Waterproofing structures installed below ground level

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Technical Notebook

WATERPROOFING STRUCTURES INSTALLED BELOW GROUND LEVEL

C.P.

MK

8387

30 -

(GB)

04/

11

Technical Notebook

WATERPROOFING STRUCTURES INSTALLED BELOW GROUND LEVEL

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Technical Notebook

WATERPROOFING STRUCTURESINSTALLED BELOW GROUND LEVEL

page 04 1. INTRODUCTION

page 05 2. GEOTECHNICSANDFOUNDATIONSpage 05 2.1 GEOTECHNICS

page 06 2.2 FOUNDATIONS

page 11 3. HYDROLOGYANDHYDROGEOLOGYpage 12 3.1 THEWATER-GROUNDRELATIONSHIP

page 12 3.2 WATERANDSUBSOIL

page 14 3.3 DRAINAGESYSTEMS

page 20 4. EXCAVATIONWORK

page 24 5. MAPEIWATERPROOFINGSYSTEMSFOR FOUNDATIONSTRUCTURESpage 24 5.1 WHYWATERPROOF?

page 26 5.2 MAPEPROOFANDBENTONITE

page 29 6. SPECIFICATIONSFORFOUNDATION CONCRETE

page 32 7. WATERPROOFINGNEWSTRUCTURES BELOWGROUNDLEVELpage 34 7.1 SEALINGCONSTRUCTIONJOINTS

page 34 7.2 WATERPROOFINGTHEBASEOFAJIBCRANE

page 35 7.3 WATERPROOFINGALIFTWELL

page 40 7.4 WATERPROOFINGHORIZONTALFOUNDATIONPADS

page 42 7.5 WATERPROOFINGPILEHEADS

page 47 7.6 WATERPROOFINGVERTICALSURFACESBEFORECASTING

page 54 7.7 WATERPROOFINGVERTICALSURFACESAFTERCASTING

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Technical Notebook


page 55 7.7.1 WATERPROOFINGVERTICALSURFACESAFTER CASTINGWITHMAPEPROOFORMAPEPROOFLW

page 56 7.7.2 WATERPROOFINGVERTICALSURFACESAFTER CASTINGWITHMAPELASTICFOUNDATION

page 58 7.7.3 WATERPROOFINGVERTICALSURFACESAFTER CASTINGWITHPRODUCTSFROMTHEPLASTIMUL RANGE

page 61 7.8 WATERPROOFINGSTRUCTURALJOINTS

page 64 7.9 SEALINGTHROUGH-PIPESINVERTICALWALLS ANDFOUNDATIONPADS

page 66 7.10 SEALINGADRAINAGEWELL

page 67 7.11 WATERPROOFINGACCESSRAMPSTOAREAS BELOWGROUNDLEVEL

page 69 7.12 WATERPROOFINGDEPURATIONTANKS

page 71 7.13 WATERPROOFINGASEWAGEWASTEOUTLET ANDVENTCASTINPLACE

page 74 7.14 WATERPROOFINGCONSTRUCTIONSBUILTUSING THETOP-DOWNMETHOD

page 77 8. WATERPROOFINGEXISTING STRUCTURESBELOWGROUNDLEVELpage 78 8.1 LININGSURFACESINROOMSBELOWGROUNDLEVEL

page 78 8.1.1 WATERPROOFINGVERTICALSURFACES

page 80 8.1.2 WATERPROOFINGHORIZONTALANDVERTICAL SURFACESWITHMAPEPROOF

page 84 8.1.3 WATERPROOFINGHORIZONTALANDVERTICAL SURFACESWITHACOMBINEDBENTONITE- CEMENTITIOUSSYSTEM

page 89 8.2 WATERPROOFINGALIFTWELLAGAINST HYDRAULICLIFT

page 90 8.2.1 WATERPROOFINGWITHOSMOTICMORTAR

page 91 8.2.2 WATERPROOFINGWITHACOMBINEDOSMOTIC MORTAR-FLEXIBLECEMENTITIOUSMORTARSYSTEM

page 92 8.2.3 WATERPROOFINGWITHACOMBINEDBENTONITE- FLEXIBLECEMENTITIOUSMORTARSYSTEM

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2. GEOTECHNICS AND FOUNDATIONS

2.1 GEOTECHNICSGeotechnics is thestudyof themechanicalaspectsof thegroundand

itsapplication inengineeringworks.Thestratographicconformationof

thegroundanditsmechanicalbehaviourisanalysedtoidentifythemost

suitabletypeoffoundationstoguaranteethestabilityanddurabilityofa

structure.

Foundations are structural elements with the function of transferring

stressesand loads,bothpermanentandaccidental, fromthestructure

constructedonthefoundationstotheground.Thetypeof foundations

determines the “footprint” that a structure leaves on the ground. The

sizeofthefootprint(plinths,groundbeams,foundationpadsandribbed

foundationpads)isinverselyproportionaltotheresistanceoftheground

and proportional to the loads to be discharged onto it. The ground,

foundationsandtheoverallstructure,therefore,formasingleunitbody

whichmustbeconsideredasasinglesystem.

Thedesignofastructurestartswithapreliminaryanalysistodetermine

the type, stratographic conformation and physical and mechanical

characteristics of the ground. It is particularly important to determine

the safety load of the ground, known as its “load-bearing capacity”,

expressedinkg/cm2.

Apartfromtheeconomicaspectstobetakenintoconsideration,thereare

anumberofotherparameterswhichalsocontributeindefiningthetype

offoundationstouse,withthemainonesbeingasfollows:

• the construction system adopted for the structure built on the

foundations;

•restraintsandguidelinesoflocalbuildingregulations;

•thedepthatwhichthelayerwithsufficientload-bearingcapacityon

whichtheloadsactislocated.

1. INTRODUCTIONThe issuesdealtwith in thismanual regardwaterproofingmethods for

various types of structures below ground level (Fig. 1.1) according to

the type of ground and obviously the effect of water acting upon the

structure.Athoroughanalysisofthemorphologicalcharacteristicsofthe

groundandwaterflowduringvariousperiodsoftheyearallowforcorrect

analysisoftheconstructiontechniqueappliedforstructuresbelowground

level.Studying thecharacteristicsof theground (geotechnics)supplies

useful informationabout the load-bearingcapacityof theground itself

anditshydrogeologicalconformation.Itisalsoimportantthatanywater

present below ground level is carefully studied (hydrology) in order to

assessthecontextinwhichnewstructuresarebuilt,suchaswaterunder

pressure,waterpercolating frombelowor thepresenceofwidespread

damp. This will then influence the type of foundations system chosen

forthestructure,thetypeofwaterproofingusedand,clearly,thetypeof

temporarysupportsrequiredtoconstructthefinalstructure.

Fig.1.1–Phasesofanexcavationforconstructionworkcarriedoutbelowgroundlevelinabuilt-uparea

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Fig.2.2-Truncated-pyramidplinth

Fig.2.1–Classificationoffoundationsaccordingtotheirloadtransfermechanismtotheground

2.2 FOUNDATIONSFoundations form a group of structural elements within a construction

system,withthefunctionoftransmittingloadstotheground.Sincethe

behaviouroftheground,thefoundationsandthestructurebuiltonthe

foundationsaredependentoneachother,thereisawidearrayofvariables

whichhave tobeconsideredwhencalculating thesizeof foundations.

Theparametersbelowmustbetakenintoconsiderationwhenchoosing

thetypeoffoundations:

•theloadsactinguponthefoundations;

•thefinaluseofthebuilding;

•typeandstratographicconformationoftheground;

•thepresenceandlevelofthestratum;

•theheightofthefoundations;

•economicimplications;

•presenceandtypeofsurroundingbuildings;

•frictionandslopeofthegroundonwhichthefoundationsareinstalled.

Theforcestransmittedfromthestructuretothefoundationsarethesum

ofthefollowing:

•loadsfromthestructure;

•permanentoverloads;

•accidentaloverloads(accordingtothefinaluseofthestructure);

•horizontalforcesduetowinds(generallybendingmoments);

•horizontalseismicloads(appliedeitherdynamicallyorstaticallytothecalculationmodel).

Foundationsmaybesub-dividedaccordingtotheirloadtransfermechanism

tothegroundoraccordingtotheTerzaghiclassificationsystem.Inthefirst

case,thefoundationsmaybeclassifiedasillustratedinFig.2.1.

With direct (or surface) foundations, the forces are transferred to the

groundbyenlarging the load-bearingelementsof the structureon the

foundations, while with indirect (or deep) foundations, the forces are

transferredmainlybyfrictionorlateraladhesionatthepile-groundinterface.

Themostsimpleformofintermittentdirectfoundationsarerepresented

by plinths, which basically consist of enlarging the pillars to distribute

the loads over a larger surface area. In certain cases, because of the

poor mechanical characteristics of the ground, restraints by seismic

regulationsor if the loadshave tobedistributedover largerareasand

theplinthsaretoolarge,foundationpadswhichcovertheentireareaof

thebuilding(continuousdirectfoundations)areamorefeasiblesolution.

Inothercases,indirectfoundationssuchaspileshavetobeused,sothat

theloadsfromthestructureonthefoundationsaretransferredtomore

compactandresistantgroundwhichmayonlybefounddeeperdown.

If theTerzaghiclassification is followed,ontheotherhand, thevarious

typesoffoundationsmaybesub-dividedaccordingtotheratioD/B(D:

depthofthefoundations,B:widthofthefoundationbase):

•directorsurfacefoundations(plinths,continuousbeams,foundationpads)D/B<4;

•semi-deepfoundations(shafts)<D/B<10;

•deepfoundations(piles)D/B>10.

Direct(orsurface)foundationsmaybeusedwhenitisnotnecessary

to excavate deep down to reach ground with good mechanical

characteristics.Accordingtotheformandsizeofthesupportbase,these

structuresmaythenbesub-dividedasfollows:

•intermittent(orisolated)foundationssuchasplinths;

•continuousfoundationssuchasgroundbeamsandfoundationpads.

Plinths (Fig. 2.2) are used to build framed structures (in reinforced

concrete or steel) for low stresses on ground with good geotechnical

characteristics.Theyaregenerallyquitepreciseelementswithatruncated

pyramidshapeandasquarebase,andformanenlargementatthebase

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INDIRECT FOUNDATIONS

ON PILES WELL-TYPE

- FITTINGS

- CAST ON SITE

- IN WOOD (NO LONGER USED)- IN REINFORCED CONCRETE- IN IRON

DIRECT FOUNDATIONS

CONTINUOUS DISCONTINUOUS

- TRAVI ROVESCE

- GRIGLIATO DI TRAVI ROVESCE

- PLATEE

- GROUND BEAMS- NETWORK OF GRADE BEAMS- FOUNDATION PADS- RIBBED FOUNDATION PAD

- ISOLATED PLINTHS- PLINTHS FOR GROUPS OF PILLARS

Pillar

Truncated-pyramidplinthSubstrate

09

Fig.2.5–Ribbedfoundationpad

Fig.2.3–Schematicdiagramofstressesactingonafoundationbeam

ofthepillars.Iftheyarenottootall,theyarewithoutadoubtthemost

economical typeof foundation.Plinthsaremainlysubjected tovertical

forces,sothesizeoftheirsurfaceisgivenbytheverticalloadsandload-

bearingcapacityof theground,while theirheight isdeterminedby the

capacityofthematerialtoresistshearloads.Iftheplinthsarerectangular,

the longer side of the plinth is parallel to the longer side of the pillar.

Plinthsmaybedefinedasbeingeithersquatorslimaccordingtotheir

heighttolongersideratio.Accordingtoparameterscontainedinbuilding

regulationsforseismiczones,theplinthsmustbeconnectedtoabeam

andcurbnetworktoguaranteethatthebehaviouroftheentirestructure

ismorehomogenous.

Continuous direct foundations, on the other hand, are formed by

continuouselementssuchasgroundbeamsorfoundationpadsandare

usuallyusedinthefollowingcases:

•whentheresistantgrounddoesnothaveaveryhighsafetyload

(load-bearingcapacity);

•whentheresistantgroundisatashallowdepthcomparedwith

groundlevel;

•whentheresistantgroundisatsuchadepththatitismore

economicaltoreachitusingdeepfoundations;

•whenparticularlyhighloadsactuponthefoundations.

Groundbeams(Fig.2.3)arestructuralelementswhichfunctionmainlyin

alongitudinaldirectionand,unlikeinthecaseofstaticoverheadbeams,

theverticalloadsactinguponthemaregeneratedbytheirreactionwith

thegroundandactinanupwardsdirection.Groundbeamsareusedwhen

alargesupportsurfaceisrequiredtotransmittheloadstotheground,or

ifthegroundhasparticularlyirregularpointtopointresistance(therefore

with the riskofdifferential settling). In thecaseof networksof ground

beams (Fig.2.4), thebeamsthemselvesareplacedat rightanglesand

intersectincorrespondencewiththepillars.

Foundationpadsareusedwhenveryhighloadsneedtobetransferred

intogroundwithpoor load-bearingcapacity,orwhen it isnotpossible

to install deep foundations. This technique may be considered a

developmentofgroundbeamsand is formedbya reinforcedconcrete

floorslabwhichcoverstheentireareaofthegroundwherethebuildingis

constructedandinwhichthepillarsareinserted.

A foundationpad isaslabsubjected tovertical forcesconcentrated in

correspondencewiththepillars,bendingmomentsatthepillar/foundation

jointsandloadsdistributeduniformlyovertheentiresurfacegeneratedby

thereactionofthegroundintheoppositedirectiontotheverticalloads

fromthepillars.Therearetwotypesoffoundationpads:

•ribbedtypeformedbyasinglelowerpadandanetworkofmainand

secondarybeams(Fig.2.5);

•fulltype.

Whichtypetousedependsoneconomicalfactors,suchaslowercosts

for materials and labour, and technical considerations, in that ribbed

foundationpadsarestifferandweigh lesscomparedwith the full type

withthesamethickness.

Semi-deep foundations are shaft type, used in the 19th Century and

nowadayscompletely abandoned.This techniqueconsistedofdigging

adeepwellor shaftwithadefinedshapedown toa layerof resistant

ground.Itwasthenfilledwithdry,well-packedmaterialoracementitious

conglomerate with a low cement content, to form masonry pylons on

whichtheconstructionwasbuiltformedbyconnectingbeamsandarches

todischargetheloads.

Deep foundations are used when, because of the poor mechanical

Fig.2.4–Latticeofagroundbeam

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Foundationbeam

Reactionfromtheground

Groundbeam

Substrate

Rib

RibFoundationpad

Foundationpad

SubstrateSubstrate

11

Fig.2.7–Phasesoftheconstructionofboredpiles

characteristicsof thesurfaceof theground,more resistant layerswith

suitableload-bearingcapacitytowithstandtheloadsfromthestructure

deep down in the ground need to be reached. Deep foundations are

formedbyfoundationpileswitharoundprofile.Theload-bearingcapacity

ofpiles(Fig.2.6)isgivenbytwodistinctcharacteristics:

•verticalload-bearingcapacity;

•lateralload-bearingcapacity.

Thefirstcharacteristicdependsonthesectionofthepileandthelayer

reachedbyitsbase(whichiswhywetrytoreachthemostresistantlayers

withthebaseofthepile).Thesecondcharacteristic,ontheotherhand,

isduetofrictionbetweenthesideofthepileandthegroundaroundthe

pileanddepends,therefore,onthetypeofpileandthetypeofground.

Veryoften,frictionisthepredominantphenomenonfortheload-bearing

capacity of piles. In fact, there is a particular category of piles, the

suspendedtype,inwhichthebaseofthepiledoesnotreachthemore

resistantlayersofthegroundanditsentireload-bearingcapacityisgiven

byfrictionalongitssides.

According to the installation technique used, piles are sub-divided as

follows:

•boredpiles (Fig.2.7): thefirststep is to remove thesoiland then

castacementitiousconglomerateinplacewhichisusuallyreinforced.

Theboredholemaybeformedbyperforation(usingrotatingorrotor-

percussionequipment)orbyexcavating(usingadiggerfittedwitha

roundtoothedbucket).Whenformingthehole,thesidewallsmaybe

mademorestablebyusingastabilisingfluidorbyinstallingatemporary

metallicliner(calledasleeve).Oncetheholehasbeencompleted,the

steel reinforcement cage is inserted and the concrete is poured in

throughatube.Oncethecastingoperationhasbeencompleted,the

temporarymetalliclinermayberemoved.

•drivenpiles(Fig.2.8):thesoilisnotremovedandthepilesaredriven

into the ground by hammering, vibrating, pressing, screwing or by

a combination of these techniques. Driven piles generate a lateral

compacting action upon the ground which increases their lateral

resistanceduetofriction.Anegativeaspectofthistechniqueisthat

thepilesmaybequitelongandahighamountofenergyisrequiredto

ramthemin.Rammedpilesmaybemadeusingthefollowingmaterials:

steel, reinforcedconcrete,wood (although thismaterial is no longer

used)oracombinationofmaterials.

Pilesusuallyhaveacircularsectionandtheirdiametervariesaccordingto

theirstructuralrequirements;smallerdiameters,between100and200mm,

areknownasmicro-piles.Thetransferofloadsfromthebuiltstructureto

eachsinglepile,whicharelevelledofftothesameheightafterinstallation,

isthroughconnectingstructuresonthesurfacesuchasplinths,ground

beamsandfoundationpads.Whenanalysingandconsideringthenature

of the ground for the foundations, its water content, one of the most

importantfactorsoftheground,mustbecarefullyassessed.Thisiswhy

it isuseful tobrieflydiscusshydrologicalandhydrogeologicalaspects,

thelatterofwhichisthestudyofundergroundwateranditsproperties.

3. HYDROLOGY AND HYDROGEOLOGYHydrologyisthesciencewhichstudieswaterontheearth,bothonthe

surfaceandbelowthesurface,howitisformed,howitcirculatesandhow

itisdistributedwithrespecttotimeandspace,itsbiological,physicaland

chemicalpropertiesandhowitinteractswiththeenvironment,including

withlivingbeings.Inbrief,hydrologyisthestudyoftheflowofwaterwhich

forms the so-called hydrological cycle. Hydrogeology is the branch of

geologywhichstudiesphreaticorundergroundwateranditsproperties.

Technical Notebook


Fig.2.6–Schematicdiagramofstrainsactingonafoundationpile

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Peakload

Friction

Coherentground

1)Boringoperation 2)Insertionofreinforcement

3)Castingtheconcrete

4)Finishedpile

Pilehammer

Drive-head

Pile

Fig.2.8–Schematicdiagramofapilebeingrammedintotheground

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3.1 THE WATER-GROUND RELATIONSHIPThegroundismadeupofvarioustypesofsolidmaterialofvariousorigin

andemptyspaces (Fig.3.1) in variousshapesandsizes.Thequantity

ofemptyspacesvaries,andtheymaycontaineitherairorwaterwhich

entersandthencirculates.

3.2 WATER AND SUBSOILThecapacityofthegroundtoletwaterpassthroughiscalledpermeability

anddependsonthepresenceofvoidsinthesolidmaterialwhichforms

thegrounditself.Ifthevoidsareformedbypores,itiscalledpermeability

byporosity.Ifthevoidsareformedbyfractures,ontheotherhand,itis

calledpermeabilityby fracturation. Inbothcases,only thevoidswhich

areconnectedtoeachotherallowwatertomove.

An example of a very porous rock with low permeability is pumice, in

whichonlyafewoftheporesintherockareconnectedtogether.Ground

formed by large-grained pieces is highly permeable. This means that

water infiltrates easily and does not tend to remain on the surface. In

ground formed by small-grained pieces, such as clayey ground, the

waterfiltersthroughmuchmoreslowly.Therefore,whereclayeyground

isfound,itismorelikelythatwaterwillbefoundonthesurface.Inground

formedbylayersofcompactrock,permeabilityvariesaccordingtothe

numberandsizeofthefracturesandhowthesefracturesareconnected

together.Therefore,tosumup,waterpassesthroughbothlayersofclay

(soil)andlayersofgravel(rock),buttheintensityofthephenomenonis

completelydifferent.Morethanacenturyago,Darcystudiedtheflowof

waterthroughhorizontalsandbeds,andestablishedthattheflowspeed

through porous matter is directly proportional to the loss in load and

inverselyproportionaltothelengthoftheroute.Darcyboundthevarious

rateswiththefollowingwell-knownequation:

v = k iwhere v is the discharge speed, k is the coefficient of permeability or

coefficient of hydraulic conductivity, and i is the hydraulic gradient

or slope of the piezometric line. Between 1915 and 1925 Terzaghi

demonstratedhowDarcy’slawcouldbeappliedtoalltypesofground.

Thecoefficientofpermeabilitykexpressesvelocityanddependsonthe

porosityofthematerialandthefluid.Variousfactorshaveaninfluenceon

thecoefficient,especiallykwhichisdirectlyproportionaltothesizeofthe

granules.Infact,gravellygroundhasahighrateofpermeability,whereas

clayeygroundismoreorlessimpermeable.Inthefollowingsection,the

term“impermeable”willbeusedanumberoftimes,whileinnature

completelyimpermeablegrounddoesnotactuallyexist.

Waterwhich infiltrates into thegroundandmoves in thesubsoil forms

underground “groundwater”. The term “aquifer” will be used in this

section, which indicates ground (compact or less compact, and either

stratifiedornon-stratified)whichhasthecapacityofstoringwater,making

itcirculateandthenreturningitinlargequantities.Anaquiferisdelimited

inthelowerpartbyalayerofimpermeablegroundandthewatermoves

aroundslowlyintheaquifer.

