthCentre

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PUBLICBUILDINGS

VisitorsCentre–“1992HassanFathyAwardforArchitectureforthePoor”

VisitorsCentre,entrance

VisitorsCentre,informationofficeand

exhibition

VisitorsCentre,accesstothecafeteria

VisitorsCentre,cafeteria

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PitangaHall,CulturalCentre

VéritéCentre,MultipurposeHall

Altecs,Electronicworkshop

Solarcollectivekitchenfor1000people

Kitchensideanddininghall

Solarcollectivekitchen

Kitchenside

Solarcollectivekitchen

Solarbowl,15mdiameter

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DeepanamSchool,

builtwithstabilisedrammedearthandCSEBdomes

DeepanamSchool

CSEBcloisterdome,5.70msquare

DeepanamSchool,

CSEBvault10.35mspan,2.25mrise

ShaktiViharaSchoolatPondicherry

AuroshikaSchool

AuroshikaSchool

IsaiambalamSchool

Kindergarten

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VIKASCOMMUNITY

Thecreationofthiscommunitywasbasedonaparticularspirit,lifestyleandsustainableapproach to development. The exclusive use of environmentally sound materials,appropriatebuildingtechnologies,renewableenergysourcesandbiologicalwastewatertreatmentwasthebasisofitsmaterialimplementation.This project was designed and built by the Auroville Earth Institute. It was the firstdevelopmentinAurovillewhichusedstabilisedearthfromfoundationstoroof.Todate,VikascommunitystillrepresentsthemostsyntheticsustainabledevelopmentwhichhasbeenmaterialisedinAuroville.Vikaswasafinalistforthe“2000WorldHabitatAward”.ThefirstprizewasgiventoasimilarprojectintheUSA.Thecommunitywasbuiltinseveralsteps,from1992to2000: Firstdevelopment:Thecollectivekitchenwasbuiltfirstin1992andthen,thefirst

blockoffourapartmentsin1993.Thesoilforbuildingwasextractedfromthehalfunderground reservoir and from the pond for the wastewater treatment. At thisstage,thesoildugfromtheseexcavationswassufficienttobuild.

Seconddevelopment:Thesecondblockofsixapartmentswasbuiltin1996.Atthisstage,therewasstillsomesoilleftfromtheexcavationofthewastewatertreatmentpond.Butitwasnotenoughtobuildtheentirestructure.ThedevelopmentofVikasdidnotneedanyfurtherexcavations,sothesoilneededtobesuppliedfromanothersource. As quarries are often savage and as no control on the management ofresources ispossible, theconceptofabasement floorwasdeveloped for the thirdbuilding.

Thirdandlastdevelopment:Thethirdblockofthirteenapartmentswasbuiltonfour floors – A basement floorwith three floors above it. The basement also hadapartments, and itwashalf underground so as to get enough light for the rooms.Thisconstructionsitestartedearly1997andwascompletedearly2000.

UNIQUEFEATURESOFTHETHIRDBUILDING

This buildingwas conceived so as to be self‐sufficient in its soil needs, an importantconsideration because of its size. The soil was dug from the basement floor (1.20mbelow theoriginal ground level) toproduceCSEB forbuilding the4‐storied structure,withacarpetareaof819m2.To protect the basement from the overflow of rainwater a particular landscape wasdesigned.Theimmediatelysurroundinglandwasshapedintoashallowcratertodrainrainwaterintoapercolationpit.The foundationsweredonewith stabilised rammedearthand the13.40mhighwallsweredonewithCSEBof24cmthick.Allfloorsandroofsweremadeofveryflatvaultsanddomesforthelivingrooms.ThesevaultsanddomeswerebuiltwithCSEBbyusingthe“Freespanning”technique.Allstabilisationused5%cementbyweight.This building implemented various appropriate architectural designs which hadpreviouslybeentested,suchas: Sunprotectionwithsunshadesandaproperorientationofthebuilding. Natural cross ventilation with a proper orientation of the building, to catch the

summerwind.Theventilationisimprovedbyanincreaseofwindvelocitythroughpierwalls.