In general, aquifers fed directly by rainwater which infiltrates from the

surface and penetrates into permeable ground, until it runs into an

impermeablelayerofmaterial(forexampleclay)whichslowsitdown(or

whichcompletelyblocksit)andstopsitgoingdeeper,areknownaswater

tablesorfreestrata.Thislayerformsthebaseor“bed”ofthewatertable.

Theupperlimitofthewatertableisbasicallyformedbyafinersaturated

zone(the“phreaticsurface”)andthepressureofthewatercontainedinit

isthesameastheatmosphericpressure.

Therearealsostrataunderpressureknownasartesianstrata (Fig.3.3)

whicharedelimitedinboththelowerandupperpartsbyanimpermeable

layer. The water which feeds these strata is the same which infiltrates

where thepermeableground,which forms the stratum itself, ison the

surfaceandmaythereforereceivethewater.Thus,theareawhichfeeds

a stratum under pressure may be quite a distance from the stratum

itself.Strata“underpressure”areknownbythistermbecausethewater

inside the stratum is subjected to a pressure which is higher than the

Technical Notebook


Fig.3.3-Sectionalviewofaportionofgroundandanartesianstratum

Fig.3.2–Sectionalviewofaportionofgroundanditswatertable

Fig.3.1–Schematicsectionalviewofaportionofground

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Aria

Granuliditerreno Acqua

Air

Grainsofearth Water

Phreaticsurface

Groundwater

Impermeablestratum

Piezometricsurface

Impermeablestratum

Artesianstratum

Impermeablestratum

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Fig.3.5–Schematicdiagramofhowthelevelofthewatertableisloweredusingawellpointsystem

Fig.3.6–Drillingoperationstoinsertwellpoints

atmosphericpressure,andwhichhelpsitrisespontaneouslyinsideahole

drilledintheground.Thewatercontainedinbothtypesofaquifermaybe

extractedbymakingawell.

Thewatercontainedinthegroundmaybeclassifieddifferentlyaccording

tothewayitbondswiththegrainsofearth:

•retainedwaterwhichadherestothegrainsofearthandisnotpartof

thehydrologiccycle;

•freewaterwhichinfiltratesintothegroundduetotheforceofgravity.

Freewater isthemost importanttyperegardingtheproblemofground

drainage.

Undergroundwatermaybeconductedtotwodifferentzones:saturated

andnon-saturated.Thenon-saturatedzonemaybe found immediately

below the surface of the ground and the empty spaces contain both

waterandair,whilethesaturatedzoneformstheactualstratum.

3.3 DRAINAGE SYSTEMSIfthereisanareaofasitewithgroundwater,asuitabledrainagesystem

mustbeinstalledinordertocarryoutconstructionoperations.Thetypeof

drainagesystemusedishighlydependentonathoroughunderstanding

ofthelithologicnatureoftheareaofgroundinquestionandtheneedto

lowerthelevelofthegroundwater.

Drainingoffthegroundwaterusingawellpointsystemallowsconstruction

worktobecarriedout,evenwhenthereiswaterpresent.Therelatively

lowcostofthissystemcomparedwiththeresultsobtainedisthemain

advantageofthissolution,anditisthequickestandmostcost-effective

methodtotemporarilyorpermanentlydrainoffgroundwater.Thewellpoint

system, which has been used for a number of years in industrial and

constructionapplications,hasbeendevelopedover the last fewyears

andisnowoftenusedforreclaimingland.

Thewellpointsystem(Fig.3.4)isjustoneofthetechniquesapplied,and

consistsinforminganumberofminiwells(wellpoints)intheareaaround

thegroundwherethelevelofgroundwaterneedstobelowered,andis

mainly used in sandyground. It is alsoused to dry off muddyground

afterformingdrainagesleevesinwhichthewellpointsarepositioned.Itis

importanttopointoutthatawellpointsystemtemporarilylowersthelevel

ofthegroundwater(Fig.3.5).

Awellpointsystem(Fig.3.6)comprisesthefollowing:

•anelectricordieselcentrifugalpump(Fig.3.7)withahighvacuum

capacitytopumpthewatertoahigherlevel;

• an intakemanifold (flexiblehoses) to connect thewellpoint to the

pump;

•wellpointswithaseriesofmetallicorplasticfilterstodrawoutthe

waterwithoutdrawingsolidparticlesfromtheground;

•dischargepipestocarrythewaterawayfromtheexcavatedarea.

If thewaterneedstobecarriedovera longdistanceawayfromthe

excavated area, supplementary booster pumps will also have to be

employed.

Inidealconditions,themaximumsuctionliftofawellpointsystemwould

be8.7m.Inrealsiteconditions,however,theperformanceofthepumps

isdrasticallyreduced,andforparticularlydeepexcavationstolowerthe

levelofthegroundwaterbymorethan4metres,wellpointsareinstalled

insteps.Insodoing,thewaterheadisreducedinsuccessivestepsby

installingwellpointsatdifferentlevels.Awellpointsystemallowsanarea

ofasitetobedriedoffsoconstructionworkmaybecarriedoutbelowthe

levelofthegroundwater.

Please note: the drainage system must not be switched until the

reinforcedconcretestructurehascuredsufficientlytowithstandthe

buoyancyforceexertedonthesite.

Technical Notebook


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Intakemanifold

Initiallevelofgroundwater Heightofsuctionpumpinlet

PumpSuctionpipe

Loweredgroundwater

Fig.3.4–Flexiblehouseusedtoconnectwellpointstoanintakemanifold

17

Thetypeofgroundinfluencesthechoiceofthemostsuitabledrainage

system. According to the various types of ground and their grain

distribution, various drainage systems may be adopted as described

below.

•Pebbles(diameter>60mm):todrainoffgroundformedbypebbles,

oneoftwowellsystemsmaybeused.Thefirstsysteminvolvesdrilling

awellatground levelusingacontinuouscoringauger.Thesecond

technique involves positioning a series of perforated concrete rings

usinganexcavator.Althoughthis techniquehasamuch lowercost,

eachsiteneedstobecarefullyassessedtoverifyifsuchasystemis

feasible.Bothsystemsuseanopenairpumpingsystemwitheithera

surfacemountpumporasubmergedpump.

• Gravel (20 mm < diameter < 60 mm): the most suitable drainage

systems are formed by a system of wells or a wellpoint system for

gravel.Thewellsystemissimilartotheonedescribedforpebblesand

isusedwhenitisnotpossibletodriveinwellpointrods.Regardingthe

wellpointtechnique,itisverysimilartothetraditionalsystembydriving

inrodswithahighpressurepump,whilethesandfilterisreplacedwith

aspecialtipforgravelcalledaprobe.Dryingoffgroundwithagravel

wellpointisasystemwhich,unlikedrainingoffwaterwithawell,works

by creating a cone of depression in the water table which forcedly

drawsthewaterfromthesubsoilandincreasesitsvelocity.Withthe

welldrainagesystem,noconeofdepression is formed in thewater

table and the water is drained off by gravitational force, that is, by

runningintothewell.Itsvelocityislowercomparedwiththevelocity

inducedbyawellpointsystemandasaresult,thewaterrequiresmore

time to reach the well and the flow rate is lower. In fact, according

tothesizeofthesiteandthepiezometric leveltobereached, ifthe

drainage capacity of a gravel matrix aquifer is interpreted correctly,

thenumberofpumpsrequiredand, therefore, theoverallcostsmay

bereduced.

•Sandwithagravelmatrix(0.6mm<diameter<20mm):sandysoil

withagravelmatrixisbasicallydrainedoffwithawellpointsystemfitted

withanti-sandfiltersorgravelprobes,accordingtothepercentageof

gravelintheground.Incertaincases,itmaybenecessarytoinstalla

mixedsystemtogetthebestresults.Thewellpointrods,witheither

anti-sand filters or gravel probes, are driven into the ground under

pressure.

•Cleansand(0.2mm<diameter<0.6mm):cleansandistheideal

groundforinstallingawellpointsystemwithmicro-porefilters.Although

it is unlikely that this type of ground is homogenous with uniform

isotropy and grain size distribution, a wellpoint system is almost

alwaysaguaranteethatthedepthtoexcavatemaybereachedindry

conditions,withanacceptablebalancebetweentheresultsobtained

andtheoverallcostofthesystem.Thesystemisalsorelativelyeasyto

install,inthattherodsaresimplydriveninunderpressure.

•Sandwithamuddymatrix(0.02mm<diameter<0.2mm):sandwith

amuddymatrixmaybedrainedoffusingatraditionalwellpointsystem

withanti-sandfilters.Ifthemuddymatrixdoesnothaveaneffecton

thepumps,therodsmaybedriveninunderpressure.If,however,the

muddymatrixtendstoclogthefilters,apre-filteringsystemmustalso

beinstalledbyboringaholeintheground.

•Silt (0.006mm<diameter<0.02mm): themostsuitabledrainage

systemforsiltyground isonewithapre-filter, that is,byboring the

ground,insertingadrainagesleeveandthenbleedingandrinsingthe

wellpointwithasuitablepump.

•Siltwithaclaymatrix(0.002mm<diam.<0.006mm):clayeysiltmay

bedrainedoffusingoneofthefollowingsystems:

-wellpointsystemwithapre-filter;

Technical Notebook


16

Fig.3.7–Centrifugalpumpusedinawellpointsystem

19

- installationofperforatedconcreteringsusinganexcavator.The

useofthistypeofsystem(muchmoreeconomicalafterassessing

itsfeasibilityonsite)dependsonthestabilityofthesidewallsofthe

excavations.

-layingadrainagepipeafterformingadrainagetrench.

•Clay(diameter<0,002):whenthegroundisclayey,therearebasically

twotypesofdrainagesystemsavailable:

-wellpointsystemwithapre-filter;

-layingadrainagepipeafterformingadrainagetrench.

Inrockyground,thewatercirculatesthroughchannelswhicharedifficult

to trace during the preliminary phase. In such conditions, therefore, it

is impossible to get good results with a wellpoint system. A wellpoint

systemmaynotbeabletocontrolthelevelofthegroundwaterinlarge-

grained ground or ground with high hydraulic conductivity. In these

cases,drainagewellswithelectricimmersionpumpsareused.Thewells

aredesignedaccordingtothegeologyofthesubsoilandtheamountand

chemicalandphysicalcharacteristicsofthewatertobedrainedoff.The

designofthewellsmustinclude:

•theboringmethod(percussionorrotating);

•thetypeand lengthofthefilterrequiredandthedepthatwhich it

mustbeinstalled;

•thegraindistributionifdrainagelayersareused.

Wellsaremadeaccordingtothefollowingsteps:

•verticalholesareboredinthegroundusingapercussionorrotating

(direct rotation or inverse rotation) boring machine, with the core

pulverisedbyacrushingcone.Linersarerecommendedtoprotectthe

verticalsidewallsofthebore.Thedepthoftheboremustbesuchthat

itreachesthelowesttheoreticallevelrequiredforthegroundwaterplus

3mmore,toformapermanentbuffer.

•filtersanddrainagepipeswitha1mmfilteringcapacityareinserted

intothebore;

•gaugedinertmaterialisusedtofillanygapsbetweenthedrainage

pipesandtheverticalsidesofthebore;

•thewelliscementedoffandisolated.

Afterinsertingthefiltersandpipesandselectingthegrainsizeandmineral

typefordraining,thewellmustbecementedtoisolatethewaterfromthe

surfaceandbetweeneachwell.Thefinaloperationsistofinishoffthewell

sothatitisasefficientaspossibleandtoavoidsandorimpuritiesbeing

draggedfromthewaterdrainedoff.

If the groundwater is on the surface and there is only a small amount

ofwatertobecontrolled,horizontalgravitationaldrainagesystemsmay

beused (Fig.3.8).Trenchesaredugat90° to theflowof thewater to

channelthewatertowardsdefinedcollectionpoints.FlexiblePVCpipes

linedwithperforatednon-wovenfabrictostopthewaterreleasingfiner

particlesintothegroundarepositionedinthecollectionpoints.Inorder

toincreasethedrainagecapacityofthesystem,thePVCpipesmayalso

beconnectedtoabatteryofsuctionpumps.Thedrainagepipesarelaid

byaspecialmachinewhichoperates inacontinuouscycleandwhich

mayreachdepthsofupto5m.Onceallconstructionoperationshave

beencompleted, thePVCpipesare leftburied intheground.Withthis

system,thetimerequiredtodrainoffthewaterisconsiderablyreduced

andtheareaistotallyaccessible.However,largespacesarerequiredfor

thelayingequipmenttocarryoutmanoeuvresandtherearenoutilities

availableunderground.

Technical Notebook


18

21

Fig.3.8–Schematicviewofahorizontalgravitationaldrainagesystem,withandwithoutadrainagepipe

Aftertakingalookatthevariousdrainagesystemsavailable,according

to the type of ground where the groundwater needs to be lowered, it

is quite clear that, before designing the drainage system, an in-depth

analysismustbecarriedouttoobtainallthedatarequiredtocalculate

anddeterminethemostsuitabledrainagesystem.

Andonlyafterobtainingacompleteunderstandingofthetypeofground,

itsstratographiccompositionandthepresenceofgroundwatermaythe

nextphaseofidentifyingthemostsuitabletypeofexcavationbetackled.

4. EXCAVATION WORKInthebuildingsector,excavationworkreferstotheremovalofrockand/

orgroundfromitsoriginallocationtoformcavitieswithvariousshapes

anddimensionstocarryoutengineeringandconstructionwork.

Excavationworkmaybedividedasfollows:

•openairexcavations;

•excavationsintunnelsandpassages.

Open air excavations may then be further divided into fixed section

(or trenching) and stripping (or open section) types. Fixed section

excavations are the same width, or narrower, than the depth of the

excavationandstartsfromthesurfaceofthegroundorthebottomofa

previousstrippingexcavation.

Goingfurtherintodetail:

• fixed section excavations are those in which the length of the

horizontal sides is less than the depth. They are generally used for

foundationplinthsorgroundbeams.

•trenchingexcavations are continuouswithanarrowsection.Theyare

generallyusedforlayingpipe-lines,buriedutilities,etc.

Stripping(oropensection)excavations(Fig.4.1)arethoseinwhichthe

horizontalsurface ismuch larger than thedepthof theexcavationand

the section is sufficiently large toallowaccess for vehicles right up to

thefrontoftheexcavation(directaccessusingtemporaryramps)sothat

thematerialdugoutmaybe loadeddirectlyon trucks.Stripping is the

most simple, economical andnatural formof excavationwork tobuild

structuresbelowgroundlevel,andbasicallyusesthefrictionangleinthe

groundtostabilisethesidesoftheexcavation.Ifwaterorrainarepresent,

apartfromthefrictionangleoftheground,thepermeabilityoftheground

isalso important. In fact, thestabilityof thesidesof theexcavation is

heavily influencedby theseparameters,since there isnovegetation to

holdthegroundtogether,asnormallyoccursonnaturalslopes.Generally

speaking, theconditionsdescribedabovearenot thereal limits to this

system. In certain cases, there are other insurmountable problems for

thissystem,suchasthelargespacesrequired,whichincreasedrastically

according to thedepthof theexcavationand thepermanent loadson

theadjacentarea.Infact,whenconstructionworkiscarriedoutinbuilt-

up areas or close to transport networks, apart from the density of the

saturatedground,theloadsofthesestructuresmustalsobetakeninto

consideration.Whentheseconditionsarepresent,theexcavationmustbe

confinedbyinsertingsupportstructures,whichhaveadoubleadvantage:

thesidesoftheexcavationmaybeverticalwhichconsiderablyreduces

theoverallareatoonlywhatisreallynecessaryfortheconstructionwork,

and theyalsosupport thegroundadjacent to theexcavationareaand

guaranteethestabilityofthesurroundingbuildings.

Thesupportstructuresusedtocontainthesidewallsoftheexcavation

aregenerallysimilartobulkheads:relativelythin,verticalstructuresdriven

intothegroundatacertaindepthbelowthe leveloftheexcavation,to

form a support which is sufficiently robust to contrast the thrust from

theembankment,thewaterandanyother loads.Thesestructuresmay

beinstalledwithorwithoutanchoringsystems.Inthefirstcase,stability

isguaranteedbythepassiveresistanceofthegroundontheembedded

Technical Notebook


20

Fig.4.1–Strippedgroundwithoutconfinement

Fillermaterial

PVCdrainagepipeGeofabric

Drainagematerial

HORIZONTALDRAINAGEBYGRAVITY

23

Fig.4.3–Strippedgroundconfinedbyboredpiles

Fig.4.2–Strippedgroundconfinedbydiaphragms

partofthestructureandthebehaviourofthebulkheadismoreorlesslike

thatofabracket.Inthesecondcase,stabilityisalsoguaranteedbystays

clampedinthegroundusingspecialmortarmadefromgroutmixedwith

CABLEJETplasticising,expansiveadditive.Thebulkheadsmaybemade

frompre-fabricatedsheetpiling(overlappedanddrivenintotheground),

reinforcedconcretediaphragmsbuiltdirectlyonsite,bypilesboredinto

theground(sidebysideoratangles)orbymicro-piles.

Thesheetpilingismadefromsteelandisavailablewithvariousprofiles

toobtainwhatevermodulusofresistanceisrequired.

Diaphgrams(Fig.4.2)arebuiltdirectlyonsite,bydiggingatrenchinwhich

theconcreteisthenpoured.Theyareformedbypanelsgenerallybetween

50and120mmthick,atleast200cmwideandmaybeextremelylong,

muchlongerthanpre-fabricatedpanelswhichareusuallyuptoonly15-

20minlength.

Piles (Fig. 4.3) are straight elements made from reinforced concrete,

and their size depends on the cohesion of the ground and the depth

towhich theyaredriven.Thepitchbetweeneachpiledependson the

characteristicsoftheground,theamountofwaterinthegroundandthe

sizeofeachpile.

Micro-pilesarepileswithadiameterlessthan300mmifboredintothe

groundand150mmifdriven in.Micro-pilesarereinforcedwithasteel

tubeorprofileorasteelcagemadefromrebar,whilethefillermaterialis

madefromeithercementitiousmortarorbeton.

Steelsheetpilingbulkheadsaregenerallymoreflexiblethandiaphragms.

This fact must be considered during the design phase because the

evolution,distributionandthefinalactionofthegroundalsodependon

howthesupportstructuresdeformandhowmuchtheydeflect.

Bulkheads are generally constructed before excavating the ground to

the depth required. The vertical bulkhead is usually installed around

theperimeterof theexcavationbeforeplacingthetoppingbeams.The

groundisthenexcavatedinsidetheperimetertothedepthofthefirstrow

ofstays(ifused),thestaysareinsertedandthentightened.Excavation

workisthencarriedoutlevelbylevel,followingthesameprocedureas

describedaboveuntilreachingthedepthrequired.

Bulkheadswithoutanchoragepointsaregenerallyacceptableforshallow

excavations,sincethemoduleofresistancerequiredincreasesquicklyas

thedepthofthegroundtobesupportedincreasesandbecausetheyare

subjecttoconsiderablelateralflexure.Bulkheadswithanchoragepoints

areusedfordeeperexcavationsandespeciallywhentheareaexcavated

is particularly widespread. The use of anchorage points reduces the

lateralmovements, themaximumbendingmomentand thedepth they

aredrivenin.Thepositionoftheanchoragepoints(Fig.4.4)forthestays

must be such that the active thrust prism (ground lift) acting on the

bulkheaddoesnotinterferewiththepassiveresistanceduetotheaction

oftheanchoragepoints.Anchoragestaysfixedinplacebyaribinjected

underpressurearegenerallybuttedtothebulkheadwithananchorplate

orothersuchanchoringmeans,whichisusedtotransmitthepullingforce

ofthestaytothestructure.

If there are constructions below ground level in the vicinity of the

excavation,itisimpossibletoanchorthebulkheads.Inthesecases,the

Top-Downsystemwillhavetobeadopted (Fig.4.5),whichalsoallows

the surface at ground level to be prepared much more quickly than

with conventional systems. The Top-Down system means building the

constructionstartingfromthetopandworkingdownwards,theopposite

ofthetraditionalmethod.Aftercompletingthetemporarystructure,the

ground is excavated to the depth required for the floor slab, which is

thenpoureddirectlyontheground(oftenwiththeuseofplasticsheets

to improve itsfinalappearance).Afterwaiting thestandard timebefore

strippingthefloorslab,excavateunderthefloorslabbypassingthrough

holespreviouslymadeorfromanaccessramp.Withthismethod,afterjust

afewmonths,theroads,squaresandgardensonwhichtheworkisbeing

carriedoutareavailableforpublicuse.Fromthismomenton,theonlyarea

occupiedbythesiteistheaccessramp.Thefloorslabsareanchoredto

thetemporarysidestructuresandbecomeself-bearingwithoutbuilding

thewallsbelow.Thereinforcementtierodsforthepouredconcreteare

theninserteddownwardsandbenttoshape.Aftercompletingallthefloor

slabs,theuprightsarethendugoutandtheconcreteispouredin,with

spacesinthefloorslabswheretheconcreteispouredin.Reinforcement

tierodsandconstructionjointsarehandledexactlytheoppositewayto

traditionalmethods.Insodoing,constructionworkiscarriedoutworking

downwardsuntilthefoundationsarereached.

Technical Notebook


22

25

In certain cases, the need to exploit areas below ground level derives

fromthe lackofnewbuilding landandspacesandthehighdensityof

thebuilt-upareasinsomecities.Constructionworkbelowgroundlevel

alsorepresentsachancetobeexploitedforbuildingauxiliaryandservice

structures (such as car-parks and production units). Structures below

groundlevelcomeintocontactwiththedampintheground,withwater

whichpercolatesupwardsandwithgroundwaterand,therefore,needto

bewaterproofedtoavoid infiltrationscompromising the functionalityof

theroomsinsidesuchstructures.Structuresalsoneedtobewaterproofed

to protect the construction from deteriorating due to the presence of

chemicalagentsinthegroundorcarriedbywaterintotheconstruction

materials,toguaranteealongerservicelifeofthestructure.

5. MAPEI WATERPROOFING SYSTEMS FOR FOUNDATION STRUCTURES

5.1 WHY WATERPROOF?Fromatheoreticalpointofview,goodconcretehasaverylowcoefficient

of permeability k (see Section 3.2), so it may be considered more or

less impermeable to water under pressure. UNI 9858 : 1991 (replaced

by EN 206-1 : 2001) established that for a concrete to be considered

impermeable, itswater/cementratiomustbe<0.55.Inrealconditions,

inspiteofthemostmodernproductiontechniquesbeingemployed,itis

extremelydifficulttomakeconcretewhichisperfectthroughoutitsentire

bulk.Infact,eventhesmallestimperfection(cracks,honeycombs,etc.)

and construction and structural joints form a preferential passage for

water.Therearevariousphenomenawhichgeneratecracksinconcrete,

suchasshrinkageduringcuring,seismicactivity,settlingoffoundations

and vibrations caused by traffic. It is obviously impossible to keep all

thesephenomenaundercontrolandbecertainthattherearenocracks

in theconcreteafter ithasbeenpoured.Also,waterwhichpenetrates

into the concrete is acid, and therefore aggressive for both the base

componentsoftheconcreteandforthereinforcementrods.Considering

theabove,theonlysolutiontoadopttostopwaterpenetratingintothe

concreteand infiltrating into the roomsbelowground level, is tousea

waterproofingsystem.

When a waterproofing system needs to be installed, the highest point

of the groundwater must be considered, whether the level is constant

or influenced by temporary events and by the type of ground. In fact,

thecharacteristicofgroundwithgooddrainage,comprisingmainlysand

andgravel, isthat itreleasesthewaterveryquickly,buttransfers large

amountsofwater justasquicklyaround thestructure, thusgenerating

high pressure. With compact, impermeable ground on the other hand,

suchasclayeyground,thewaterisreleasedveryslowlywiththeriskof

watercollectingandgeneratinginfiltrationsinroomsbelowgroundlevel.

Evenwhenthereisnogroundwater,theinfiltrationofrainwaterprovokes

aggressionactiononthestructurewiththepossibilityofwaterpermeating

intoroomsbelowgroundlevel.

Therefore,fromapracticalpointofview,waterproofingmaybeinstalled

tosolvethreedifferenttypesofproblem:

• damp present in drainage ground which does not cause water to

accumulateduringexcavationwork;

• non-draining ground in excavations which causes water to

accumulate;

•groundwithwaterunderpressure.

Inthefirstcase,thewaterproofinglayerisnotsubjecttohighhydrostatic

loads.Thisismainlyduetotheformationoftheground,generallyformed

by sand and gravel, which have good drainage characteristics and,

therefore, are able to release the water which percolates quite quickly

Technical Notebook


24

Fig.4.4–Anchoragepointsforstaysinsertedoutoftheground’sactivethrustzone

Fig.4.5–ExampleofaTop-Downconstruction.Excavationworkcarriedoutunderthereinforcedconcretefoundationpadcastbeforeexcavating

Bulkhead

Plate

Groundlevel

Tie-rod

Anchoragezone

ActivethrustprismofthegroundLowestpointofexcavation

27

Technical Notebook


withoutitcollecting.Thisconditionmayalsobeachievedongroundwith

poordrainagebyapplyingasuitabledrainagesystematthebaseofthe

foundationsandonalltheverticalsurfaces.

Inthesecondcase,thepresenceofcompactgroundorclayeyground

withnodrainagesystemcauseswatertocollect.Excavationoperations

modify the intrinsic balance between the ground and the water. After

completingtheconstructionworkandfillingintheexcavatedareas,the

groundwillbeconsiderably lesscompactandmoreporous, therefore,

compared with the adjacent ground. This will form a drainage area

towardswhichthewater fromtheadjacentgroundwill tendtomigrate

and generate temporary, high pressures, also due to the fact that the

waterisreleasedveryslowly.Itisworthrememberingthatawaterhead

ofonemetreisequaltoapressureof1000kg/m2(Fig.5.1).

In the third case the water under pressure, due to the presence of

groundwater, is indirectcontactwith thestructureandwillhave tobe

consideredwhenchoosingboththewaterproofingsystemandthetype

ofstructure itself.Therefore,whengroundwater ispresent,even ifonly

duringcertainperiodsoftheyear,afoundationstructurewillhavetobe

installedwhichhasthecapacityofcontrastingtheliftfromwaterunder

pressure.Theonlyfoundationstructurewiththiscapacityisafoundation

pad.

5.2 MAPEPROOF AND BENTONITEMAPEI offers a wide range of products for waterproofing structures

belowgroundlevel(refertotheWaterproofingProductscatalogue)which

aresuitable forbothnewconstructionsandforrepairworkonexisting

structures. Below is a brief description of MAPEI MAPEPROOF and

MAPEPROOF LW bentonite sheets, which completes the information

available on the Technical Data Sheets for each product and in the

WaterproofingProductscatalogue.

MAPEPROOF and MAPEPROOF LW are composed of two layers of

polypropylenegeo-textilefabric.Theupper layer isanon-wovenfabric

whilethelowerlayerisawovenfabric.Theyareneedle-punchedtogether

with a layer of natural sodium bentonite sandwiched between the two

layers.Theneedle-punchprocess(Fig.5.2)involvestheuseofthousands

ofneedleswithahookedtip,whichforcepartofthefibresoftheupper

layerofnon-wovenfabricthroughthemiddlelayerofbentonite,andstitch

ittothelowersupport layerofgeo-textilefabric.Thankstothisspecial

weavingsystem,thenaturalsodiumbentonitecontainedinMAPEPROOF

remains fixed in place, even after hydration. The special grain size of

the bentonite, together with the type of non-woven geo-textile fabric,

guarantee saturation of the non-woven fabric which is in contact with

thepouredconcrete.Thischaracteristicgivestheproductanimportant

technicaladvantage:thefabricmaybeappliedafterpouringtheconcrete

(Fig.5.3).Thedifferencebetweenthetwosheetsistheamountofnatural

sodium bentonite each one contains: MAPEPROOF contains 5.1 g/m2,

whileMAPEPROOFLWcontains4.1g/m2.

Forthisreason,MAPEPROOFLWisonlyrecommendedforwaterproofing

concrete structures below ground level with a hydraulic head of less

than5m.AccordingtoASTMD5887,MAPEIbentonitesheetshavea

permeabilitycoefficientk<1E-11m/s.Thus,onthebasisoftheequation

v=ki(Section3.2),thevelocityvatwhichthewaterpassesthroughthe

sheetissolowthatitispracticallyzero.

The basis of the waterproofing capacity of MAPEPROOF sheets is

bentonite,aclaymineralcomposedmainlyofmontmorilloniteandsodium.

Bentonite originates from the alteration of volcanic ash. It devitrifies in

awatery environmentwith removal of apart of the silica content. The

montmorilloniteisthencrystallised,anditschemicalcontentdependson

thechemicalcontentofthewaterinwhichthevolcanicashprecipitated.

Bentonite is generally divided into two types: sodium bentonite and

calciumbentonite.Sodiumbentoniteexpandswhenitcomesintocontact

withmoisturewhichmakes itparticularly suitable for sealingpurposes

andtocreatewaterproofbarriers.

Calciumbentoniteisausefulabsorbentofionsinsolutionaswellasfats

andoil,whichiswhyitwasprobablyoneofthefirstcleaningagentsused

onanindustrialscale.

26

Fig.5.2–Aschematicviewoftheneedle-punchprocess

Needle

Whitenon-wovenfabric

Sodiumbentonite

Dark-colouredfabric

Fig.5.1–Aonemeterheadofwatergeneratesaloadof1000kg

29

Technical Notebook


Bentoniteisusedinvarioussectors.Becauseofitsviscosisingproperties,

it is used in cement, adhesives, and ceramics and as a binder in the

productionofpelletsforthesteelindustry.Itisalsousedincosmetics

fortreatingacneandoilyskinbecauseofitscapacitytoabsorbexcess

sebumandcleanporesintheskin.Anotherinterestingcharacteristicof

bentoniteisitscapacitytoabsorblargequantitiesofproteinmolecules

fromwaterysolutions,whichmakesitanexcellentagenttoreducethe

levelofproteinscontainedinwhitewine.

Montmorillonite, from which bentonite is made, has a special lamellar

crystalline structure and is non-toxic and chemically inert. The high

specificsurfaceareaofbentoniteandthenegativechargeofthelamellas

which form the structure give this mineral the property to absorb and

adsorbvariouselements.

Themechanismthroughwhichbentoniteisabletoholdwaterwithinits

molecularstructureisbasedonitscapacitytoswell inthepresenceof

waterandmoisture.Confined,swollenbentoniteblocksthepassageof

waterbetween theparticles (Fig. 5.4). This isdue toboth an increase

in the length of the route of the water molecules and the formation

of a stable structure which maintains the energy bond between the

sodiumionsandthewateratahighlevel.Thisstopsthewaterpassing

through thebentonite and it is trapped inside thecrystalline structure.

Whatactuallyhappensisthat,inthepresenceofwaterormoisture,the

bentonite forms a waterproof, water-repellent gel. Hydration rates and

timesvaryaccordingtoanumberoffactors,includingthegrainsizeofthe

mineralandthesurroundingtemperaturewherethephenomenonoccurs.

Thewaterproofing propertiesof bentonite laidon site isdemonstrated

whenexpansionofthebentoniteisblockedbythefoundationstructure.

Thebentonitehydratesandincreasesinvolumeaccordingtothespace

available.Thisincreaseinvolume,asmaybeeasilyimagined,allowsthe

materialtoblockthepassageofthewaterthroughitsstructureandstops

itmigratinglaterally.

Expandedbentoniteobstructsthecavitiesandsaturatescracksupto3

mmwidecausedbyhygrometricshrinkageorsettlingafterpouringthe

concrete.

6. SPECIFICATIONS FOR FOUNDATION CONCRETE

Before analysing typical site conditions and problems and suitable

technical solutions to be adopted, a brief overview of foundation

structuresandtheconcreteusedforsuchstructureswouldbeveryuseful.

Asdiscussedpreviously,withconstructionworkbelowgroundlevelinthe

presenceofgroundwater,whetheritiscontinuousorduetotemporary

events,theonlytypeofstructurecapableofwithstandinghydrostaticlift

isacontinuousfoundation.Asfarasdurabilityisconcerned,theconcrete

must be designed according to EN 206-1 : 2001, which defines the

environmentalexpositionclasses(Table1a-b),onthebasisofwhichthe

limitvaluesaredefined (Table2) for thecompositionandpropertiesof

concrete:themaximumwater/cementratio,theminimumstrengthclass

andtheminimumcementcontent.

Concretemustbewellvibratedtoeliminategravelclusters,andsuitable

admixesmustbe includedso itfillsall thespacesandgapsandflows

freely around the steel reinforcement. In this case, we recommend

using a super-plasticising admix from the DYNAMON range, produced

by MAPEI S.p.A. The DYNAMON system is based on DPP (Designed

Performance Polymer) technology, a new chemical process which,

through total monomer design (exclusive know-how of MAPEI), allows

thecharacteristicsoftheadmixtobemodulatedaccordingtothespecific

performance requirements of the concrete employed. Concrete made

withproductsfromtheDYNAMONrangeiseasytoapplywhilefreshand

offersveryhighmechanicalperformancewhenhardened.

Fig.5.3–AnexampleofMAPEPROOFappliedaftercasting

Fig.5.4–HydrationprocessofsodiumbentonitecontainedinMAPEPROOFandMAPEPROOFLW.

Ifthebentoniteisconfined,whenitswellsitblocksporosityandimpedesthepassageofwater

Porosityof concrete

Bentonite sheet

28

31

Technical Notebook


30

EXPOSURE CLASSESClass

denominationType of conditions and surroundings Examples of conditions and surroundings when the exposure

classes may be applied1 No risk of corrosion or attack

XO Concrete with no metallic reinforcement or inserts: all exposures except freeze/thaw cycles and chemical attack. Concrete with metallic reinforcement or inserts: in very dry surroundings.

In buildings with a relatively low level of damp.Concrete without reinforcement inside buildings.Concrete without reinforcement embedded in non-aggressive ground or water.Concrete without reinforcement subjected to wet/dry cycles but not subjected to abrasion, freezing weather or chemical attack.

2 Corrosion induced by carbonatationNote – The levels of humidity refer to those present in the concrete or material used to cover steel reinforcement or metal inserts. In many cases, such levels may be considered as the same as the surrounding environment. in such cases, classification of the surrounding may be considered sufficient. This may not necessarily be the case if there is a barrier between the concrete and the surroundings.

XC1 Dry or permanently wet In buildings with a relatively low level of damp.Conventional reinforced concrete or pre-compressed concrete with the exposed surface in the building, apart from the areas exposed to condensation or immersed in water.

XC2 Wet, rarely dry Parts of structures for containing liquids and foundations.Conventional reinforced concrete or pre-compressed concrete usually immersed in water or non-aggressive ground.

XC3 Moderately damp Conventional reinforced concrete or pre-compressed concrete with external surfaces protected from the rain, or inside areas with a moderate to high level of humidity.

XC4 Cyclically wet and dry Conventional reinforced concrete or pre-compressed concrete cast outside with surfaces subjected to dry/wet cycles.Natural-finish concrete in urban environments.Surfaces in contact with water not included In class XC2.

3 Corrosion induced by chlorides excluding chlorides from seawater

XD1 Moderately damp Conventional reinforced concrete or pre-compressed concrete on surfaces or parts of bridges and viaducts exposed to sprayed water containing chlorides.

XD2 Wet, rarely dry Conventional reinforced concrete or pre-compressed concrete in structural elements completely immersed in water, including industrial water, containing chlorides (swimming pools).

XD3 Cyclically wet and dry Conventional reinforced concrete or pre-compressed concrete for structural elements directly subjected to de-icing agents or sprayed water containing de-icing agents.Conventional reinforced concrete or pre-compressed concrete for elements with one surface immersed in water containing chlorides and the other surface exposed to the air.Parts of bridges and floors in carparks.

4 Corrosion induced by chlorides except chlorides from seawater

XS1 Exposed to salty seawater but not directly in contact with seawater

Conventional reinforced concrete or pre-compressed concrete with structural elements on or near to the coast.

XS2 Permanently submerged Conventional reinforced concrete or pre-compressed concrete for marine structures completely immersed in water.

XS3 Zones exposed to sea-spray or high tides. Conventional reinforced concrete or pre-compressed concrete with structural elements exposed to tidal areas or for zones exposed to sea-spray or waves.

5 Attack from freeze/thaw cycles with or without de-icing agents

XF1 Moderate saturation of water without de-icing agents Vertical concrete surfaces, such as façades of columns exposed to the rain and freezing weather. Non-vertical surfaces whichh are not completely saturated but exposed to freezing weather, rain or water.

XF2 Moderate saturation of water with de-icing agents Elements such as parts of bridges whichh would otherwise be classified as XF1, but whichh are directly or indirectly exposed to de-icing agents.

XF3 High saturation of water without de-icing agents Horizontal surfaces in buildings where water may accumulate and whichh may be subjected to freezing weather and elements subjected to frequent wetting and exposed to freezing weather.

XF4 High saturation of water with de-icing agents or with seawater

Horizontal surfaces, such as roads and floors exposed to freezing weather and indirectly or directly to de-icing salts, and elements exposed to freezing weather and subjected to frequent wetting with de-icing agents or seawater.

LIMIT VALUES FOR THE COMPOSITION AND PROPERTIES OF CONCRETE

EXPOSURE CLASSESNo risk of corrosion to steel

reinforcement

Corrosion of steel reinforcement induced by

carbonatation

Corrosion of steel reinforcement inducedby chlorides

Environment with freeze/thaw cycles

Aggressive environment due to

chemical attackSeawater Chloride fromother sources

XO XC1 XC2 XC3 XC4 XS1 XS2 XS3 XD1 XD2 XD3 XF1 XF2 XF3 XF4 XA1 XA2 XA3

Maximum water/cement ratio - 0,60 0,55 0,50 0,50 0,45 0,55 0,50 0,45 0,50 0,50 0,45 0,55 0,50 0,45

Minimum strength class C12/15 C25/30 C28/35 C32/40 C32/40 C35/45 C28/35 C32/40 C35/45 32/40 25/30 28/35 28,35 32/40 35/45

Minimum cement content (kg/m3) - 300 320 340 340 360 320 340 360 320 340 360 320 340 360

Minimum air content (%) 3,0a)

Other requirements Aggregates in compliance with UNI EN 12620 for sufficient resistance to freeze/thaw cycles

Cement resistant to sulphatesb) is required

*) Table 7 from EN 206-1 mentions class C8/10 which corresponds to specific concrete for substrates and for covering purposes. For this class, durability regarding water and aggressive ground must be defined.a) When the concrete does not contain added air, its performance must be checked compared with aerated concrete with a proven value for resistance to freeze/thaw cycles determined according to UNI 7087 for respective exposure class.b) If the presence of sulphates leads to exposure classes XA2 and XA3, it is essential that cement resistant to sulphates according to UNI 9156 is used

Class denomination

Type of conditions and surroundings Examples of conditions and surroundings when the exposure classes may be applied

6 Attacco chimico**)

XA1 Weak chemically aggressive environment according toTable 2 from EN 206-1

Sludge basins and decantation basins.Containers and basins for waste water.

XA2 Moderate chemically aggressive environment according to Table 2 from EN 206-1

Structural elements or walls in contact with aggressive ground.

XA3 High chemically aggressive environment according toTable 2 from EN 206-1

Structural elements or walls in contact with highly aggressive industrial water.Containers for forage, animal feed and sewage.Cooling towers for industrial fumes and discharge gases.

*) the level of saturation in the second column reflects the frequency at which freezing occurs in saturated conditions: - moderate: occasional freezing in saturated conditions; - high: high frequency of freezing in saturated conditions.**) By water from the ground and flowing water

Tab2–Table4fromEN206-1:2001withindicationsoflimitvaluesforthecompositionandpropertiesofconcrete.

Tab1a-b–Table1fromEN206-1:2001withindicationsofenvironmentalexposureclasses.

33

Technical Notebook


7. WATERPROOFING NEW STRUCTURES BELOW GROUND LEVEL

This section will discuss the problem of waterproofing new structures

below ground level, and will offer a series of technical solutions to be

adopted, theproducts requiredandmethodsand techniques to install

and apply the products. All the information will be accompanied by

specifictechnicaldetails.

When excavation work is carried out, an artificial space is created

in which the part of the structure below ground level will be installed.

The hydrogeological balance of the site is modified and, even if there

is no groundwater present, after stripping the ground, rainwater and

precipitationswillcollectintheartificialspaceandformanartificialpond.

Insuchconditions, thestructuresof thebuildingwillhave tobemade

waterprooftoprotectthemfromlargequantitiesofwaterwhichcollects

intheareabelowgroundlevelaroundtheconstruction.

Inviewof theabove, it isclear thatastructuremustbewaterproofed

correctlyusingtheso-called“basin”or“pouch”methodwhichissuitable

to contrast the lift from the water, especially from groundwater. The

waterproofingsystemisappliedbystickingittothestructure(foundations

andwalls)withnopointleftuncovered.

Therenowfollowsadescriptionofaseriesofwaterproofinginterventions

tobecarriedoutonsitetoguaranteethatstructuresbelowgroundlevel

arewatertight.

Thefirstinterventionwhichmaybenecessarytocarryoutonsite,butwhich

isoftenoverlooked,istowaterproofthebaseofjibcraneswhentheyare

positionedinthefoundationstructure,whichshouldthenbefollowedby

waterproofingtheliftwells.Waterproofingofliftwellsisoftenoverlooked,

andmustbecarriedoutbeforewaterproofing theplinth.Thisshouldbe

carriedoutbecause,aswewillseelater,thebaseoftheliftwellisusually

thelowestpointoftheentireconstruction.Inthecaseoffoundationpads

restingonpiles,beforepreparingtheareaforlayingthebentonitesheetsto

waterproofthestructure,theheadsofthepilesmustbesealed.

ThemethodappliedtolayMAPEPROOFwillbedifferentaccordingtothe

typeofexcavation.Inthecaseofexcavationswithoutconfinement(see

Section4),thebentonitesheetsmustbehemmeduponformwork.With

confinedexcavations,ontheotherhand,thesheetsmustbeappliedon

thecontainmentbulkheadsonthesidewallsoftheexcavationwithone

ofthefollowingfourdistinctlayingsituations:onsheetpiling,piles,micro-

pilesanddiaphragms.