A solar chimney to create a natural draft which cools the building, especially atnight. The sun heats a heavy black slab laid on the chimney top: this creates anaturaldraftduetothetemperaturedifferenceinthechimney.

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SITELAYOUT23apartmentswithacollectivekitchenfor50people(1448m²carpetarea)

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CROSSSECTIONOFTHETHIRDBUILDING13apartmentson4floors

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As the thirdbuildingwasbuiltonabasement floor, itwasessential toprotect it fromany rainwater intrusion. A drain, made of slotted PVC pipe, was laid against thefoundation and the collected water was sent into an underground percolation pit (±10m3), which was filled with sand. This pit collected the rainwater which wentunderground.Ithadnoconnectionwiththesurfacerainwater.The land immediately surrounding the building was shaped like a shallow crater toharvestrainwater.Thelatterwassentintoapitofabout73m3,whichwasshapedintoaconicalcraterwithafewstepstoaccessit.Anextrapitof44m3wasaddedasabackupincaseofveryexceptionalrainfall.Anyoverflowof themainpercolationpitwouldgointothesecondpit,whichwasfilledwithsand.Thissystemharvestsrainwaterwhichfallsonthebuildingandthecrater immediatelyaround it. The roof and the percolation system cover about 1200 m². The system isprotected by a strong bund all around to avoid any intrusion of rainwater from theadjacentland.An unusual and exceptional rainfall proved the effectiveness of the system. Aurovillereceives around 1250mmof rainfall per year: about 3/4 during the 2months of thewinter monsoon (mid‐October to mid‐December) and about 1/4 during the summermonsoon(aroundJune).Italmostneverrainsinbetween.February2000sawsomethingveryunusual:a402mmrainfallover5daysfromthe23rdtothe27th.ThemostintenserainwasonFebruary26th,mostlyatnight,with198mmofrainfall.Therainsloweddownonthemorningofthe27thandafter4‐5hoursthewaterlevel inthepercolationsystemwentdownby20cm.Thismeansthatduringthistimethesystempercolatedaround48m3.Thesystemcollectedabout450m3ofrainfallin5days.Oneandahalfdaysafterthelastdrops,everythinghadpercolatedandthesystemwasempty.

RAINWATERHARVESTINGSYSTEM15

Halfundergroundreservoir

Communitykitchenfor50people

Thefourfirstapartments

Apartmentinthethirdbuilding

Firstapartments

Apartmentsinthethirdbuilding

Childrenpool

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Excavationofthebasementforthethirdbuilding

Stairsofthethirdbuilding

Thirdbuilding,gardenside

Thirdbuilding,gardenside

Thirdbuilding,greenstreetside

23apartments,viewfromthegreenstreet

23apartmentsviewfromthewindpump

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THEAUROVILLEEARTHINSTITUTE

TheAurovilleEarth InstitutewaspreviouslynamedtheAurovilleBuildingCentre /EarthUnit,whichhadbeenfounded byHUDCO, Government of India, in 1989. Thedevelopment of the former building centre evolved insuch away that theAurovilleEarth Institute came intoexistencein2004.TheAurovilleEarthInstituteisresearching,developing,promoting and teaching earth‐based technologies thatare cost and energy effective. These technologies aredisseminated through training courses, seminars,workshops, publications and consultancy within andoutsideIndia.