In excavations without confinement, waterproofing of the reinforced

concrete facing walls is carried out after pouring the concrete. MAPEI

offersarangeofproductswithdifferentcharacteristicsandperformance

levelsforthistypeofapplication:

•MAPEPROOF(seeSection5.2);

•MAPEPROOFLW(seeSection5.2);

• MAPELASTIC FOUNDATION two-component, flexible cementitious

mortar for waterproofing surfaces subject to negative and positive

hydrauliclift;

•PLASTIMULbitumenwaterproofingemulsion;

•PLASTIMUL1KSUPERPLUS solvent-free,one-component,quick-

drying,low-shrinkage,high-yield,high-flexibilitybitumenwaterproofing

emulsioncontainingpolystyrenebeadsandrubbergranules;

• PLASTIMUL 2K PLUS solvent-free, one-component, quick-drying,

low-shrinkage, high-flexibility bitumen waterproofing emulsion

containingcellulosefibres;

•PLASTIMUL2KSUPERsolvent-free,two-component,quick-drying,

low-shrinkage, high-flexibility bitumen waterproofing emulsion

containingpolystyrenespheres.

Special care must be taken when sealing around structural joints,

elementswhichpassthroughthefoundationpadandsidewalls,drainage

wellsandwellpoint rods.Waterproofing interventionsonaccess ramps

belowgroundlevelanddepurationtankswillbeillustratedlater.

32

35

Technical Notebook


7.1 SEALING CONSTRUCTION JOINTSConstructionjointsrepresentapointofdiscontinuityinthepouredconcrete

onbothhorizontalandverticalfaces.Theymustbemadewatertightto

avoid thepointsofdiscontinuity formingapreferential route forwater.

MAPEIoffersaproductdevelopedspecifically for sealingconstruction

jointscalledIDROSTOPB25(Fig.7.1-2).Itformsahydro-expanding,self-

sealingjointandhasasectionof20x25mm.itismadefromamixtureof

naturalsodiumbentoniteandpolymers,whichgivetheproductexcellent

characteristics of compactness, flexibility and stability. The swelling

processtakesplaceinacontrolled,uniformandgradualmannerwithout

the riskofaltering theequilibriumof themixture.Afterswelling,which

occurswhentheproductcomesintocontactwithwater,IDROSTOPB25

adaptsperfectlytothevolumedefinedbytheconfinementand,thanks

tothisspecialcharacteristic,perfectlysealsbothconstructionjointsand

localisedgravelclustersinthecastconcrete.BeforeapplyingIDROSTOP

B25, carefully clean the surface to eliminate all traces of debris, and

especiallytheslurrywhichbleedsfromthesurfaceandusuallyformswhen

compactingthecementitiousconglomerate.Thennailarib(1nailevery25

cm)alongthemiddleoftheverticalwallbetweenthesteelreinforcement.

Jointheendstogetherbysimplylayingthepiecesalongsideeachother

foratleast6cm(Fig.7.3).AsanalternativetoIDROSTOPB25,IDROSTOP

pre-formed, hydro-expanding, acrylic polymer tape may be used. This

productwasdevelopedtomakejointsintheconstructionindustrywhich

remainwaterproofuptoapressureof5atm.

The following paragraphs illustrate specific cases in which IDROSTOP

B25mustbeusedandhowtolaytheproduct.

7.2 WATERPROOFING THE BASE OF A JIB CRANEThebaseofajibcrane(Fig.7.4)ismadebyexcavatingaholewhichis

then linedwithawaterproofingsystembeforepouring in theconcrete.

Belowisadescriptionofthephasestobecarriedouttowaterproofthe

excavation.

- To form a suitable laying surface and make application of the

waterproofing system easier, the bottom of the excavation must be

evenedoutbyapplyingalayerofleanconcreteabout10cmthick.

-Tolaytheverticalpartofthewaterproofingsystem,installformwork

onwhichtheMAPEPROOFwillthenbeapplied.Positiontheunderside

(thedarkside)ofthegeo-textilepolypropylenefabriconthesubstrate

and overlap the edges of the sheets by at least 10 cm. Fasten the

sheetsinplacewithnailsandMAPEPROOFCDpolyethylenewashers

approximatelyevery30cm.

-Afterlayingthesystemontheverticalsurfaces,laytheMAPEPROOF

onthehorizontalsurfacebypositioningtheunderside(thedarkside)

of the geo-textile polypropylene fabric on the surface of the lean

concreteandtheuppersideofthefabric(thewhiteside)onthevertical

surfaces.Overlaptheedgesofthesheetsbyatleast10cm.Fastenthe

sheetsinplaceonthehorizontalsurfacewithnailsandMAPEPROOF

CDpolyethylenewashersapproximatelyevery50cm.Avoid forming

creaseswhenlayingthefabricontheleanconcrete.

-Afterlayingthebentonitesheets,thesteelreinforcementforthebase

mustbeplaced inposition,withspacersbetweenthereinforcement

andtheMAPEPROOFsheetstoguaranteethattheconcreteflowsfreely

betweenthereinforcementandthebentonitesheetsandcompletely

coversthereinforcement.Thenpourintheconcretetoformthebase

forthecranesothattheheightofthetopfaceofthebasecoincides

withtheheightofthefoundationpadinwhichitwillbeincorporated.

7.3 WATERPROOFING A LIFT WELLAliftwelliswithoutadoubtthepartofaconstructionwhichismostlikely

tocomeintocontactwithgroundwater.Infact,itoftenhappensthatlift

wellsarewaterproofedafterconstructiontoeliminateproblemsofwater

infiltrationandtomaketheelectricalequipmentoftheliftsafe.Thispart

Fig.7.1-IDROSTOPB25appliedtosealhorizontalandverticalconstructionjoints

Fig.7.2–TheminimumdistanceswhichmustbemaintainedbetweenIDROSTOPB25andthebladesinformwork,andbetweenIDROSTOPB25andtheoutersurfaceofconcrete,toguaranteecorrectconfinement

Fig.7.3–JointbetweentheendsoftwostripsofIDROSTOPB25bysimplylayingthemalongsideeach

otherforatleast6cm

34

been applied), which also help the concrete to flow under the steel

reinforcementandguaranteethatitiswellcovered.

-Pourintheconcretefortheliftwellfoundationpadwhichmustbe

calculatedtowithstandthein-serviceloadsandthehydraulicliftfrom

thegroundwater.

-Oncetheconcretehascuredcorrectly,sealtheconstructionjoints

between the foundationpadand theverticalwallsusing IDROSTOP

B25 hydro-expanding, self-sealing bentonite jointing material with a

sectionof20x25mm.BeforeapplyingIDROSTOPB25,carefullyclean

thesurfacetoeliminatealltracesofdebris,andespeciallytheslurry

whichbleedsfromthesurface,whichusuallyformswhencompacting

thecementitiousconglomerate.

37

Technical Notebook


ofthestructure,therefore,isthefirstonetoconsiderwhendesigninga

waterproofingsystemtoprotectitagainsttheaggressiveactionofwater.

Excavationsforliftwellsmaybecarriedoutusingthefollowingmethods:

a)withadeterminedshape(Fig.7.5);

b)bystripping.

Inthecaseofanexcavationwithadeterminedshape,waterproofingof

theliftwell(Fig.7.6)iscarriedoutasfollows.




- To lay the waterproofing system on the vertical surfaces, form a

relativelyevensurfaceonwhichtheMAPEPROOFisappliedandfold

the geo-textile over onto the laying surface of the foundation pad.

Positiontheunderside(thedarkside)oftheMAPEPROOFgeo-textile

polypropylene fabricon the substrate andoverlap the edgesof the

sheetsbyat least10cm.Fasten thesheets inplacewithnailsand

MAPEPROOFCDpolyethylenewashersapproximatelyevery30cm.

-SpreadMAPEPROOFonthehorizontalsurfaceandfastenitinplace

every50cmwithnailsandMAPEPROOFCDpolyethylenewashers.

Avoidformingcreaseswhenlayingthefabricontheleanconcrete.

-Inordertoprotectthesheetswhenpositioningthesteelreinforcement

before pouring on the concrete for the lift well foundation pad, a

5-10cmthickprotective layerof thesameconcreteasusedforthe

foundationpadmayberequiredontheMAPEPROOF.Thisoperation

is not absolutely necessary because the bentonite sheets are able

toresistdamagefromboththespacersandthesteelreinforcement.

Specialplasticspacersmustbeusedtokeepthereinforcementcage

for the lift well away from the sheets (if a protective layer has not

Fig.7.5c–Positioningthesteelreinforcement

Fig.7.5d–CastingthefoundationpadforaliftwellFig.7.5a–Oneofthephasesofwaterproofingandcastingaliftwell:applicationofMAPEPROOFonthesidewallsoftheexcavation

36

Fig.7.6–Detailedlayoutofwaterproofingaliftwell

Reinforced concrete foundation pad

Protective concrete layer with the same Rck value as the concrete for the foundation pad

MAPEPROOF

4 Regulating layer of lean concrete

1

2

3

4

Ground

Reinforced concrete structure

IDROSTOP B25

Fixing rods

5

6

7

8

Fig.7.4–WaterproofingthebaseofajibcranewithMAPEPROOFbentonitesheets

Fig.7.5e–Positioningwoodenformworkbeforesealingconstructionjointsbetweenafoundationpadandthe

wallsusingIDROSTOPB25

Fig.7.5b–LiftwelllinedwithMAPEPROOF

39

Technical Notebook


Thennail a rib (1nail every25cm)along themiddleof the vertical

wallbetweenthesteelreinforcement.Jointheendstogetherbysimply

layingthepiecesalongsideeachother,andneverontopofeachother,

foratleast6cm.

-Afterinstallingtheinternalformwork,pourintheconcretetoformthe

verticalwallsoftheliftwell.Toachievethecorrectdurability,itmustbe

designedaccordingtothespecificationsinSection6.

Whencreatingaliftwellbythestrippingmethod(Fig.7.7)thestructure

mustbewaterproofedasfollows.




-Installtheouterformworktocastthefoundationpad.Thenlaythe

MAPEPROOF with the polypropylene underside of the geo-textile

polypropylene fabric (the dark side) on the sides of the formwork

(Fig.7.8)andthenfolditoveratleast20cmontotheleanconcrete.

Theuppersideofthegeo-textilefabric(thewhiteside)willbeturned

towardstheinsidesoitisvisible.

- Overlap the edges of the sheets by at least 10 cm. Fasten the

sheetsinplacewithnailsandMAPEPROOFCDpolyethylenewashers

approximately every 30 cm. Avoid forming creases when laying the

fabricontheformwork.Whenlayingneartopipe-workwhichpasses

throughthesurface(seeSection7.9)thesheetsmustbecuttoshape

tosuittheshapeofsuchelements.

-SpreadMAPEPROOFonthehorizontalsurfaceandfastenitinplace

every50cmwithnailsandMAPEPROOFCDpolyethylenewashers.

Avoid forming creases when laying the fabric on the lean concrete.

Whenlayingneartoelementswhichpassesthroughthesurface

(drains,pipe-work,etc.)thesheetsmustbecuttoshapetosuitthe

shapeofsuchelements.

-Inordertoprotectthesheetsduringnormalsiteactivitiesandwhile

positioning the steel reinforcement for the poured concrete for the

foundationpad,itmaybenecessarytocovertheMAPEPROOFwitha

5-10cmthicklayerofthesametypeofconcreteaswillbeusedforthe

foundations.7.9).Thisoperationisnotabsolutelynecessarybecause

thebentonitesheetsareabletoresistdamagefromboththespacers

andthesteelreinforcement.Inthiscase,specialplasticspacersmust

beusedtokeepthereinforcementcagefortheliftwellawayfromthe

MAPEPROOFsheets,whichalsohelptheconcretetoflowunderthe

steelreinforcementandguaranteethatitiswellcovered.

Fig.7.5f–Castingverticalwalls

38

Fig.7.7–Waterproofingaliftwellbuiltinastripped-typeexcavation

Fig.7.8–DetailedlayoutofMAPEPROOFappliedonwoodenformwork



MAPEPROOF

Regulating layer of lean concrete

Ground

Wooden formwork

1

2

3

4

5

6

41

Technical Notebook


-Pourintheconcretefortheliftwellfoundationpadwhichmustbe

calculatedtowithstandthein-serviceloadsandthehydraulicliftfrom

thegroundwater.

-Oncetheconcretehascuredcorrectly,sealtheconstructionjoints

between the foundationpadand theverticalwallsusing IDROSTOP

B25 hydro-expanding, self-sealing bentonite jointing material with a

sectionof20x25mm.Beforeapplying the IDROSTOPB25, carefully

cleanthesurfaceandfastenthebentonitejointasdescribedpreviously.

-Installthedoubleformworkfortheverticalconcretewalls,andmakesure

thatthefirstrowoflowerspacersis5-10cmfromtheIDROSTOPB25.

- Pour in the concrete for the walls of the lift well. Use concrete

designedaccordingtothespecificationsinSection6.

- Once the walls have cured correctly, strip the formwork and

waterproof the walls by applying MAPEPROOF (see Section 7.7.1).

Sealthefilletjointsbetweenthefoundationpadandtheverticalwalls

usingIDROSTOPB25hydro-expanding,self-sealingbentonitejointing

materialwithasectionof20x25mm.

- After completing the waterproofing operations of the lift well, lay

theMAPEPROOFon the leanconcreteas illustrated in the following

Section.It isabsolutelyessentialtoguaranteethattheMAPEPROOF

sheetsbetweentheverticalwallsandthehorizontalsheetsunderthe

foundationpadarecontinuous,andoverlapbyatleast10cm.

7.4 WATERPROOFING HORIZONTALFOUNDATION PADS

Tomakeapplicationofthewaterproofingsystemeasier,thelayingsurface

mustbeevenwithnobulges,largegapsand/orsharpprotuberancesso

thesystemmaybe laidcorrectly.Evenover thesurfaceof theground

withalayerofleanconcretewithanaveragethicknessofaround10cm.

Werecommendformingthelayerofleanconcreteinacontinuous,single

layer.

Inthecaseofexcavationswithoutconfinement(seeSection4)applythe

waterproofingsystemasindicatedbelow:

- Install theouterformworktocastthefoundationpad.Thenlaythe

MAPEPROOF with the underside (the dark side) of the geo-textile

polypropylenefabricontheinnersidesoftheformwork(Fig.7.7andFig.

7.10)andthenfolditoverby20cmontotheleanconcrete.Theupper

sideofthegeo-textilefabric(thewhiteside)willbeturnedtowardsthe

insidesoitisvisible.Theedgesofthesheetsmustoverlapbyatleast

10 cm. Fasten the sheets in place with nails and MAPEPROOF CD

polyethylenewashersapproximatelyevery30cm.

Inthecaseofexcavationswithoutconfinement(seeSection4)applythe

waterproofingsystemasindicatedbelow:

-laytherollsofMAPEPROOFbypositioningtheunderside(thedark

side) of the geo-textile polypropylene fabric on the surface of the

leanconcreteandtheuppersideofthefabric(thewhiteside)facing

upwardsso it isvisible.Theedgesmustoverlapbyat least10cm.

FastenthesheetsinplaceonthesubstratewithnailsandMAPEPROOF

CDpolyethylenewashersapproximatelyevery50cm.

-ApplyMAPEPROOFinthelowerpartofthecontainmentbulkheads

of the excavation, and fold a strip at least 20 cm wide on the lean

concrete. The underside of the geo-textile polypropylene fabric (the

darkside)mustbeplacedonthesubstrateandtheuppersideofthe

geo-textilefabric(thewhiteside)mustfaceupwardssoitisvisible.

After laying thegeo-textile fabricon the formworkor the lowerpartof

40

Fig.7.9–OneofthephasesofcastingtheprotectivelayerofconcreteonMAPEPROOF,usingconcretewiththesameRckasthatofthefoundationpad

Fig.7.10–NailingMAPEPROOFtowoodenformwork Fig.7.12–LayingMAPEPROOFusingametalliftingrig

43

Technical Notebook


the bulkheads, lay the rolls of MAPEPROOF on the lean concrete as

describedbelow.

-Lay(Fig.7.12)therollsofMAPEPROOFbypositioningtheunderside

(thedarkside)ofthegeo-textilepolypropylenefabriconthesurface

oftheleanconcreteandtheuppersideofthefabric(thewhiteside)

facing upwards so it is visible. The edges must overlap by at least

10 cm. Fasten the sheets in place on the substrate with nails and


-Inordertoprotectthesheetsduringnormalsiteactivitiesandwhile

positioning the steel reinforcement for the poured concrete for the

foundationpad,itmaybenecessarytocovertheMAPEPROOFwitha

5-10cmthicklayerofthesametypeofconcreteaswillbeusedforthe

foundations.Thisoperation isnotabsolutelynecessarybecausethe

bentonitesheetsareabletoresistdamagefromboththespacersand

thesteelreinforcement.Inthiscase,thesteelreinforcementmustbe

positionedatacertaindistancefromtheMAPEPROOFusingspecial

plasticspacers(Fig.7.13)whichalsohelptheconcretetoflowunder

thesteelreinforcementandguaranteethatitiswellcovered.

- Position the steel reinforcement and pour in the concrete for the

foundationpad,calculatedtowithstandthein-serviceloadsandthe

hydraulicliftofthegroundwater.Useconcretedesignedwithdurability

characteristicsaccordingtothespecificationsinSection6.

7.5 WATERPROOFING PILE HEADSDesignersoftenhavetodesignfoundationstructuresongroundwithpoor

load-bearingcapacity,andarethereforeobligedtousedeepfoundation

systemssuchasreinforcedconcretepiles.Thepilesworkinconjunction

withthefoundationpadtocomplywiththerequirementsoftheproject.

Whenwaterproofingafoundationpadrestingonpiles,itisnecessaryto

differentiatebetween twodifferentapplicationmethods.Thedifference

liesinthewaytheMAPEPROOFislaid,inthatitmayhavetheheadsof

thepilespassingthroughit.

Inthecaseoftheheadsofthepilespassingthroughthebentonitesheets

(Fig.7.14)applythewaterproofingsystemasindicatedbelow:

-croptheheadofthepileuntilthescarifiedsurfaceisatleast10cm

belowtheleveloftheouterfaceoftheleanconcrete.

Thepileshouldbecropped(Fig.7.15)byscarifyingwithalightweight

pneumatic hammer to leave a rough surface. Carefully clean the

scarified surface using high-pressure water jets (120-180 atm) to

completelyremovealltracesofdustoranyothertypeofmaterialwhich

couldcompromisethebondofthesuccessivelayerofrepairmortar.

-Positionacylindricalmetalmould(Fig.7.16)15cmhighwithawidth

suitable for the section of the pile. Then, to guarantee a monolithic

bond between the head of the pile and the new repair mortar, we

recommend applying EPORIP solvent-free, two-component epoxy

adhesiveonthesurfaces.

42

Fig.7.11–WaterproofingaribbedfoundationpadbyapplyingMAPEPROOF

Fig.7.13–MetallicreinforcementpositionedonMAPEPROOFandseparatedfromthesheetswithspacers

Fig.7.14–Detailedlayoutofwaterproofingtheheadsofpileswhichworktogetherwiththefoundationpadandpassthroughthebentonitesheet



MAPEPROOF


Ground

MAPEPROOF MASTIC

1

2

3

4

Steel rebar or round bar

Foundation pile

MAPEGROUT HI-FLOW

IDROSTOP B25

MAPEPROOF SEAL

7

8

9

10

5

6

11

45

Technical Notebook


ApplyEPORIPonthesubstrate,whichshouldbedryoronlyslightly

damp,makingsureitpenetratesintotheparticularlyroughandporous

areastoguaranteeaperfectbondoverthewholesurface;

- Pour (Fig. 7.17-18) MAPEGROUT HI-FLOW controlled-shrinkage,

fibre-reinforcedmortarforrepairingconcretewith30%ofgravelwitha

grainsizebetween5and8-10mmand0.25%MAPECURESRAcuring

compoundtoreducehygrometricandplasticshrinkageintothemould

whiletheEPORIPisstillfresh.MAPEGROUTHI-FLOWguaranteesboth

aperfectwatertight jointandhighcompressivestrengthatthehead

ofthepile.

-Afterremovingthemould,theperimeteroftheheadofthepilewill

needtobesealed(Fig.7.19)byinserting300gpermetreofpowdered

MAPEPROOFSEAL.

- Lay on the MAPEPROOF andcut the sheets to shapearound the

heads of the piles (Fig. 7.20) positioning the underside of the geo-

textilepolypropylenefabric(thedarkside)ontheleanconcrete.The

edgesofthesheetsmustoverlapbyatleast10cm.Fastenthesheets

tothesubstratewithnailsandMAPEPROOFCDpolyethylenewashers

approximately every 50 cm. Take care when unrolling the fabric to

avoidformingcreaseswhenlayingthefabricontheleanconcrete.

-Aroundtheheadsofthepiles,nailtheIDROSTOPB25inposition(Fig.

7.21)hydro-expanding,self-sealingbentonitewithasectionof20x25

cm.Jointheendsbysimplylayingthemalongsideforatleast6cm.

- Finish off the waterproofing system by grouting all the steel

reinforcement in the heads of the piles by trowelling around each

rod with MAPEPROOF MASTIC natural sodium bentonite grout with

plasticisingadditives(Fig.7.22).

Iftheheadsofthepilesdonotpassthroughthebentonitesheets(Fig.

7.23)applythewaterproofingsystemasindicatedbelow:

-LayontheMAPEPROOFandmakeholesinittoallowthereinforcement

rodsintheheadofthepilestopassthrough(Fig.7.24)andpositionthe

underside(thedarkside)ofthegeo-textilepolypropylenefabriconthe

surfaceoftheleanconcretewiththeuppersideofthefabric(thewhite

side) facing upwards so it is visible. The edges must overlap by at

least10cm.Fastenthesheetsinplaceonthesubstratewithnailsand


-AftergroutingallthereinforcementrodswithMAPEPROOFMASTIC

applyapieceofbentonitesheetovereachrod.

Thefilletbetweenthepiecesofsheetandthereinforcementrodsmust

alsobegroutedwithMAPEPROOFMASTIC(Fig.7.25-27).

Fig.7.13–MetallicreinforcementpositionedonMAPEPROOFandseparatedfromthesheetswithspacers

44

Fig.7.16–MetalliccylindricalmouldinplacebeforecastingMAPEGROUTHI-FLOW

Fig.7.15–Croppingtheheadofapile Fig.7.17–TheheadofapilerebuiltwithMAPEGROUTHI-FLOW

Fig.7.18–Anoverallviewofaseriesofpilesduringtherebuildingoftheheads

Fig.7.23–Detailedlayoutofwaterproofingtheheadsofpileswhichworktogetherwiththefoundationpadwithoutpassingthroughthebentonitesheet



MAPEPROOF


1

2

3

4

Ground

MAPEPROOF MASTIC

Steel rebar or round bar

Foundation pile

5

6

7

8

47

Technical Notebook


Towaterproofthefoundationpad,thetechniqueusedtolaythebentonite

sheetsisthesameasdescribedinSection7.4.

InordertoprotecttheMAPEPROOFfrombeingdamagedduringnormal

siteactivitiesandwhilepositioningthesteelreinforcementforthepoured

concreteforthefoundationpad,itmaybenecessarytocoverthesheets

witha5-10cmthicklayerofthesametypeofconcreteaswillbeused

forthefoundations.Thisoperationisnotabsolutelynecessarybecause

the bentonite sheets are able to resist damage from both the spacers

andthesteelreinforcement.Inthiscase,specialplasticspacersmustbe

usedtokeepthesteelreinforcementawayfromtheMAPEPROOFsheets,

whichalsohelptheconcretetoflowunderthesteelreinforcementand

guaranteethatitiswellcovered.

After positioning the steel reinforcement, pour on the concrete for the

foundationpadaccordingtothespecificationsfortheconcreteinSection

6.Iftheconcreteneedstobepouredindifferentsteps,thejointsbetween

each cast must be sealed (Fig. 7.28-29) using IDROSTOP B25 hydro-

expandingbentonitejointingmaterialwithasectionof20x25mmmade

fromnaturalsodiumbentoniteandpolymers.Theribmustbefastened

onthefoundationpadatthemid-pointoftheperimeterwallswithnails

(1nailevery25cm).Theendsarejoinedbysimplylayingthemalongside

eachother(andneverbyoverlapping)foratleast6cm.TheIDROSTOP

B25usedtosealtheconstructionjointsinthefoundationpadandtoseal

theconstructionjointsintheverticalwallsmustalsobejoinedtogether

bylayingthestripsalongsideeachother(Fig.7.30).

After completing casting of the foundation pad, there will be one of

two situations: if the excavation is confined, the waterproofing system

maybe laidontheverticalsurfacesbeforecasting (Section7.6). If the

excavationisnotconfined,theverticalconcretewallsmaybecastbefore

waterproofingthem(Section7.7).

7.6 WATERPROOFING VERTICAL SURFACESBEFORE CASTING

The laying of MAPEPROOF on the containment bulkheads of the side

wallsofexcavationsmaybedividedintofourdifferentcases,accordingto

thetypeofstructuralelementusedtoconfinetheexcavation:sheetpiling,

piles,micro-pilesanddiaphragms.

Sheetpiling

MAPEPROOF may be applied directly on sheetpiling if the sheetpiling

doesnothavetoberecoveredafterconstruction,oronOSB(Oriented

StrandBoard)attachedtothesheetpiling(Fig.7.31).

Bentonitesheetsmaybecuttoshapesotheymaybelaiddirectlyonthe

sheetpilingandperfectlyadapttoitsshape.Thefirstoperationtocarry

outistocleantheentiresurfacewithhighpressurewaterjets(150-180

Fig.7.19–SealingaroundtheperimeteroftheheadofapilewithMAPEPROOFSEAL

Fig.7.20-MAPEPROOFcuttoshapearoundtheheadofapile

46

Fig.7.22–GroutingthereinforcementinapilewithMAPEPROOFMASTIC

Fig.7.24-MAPEPROOFwiththesteelreinforcementofapilepassingthroughit

Fig.7.25–LocalisedreinforcementofthewaterproofingwithapieceofMAPEPROOFgrouted

withMAPEPROOFMASTIC

Fig.7.28–Detailedlayoutofsealingaconstructionjointonafoundationpad

Ground


MAPEPROOF


1

2

3

4


Adjacent reinforced concrete foundation pad

IDROSTOP B25

Fixing rods

5

6

7

8

Fig.7.21-ApplicationofIDROSTOPB25aroundtheheadofapile

applywaterproofingsheetsonalltheverticalsurfaces,startingfromthe

top.Overlapthesheetsbyatleast10cmandfastentheminplacewith

nailsandMAPEPROOFCDpolypropylenewashersapproximatelyevery30

cm.Thetoppingbeamonthebulkheadmustalsobewaterproofed.Clean

thesurfaceswithhighpressurewaterjets(180-300atm)andthensmooth

offthesurfacewithPLANITOP400quick-setting,compensated-shrinkage,

thixotropicmortar forquick repairson thesurfaceofconcrete,orwith

PLANITOP 430 fine-grained, fibre-reinforced, compensated-shrinkage

thixotropic mortar for repairing deteriorated concrete or products from

theMAPEGROUTrange.Oncethesurfacehasbeensmoothedoff,apply

twocoatsofMAPELASTICFOUNDATIONwithabrush,arollerorbyspray

toformalayeratleast2mmthick.Approximately4hoursafterapplying

thefirstlayeringoodweather,andinallcasesonlywhenthefirstlayer

hasdried,thesecondlayermaybeapplied.MAPELASTICFOUNDATION

Fig.7.34–DetailedlayoutofapplyingMapeproofagainstapilebulwarkwithasurfacewhichhasbeenlevelledoff

49

Technical Notebook


atm)toeliminatelooseparts.TheMAPEPROOFisthenapplied,starting

fromthetopandunrollingtherollsofgeo-textilefabricwiththeunderside

(thedarkerside)against thesheetpiling,withanoverlapofat least10

cmbetweeneachsheet.Thesheetsarethenfixedtothesubstratewith

nails insertedwithanailgunapproximatelyevery30cm.Thissolution

avoidstheoverlapsopeningupundertheweightoftheconcretewhich

couldoccurwhenitispoured.Ifthesheetpilingneedstoberecovered

when construction work has been completed, OSB (Oriented Strand

Board)panelsmustbeplacedagainstthesheetpiling.Thissolutionmay

be adopted even if just a flat laying surface needs to be prepared to

guarantee a suitable support so the bentonite sheets may be fixed to

thepanelsusingadenseseriesofstaples.Beforecastingtheconcrete

walls, the gaps between the OSB panels and the sheetpiling must be

filledwithsandtomakesurethepanelshaveasolidsupportalongthe

entirestretch.

The techniques used to lay MAPEPROOF on piles, micro-piles and

diaphragms are very similar to each other, but each technique will be

describedseparatelytohighlighttheirdifferences.

Piles

Ifparticularlylargepilesareused,thebentonitesheetsmaybelaiddirectly

onthepilesthemselves(Fig.7.32)aspreviously illustratedwhenlaying

MAPEPROOFonsheetpiling.AvalidalternativeistoapplyMAPEPROOF

onOSBpanels (Fig.7.33-34)placedagainst thepiles, like thesystem

usedforsheetpiling.Ifsmallpilesareinserted,firstofallthesurfacemust

be cleaned with high pressure water jets, followed by levelling off the

layingsurfaceandtheheadsofthetie-rods(ifpresent)withMAPEGROUT

T60 sulphate-resistant, fibre-reinforced thixotropic mortar mixed with

025%ofMAPECURESRAcuringagenttoreducehygrometricandplastic

shrinkage.

Oncetheconcretehashardened,applypiecesofMAPEPROOFonthe

heads of the tie-rods to locally reinforce thewaterproofing layer. Then

48

Fig.7.29–SealingaconstructionjointonafoundationpadwithIDROSTOPB25.TheprotectivePEsheetonthe

stripofMAPEPROOFmaybeseenprotrudingfromthefoundation,whichisthenoverlappedwiththeadjacent

sheetlaidbeforecastingthenextlayerofconcrete

Fig.7.30–StripsofIDROSTOPB25usedtosealconstructionjointsinthefoundationpadalongsideastripusedtosealconstructionjointsbetweenthe

foundationpadandthewallsandbetweenthewalls



MAPEPROOF


1

2

3

Ground

Reinforced concrete wall

IDROSTOP B25

Pile bulkhead

Smoothing and levelling layer on pile bulkhead

Fixing rods

5

6

7

84 9

10

Fig.7.26–Apieceofsheetnailedtothesubstrate Fig.7.27–Anoverallviewofthewaterproofinglayerontheheadofaseriesofpiles

51

Technical Notebook


must be applied on all the front face of the topping beam (Fig. 7.35),

on the inner faceof thebeamandon theupperpartof thebulkhead,

and thenoverlap itbyat least30cmwithMAPEPROOF tocompletely

sealthewaterproofingsystem.ThefilletjointbetweenMAPEPROOFand

MAPELASTICFOUNDATIONmustbesealedbyapplyingIDROSTOPB25.

Micro-piles

Bulkheadsmadefrommicro-pileshaveanunevensurfaceandsoaflat

laying surface suitable for applying MAPEPROOF must be created. As

analternative,asuitablemeansofsupporttofixtheverticaloverlapsof

thebentonitesheetsinplacemaybeused.Therearethreemainstepsto

applythewaterproofingsystem:

-layacontinuousrowofOSB(OrientedStrandBoard)panelsagainst

themicro-piles;

-cleanthesurfacewithwaterjetsandevenoutthesurface(Fig.7.36)

by applying MAPEGROUT T60 sulphate-resistant, fibre-reinforced

thixotropicmortarmixedwith0.25%ofMAPECURESRA;

-fastenplanksofwoodtothemicro-pilesatapitchequaltothewidth

ofthebentonitesheetstofixtheverticaloverlapsoftheMAPEPROOF

inplace.

Aftercarryingouttheaboveoperations,laytheMAPEPROOFstartingfrom

thetopandoverlapthesheetsbyatleast10cm.Fixthesheetsinplace

with nails and MAPEPROOF CD polyethylene washers approximately

every30cm.

Diaphragms

ThesurfaceofdiaphragmsissmoothenoughtolayMAPEPROOFsheets

directly(Fig.7.37-39).Thelayingprocedureisidenticaltotheprocedure

used for sheetpiling, so the first operation to carry out is to clean the

surface with high pressure water jets (150-180 atm) to eliminate loose

parts.Leveloff theheadsof the tie-rods (ifpresent)withMAPEGROUT

T60 sulphate-resistant, fibre-reinforced thixotropic mortar mixed with

025%ofMAPECURESRAcuringagentwhichreduceshygrometricand

plasticshrinkage.

Oncethemortarhashardened,applypiecesofbentonitesheetonthe

heads of the tie-rods to locally reinforce the waterproofing layer. Then

laytheMAPEPROOFstartingfromthetopwiththeunderside (thedark

side)ofthegeo-textilefabriconthesubstrate,overlappingthesheetsby

atleast10cm.Fixthesheetsinplacewithnailsapproximatelyevery30

cm.Thissolutionavoidstheoverlapsopeningupundertheweightofthe

concretewhichcouldoccurwhenitispoured.Ifseepingwaterispresent,

includingwaterunderpressure,beforelayingtheMAPEPROOFsealthe

leaks by applying LAMPOSILEX ultra quick-hardening hydraulic binder

manually,aproductusedtoblockinfiltrationsofwater.

Fig.7.31–MAPEPROOFapplieddirectlyonsheetpiling

50

Fig.7.33–ApplicationofMAPEPROOFonOSBpanelslaidagainstpiles

Fig.7.35–Waterproofingthetoppingbeamonabulwark

1

2

3

4

Pile bulkhead

Smoothing and levelling layer

MAPEPROOF


5 IDROSTOP B25

MAPELASTIC FOUNDATION

Topping beam

Ground

5

6

7

8

Fig.7.32–MAPEPROOFapplieddirectlyonapilebulkhead

In all four examples described above, the bentonite sheets applied

verticallymustoverlapthesheetlaidbeforecastingthefoundationpad.

This will guarantee structural continuity between the horizontal and

verticalwaterproofinglayers.

In certain cases, to reduce the thickness of the reinforced concrete

structures to be built, insert reinforcement connectors between the

bulkhead and the structure to be cast to form a static union between

the two structural elements (Fig. 7.40). In correspondence with the

reinforcementconnectors,holesmustbemadeintheMAPEPROOF for

theconnectorspassthrough.AfterlayingtheMAPEPROOF,theymustbe

sealedinthreestepsasfollows:grouttheconnectorswithMAPEPROOF

MASTIC natural sodiumbentonitegroutwithplasticisingagents; apply

piecesofbentonitesheetandnailtheminplace;groutthefilletaround

thetie-rodwithMAPEPROOFMASTIC.

53

Technical Notebook


After applying the MAPEPROOF, seal the construction joints between

the foundation pad and the reinforced concrete vertical walls with

IDROSTOPB25hydro-expandingbentonitejoint,nailedinplaceevery25

cmatthemid-pointofthesectionoftheverticalwallsbetweenthesteel

reinforcementrods.

BeforeapplyingIDROSTOPB25,carefullycleanthesurfacetoeliminateall

tracesofdebris,andespeciallytheslurrywhichusuallybleedsfromthe

surfacewhencompactingthecementitiousconglomerate.Thensealthe

formworkandcasttheverticalreinforcedconcretewallswithreinforced

concrete according to the specifications in Section 6. The sealing

operationwith IDROSTOPB25mustbe repeated foreachconstruction

jointintheverticalwalls,makingsurethattheriblaidverticallybetween

thewallsislaidalongsidetheribonthehorizontalsurfaceforatleast6

cm(Fig.7.41).

Fig.7.37-LayingMAPEPROOFagainstadiaphragm

52

Fig.7.36–Bulkheadinmicro-pileslevelledoffwithMAPEGROUTT60

Fig.7.39–DetailedlayoutofapplyingMAPEPROOFagainstadiaphragm

1

2

3

4



MAPEPROOF


Ground


IDROSTOP B25

Diaphragm

Fixing rods

5

6

7

8

9

Fig.7.40–DetailedlayoutofapplyingMAPEPROOFagainstadiaphragmwhichworkstogetherwiththestructure

1

2

3

4



MAPEPROOF


Ground


IDROSTOP B25

Diaphragm

Fixing rods

5

6

7

8

9

55

Technical Notebook


7.7 WATERPROOFING VERTICAL SURFACESAFTER CASTING

As previously discussed, if an excavation has no confinement, it is

possibletooperateontheexternalsideoftheverticalwallsandinstall

the waterproofing system after casting. In these cases, after casting

the foundation pad and once the foundation pad has cured, seal the

constructionjointsbetweenthefoundationpadandthereinforcedconcrete

verticalwallswithIDROSTOPB25hydro-expandingbentonitejoint,nailed

inplaceevery25cmatthemid-pointofthesectionoftheverticalwalls

between thesteel reinforcement rods.Beforeapplying IDROSTOPB25,

carefullycleanthesurfacetoeliminatealltracesofdebris,andespecially

theslurrywhichusuallybleeds fromthesurfacewhencompacting the

cementitiousconglomerate.Thensealtheformworkandcastthevertical

reinforced concrete walls with reinforced concrete according to the

specifications inSection6).Thesealingoperationwith IDROSTOPB25

mustberepeatedforeachconstructionjointintheverticalwalls,making

surethattheriblaidverticallybetweenthewallsislaidalongsidetherib

onthehorizontalsurfaceforatleast6cm.AsanalternativetoIDROSTOP

B25,IDROSTOPmaybeappliedaspreviouslyillustratedinSection7.1.

MAPEI offers a wide range of technical solutions and products for

waterproofing vertical surfaces after casting, which will be described

below.

Continuity between waterproofing layers applied before casting

(foundationpad)andaftercasting(walls)isguaranteedbyoverlappingthe

sheetsby10cm,andonverticalsurfacesMAPEPROOForMAPEPROOF

LW isalsoused. If thewaterproofing layerappliedonverticalsurfaces

aftercastingismadeusingMAPELASTICFOUNDATIONorwithaproduct

fromthePLASTIMULrange,theymustbeappliedinsuchawaythatthey

jointotheMAPEPROOFappliedbeforecasting.Therefore,toguarantee

continuityinthewaterproofinglayer,applyastripofMAPEPROOFstarting

from the wall-foundation pad fillet joint, grouted with MAPEPROOF

MASTIC,until itoverlapsthewaterproofinglayerappliedbeforecasting

byatleast10cm.

7.7.1 WATERPROOFING VERTICAL SURFACES AFTER CASTING WITH MAPEPROOF OR MAPEPROOF LW

TheMAPEPROOFandMAPEPROOFLWsheetsmayalsobeappliedafter

casting(Fig.7.42).BeforeapplyingtheMAPEPROOFthespacersmustbe

eitherremovedorsealed(Fig.7.43-44)accordingtowhetherthespacers

aremetallic(forwoodenformwork)orplastic(formetallicformwork).Then

eliminateallirregularitiesinthesubstratesandsmoothovergravelclusters

in thesurfacewithMAPEGROUTFAST-SETfibre-reinforced,controlled-

shrinkage,quicksettingandhardeningmortar for repairingconcreteor

PLANITOP400quick-setting,controlled-shrinkagethixotropicmortarfor

repairingthesurfaceofconcrete.

Inthevicinityofthe90°jointbetweenthewallandthefoundationpad,we

recommendformingabeadtosupportthefilletbetweenthehorizontal

andverticalsurfacesusingMAPEGROUTFAST-SETorPLANITOP400,or

withmortarmadeusingsandandcementwithPLANICRETEsynthetic

latexrubberadmixforcementitiousmixesataratioof1to3.

Astripatleast50cmwideatthetopofthewallmustbewaterproofed

withMAPELASTICFOUNDATIONappliedintwocoatstoformalayerat

least2mmthick.ThenlaytheMAPEPROOFstartingfromthetop,making

surethatitoverlapstheMAPELASTICFOUNDATIONbyatleast20cm.

Inthefilletbetweenthetwosystems,applyMAPEPROOFMASTICon

topof theMAPELASTICFOUNDATION.Fasten thesheets inplacewith

nailsandMAPEPROOFCDpolyethylenewashersapproximatelyevery30

cm.Whenappliedaftercasting(Fig.7.45),thebentonitesheetsarelaid

withtheuppersideofthegeo-textilefabric(thewhiteside)againstthe

reinforcedconcretewall,whiletheundersideofthegeo-textilefabric(the

darkerside)facestheoutside,thatis,incontactwiththeground.Please

note that thewhite non-woven fabricof MAPEPROOF must alwaysbe

laidincontactwiththesurfacetobewaterproofed.Whenlayingnearto

pipe-workwhichpassesthroughthesurface,thesheetsmustbecutto

shapetosuittheshapeofsuchelements,whichmustthenbesealedas

describedinSection7.9.

54

Fig.7.38–ApplicationofMAPEPROOFonthelowerpartofdiaphragms

57

Technical Notebook


AfterlayingtheMAPEPROOF,lay250g/m2non-wovenfabrictoprotect

thewaterproofinglayerwhenfillinginexcavations.Fillwithhomogenous

fineandmixedlooseearthinwell-compactedlayers40to50cmthick,to

guaranteethat,oncethefillingoperationshavebeencompleted,thereare

nogapsorvoidsandthereisbetterconfinementofthesystem.

7.7.2 WATERPROOFING VERTICAL SURFACES AFTER CASTING WITH MAPELASTIC FOUNDATION

MAPELASTIC FOUNDATION is a two-component, flexible cementitious

mortarspecificallyforwaterproofingconcretesurfacessubjecttopositive

hydrauliclift(Fig.7.46)andnegativehydrauliclift(upto1.5atm,equalto

a15mheadofwater).Thesurfacestobetreatedmustbecleanandfree

ofstrippingcompound,greaseandalltracesofdirtoranyothermaterial

which could potentially compromise the bond of the waterproofing

material. The surfaces, therefore, must be thoroughly cleaned by dry

sandblasting at a controlled pressure or with high pressure water jets

(150-180atm).

Eliminateallirregularitiesinthesubstratesandsmoothovergravelclusters

with MAPEGROUT FAST-SET fibre-reinforced, controlled-shrinkage,

quicksettingandhardeningmortar for repairingconcreteorPLANITOP

400quick-setting,controlled-shrinkagethixotropicmortarforrepairingthe

surfaceofconcrete.