OneoftheaimsoftheAurovilleEarthInstituteistogivepeoplethepossibilitytocreateandbuildtheirhabitatthemselves,usingearthtechniques.The Auroville Earth Institute is part of a world network with CRATerre (TheInternationalCentreforEarthConstruction),ABCTerrainBrazilandanumberofIndianNGO’s.AtrainingagreementhasbeenmadewiththeSchoolofArchitectureofGrenoble,France, toprovide long‐term trainingcourses to its students.ApartnershipagreementhasbeensignedwithUNESCOfortheChair"EarthenArchitecture–ConstructiveCulturesand Sustainable Development". The Auroville Earth Institute is today the South AsianrepresentativeandResourceCentreforthischair.Overthepastdecade,theendeavourtopromoteanddisseminaterawearthasabuildingmaterialforsustainableandcost‐effectivedevelopmenthasbroughtaseriesofawards:ninenationalawardsandoneinternationalaward.

TRAININGCOURSEACTIVITIESTraining activities started in 1990 and since, regular courses of 2‐week duration arescheduledinAuroville.MajorprogrammesarealsoorganisedatAurovilleorelsewhereinIndiaattherequestofGO’sorNGO’s.SomeprogrammesarealsoconductedoutsideIndia,ashashappenedinZaire,Eritrea,SriLanka,SaudiArabiaandTurkey.Regular programmes are conducted every year in the following fields, at the AurovilleEarthInstitute: ProductionandmasonryofCSEB. TheoryandpracticeofArches,vaultsanddomes. Long‐termtrainingforstudentsofarchitecture. Awarenessprogramsonappropriatebuildingtechnologies. Specialcoursesonearthquakeresistance.Since1990,3551traineeshavebeentrainedinIndiaand62abroad:

INDIA 1877students,architects,projectmanagers,during1or2‐dayawarenessprogrammes,inAuroville.

1301 Indian trainees with various skills, during 1‐week courses in Auroville orelsewhereinIndia.

219 foreign traineeswith various skills, from 30 countries, during 1‐week or long‐termcourses.

40Indianstudentsorarchitects,duringlong‐termcourses(Severalweekstoseveralmonths).

114 masons, with “on the job training”, on various construction sites (Auroville and TamilNadu).

ABROAD 132traineeswithvariousskills,duringworkshops,inEritrea,Turkey,SriLankaandZaire..

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AURAMEQUIPMENTFOREARTHCONSTRUCTION

Awiderangeofequipmentforbuildingwithearthhasbeenresearchedanddevelopedfrom the very onset. It ranges from presses for compressed stabilised earth blocks,quality control devices for blockmaking, handling equipment, hand tools, scaffolding,andrammedearthequipment.

AuramPress240

Rammedearthform220

AuramPress3000

Today,thepress3000forcompressedstabilisedearthblocksisbeingsoldworldwide–mostlyinSouthAsiaandinAfrica.AfewmachineshavealsobeensoldinEurope,USA,Dubai and China. The press 3000 with hollow interlocking moulds was sold in largequantities to Gujarat‐India, for the rehabilitation of the zones affected by the severeearthquakeofJanuary2001.

Widevarietyofcompressedstabilisedearthblocks.

APPROPRIATEBUILDINGTECHNOLOGIESBASEDONEARTH

Thisresearchaimsatmakingextensiveuseofrawearthasthemainbuildingmaterial,therebyusingalocalresourcetohelpdeveloptechnologiesthatareenergysaving,eco‐friendlyandsustainable.Themainresearchanddevelopmentisfocussedonminimisingtheuseofsteel,cementandreinforcedcementconcrete(RCC).Mostofthetechnologiesdevelopedhavenowbeenmasteredandthepresentresearchisfocussed on alternative stabilizers to cement and alternative water proofing withstabilizedearth,composedofsoil,sand,cement,lime,alumandtannin.

Stabilisedrammedearth

Thesoilismixedwithsandandstabilisedwithanaverageof5%cement,andrammedbyhand.Foundationsare rammeddirectly in the trenchand thewallsare rammed inbetweenformworks.

Stabilisedrammedearthfoundation

Stabilisedrammedearthwalls

Compositebasementandplinthbeam

BasementsaremadewithCSEBstabilisedwith5%cementandtheplinthbeamiscastintoaUshapedCSEB.Thecompositeplinthbeamactsalsoasadampproofcourse.