MAPELASTICFOUNDATIONmustbeappliedbybrush (Fig.7.48),with

a rollerorbyspray to formacoatat least2mmthick.Approximately4

hoursafterapplyingthefirst layer ingoodweather,andinallcasesonly

when the first layer has dried, the second layer may be applied. Apply

MAPEBAND TPE (Thermoplastic Elastomer) high-flexibility, waterproof

tapeincorrespondencewiththestructuraljoints,aproductrecommended

forflexiblesealingandwaterproofingofexpansionjointsupto10mmwide

56

Fig.7.44–Levellingofftheconcretesurfaceafterremovingthebladesoftheformwork

Fig.7.43–Thebladesoftheformworkstickingthroughareinforcedconcretewallbeforebeingremoved

Fig.7.41–StripsofIDROSTOPB25usedtosealconstructionjointsbetweenafoundationpadandthewallsandconstructionjointsbetweenadjacentwalls

FIG.7.42–DETAILEDLAYOUTOFWATERPROOFINGAFTERCASTINGWITHMAPEPROOF

Fig.7.46–DetailedlayoutofwaterproofingafoundationpadwithMAPEPROOFandMAPELASTICFOUNDATIONappliedonthewall

1

2

3

4



MAPEPROOF


Ground


IDROSTOP B25

MAPEPROOF MASTIC


Continuous-yarn NWF (non-woven fabric) (weight ≥250 g/m2)

Fixing rods

5

6

7

8

9

10

11



MAPEPROOF


Ground


IDROSTOP B25

Bead of MAPEGROUT RAPIDO/PLANITOP 400


Fixing rods

4

5

6

7

8

9

10

1

2

3

59

Technical Notebook


subjecttomovement.Thetapeis1mmthickwithedgesreinforcedwith

polyesterfabric,andmustbebondedinplacewithADESILEXPG4two-

component,thixotropicepoxyadhesiveasfollows(Fig.7.48):

-applyaneven1-2mmthicklayerofADESILEXPG4withasmooth

trowelontheclean,drysubstrate.Trytoavoidtheadhesiverunning

into the joint.Lay theMAPEBANDTPEbypressingalong thesides,

makingsuretherearenocreasesorairbubbles.

-ApplyasecondlayerofADESILEXPG4freshonfresh,andcompletely

coverthesidesofthetapewiththesecondlayer.Smoothoverwith

aflattroweland,whiletheproductisstillfresh,sprinkleonalayerof

0.5 spheroid quartz to form a rough layer to help the MAPELASTIC

FOUNDATIONformagoodbond.

- Once the reticulation process of the ADESILEX PG4 has been

completed, remove any loose quartz and lay the MAPELASTIC

FOUNDATION.Whenthemortarhashardened,applyalayerof250g/

m²non-wovenfabrictoprotectthewaterproofingsystemwhenfilling

in(Fig.7.49).

7.7.3 WATERPROOFING VERTICAL SURFACES AFTER CASTING WITH PRODUCTS FROM THE PLASTIMUL RANGEVerticalsurfacesmaybewaterproofedaftercastingwithproductsfrom

thePLASTIMULrange,bituminousemulsionwaterproofingproductswith

differenttechnicalpropertiesandfinalperformancecharacteristics.

Before applying one of the products from the PLASTIMUL range, the

surfacetobetreatedmustbecleanandfreeofalltracesofdirtorany

other material which could potentially compromise the bond of the

waterproofingmaterial.Concretesurfacesmustalsobefreeofallrough

edgesandhoneycombs.Sealcracksandimperfectionsinthesubstrate

with PLANITOP 400 quick-setting, compensated-shrinkage thixotropic

mortarusedforrepairingthesurfaceofconcrete,orwithproductsfrom

theMAPEGROUTrange.

PLASTIMUL is a solvent-free bitumen emulsion which may be used to

protect rendered, brickwork structures or concrete structures against

risingdampfromthegroundoraccumulatedwater.Thesurfacestobe

treatedmustbedampenedbeforeapplyingtwolayersofPLASTIMULas

follows:

- first layer (primer). Dilute PLASTIMUL with approximately 45-50%

ofwaterandmixuntilcompletelyblended.Applythesolutionwitha

brush.When it iscompletelydry,whichnormally requires3-6hours

according to the surrounding temperature and the ventilation, apply

thesecondlayer.

-Second layer.Applya1mmthickcoatofneatPLASTIMULwitha

trowel(Fig.7.50)orwithaflatbrush.Oncecompletelydry,PLASTIMUL

forms a waterproof plastic dressing coat which is resistant to re-

emulsification after long periods of immersion in water, including

waterwhichisslightlyacidicoralkaline,andwhichisalsoresistantto

aggressiveagentsintheground.

PLASTIMUL1KSUPERPLUS is aone-component, solvent-free, quick-

drying, low-shrinkage, high-yield, high-flexibility bitumen waterproofing

emulsion containing polystyrene beads and rubber granules. The

polystyrene beads guarantee the minimum thickness while the rubber

increases the product’s flexibility. Thanks to these components, the

productiseasytoapplywithaflatornotchedtrowelorbyspraywitha

peristalticpump.PLASTIMUL1KSUPERPLUS isresistanttothealkalis

intheconcreteandaggressivesubstancesusuallyfoundintheground.

Itisusedtoformathickbitumenwaterproofinglayeronhorizontaland

vertical concrete and brick surfaces subject to high dynamic stresses.

Thethicknessof thedry layermustbeat least3mmwhendryandat

least4mmifthereiswaterinpressure.Inthiscase,insertMAPENET150

alkali-resistant glass fibre mesh between the two layers. Before laying

58

Fig.7.45b–AverticalwallwaterproofedwithMAPEPROOFaftercasting

Fig.7.47–ApplicationofMAPELASTICFOUNDATIONwithabrushontheupperpartofawallbeforeapplyingMAPEPROOF

Fig.7.48a–Phasesofwaterproofinganexpansionjointsubjecttomovementsofupto10mmwith

MAPEBANDTPE:toavoidtheepoxyadhesiveleavingaroughedge,applymaskingtapealongthesidesof

thejoint

Fig.7.45A–NailingMAPEPROOFtothesubstrateaftercasting

61

Technical Notebook


the product, apply an even coat of PLASTIMUL PRIMER (solvent-free,

ready-to-use,low-viscosity,quick-dryingbitumenemulsion)witharoller,

bybrushorbysprayonthesubstrate(Fig.7.51).

PLASTIMUL1KSUPERPLUS(Fig.7.52)mustbelaidinanevenlayerover

theentiresurface.Ifworkneedstobeinterrupted,spreadthePLASTIMUL

1KSUPERPLUSdowntoafeatheredgeandthenoverlapwiththenew

materialby10cmwhenworkrecommences.

PLASTIMUL 2K PLUS (Fig. 7.53) is a two-component, solvent-free,

highly-flexible,quick-drying,low-shrinkagebitumenemulsionwithadded

cellulosefibressuitableforwaterproofinghorizontalandverticalconcrete

andbrickworksurfaces.PLASTIMUL2KPLUSiseasytoapplywithaflat

ornotchedtrowelorbyspraywithaperistalticpumpandisresistantto

thealkalis in theconcreteandaggressivesubstancesusually found in

theground.Itisparticularlyrecommendedwhenthewaterproofinglayer

isappliedatlowtemperaturesorwithhighlevelsofdamporifthelayer

isappliedonsmoothsurfaces.Thethicknessofthedrylayermustbeat

least3mmwhendryandatleast4mmifthereiswaterinpressure.Inthis

case,insertMAPENET150alkali-resistantglassfibremeshbetweenthe

twolayers.Beforelayingtheproduct,applyanevencoatofPLASTIMUL

PRIMER(solvent-free,ready-to-use,low-viscosity,quick-dryingbitumen

emulsion)witharoller,bybrushorbyspraytoevenoutthesubstrate.

PLASTIMUL2KPLUSmustbeappliedinaneventhicknessoverthewhole

surface.Ifworkneedstobeinterrupted,spreadthePLASTIMUL2KPLUS

downtoafeatheredgeandthenoverlapwiththenewmaterialby10cm

whenwork recommences.PLASTIMUL2KSUPER (Fig. 7.54) is a two-

component, solvent-free, quick-drying, low-shrinkage, high-flexibility

bitumenwaterproofingemulsioncontainingpolystyrenespheres.These

characteristics make the product easy to apply with a flat or notched

trowel on bricks or reinforced concrete. PLASTIMUL 2K SUPER is

resistant toalkalis in theconcreteandaggressivesubstancesnormally

containedintheground.Thethicknessofthedrylayermustbeatleast

3mmwhendryandat least4mmif there iswater inpressure. In this

case,insertMAPENET150alkali-resistantglassfibremeshbetweenthe

twolayers.Beforelayingtheproduct,applyanevencoatofPLASTIMUL

PRIMER(solvent-free,ready-to-use,low-viscosity,quick-dryingbitumen

emulsion)witharoller,bybrushorbysprayonthesubstrate.PLASTIMUL

2KSUPERmustbeappliedinaneventhicknessoverthewholesurface.

Ifworkneedstobeinterrupted,spreadthePLASTIMUL2KSUPERdown

toafeatheredgeandthenoverlapwiththenewmaterialby10cmwhen

work recommences. Once dry, a process which is accelerated by the

hydraulicfillingbindercontainedintheproduct,PLASTIMUL2KSUPER

formsahighly-flexiblewaterproofdressingcoat.

ThestrongpointofPLASTIMUL1KSUPERPLUS,PLASTIMUL2KPLUS

andPLASTIMUL2KSUPERistheirversatilitywhichmakesthemsuitable

forapplicationonawiderangeofsubstrates,suchas:limestonemasonry,

cellular concrete, pumice stone, lightweight bricks and breeze blocks.

These substrates do not need to be rendered, but the joints between

thebricksorblocksmustbegroutedwithPLANITOP400quick-drying,

controlled-shrinkagethixotropicmortar.ThenapplyacoatofPLASTIMUL

PRIMERwitharoller,bybrushorbysprayand,whenthisproducthas

cured,spreadonPLASTIMUL1KSUPERPLUS,PLASTIMUL2KPLUSor

PLASTIMUL 2K SUPER, with MAPENET 150 alkali-resistant glass fibre

meshbetweenthefirstandsecondcoat.

After applying theproduct, check that it is completelydry and,before

filling in the trenches, protect the waterproofing layer with a suitable

perforation-proofsystemtoensureitisnotdamagedandthatitremains

water-tight.

7.8 WATERPROOFING STRUCTURAL JOINTSIncivilengineering,astructuraljointisaninterruptioninthecontinuityof

aconstruction.Thisinterruptionisindispensable:

-toavoidtemperaturevariationsprovokingco-actionstates;inthese

cases,theyallowforfreeexpansionofastructuretensofmetreslong

withoutdamagingorcrackingthestructure.

60

Fig.7.48b–SpreadingonADESILEXPG4withatrowel

Fig.7.48c–PositioningMAPEBANDTPE Fig.7.48e–BeforereticulationofADESILEXPG4,sprinklequartzsandonthesurfaceandremovethe

maskingtape

Fig.7.48d–SpreadingonthesecondlayerofADESILEXPG4withatrowel

63

Technical Notebook


- To avoid damage by seismic activity; during seismic activity, two

adjacentareasofthesamestructurewithdifferentseismicbehaviour

riskbeingdamaged in thepointwhere theyare joined togetherand

hittingeachother (hammeringphenomenon) if the jointbetweenthe

twostructuresisnotwideenoughallowforfreemovements.

To overcome such phenomenon, the Italian Construction Techniques

Norms & Regulations (Ministerial Decree 14th January 2008, article

7.2.2GeneralConstructionCharacteristics)establishedthatthedistance

between two adjacent constructions must be at least the sum of the

maximumcalculatedhorizontalmovementsaccordingtotheSafeguard

LimitState(SLS)and,inallcases,neverlessthanthevalueestablished

bytheNorms&Regulations.

Therefore,awell-designedstructuraljointallowsforenoughmovementof

theoscillatingcomponentssothatthestructureremainsundamagedby

seismicbehaviourbut,asfarashydraulicsealingisconcerned,thejoint

representsapointwhichmustbetreatedwithparticularcare.Thewater

tightnessofajointisguaranteedbytheuseofspecialPVCwaterstops

insertedinthecastconcrete:IDROSTOPPVCBEandIDROSTOPPVCBI.

IDROSTOP PVC BE is a pre-formed, flexible external waterstop made

by extruding high quality PVC designed for sealing construction and

expansion joints in reinforced concrete structures. In correspondence

withthejoint,werecommendapplyingafurtherstripofMAPEPROOF1

mwidetoformadoublelayerofbentonitesheetbetweenthetwosides

ofthejoint.IDROSTOPPVCBEisthennailedontopofthisstrip,whichis

embeddedinthecastconcrete(Fig.7.55).

DROSTOP PVC BI is a pre-formed, flexible external waterstop made

by extruding high quality PVC designed for sealing construction and

expansionjointsinreinforcedconcretestructures.Thejointispositioned

at themid-pointof the foundationpadorwall (Fig.7.56)andmustbe

stretchedandheldinpositionwithwire.Oneendofthewireisattached

tothereinforcementrodswhiletheotherendisattachedtothewaterstop.

62

Fig.7.49–Protectionofthewaterproofingmaterialwhenre-fillingbyapplying250g/m2nonwovenfabricinacontinuousthread

Fig.7.55–DetailedlayoutofsealingastructuraljointwithIDROSTOPPVCBE

1

2

3

4

Ground


MAPEPROOF


IDROSTOP PVC BE


Separation element

Adjacent reinforced concrete

structure

5

6

7

8

Fig.7.57–DetailedlayoutofsealingastructuraljointwithIDROSTOPPVCBI

1

2

3

4

Ground


MAPEPROOF

MAPEPROOF MASTIC

Rods bent to hold IDROSTOP PVC BI in place


Separation element

Idrostop PVC BI

Adjacent reinforced concrete structure

5

6

7

8

9

Fig.7.50–UsingatroweltoapplyPLASTIMULonaverticalretainingwall

65

Technical Notebook


Also in thiscase,we recommendapplyinga further1mwidebandof

bentonitesheetontheouterface,tobeinsertedinthejointandbentto

formaΩshape(Fig.7.57).

7.9 SEALING THROUGH-PIPES IN VERTICAL WALLS AND FOUNDATION PADS

AsindicatedinthedescriptionforlayingMAPEPROOF,incorrespondence

with elements which pass through vertical walls and foundation pads,

thebentonitesheetmustbecuttoshapesoitfitsperfectlyaroundthe

elements.Theinterfacebetweendifferentmaterialsformsapreferential

route for water and, therefore, it is good practice to take the right

precautions toguarantee that it isperfectlywatertight.Apipepassing

throughaverticalwallmustbesealedbyadoptingtwoprecautions.

ThefirstoneistoapplyIDROSTOPB25hydro-expandingbentonitejointing

materialaroundthepipe(atthemid-pointofthewall)beforecastingthe

concrete. The second precaution is to apply a piece of MAPEPROOF

bentonitesheetaroundthethroughelementandover the layeralready

applied, and to seal the edges of the piece of sheet by grouting with

MAPEPROOFMASTIC(Fig.7.58).

In the case of through-pipes in the foundation pad (Fig. 7.59), the

MAPEPROOFsheetmustbecuttoshapearoundthepipeandtheouter

partofthethroughelementmustbesealedasfollows(Fig.7.60):

-applyMAPEPROOFSEALnaturalsodiumbentoniteinpowderform

onthesheet.

- Apply IDROSTOP B25 hydro-expanding bentonite joint around the

throughelementandovertheMAPEPROOF.

-SealoverthebentoniteribwithMAPEPROOFMASTICnaturalsodium

bentonitegroutwithplasticisingadditives.

64

Fig.7.54–ApplicationofPLASTIMUL2KSUPER

Fig.7.53–ApplicationofPLASTIMUL2KPLUSFig.7.51–UsingarollertoapplyPLASTIMULPRIMER

Fig.7.52–ApplicationofPLASTIMUL1KSUPERPLUS

Fig.7.56b–Demolitiontoadepthof15cmfromtheupperpartofthefoundationpad

Fig.7.59–Detailedlayoutofsealingapipewhichpassesthroughafoundationpad

1

2

3

4



MAPEPROOF


Ground

MAPEPROOF SEAL

IDROSTOP B25

MAPEPROOF MASTIC

Through pipe

5

6

7

8

9

Fig.7.58–Detailedlayoutofsealingapipewhichpassesthroughafacingwall

1

2

3


IDROSTOP B25

MAPEPROOF

Through pipe

MAPEPROOF MASTIC

4

5

EXTERNAL INTERNAL

Fig.7.56a–AnexampleoflayingIDROSTOPPVCBIalongthecentreofawallwhenthewaterstophasnotbeenclampedinthecastconcrete:twolengthsofrebarfastenedinplacewithmetalwireattheendsofthewaterstop

67

7.10 SEALING A DRAINAGE WELLIfdrainagewellshavebeenusedwithin theareawhere the foundation

pad is tobe laid, theywill have tobesealedoff (Fig.7.61-62).Please

note that thepipingmusthaveanti-slipclampsconnectedto thesteel

reinforcementofthefoundationpad.AfterlayingtheMAPEPROOFsheet

cuttoshapearoundthewell,theouterpartofthethroughelementmust

besealedasfollows:

-applyMAPEPROOFSEALnaturalsodiumbentoniteinpowderformon

thesheet.

-ApplyIDROSTOPB25hydro-expandingbentonitejointaroundthewell

andovertheMAPEPROOF.

-SealoverthebentoniteribwithMAPEPROOFMASTICnaturalsodium

bentonitegroutwithplasticisingadditives.

Afterthesesteps,placeformworkaroundtheheadofthewelltoprotect

itwhencastingthefoundationslab.

Whentheconcreteforthefoundationslabhascured,place IDROSTOP

B25bentonitecordaroundthewellandthenblockthewellwithmasses

of MAPEPROOF SEAL natural sodium bentonite in powder form, and

thencompletelyfillthewellwithcastconcrete.Beforesealingoffthewell

withametalliccoverfixedto theheadof thewellwithstudbolts,seal

thejointbetweenthewellcoverandthewellwithMAPEPROOFSWELL

one-component,hydro-expandingpaste.Thegapleft inthefoundation

slabtoseal thewellmustthenbefilledbycasting inMAPEGROUTHI-

FLOWcontrolled-shrinkage,fibre-reinforcedmortarforrepairingconcrete

with30%ofgravelwithagrainsizebetween5and8-10mmand0.25%

MAPECURESRAcuringcompound.

7.11 WATERPROOFING ACCESS RAMPS TO AREAS BELOW GROUND LEVEL

Fromastructuralpointofview,accessrampstoareasbelowgroundlevel

maybemadeinoneoftwoways:

a)withareinforcedconcretefloorslabstructurallyindependentfromthe

restofthebuilding,laiddirectlyontheground;

b)withafoundationpadandsidewallstoformabox-likestructurewhich

runspartlyunder the rampandonwhich the reinforcedconcretefloor

slaboftherampisthenplaced.

In the first case, the waterproofing (Fig. 7.63) is installed in various

steps,inthatthelayingsurfacesoftherampandofthefoundationpad

aredifferent. In the jointbetween the twostructures,adouble layerof

bentonitesheetmustbeapplied.Theprocedureisasfollows:

-laytwolayersofMAPEPROOF,withtheunderside(thedarkside)of

thegeo-textilepolypropylenefabricontheinnerfacesoftheformwork

and overlap the edges of the sheets by at least 10 cm. Fasten the

sheets inplaceonthe leanconcretewithnailsandMAPEPROOFCD

66

Fig.7.56c–PositioningandfasteningIDROSTOPPVCBItothesteelreinforcement

Fig.7.56d–SealingwithMAPEPROOFSWELL

Fig.7.56e–RepairingfoundationswithMAPEGROUTCOLABILE

Fig.7.60a–Oneofthephasesofsealingapipewhichpassesthroughthefoundationpad:applicationof

MAPEPROOFSEALaroundthepipe

Fig.7.60b–ApplicationofMAPEPROOFMASTIConthesheet

Fig.7.60c–LayingIDROSTOPB25Fig.7.62–Detailedlayoutofsealingadrainagewellembeddedinthefoundationpad

1

2

3

4



MAPEPROOF


Ground

MAPEPROOF SEAL

IDROSTOP B25

Cast-iron manhole cover

MAPEPROOF MASTIC

5

6

7

8

9

MAPEGROUT HI-FLOW

Concrete

MAPEPROOF SWELL

Embedded fixing clamps

Tie-rod

10

11

12

13

14

69

Technical Notebook


plastic washers approximately every 50 cm. Avoid forming creases

whenlayingthefabricontheleanconcrete.

- When casting the concrete, protect the ends of the two layers of

MAPEPROOFwithpolyethylenesheet.

-ApplyIDROSTOPPVCBIpre-formedwaterstop,madebyextruding

highqualityPVC,atthemid-pointofthefoundationpad,andtighten

itwithmetalwireconnectedtothewaterstopatoneendandthesteel

reinforcementinthewallattheotherend.

-Castthefoundationpad.

- Lay MAPEPROOF on the lean concrete on the ramp and overlap

it on the two layers previously laid after removing the protective

polyethylenesheet.Beforecastingtheramp,placemetalgutteringto

collectrainwaterandfixittothesteelreinforcementintherampwith

clamps.

In the second case, the box-like structure must be waterproofed as

illustrated previously for waterproofing vertical surfaces after casting

(Section7.7.1),foldingtheMAPEPROOFundertherampwhichmustthen

bewaterproofedasfollows:

- thesurfaces tobe treatedmustbecleanand freeofoil, stripping

compound, grease and all traces of dirt or any other material

which could potentially compromise the bond of the waterproofing

material.Thesurfaces,therefore,mustbethoroughlycleanedbydry

sandblastingatacontrolledpressureorwithhighpressurewaterjets

(150-180atm).

- Eliminate all irregularities in the substrate and smooth over gravel

clusters with MAPEGROUT FAST-SET fibre-reinforced, controlled-

shrinkage,quicksettingandhardeningmortarforrepairingconcreteor

PLANITOP400quick-setting,controlled-shrinkagethixotropicmortar

forrepairingthesurfaceofconcrete.

- Apply MAPELASTIC FOUNDATION two-component, flexible

cementitious mortar for waterproofing concrete surfaces subject to

positiveandnegativehydrauliclift(upto1.5atm,theequivalentofa

15mheadofwater).Theproductmaybeappliedbybrush,witharoller

orbyspraytoformacoatatleast2mmthick.Approximately4hours

afterapplyingthefirstlayeringoodweather,andinallcasesonlywhen

thefirstlayerhasdried,thesecondlayermaybeapplied.

7.12 WATERPROOFING DEPURATION TANKSFor collection basins for waste water (Fig. 7.64) the basins must be

preparedbeforeapplyingthewaterproofingsystemasfollows:

68

Fig.7.60d–FasteningIDROSTOPB25inplacewithmetalwire

Fig.7.60e–FurthergroutingwithMAPEPROOFMASTIC

Fig.7.61–ExtrusionofMAPEPROOFSWELLtosealthejointbetweenamanholecoverandawell

Fig.7.63–Detailedlayoutofwaterproofinganaccessramptoanundergroundgaragewhichisstructurallyindependentfromtherestofthebuilding

1

2

3

4


Steel connector rods


MAPEPROOF


Ground

IDROSTOP PVC BI

Access ramp

Rainwater channel

MAPEFLEX PU45 with MAPEFOAM cord

5

6

7

8

9

10

71

Technical Notebook


-theinnerfacesofthebasin(floorandwalls)mustbeclean,freeof

strippingcompound,grease,dirtandanyothermaterialwhichcould

compromise the bond of the waterproofing system. The surfaces,

therefore, must be thoroughly cleaned by dry sandblasting at a

controlledpressureorwithhighpressurewaterjets(150-180atm).

-Form5x5cmtriangularfilletsbetweenthefloorof thebasinand

theverticalwallsandbetweentheadjacentwallsbyapplyingEPORIP

two-component, solvent-free epoxy adhesive mortar with a trowel

orbrush,andthen,while it isstill fresh,PLANITOP430fine-grained,

fibre-reinforced, controlled-shrinkage, medium-strength (30 MPa)

thixotropicmortarforrepairingconcrete.

-RoughareasinthesubstratemustbesmoothedoverwithMAPEFINISH

two-componentcementitiousmortarforfinishingoffconcrete,applied

by trowel at a thickness of up to 2-3 mm. After the MAPEFINISH

has cured, apply TRIBLOCK P three-component epoxy primer, with

the capacity of reticulating on damp surfaces, including particularly

smoothones(suchasporcelainandceramictiles,marble,etc.),onthe

floorandwallsofthebasintocreateanefficientbarrieragainstrising

damptoguaranteeagoodbond,includinginconditionsofpositivelift,

ofthewaterproofinglayer.TRIBLOCKPdilutedaccordinglyisapplied

intwocoatsbybrush,witharollerorbyairlesssprayonthesurfaces

tobetreated.Thetwocoatsshouldbeappliedcriss-crossed,making

surethattheyarealsoappliedevenly.Thesecondcoatmaybeapplied

4-6hoursafterthefirstone.

-Approximately24hoursafterapplyingthesecondcoatofTRIBLOCK

P,coverallthesurfacesofthebasinwithDURESILEBprotectiveanti-

acidtreatmentmadefromtwo-componentepoxypaintmodifiedwith

hydrocarbonresinandspecialadditives,resistanttofreezingweather

anddirectsunlight.Applytheproductintwocoatsusingconventional

methods,suchasbybrushwitharollerorbyairlessspray.Waitfrom

6 to 24 hours between the first and second coat, according to the

surroundingconditions.

-Onceithascompletelyhardened,DURESILEBmaycomeintocontact

withsewagewasteand,therefore,maybeusedforcoatingdepuration

basinsandbasinsforrun-offwaterfromdrains.Itisresistanttoacids,

dilutedalkalis,basematerials,salts,mineraloilandhydrocarbons,as

wellasthemainaggressivechemicalproductscarriedinsewagewaste

suchaschloridesandsulphates,andprotectsagainsttheaggressive

actionofcarbonatationandfreeze/thawcycles.

7.13 WATERPROOFING A SEWAGE WASTE OUTLET AND VENT CAST IN PLACE

Waterproofingofasewagewasteoutletandventcastinplaceiscarried

outby takingspecialcarewhen foldingover theMAPEPROOF (laidon

theverticalwall)insidetheholeinthewallforthestructure.The250g/m2

non-wovenfabricusedtoprotect thewaterproofing layermustalsobe

folded into thehole in thewall forwhen thestructure is filled inup to

thebaseofthesewagewasteoutletandvent.Fillintrenchesandgaps

withhomogenousfineandmixed looseearth inwell-compacted layers

40to50cmthick,toguaranteethat,oncethefillingoperationshavebeen

completed,therearenogapsorvoidsandthereisbetterconfinementof

thesystem.Thencastalayerof leanconcrete10cmthicktoevenout

thehorizontallayingsurface,onwhichtheMAPEPROOFfoldedintothe

holeforthestructureisthenoverlapped,thensealtheconstructionjoints

betweenthewallsofthebuildingandthebaseofthesewagewasteoutlet

andventbyapplyingIDROSTOPB25inbetweenthesteelreinforcement.

MAPEPROOFisthanappliedintheformworkwherethefoundationpad

ofthesewagewasteoutletandventistobecast,andthenfoldedover

onto the lean concrete to guarantee that it overlaps with the sheet on

thehorizontalsurface.TherollsofMAPEPROOFmustbepositionedwith

the underside (the darker side) of the geo-textile polypropylene fabric

70

Fig.7.64–Sedimentationtankinanadvancedstateofdeterioration

73

Technical Notebook


aroundtheformwork,whiletheupperside(thelighterside)isfoldedon

the inside so it is visible. Theedgesof the sheetsmustoverlapbyat

least10cm.Fasten thesheets inplace to the leanconcretewithnails

andMAPEPROOFCDpolyethylenewashersapproximatelyevery50cm.

Thesteelreinforcementforthefoundationpadmustbeplacedonspecial

plasticspacerstohelptheconcretetoflowunderthereinforcementand

guaranteethatitiswellcovered.Afterpositioningthesteelreinforcement,

pourontheconcreteforthebaseofthesewagewasteoutletandvent

according to the specifications for the concrete in Section 6. After

casting the base for the sewage waste outlet and vent and once the

basehascured,sealtheconstructionjointsbetweenthebaseandside

wallsof thesewagewasteoutletandventwith IDROSTOPB25hydro-

expandingbentonitejoint,nailedinplaceevery25cmatthemid-point

ofthesectionoftheverticalwallsbetweenthesteelreinforcementrods.

Thenseal the formworkandcast thevertical reinforcedconcretewalls

withconcreteaccordingtothespecificationsinSection6).Thesealing

operationwithIDROSTOPB25mustberepeatedforeachconstruction

jointintheverticalwalls,makingsurethattheriblaidverticallybetween

thewalls is laidalongside the ribon thehorizontalsurface forat least

6cm.Asanalternative, IDROSTOP hydro-expanding rubberprofile for

waterproofingworkingjointsuptoapressureof5atmmayalsobeused.

Oncethecastwallshavecured,thesurfaceofthereinforcedconcrete

mustbe smoothedover as follows: remove the spacers to adepthof

1-2cm,smoothovertheroughareasandgravelclusterswithPLANITOP

400quick-setting,compensated-shrinkage, thixotropicmortar forquick

repairson thesurfaceofconcrete,orwithPLANITOP430fine-grained,

fibre-reinforced,compensated-shrinkagethixotropicmortarforrepairing

deterioratedconcreteorproductsfromtheMAPEGROUTrange.

Astripat least50cmwideat thetopof thewallof thesewagewaste

outletandventmustbewaterproofedwithMAPELASTICFOUNDATION

appliedintwocoatstoformalayeratleast2mmthick.

Then lay the MAPEPROOF starting from the top, making sure that it

overlapstheMAPELASTICFOUNDATIONbyat least20cm. In thefillet

between the two systems, apply MAPEPROOF MASTIC on top of the

MAPELASTICFOUNDATION (Fig.7.65).Whenappliedaftercasting, the

bentonite sheets are laid with the upper side of the geo-textile fabric

(thewhiteside)againstthereinforcedconcretewall,whiletheunderside

ofthegeo-textilefabric(thedarkerside)facestheoutside.Pleasenote

thatthewhitenon-wovenfabricofMAPEPROOFmustalwaysbelaidin

contactwiththesurfacetobewaterproofed.Avoidformingcreaseswhen

layingthe fabric.When layingnear topipe-workwhichpassesthrough

thesurface,thesheetsmustbecuttoshapetosuittheshapeofsuch

elements,whichmustthenbesealedasdescribedinSection7.9.After

laying the MAPEPROOF, lay 250g/m2non-woven fabric toprotect the

waterproofinglayerwhenfillinginexcavations.

Fillwithhomogenousfineandmixedlooseearthinwell-compactedlayers

40to50cmthick,toguaranteethat,oncethefillingoperationshavebeen

72

Fig.7.65–SchematiclayoutofsealingafilletjointbetweenMAPEPROOFandMAPELASTICFOUNDATIONusingMAPEPROOFMASTIC

Concretewall

Fig.7.64–Detailedlayoutofwaterproofinganaerationoutletcastinplace

1

2

3

4


Window or door fitting


Wall of sewage waste outlet


Ground

Fixing rods

IDROSTOP B25

MAPEBAND

MAPEFLEX PU45

5

6

7

8

9

10

11 Waste outlet

Foundation pad of sewage waste outlet

MAPEPROOF MASTIC

Manifold for run-off water

MAPEPROOF


Screed to create slope

12

13

14

15

16

17

75

Technical Notebook


completed, therearenogapsorvoidsandthere isbetterconfinement

of thesystem.Thesewagewasteoutletandvent isalsowaterproofed

(Fig. 7.64) on the inside to avoid rainwater seeping into the reinforced

structure,otherwiseitmaydeteriorateprematurelyandreduceitsservice

life.Thesurfacetobetreatedmustbesolidandperfectlyclean.Remove

anycementlaitancepresentonthesurface,aswellaslooseandcrumbly

partsandtracesofdust,strippingcompoundandgreasebysandblasting

or with high pressure water jets. Even out the surface as described

previouslyfortheouterfaceofthewallsofthesewagewasteoutletand

vent,andthenwaterproof thesurfacewithMAPELASTICFOUNDATION

two-component,flexiblecementitiousmortarforwaterproofingconcrete

surfacessubjecttopositiveandnegativehydrauliclift.Incorrespondence

withtheholeforthefloordrain,applyaspecialshapedpieceofMAPEBAND

rubbertapewithafeltbackingresistanttoalkalisbondedtothesubstrate

withMAPELASTICFOUNDATION.MAPELASTICFOUNDATIONisapplied

bybrushorwitharollertoformalayeratleast2mmthick.Approximately

4hoursafterapplyingthefirstlayer,andinallcasesonlywhenthefirst

layerhasdried,thesecondlayermaybeapplied.

7.14 WATERPROOFING STRUCTURES BUILT USING THE TOP-DOWN METHOD

Thetop-downmethodwasdescribedbrieflyattheendofSection4.The

waterproofing(Fig.7.65)ofaconstructionbuiltusingthismethodmust

bemadestartingfromthetopworkingdownwards.Infact,afterpreparing

thetemporarystructures,aholeisexcavatedforthefirstfloorslab,which

iscastonthegroundwherepolyethylenesheetshavebeenplaced(Fig.

7.66)to improveitsfinalappearance.Whenithascured,thegroundis

dugoutunder thefloor slab throughspecialpassagesor accesses to

the future ramp. Special attention must be paid to guarantee that the

waterproofinglayeriscontinuousincorrespondencewiththeanchorage

pointsfortheendsofthefloorslabinthebulkheadsfortheexcavation.In

fact,ifcareistakenwiththeseconstructionfeatures,itwillguaranteethat

thebasementiswaterproof.Wheninstallingtheintermediatefloorslabs,

oncethegroundhasbeendugouttotheexternalfaceofthefloorslab,the

surfaceofthecontainmentwallsmustbecleanedwithhighpressurewater

jets(180-300atm)andlevelledoffwithMAPEGROUTT60sulphate-resistant,

fibre-reinforcedthixotropicmortarwith0.25%ofMAPECURESRA.

ThenlayontheMAPEPROOFstartingatleast1m(Fig.7.67)fromthebottom

oftheexcavationandoverlapthesheetsbyatleast10cm.Fixthesheetsin

placewithnailsandMAPEPROOFCDpolyethylenewashersapproximately

every30cm.MAPEPROOFmustbefoldedover(Fig.7.68)ontotheground,

makingsurethatitisprotectedbyasheetofpolyethylenetoguaranteethat

theconcretedoesnotattachtotheMAPEPROOFandthatitisprotectedand

undamageduntilallworkiscompleted.Thebentonitesheetandbulkheads

must thenbeperforatedso that themetalconnectorsused toanchor the

floorslabmaybecastfirmlyinplace.Theseanchorpointsarethensealedby

applyingMAPEPROOFMASTIC (Fig.7.69)naturalsodiumbentonitegrout

withplasticisingadditives.Thecycledescribedabovemustberepeatedfor

eachintermediatefloorslabuntilthelevelofthefoundationpadisreached

where,unlikeotherfloorslabs,thehemoftheMAPEPROOFisnotprotected

byasheetofpolyethylene,butoverlapsthebentonitesheetappliedallover

thesurfaceoftheleanconcrete.Onthesurface,toguaranteecontinuityofthe

waterproofinglayer,MAPEPROOF isoverlappedwiththesheetlaidbefore

castingthefloorslab.

The toppingbeamon thebulkheadmustalsobewaterproofed.Clean the

surfaceswithhighpressurewater jets (180-300atm)and thensmoothoff

the surface with PLANITOP 400 quick-setting, compensated-shrinkage,

thixotropic mortar for quick repairs on the surface of concrete, or with



the MAPEGROUT range. Once the surface has been evened off, apply

MAPELASTIC FOUNDATION (Fig. 7.70) in two coats one after the

otherusingaroller,brushorbysprayto forma layerat least2mmthick.

Approximately4hoursafterapplyingthefirstlayeringoodweather,and

inallcasesonlywhenthefirstlayerhasdried,thesecondlayermaybe

74

Fig.7.69–GroutingmetallicconnectorswithMAPEPROOFMASTIC

Fig.7.70–ApplicationofMAPELASTICFOUNDATIONonthetoppingbeamsonthebulkhead

Fig.7.71–SealingafilletjointbetweenMAPELASTICFOUNDATIONandMAPEPROOFwithMAPEPROOF

MASTICandthennailingIDROSTOPB25inplace

Fig.7.66–ApplicationofasheetofPEtoformafloorslabwitharegularinnerside

Fig.7.68–Bentonitesheetlaidontheverticalsurfaceandthenhemmedoverontothehorizontalsurface

Fig.7.67–TakingmeasurementsbeforecuttingMAPEPROOFsheets:startlayingthesheetsatleast1mfromthebottomoftheexcavation

8. WATERPROOFING EXISTING STRUCTURES BELOW GROUND LEVEL

Upuntilthispoint,wehavediscussedwaterproofinginterventionscarried

out on new constructions. Very often, however, the water tightness

of existing structures must also be guaranteed, and for which no

waterproofingsystemhadbeenconsideredduringthedesignphase.

Also,itisquitecommontocarryoutinterventionsonexistingwaterproofing

systemswhicharenolongercapableofcarryingouttheiroriginalfunction.

Belowwewilldiscussandanalyseanumberofconditionswhichoften

occuronexistingstructures,andsupplysuitable technicalsolutions to

be adopted, the products to be used and the methods for laying and

applying these products. All the information will be accompanied by

specifictechnicaldetails.

applied. MAPELASTIC FOUNDATION must be spread over all the front

face of the topping beam, on the inner face of the beam and on the

upperfaceofthebulkhead,soitmaybeoverlappedwithMAPEPROOF

for at least 30 cm to form a completely water-tight system. The fillet

joint between MAPEPROOF and MAPELASTIC FOUNDATION must be

sealed by applying IDROSTOP B25. In certain cases, this seal may be

reinforced by grouting with MAPEPROOF MASTIC (Fig. 7.71) between

the MAPELASTIC and MAPELASTIC FOUNDATION before applying

IDROSTOPB25,andthenextrudedMAPEPROOFSWELL(Fig.7.72)

77

Technical Notebook


76

Fig.7.73-Excavationworkcarriedoutunderthereinforcedconcretefoundationpadcastbefore

excavating

Fig.7.75–Aholeleftinthefloorslabtopourconcreteintotheverticalwalls

Fig.7.72–ExtrusionofMAPEPROOFSWELLontoIDROSTOPB25inthefilletjointbetweenMAPELASTICFOUNDATIONandMAPEPROOF

Fig.7.74–MAPEPROOF,appliedbeforecastingthefloorslab,ishemmedovertoguaranteethatitoverlapswiththenextsheetlaidontheverticalsurface

Fig.7.65–Detailedlayoutofwaterproofingtheendofanintermediatefloorslabinatop-downconstruction

1

2

3

4

Ground

Protective PE sheet

Intermediate floor slab

Pieces of MAPEPROOF

MAPEPROOF MASTIC

Rods for anchoring to the bulkhead

Bulkhead

IDROSTOP B25

Fixing rods

Reinforced concrete counter-wall

Smoothing and levelling layer on bulkhead

MAPEPROOF

6

7

8

9

10

11

5

12

Fig.7.76–Waterproofingthetoppingbeamonabulkhead

1

2

3

4

Pile bulkhead

Smoothing and levelling layer

MAPEPROOF


IDROSTOP B25


Topping beam

Ground

5

6

7

8

79

8.1 LINING SURFACES IN ROOMS BELOWGROUND LEVEL

Ifwaterseepsintoroomsbelowgroundlevel,therearevariouswaysto

intervene:

•waterprooftheverticalsurfaces(MAPELASTICFOUNDATION);

•waterproofboththehorizontalandverticalsurfaces(MAPEPROOFor

MAPEPROOFinconjunctionwithMAPELASTICFOUNDATION).

Below, for each type of intervention mentioned above, there is a

descriptionoftheapplicationcycleofthewaterproofingsystem.

8.1.1 WATERPROOFING VERTICAL SURFACES AFTER CASTING

This typeof intervention iscarriedoutwhenwater fromvertical facing

wallsseepsintotheroom,mainlyduetopercolatingwaterpresentinthe

ground.Inthiscase,onlytheretainingwallswillbeinvolved,andconsists

intreatingthesurfaceswithMAPELASTICFOUNDATIONtwo-component,

flexible cementitious mortar specially developed for waterproofing

surfaces subjected to negative and positive hydraulic lift. The various

phasesforthistypeofapplicationaredescribedbelow.

Concrete walls

-Removetherenderdowntotheleveloftheunderlyingmasonry.

-Remove thegravelclustersand leveloff theverticalsurfaceswith

PLANITOP 400 quick-setting, compensated-shrinkage, thixotropic

mortarforquickrepairsonthesurfaceofconcrete,orwithPLANITOP

430fine-grained,fibre-reinforced,compensated-shrinkagethixotropic

mortar for repairing deteriorated concrete or products from the

MAPEGROUTrange.

-Constructionjoints(Fig.8.1),cracksinthesubstrateandpipe-work

(Fig.8.2)andotherelementswhichpassthroughtheconcretewalls

must be sealed with MAPEPROOF SWELL one-component, hydro-

expanding paste for waterproof seals. Carefully demolish the area

around the through elements, cracks and construction joints with

suitabletoolstoadepthofatleast6cm.Tosealconstructionjoints

between old substrates and repairs, extrude MAPEPROOF SWELL

andthenrepairthesubstratewithMAPEGROUTT40orMAPEGROUT

BMmortar.Whendemolishing theareas, ifwatercontinues toseep

through,stoptheflowwithLAMPOSILEXquick-settingandhardening

hydraulicbinderforstoppinginfiltrationofwater(Fig.8.3).

- Once the surface has been smoothed off, apply two coats of

MAPELASTICFOUNDATIONwithabrush,arollerorbyspraytoform

alayeratleast2mmthick.Approximately4hoursafterapplyingthe

first layer ingoodweather,and inallcasesonlywhenthefirst layer

hasdried, thesecond layermaybeapplied.OncetheMAPELASTIC

FOUNDATION is completely cured, spread a layer of POROMAP

INTONACO macro-porous, de-humidifying render which acts as an

anti-condensationbufferonthenewwaterproofingsystem(following

thecycleindicatedontheTechnicalDataSheet).

Brick walls

-Removethedeterioratedrenderdowntotheleveloftheunderlying

brickwork.

-Pipe-workandotherelementswhichpassthroughtheconcretewalls

must be sealed with MAPEPROOF SWELL one-component, hydro-

expandingpasteforwaterproofseals.Carefullydemolishtheareaaround

thethroughelements,cracksandconstructionjointswithsuitabletools

toadepthofatleast6cm.ExtrudeMAPEPROOFSWELLaroundthe

through elements and then repair the substrate with MAPEGROUT

78

Fig.8.2–SealingapipepassingthroughthesurfacebyextrudingMAPEPROOFSWELLandthenconfining

thepipewithMAPEGROUTBM

Fig.8.1e–Asealed,repairedconstructionjoint

Fig.8.1a–Oneofthephasesofsealingaconstructionjoint:mechanicaldemolitionaroundaconstructionjointtoadepthofapproximately6cm

Fig.8.1b–ExtrusionofMAPEPROOFSWELL

Fig.8.1d–ConfinementofMAPEPROOFSWELLbyapplyingMAPEGROUTT40

Fig.8.1c–ConstructionjointsealedwithMAPEPROOFSWELL

81

Technical Notebook




hydraulicbinderforstoppinginfiltrationofwater.