Compositeplinthbeam

Castingacompositeplinthbeam

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Compositecolumns

RoundhollowCSEBarereinforcedwithcementconcrete.Reinforcementsvarywiththeheightandload,buttheroddiametercannotexceed10mmfortheblocks290and12mmfortheblocks240.

Compositecolumn240

Compositecolumn290

Compositecolumn240&290

Compositebeamsandlintels

U‐shaped CSEB are with reinforced cement concrete. Reinforcements vary with thespan,buttheroddiametercannotexceed12mmfortheblocks290&295and16mmfortheblocks240&245.Thebottompartofthebeamisprecastinareversedpositionontheground.Oncecured, it is liftedandthemiddleandtoppartsarebuiltonit.Theblocks are used as lost shuttering, but they also help the compressive strength of thebeam.

Singleheightbeam240

Doubleheightbeam240

Tripleheightbeam240

Typicalsectionsofcompositebeams

Assemblingacantilevered(1.60m)compositebeam,tripleheight

Testinga2mspandoubleheightbeam2951750Kg/m,5.54mmdeflectionwithcracks

Testinga2.5mspantripleheightbeam2401280Kg/m,4mmdeflectionwithoutcracks

Stabilisedearthwaterproofing

The earth is mixed with sand and stabilised with cement and a paste made of lime,tannin,alum(Ammoniumsulphate)andwater.Tannin is extracted by soaking into water broken seeds of an Indian tree, named“kaddukai” inTamilNadu. Itsbotanicalname isTermineliaChebula.The limepaste ispreparedbymixingpowderedalumwithlimeandtanninjuiceandextrawater.Threecoatsofplasteraredonewithdifferentproportionsofthesecomponents.Thelastcoat,whichisthemostwaterproof,isdonewitha5mmthickplastercomposedofsoil,sandandlimepaste.Nocementisaddedtothelatter.Notethatcementisgivingstrengthtotheplasterandalsohelping thewaterproofing,but theeffectivenessof thiswaterproofing is givenbythecombinationofsoil,lime,alumandtannin.Theresultsobtainedwiththiswaterproofingareexcellent:seefurtheronthefeedbackobtained for the trainingcentre.But thisresearch isstillunderwayand therefore therecipesarenotyetdisseminatedthroughdocumentationortrainingcourses.

Preparingthelimepaste

Preparingthemortar

Plasteringavault

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VAULTEDSTRUCTURES

Theresearchwith thiskindofroofingaimstoreviveand integrate in the21stcenturythetechniquesusedinpastcenturiesandmillennia,suchasthosedevelopedinancientEgyptorduringtheperiodofGothicarchitectureinEurope.ThisR&Dseekstoincreasethespanoftheroof,decreaseitsthickness,andcreatenewshapes.Notethatallvaultsanddomesarebuiltwithcompressedstabilisedearthblockswhich are laid in “Free spanning” mode, meaning without formwork. This waspreviously called the Nubian technique, from Egypt, but the Auroville Earth Institutedevelopeditandfoundnewwaystobuildarchesandvaults.ThetraditionalNubiantechniqueneededabackwalltosticktheblocksonto.Thevaultwas built arch after arch and therefore the courses were laid vertically. The binder,about1cmthick,wasthesilty‐clayeysoilfromtheNileandtheblocksusedwereadobe.TheevenregularityofcompressedstabilisedearthblockproducedbytheAurampress3000allowsbuildingwithacement‐stabilisedearthglueof1‐2mmonlyinthickness.The free spanning technique allows courses to be laid horizontally, which presentscertain advantages compared to the Nubian technique which has vertical courses.Dependingontheshapeofvaults,thestructuresarebuilteitherwithhorizontalcourses,vertical ones or a combination of both. All vault shapes are calculated to developcatenaryforcesinthemasonry.Theirthicknessandspancanthereforebeoptimised.

Egyptianshapedcatenaryvault,5mspan,9mlong

Egyptianvault,builtin12days

Catenaryshapedvault,6mspan,3mrise

Bulleye,80cmdiameter,builtin2days

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Startingalunette

Lunette,1.2span

Lunettebuiltin3days

Startingthesquincheforasegmentalvault

Completedsquinche,startingthesegmentalvault

Segmentalvault,10.35mspan,2.20mrise,6mlongwithasquinche,builtin18dayswith4masons

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Semicircularvault,6mspan,11mlong

Semicircularvault,builtin37dayswith4masons

Equilateralvault,3.60mspan,8mlong

Equilateralvault,builtin36dayswith4masons

Cloisterdome,3.60msquare,60cmrise

Hemisphericaldomeonpendentives,3.70mspan

Cloisterdome,5.70msquare,2.15mrise

Pointeddomeonanoctagon,6.4mspan,4mrise

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DISASTERRESISTANTBUILDINGS

Since 1995, research has been oriented towards the development of a cost‐effectivetechnologywhichisbasedonreinforcedmasonrywithhollowinterlockingCSEB.Two types of blocks have been developed: the square hollow interlocking block 245,which allows building up to 2 storeys high, and the rectangular hollow interlockingblock295,whichisusedonlyforgroundfloors.InJune1996,attherequestofCRATerreandthe United Nations (UNCHS/Habitat), theAuroville Earth Institute built a prototype ofthis technology for a 9 m2 demonstrationhouse – the Minimum Emergency House, atIstanbul‐Turkey, during the “1996 CitySummit/HABITAT”.This house was precast in 10 days andassembledin8days.

In1999,at therequestof theHousingandUrbanDevelopmentCorporation(HUDCO),the Auroville Earth Institute built another demonstration house of 23m2 – the AUMHouse,inNewDelhiduringthe“AllIndiaInternationalTradeFair”.Thishousewasprecast in3weeks intAuroville. Itwas transportedbya lorryof22.5ton, over2900Km in5days, and assembled inNewDelhi in 66hoursby an18‐manteam.ItwasgrantedaGoldMedalbyITPOforthequalityofthespecialdemonstration.Another AUM House was precast at Auroville and assembled in Gujarat, India, in 62hoursbya20‐menteam.ThisdemonstrationstartedrehabilitationprogrammesinthezonesaffectedbythesevereearthquakewhichstruckthedistrictofKutchdin2001.Since then, this technology has been developed and it has been transferred to TheCatholicReliefServices(CRS),anNGOthatimplementeditforlargescalerehabilitationofKutchDistrict. CRSdesignedvarious typesof housesof 28m2 and4000houses arebeingbuiltinayearbylocalteams.

AUMHouseassembledinNewDelhi,in66hours.

GoldmedalbyITPOin1999

AumHousebuiltinGujarat,India,in62hours.Rehabilitationofearthquakeaffectedareas

ThistechnologyhasbeenapprovedbythegovernmentofGujaratasasuitablemethodofconstructionfortherehabilitationofthezonesaffectedbythe2001earthquake.

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BUILDINGWITHEARTHFROMHEADTOTOE:TRAININGCENTRE

Todate,themainsynthesisoftheresearchonearth‐basedtechnologiesisachievedwiththetrainingcentreoftheAurovilleEarthInstitute.Thisbuildingisentirelyconstructedfromthefoundationstothewaterproofingwithstabilisedearth.Yearsofresearchandtrainingcourseshavehighlightedtheneedfortrainingfacilities,which could also be living examples of what could be done with these technologies.HencethenewpremisesoftheTrainingCentrewereentirelybuiltwithstabilisedearthfromfoundationstovaults.Thewaterproofing,aswell,wasdonewithstabilisedearthplasters.Thefoundationsandwallsweremadewithstabilisedrammedearth.Allroofsweredonewithvariouscatenaryvaults,whichwerebuilt“Freespanning”withCSEB.Theflooringwas also done with CSEB tiles. The entire structure used earth stabilised with 5%cement.Thestabilisedearthwaterproofingwasmadewiththreecoatsofvariousmixesofsoil,sand,cement,lime,alumandtannin.An exceptional rainfall in February 2000 showed the effectiveness of this stabilisedearth waterproofing, when 402 mm of rainfall occurred in five days and there wasneitherleakagenordampnessinsidethevaults.Thiscomparativesurveywasmeasuredwithanelectronichygrometer:

Immediatelyafter402mmrainfallin5days

2weeksaftertherainfall,underfullsun

MOISTURECONTENT

Outside Inside Outside InsideVaultsapex 100% 31.6% 19.4% 22%Windowsill 59.8% 27.8% 20% 21.8%

MAINPECIFICATIONS

WORK TECHNIQUE MAINDETAILSFOUNDATIONS Stabilisedrammedearth Soilstabilisedwith5%cementBASEMENT AURAMplainblocks240,9cmthick CSEBinstabilisedearth‐sandmortar1:6:

6PLINTHBEAM Composite with U blocks 240 and

RCC5% cement CSEB filledwith concrete 1:2:4

INSIDEFLOORING

AURAMtiles240,2.5cmthick 5% cement CSEB tiles, laid on cement‐sandmortar1:4+cementmilk

FLOORINGOFTHECOURTYARD

Stabilisedearthconcrete Stabilised earth‐sand‐gravel concrete(Cement+lime+‐alum+tannin)

WALLS Stabilisedrammedearth Soil stabilised with 5% cement and a“homeopathicmilkoflimeandalum”

RINGBEAM Composite with U blocks 240 andRCC

5% cement CSEB filledwith concrete 1:2:4

SPRINGERBEAMS

RCC beams for resting the variousvaults

‐RCCcastinferrocementlostshuttering‐RCCcastinconventionalshuttering

LINTELS

CompositesingleheightwithUblocks240andRCC


BEAMS

Composite, double or triple height,withAURAMUblocks240+RCC


COLUMNS CompositewithAURAMroundhollowblocks240&290andRCC

5% cement CSEB filledwith concrete 1:2:4stonechips

FLOORS Precastferrocementchannels,2.5cmthick

Channelswithcement‐sandmortar1:2

ROOFS

Various vaults built “free spanning”withAURAMplainblocks240&290

5% cement CSEB laid with a cementstabilisedearth‐sandglue1:9:3

PAINTS&PLASTERS

‐Variousstabilisedearthplasters‐Whitecementstabilisedearthpaints

Cement stabilised earth plasters andpaintsofvariouscompositionsaccordingtothework

WATERPROOFING

Stabilisedearthplaster(3coats) Earth‐sand plasters stabilised withvariouspercentageofcement,lime,alumandtannin

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TRAININGCENTREOFTHEAUROVILLEEARTHINSTITUTEGroundfloorplan

28

SECTIONOFTHEEGYPTIANSHAPEDVAULTOFTHETRAININGCENTREDetailsofthevarioustechniquesimplemented

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Entranceofthelecturehall

Lecturehall

Kitchenofthetrainees

Detailonabulleye

BacksideoftheTrainingCentre

30

EARTHVERSUSOTHERBUILDINGMATERIALSThetraditionalbuildingmaterialusedaroundAurovilleisfiredbrick.Villagersfiretheirownbricks in countrykilnswhicharenotveryefficient.Theyconsumea lotofwood,pollute a lot and, in the end, give poor quality buildingmaterials. Good quality firedbricksarealsoavailablefromfactoriesandtheyarecalledwirecutbricks.

HalfCSEB240(24x24x9cm)

Wirecutfiredbrick(22x10.5x7.2cm)

Countryfiredbrick(±22x10.5x6.5cm)

COSTEFECTIVENESS

Earthen buildings have the advantage of using local resources and being labourintensive. Therefore,most of the time, they cost less than conventionalmaterials andtechnologies.Thefinalcostofabuildingwilldependmainlyonthedesign, thetypeoffinishesandtheprojectmanagement.Inallcases,thetechnologiesimplementedwillbecosteffective.InthecontextofAuroville,afinishedm3ofCSEBmasonryisalwayscheaperthanfiredbricks: 19.6% less than country fired bricks and 53.3 % less than wire cut bricks(November2002costs).Walls made of compressed stabilised earth blocks are already less costly than firedbricks, but stabilised rammed earthwalls are even lower in cost thanCSEBmasonry.ThematerialforCSEBorrammedearthisthesame,butthedifferencecomesfromthefactthattheblockshavetobecuredontheground,thenliftedandbuiltbymasonslateron. In the case of rammed earth, thewalls aremade by semi‐skilled labour and theystandinplaceattheendoftheday.Therefore,afinishedm3oframmedearthwallcosts22.6%lessthanCSEBwall,37.8%lessthancountrybricksand63.9%lessthanwirecutbricks.

THEENVIRONMENTALCOSTSCosts are toooften limitedonly to amonetary value.Another important aspect is theenergyconsumption involved inthematerial.Theproductionofearth‐basedmaterialsconsumesmuchlessenergyandpollutesmuchlessthanfiredbricks.CSEBandrammedeartharemuchmoreeco‐friendly.Theyhavetheseadvantagescomparedtofiredbricks:Pollutionemission(KgofCO2

/m2)

Energyconsumption(MJ)

2.4

7.9

timeslessthanwirecutbricks

timeslessthancountryfired

4.9

15.1

timeslessthanwirecutbricks

timeslessthancountryfired

bricks bricks

(Source:DevelopmentAlternatives,NewDelhi,1998)

31

COMPARISONOFBUILDINGMATERIALSINAUROVILLE

WIRECUTBRICKS

COUNTRYFIRED

BRICKS CSEB240

RAMMED

EARTH

Bricksize(L,W,H,incm) 22x10.5x7.2 22x10.5x6.5 24x24x9

(Wallcastinsitu)

Volumeofbrick 1.66Litres 1.50Litres 5.18Litres(Wallcastin

situ)

Weightperunit3.12Kg=1876

Kg/m3 2.81Kg=1871Kg/m310.00Kg=1929

Kg/m3 ±1950Kg/m3Stabilisation Fire Fire 5%cement 5%cementWastageofrawmaterial 3 % 12 % 5% 0%Unitsperm3(rawmaterial) 601 No. 666 No. 193No. NobricksPollutionemission(CO2)* 39 Kg/m3 126 Kg/m3 16Kg/m3 16Kg/m3Energyconsumption* 539 MJ/m2 1657 MJ/m2 110MJ/m2 110MJ/m2Drycrushingstrength 100 Kg/cm2 35 Kg/cm2 50Kg/cm2 50Kg/cm2

PRODUCTINFORMATION

Waterabsorption 9to11% 10to14% 9to12% 8to11%Wallthickness 22cm 22cm 24cm 24cm

Mortarused 1cement:5sand 1cement:5sand1cement:6soil:6

sand NomortarMortarQtyperm2ofwall 72.4Litres 76Litres 36.1Litres Nomortar

Unitsperm2ofwall98(with1.5cm

mortar)106(with1.5cm

mortar) 40(with1cmmortar) NobricksWALLDETAIL

Dailyoutputperteam 3.3m2=320bricks 4.6m2=490bricks 3.8m2=150blocks 8m2Unit(Brick)onsite 3.50 1.425 4.47 NobricksRawmaterialperm3** 2168perm3 1063 perm3 906 perm3 956Perm3

Mortarperm3 1481perm3 1481 perm3 726 perm3 Nomortar

Finishedwallperm3 2724perm3 1810 perm3 1334 perm3 1061Perm3

COST

Finishedwallperm2 599perm2 398 perm2 320 perm2 255Perm2

Sievedsand 360 perm3 Mason :150perdayLabourmale :100perdaySievedsoil 70 perm3 Helper :75perday Labourfemale:60perday

DATA

Cement(43grades) 150 (50Kgbag)

AllcostsareinIndianRupees Value:Auroville,April2005,1US$=±43.5Rs.*Source:DevelopmentAlternatives,NewDelhi,1998

Wirecutbricksarealsocalledkiln‐firedorchamberbricks

**Thecostofrawmaterialincludethewastage Countryfiredbricksarealsocalledvillagebricks

AllmaterialcostsincludesthedeliveryonsiteTheCSEBpriceistheproductioncoston

siteBlocklayingteam=1mason,1helper,1/2labourmale,1/2labourfemale

TeamforproducingCSEB=9labourmale

NOTES

Thelabourcostincludestheyearlybonusandtheemployeeprovidencefund Rammedearthteam=5labourmale

ENVIRONMENTALCOST MONETARYCOST STRENGTH

CSEBandrammedeartharemore CSEBandrammedearthalways CSEBandrammedearthare:eco‐friendlythanfiredbricks costlessthanfiredbricks

Pollutionemission: Afinishedm3ofCSEBwallis: 1.4timesstrongerthan

SUMMARY

2.4timeslessthanwirecutbricks26.3%cheaperthancountryfiredbricks countryfiredbricks

7.9timeslessthancountryfiredbricks

51.0%cheaperthanwirecutbricks

Energyconsumption:Afinishedm3oframmedearth

wallis: 0.5timesweakerthan4.9timeslessthanwirecutbricks 20.4%cheaperthanCSEBwall wirecutbricks15.1timeslessthancountryfiredbricks

41.4%cheaperthancountryfiredbricks

61.0%cheaperthanwirecutbricks

32

TOWARDSTHEFUTUREBuildingwithearthhasagreatpast,butalsoapromisingfuture,especiallyinAuroville.It is definitely an appropriate, cost and energy‐efficient, and eco‐friendly technologywhichcanpromoteasustainablefuture.Obviously,onehastomasterthematerial thetechniques so as to obtain the optimum possibilities for a harmonious, durable,agreeable and efficient architecture. One can note these advantages of earth as abuildingmaterial: Theearthisalocalmaterial,contributingtosustainabledevelopment. Theproductionofthebuildingcomponentsdemandsalotofsemi‐skilledmanpower. Thetechnologyiseasilyadaptableandtransferable. The monetary and environmental costs are much lower than that of most othermaterials.

Thethermalcomfortandvibratoryatmosphereareverypositive.Onehasalsotomasterthedisadvantagesofthematerialwhich,normally,arevariationsin the soil quality, and hence the block quality and the production of blocks on site.Thesereductiveaspectscanbeunderlined: Mechanicalqualitiesarelessregular. Sensiblebuildingdetailsarerequired. The constraints of organizing and managing the production of one’s own buildingmaterialonsite.

Despite thepossibilitiesandadvantagesofferedbystabilisedearthmaterials,buildingwith earth in Auroville is still not the common practice. Either people don’t want toacknowledge the advantage of this material or they don’t want to get the burden toorganisetheblockproductionontheirsiteandmanageeverythingthemselves.ThegeneraliseduseinAurovilleofcompressedstabilisedearthblocksandotherearthtechniquesneedsacentralisedproductionofblocksandacoordinatedmanagementofresources–physicalandhuman.Thisdevelopmentstepwouldinsureacontrolledandmoreregularqualityofrawmaterialsandfinishedproducts.Thisisoneoftheaimsforthenextyearstocome.Thechallengeinfrontofus:How can realize architecturewhich is full of light, suppleness, simplicity, imaginationandbeautywithadark,heavyandformlessmud?ThisiswhatwearetryingtoachieveinAuroville.

“Auroville,thecitytheearthneeds"

ha12 building with earth in av - auroville green...

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