- Smooth over the surfaces with a new layer of render 2 cm thick,

reinforcedwithmetalmeshfastenedtothesubstratewithplugs.Forthe

newlayerofrender,applyMAPEGROUTT60sulphate-resistant,fibre-

reinforced thixotropic mortar or MAPEGROUT BM two-component

mortar with a low modulus of elasticity. As a substitute for the

reinforcedrender,thesurfacemaybesmoothedoverwithPLANITOP

HDM MAXI two-component, fibre-reinforced, high-ductile mortar

madefrompozzolan-reactionbindersinconjunctionwithMAPEGRID

G120orMAPEGRIDG220alkali-resistant,primedglassfibremesh.

- When the render is cured, apply two coats of MAPELASTIC

FOUNDATIONwithabrush,arollerorbyspraytoformalayeratleast

2 mm thick. Approximately 4 hours after applying the first layer in

goodweather,andinallcasesonlywhenthefirstlayerhasdried,the

second layermaybeapplied.Once theMAPELASTICFOUNDATION

iscompletelycured,spreadalayerofPOROMAPINTONACOmacro-

porous, de-humidifying render which acts as an anti-condensation

bufferonthenewwaterproofingsystem(followingthecycleindicated

ontheTechnicalDataSheet).

8.1.2 WATERPROOFING HORIZONTAL AND VERTICAL SURFACES WITH MAPEPROOF

Thistypeofinterventioniscarriedoutwheneverthestoreybelowground

levelisinfiltratedwithwaterfromthefloorandverticalretainingwallsdue

tothepresenceofgroundwaterunderpressure.Inthesecases,various

techniques and products may be used according to the construction

characteristicsofthestructureandthehydrostaticpressurewhichacts

onthesubstrates.Thevariousstepsarelistedbelow.

-Demolishthefirst3or4stepsofanystairwayspresentinthearea

belowgroundlevel.Allthepartitionwalls,floorsandsubstratesmust

alsoberemoved.

- Level off the vertical surfaces with PLANITOP 400 quick-setting,

compensated-shrinkage, thixotropic mortar for quick repairs on

the surface of concrete, or with PLANITOP 430 fine-grained, fibre-

reinforced, compensated-shrinkage thixotropic mortar for repairing


- Construction joints, cracks in the substrate and pipe-work and

other elements which pass through the substrates must be sealed

with MAPEPROOF SWELL one-component, hydro-expanding paste

forwaterproofseals.Carefullydemolishtheareaaroundthethrough

elements,cracksandconstructionjointswithsuitabletoolstoadepth

ofat least6cm.Tosealconstruction jointsbetweenoldsubstrates

and repairs, extrude MAPEPROOF SWELL and then repair the

substrate with MAPEGROUT T40 or MAPEGROUT BM mortar. When

demolishing the areas, if water continues to seep through, stop the

flowwithLAMPOSILEXquick-settingandhardeninghydraulicbinder

forstoppinginfiltrationofwater.

-Line the inner facesof the roombyapplyingMAPEPROOFsheets

on thehorizontalandverticalsurfaces (Fig.8.4-5)bypositioning the

underside(thedarkside)ofthegeo-textilefabriconthesurfaceofthe

leanconcreteandtheverticalwallsandtheuppersideofthefabric(the

whiteside)facingupwardssoitisvisible.Theedgesmustoverlapbyat

least10cm.Fastenthesheetsinplacetothesubstratewithnailsand

MAPEPROOFCDpolyethylenewashersapproximatelyevery50cmon

horizontalsurfacesandevery30cmonverticalsurfaces.Whenlaying

theproductaroundthroughelements(pillars,pipe-work,etc.)thesheets

mustbecuttoshapesotheyfitperfectlyaroundtheelements,which

80

Fig.8.3–ExtrusionofMAPEPROOFSWELLonazonedamagedbyseepingwaterblockedbeforehandwithLAMPOSILEX

83

Technical Notebook


mustalsobesealedwithIDROSTOPB25(incertaincases,itmaybe

necessarytoextrudeMAPEPROOFSWELLovertheIDROSTOPB25).

Makesurethereareabsolutelynocreaseswhenlayingthesheets.

-Ifthereisahorizontalstructuretowhichthenewfoundationsmay

be anchored, the MAPEPROOF must be perforated so that metallic

connectors may be cast in place. This operation means that the

thicknessofthenewfoundationsmaybelower,inthattheoldstructure

willactasballastforthenewone.MAPEPROOFmustbeperforated

according to the results of structural calculations. Apart from the

thicknessofthenewfloorslabandwalls,thestructuralanalysismust

alsoindicatethenumberpersquaremetreanddiameterofthemetallic

connectorswhichmustbeusedonthehorizontalsurfaces(foundation

pad)andverticalsurfaces(walls).Anchorageoftheconnectorstothe

horizontal surfaces must be carried out by casting EPOJET super-

fluid epoxy resin, while ADESILEX PG1 two-component, thixotropic

epoxyadhesivemustbeusedfortheverticalsurfaces.Thepointsin

whichtheconnectorspassthroughthesheetsmustbegroutedwith

MAPEPROOFMASTIC.

- After carrying out the operations described above, position the

steelreinforcementforthenewreinforcedconcretefloorslabonthe

horizontal surfaces, at a suitable distance from the MAPEPROOF

sheetsusingplasticspacers.Thesespacersallowtheconcretetoflow

freelyunderandaroundthesteelreinforcementandguaranteethatthe

reinforcementiswellcovered.Thencastthereinforcedconcrete,the

thicknessofwhichmustbesufficient toresist thehydraulic lift from

thegroundwater.

-Aftercastingandcuring theconcrete for thenew foundationpad,

positionIDROSTOPB25hydro-expandingbentonitecordbetweenthe

steel reinforcement for the walls and cast the concrete to form the

verticalstructures,whichmustalsobeconnectedtotheexistingwalls

of the area below ground level with new anchored, sealed metallic

connectors. The 20x25 mm jointing material must be nailed to the

substrateevery25cm.ThesealingoperationwithIDROSTOPB25must

berepeatedforeachconstructionjointintheverticalwalls,makingsure

thattheriblaidverticallybetweenthewallsislaidalongsidetheribon

thehorizontalsurfaceforatleast6cm.Asanalternative,IDROSTOP

hydro-expandingrubberprofileforwaterproofingworkingjointsupto

a pressure of 5 atm may also be used. Before applying IDROSTOP

B25,carefullycleanthesurfacetoeliminateall tracesofdebris,and

especially the slurry which usually bleeds from the surface when

compacting the cementitious conglomerate used for the foundation

pad.

82

Fig.8.5a–OneofthephasesofliningtheinsideofaroomwithMAPEPROOFonthehorizontalandverticalsurfaces:applicationofMAPEPROOFonthelowerpartoftheverticalwallswiththesheethemmedoverontotheleanconcrete

Fig.8.5b–Afterlayingthesheetonthehorizontalsurface,thesteelreinforcementforcastingthereinforcedconcretefloorslabandcounter-wallisplacedinposition

Fig.8.4–DetailedlayoutofreliningtheinsideofaroombyapplyingMapeproofonthehorizontalandverticalsurfacesandthencastingthereinforcedconcretefloorslabandretainingwalls

1

2

3

4

Old reinforced concrete structure

MAPEPROOF

MAPEPROOF MASTIC

Connectors

IDROSTOP B25


Ground

New reinforced concrete structure sized to resist against hydraulic lift

5

6

7

8

85

Technical Notebook


-Thensealalltheformworkandcastthereinforcedconcretecounter-

walls. The thickness of the walls must be calculated to resist the

hydraulic lift from thegroundwater.Theconcretecounter-wallsmay

alsobemadetoformasinglebodywiththeexistingstructurefollowing

theindicationsdescribedpreviously.

8.1.3 WATERPROOFING HORIZONTAL AND VERTICAL SURFACES WITH A COMBINED BENTONITE-CEMENTITIOUS SYSTEM

Thechoiceofwhichsystemtouseforthistypeofinterventiondoesnot

dependonthehydrostaticpressureactingonthestructure(bearinmind

thatMAPELASTICFOUNDATIONishighlyresistanttonegativelift,upto

1.5baror a 15mheadofwater), but ratheron twomain factors: the

spaceavailableintheroombelowgroundlevelandthetimerequiredto

carryoutthework.Itisquiteobviousthatliningtheinnersurfaceswith

MAPEPROOFreducestheareaavailableintheroombelowgroundlevel,

inthatthecounter-wallmustbethickenoughtoresistthehydraulicliftof

thegroundwater.Theuseofacementitioussystem,ontheotherhand,

doesnotreducethespaceavailablebutmayleadtolongdelayswhen

carryingouttheworkifithastobeappliedonareinforcedrenderlevelling

layer. Therefore, when choosing which system to use in rooms below

groundlevel,theanalysismusttakeintoconsiderationboththetechnique

andtimeaspectsandtheoverallcostoftheintervention.

Concrete walls



alsoberemoved.

- Level off the vertical surfaces with PLANITOP 400 quick-setting,

compensated-shrinkage, thixotropic mortar for quick repairs on

the surface of concrete, or with PLANITOP 430 fine-grained, fibre-

reinforced, compensated-shrinkage thixotropic mortar for repairing


- Construction joints, cracks in the substrate and pipe-work and

other elements which pass through the substrates must be sealed

with MAPEPROOF SWELL one-component, hydro-expanding paste

forwaterproofseals.Carefullydemolishtheareaaroundthethrough

elements,cracksandconstructionjointswithsuitabletoolstoadepth

ofat least6cm.Tosealconstruction jointsbetweenoldsubstrates

and repairs, extrude MAPEPROOF SWELL and then repair the

substrate with MAPEGROUT T40 or MAPEGROUT BM mortar. When

demolishing the areas, if water continues to seep through, stop the

flowwithLAMPOSILEXquick-settingandhardeninghydraulicbinder

forstoppinginfiltrationofwater.

84

Fig.8.5c–ReinforcedconcretefloorslabcastontheMAPEPROOFatathicknesscalculatedtowithstandhydraulicliftfromthegroundwater

Fig.8.5d–SealingafilletjointbetweenMAPEPROOFandMAPELASTICFOUNDATIONwithIDROSTOPB25

Fig.8.6d–Metalconnectorsarerequiredtomakethenewstructurepartoftheexistingone

Fig.8.6a–OneofthephasesofreliningtheinsideofaroomwithMAPELASTICFOUNDATIONontheverticalwallsandMAPEPROOFonthehorizontalsurfaces:applicationofMAPELASTICFOUNDATIONontheverticalwallsandonthenewleanconcreteatawidthofatleast50cm

Fig.8.7a–DetailedlayoutofreliningtheinsideofaroombyapplyingMAPEPROOFonthehorizontalsurfacesandMAPELASTICFOUNDATIONontheverticalsurfaces:filletjointbetweenthefloorslabandretainingwall

1

2

3

4



MAPEPROOF MASTIC

Connectors


IDROSTOP B25

MAPEPROOF


Ground

6

7

8

9

5

87

Technical Notebook


-Ontheverticalwalls(Fig.8.6-7)andhorizontalsurfaces,applytwo

coatsofMAPELASTICFOUNDATIONoneaftertheothertoformastrip

atleast50cmwidewithabrush,arollerorbyspraytoformalayerat

least2mmthick.Approximately4hoursafterapplyingthefirstlayerin

goodweather,andinallcasesonlywhenthefirstlayerhasdried,the

secondlayermaybeapplied.

- When applying the waterproofing system on horizontal surfaces,

referalsototheindicationsattheendofthisSection.

Brick walls



alsoberemoved.

-Removethedeterioratedrenderdowntotheleveloftheunderlying

masonry.

-Smoothovertheverticalwallswithanewlayerofrender4cmthick,

reinforcedwithmetalmeshfastenedtothesubstratewithplugs.Forthe

newlayerofrender,applyMAPEGROUTT60sulphate-resistant,fibre-

reinforced thixotropic mortar or MAPEGROUT BM two-component

mortar with a low modulus of elasticity. As a substitute for the

reinforcedrender,thesurfacemaybesmoothedoverwithPLANITOP

HDMMAXItwo-component,fibre-reinforced,high-ductilemortarmade

frompozzolan-reactionbindersinconjunctionwithMAPEGRIDG120

orMAPEGRIDG220alkali-resistant,primedglassfibremesh.

-Pipe-workandotherelementswhichpassthroughthewallsmustbe

sealed with MAPEPROOF SWELL one-component, hydro-expanding

paste for waterproof seals. Carefully demolish the area around the

throughelements, cracksandconstruction jointswith suitable tools

toadepthofat least6cm.Tosealconstruction jointsbetweenold

substrates and repairs, extrude MAPEPROOF SWELL around the

through elements and then repair the substrate with MAPEGROUT



hydraulicbinderforstoppinginfiltrationofwater.

- On vertical walls and horizontal surfaces, apply two coats of

MAPELASTICFOUNDATIONoneaftertheothertoformastripatleast

50cmwidewithabrush,arollerorbyspraytoformalayeratleast2

mmthick.Approximately4hoursafterapplyingthefirstlayeringood

weather,andinallcasesonlywhenthefirstlayerhasdried,thesecond

layermaybeapplied.

86

Fig.8.6e-LayIDROSTOPB25incorrespondencewiththejointsbetweenMAPELASTICFOUNDATIONand

MAPEPROOF

Fig.8.6f–GroutingthemetalconnectorswithMAPEPROOFMASTIC

Fig.8.6c–AfterlayingMAPEPROOFontheleanconcrete,makeholestoinsertthemetalconnectors

Fig.8.6b–MAPELASTICFOUNDATIONisalsoappliedalsoonthepillars

Fig.8.6g–Metalconnectorsgroutedbeforepositioningthesteelreinforcementforthenewfloorslabtobeinstalled

Fig.8.7b–DetailedlayoutofreliningtheinsideofaroombyapplyingMAPEPROOFonthehorizontalsurfacesandMAPELASTICFOUNDATIONontheverticalsurfaces:filletjointbetweenthefloorslabandapillarorpartingwall

1

2

3

4



MAPEPROOF MASTIC

Connectors


IDROSTOP B25

MAPEPROOF


Ground

6

7

8

9

5

89

Technical Notebook


Horizontal surfaces

WhentheMAPELASTICFOUNDATIONiscompletelycured,applythe

MAPEPROOFonthehorizontalsurfacesbypositioningtheunderside

(thedarkside)ofthegeo-textilefabriconthesubstrateandtheupper

sideofthefabric(thewhiteside)facingupwardssoit isvisible.The

edgesmustoverlapbyatleast10cm.Fastenthesheetsinplaceto

thesubstratewithnailsandMAPEPROOFCDpolyethylenewashers

approximatelyevery50cm.Whenlayingtheproductaroundthrough

elements (pillars, pipe-work, etc.) the sheets must be cut to shape

sotheyfitperfectlyaroundtheelements,whichmustalsobesealed

withIDROSTOPB25(incertaincases,itmaybenecessarytoextrude

MAPEPROOFSWELLover the IDROSTOPB25).Makesure thereare

absolutelynocreaseswhenlayingthesheets.

-JointsbetweenMAPEPROOFandMAPELASTICFOUNDATIONmust

be sealed with IDROSTOP B25 hydro-expanding bentonite jointing

material,fixedtothesurfacewithnailsevery25cm.Asanalternative,

IDROSTOPhydro-expandingrubberprofileforwaterproofingworking

jointsuptoapressureof5atmmayalsobeused.

-Ifthereisahorizontalstructuretowhichthenewfoundationsmay

be anchored, the MAPEPROOF must be perforated so that metallic

connectors may be cast in place. This operation means that the

thicknessofthenewfoundationsmaybelower,inthattheoldstructure

willactasballastforthenewone.MAPEPROOFmustbeperforated

according to the results of structural calculations. Apart from the

thicknessofthenewfloorslabandwalls,thestructuralanalysismust

alsoindicatethenumberpersquaremetreanddiameterofthemetallic

connectorswhichmustbeusedonthehorizontalsurfaces(foundation

pad)andverticalsurfaces(walls).Anchorageoftheconnectorstothe

horizontal surfaces must be carried out by casting EPOJET super-

fluid epoxy resin, while ADESILEX PG1 two-component, thixotropic

epoxyadhesivemustbeusedfortheverticalsurfaces.Thepointsin

whichtheconnectorspassthroughthesheetsmustbegroutedwith

MAPEPROOFMASTIC.







thicknessofwhichmustbesufficienttoresistthehydraulicliftfromthe

groundwater.

8.2 WATERPROOFING A LIFT WELL AGAINST HYDRAULIC LIFT

Waterproofingaliftwellagainsthydrauliclift(Fig.8.7)maybecarriedout

inoneofthreeways:

1. by applying a layer ofwater-repellentmortarmadewith IDROSILEX

andIDROSILEXPRONTOontheverticalwalls;

2. applicationofawaterproofcoatingwithwater-repellentmortarmade

withIDROSILEXonthehorizontalsurfaceandMAPELASTICFOUNDATION

ontheverticalandhorizontalsurfaces;

3. applicationofMAPEPROOFon thehorizontal surface inconjunction

withMAPELASTICFOUNDATIONontheverticalsurfaces.

With all three solutions, the construction joints, cracks and pipe-work

andelementswhichpassthroughtheconcretemustfirstlybesealedby

applyingMAPEPROOFSWELLone-component,hydro-expandingpaste

for waterproof seals. Carefully demolish the area around the through

elements,cracksandconstructionjointswithsuitabletoolstoadepthof

atleast6cm.ExtrudeMAPEPROOFSWELLaroundthethroughelements

andthenrepairthesubstratewithMAPEGROUTT40orMAPEGROUTBM

mortar.Whendemolishingtheareas,ifwatercontinuestoseepthrough,

stop the flowwith LAMPOSILEX quick-setting andhardeninghydraulic

binderforstoppinginfiltrationofwater.

88

Fig.8.6h–Castingofthereinforcedconcretefloorslab,calculatedtowithstandthehydraulicliftfromthegroundwater

Fig.8.7–Infiltrationsincorrespondencewiththeconstructionjointsinthereinforcedconcretestructureforaliftwell

Technical Notebook


The surfaces to be waterproofed must be perfectly clean and solid.

Anygravelclustersmustberemovedandtheverticalsurfacesmustbe

levelled off with PLANITOP 400 quick-setting, compensated-shrinkage,

thixotropicmortar forquick repairson thesurfaceofconcrete,orwith



theMAPEGROUTrange.Thenremovealldustandresiduesofprevious

operations with a mechanical brush, by sand-blasting or with high

pressurewaterjets.

After preparing the substrate as described above, the waterproofing

productmaybeappliedasdescribedbelow.

8.2.1 WATERPROOFING WITH OSMOTIC MORTAR

-Afterpreparingthesubstrateasdescribedabove,wetthesubstrate

untilitissaturatedwithadrysurface,thenapplyIDROSILEXPRONTO

waterproof osmotic cementitious mortar with a brush, trowel or by

spray.Payparticularattentionwhenapplyingtheproductonthefillet

jointbetweenthewallsandhorizontalsurfaceandbetweenadjacent

walls, and make sure it penetrates into the substrate. Spread the

IDROSILEXPRONTOontheverticalsurfacesandformanoverlapon

thehorizontalsurfaceatleast30cmwide.Theproductmustforma

layer at least 2-3mm thick and thecharacteristicsof thehardened

layermakeitsuitableonlyforformingrigidwaterproofinglayers.

- Complete the waterproofing system by applying several layers of

water-repellentmortarmadewithIDROSILEXinpowderorliquidform,

as described above. On the surface, spread bonding slurry made

from PLANICRETE, synthetic latex rubber for cementitious mixes

andthesameamountofwater,blendedwiththecementataratioof

1:3.Using the freshon fresh technique,applya7-8mmthick layer

of mortar with a plastic consistency made from sand, cement and

IDROSILEXaccordingtotheproportionsintheTechnicalDataSheet.

After approximately one hour, before the substrate has completely

91

hardened,installa40mmthickscreedmadefromsand,cementand

IDROSILEXaccordingtotheproportionsintheTechnicalDataSheet.

-Thescreedmustbewellcompactedandsmoothedoverandmust

be cured for at least two days. Then apply a layer of EPORIP two-

component, solvent-freeepoxyadhesiveon thefillet jointsbetween

thehorizontalandverticalsurfacesandbetweentheadjacentwalls.On

thefreshEPORIP,formfilletswithMAPEGROUTBMtwo-component

mortarwithalowmodulusofelasticity.

8.2.2 WATERPROOFING WITH A COMBINED OSMOTIC MORTAR-FLEXIBLE CEMENTITIOUS MORTAR SYSTEM

- After preparing the substrate as described above, apply several

layers of water-repellent mortar made with IDROSILEX in powder or

liquid form,asdescribedbelow.Spreada layerofbondingslurryon

thesurface(Fig.8.8)madefromPLANICRETEsyntheticlatexrubberfor

cementitiousmixesandthesameamountofwater,blendedwiththe

cementataratioof1:3.Usingthefreshonfreshtechnique,applya7-8

mmthicklayerofmortarwithaplasticconsistencymadefromsand,

cementandIDROSILEXaccordingtotheproportionsintheTechnical

Data Sheet. After approximately one hour, before the substrate has

completelyhardened, installa40mmthickscreedmade fromsand,

cementandIDROSILEXaccordingtotheproportionsintheTechnical

DataSheet.

-Thescreedmustbewellcompactedandsmoothedoverandmust

be cured for at least two days. Then apply a layer of EPORIP two-

component,solvent-freeepoxyadhesiveonthefilletjointsbetweenthe

horizontalandverticalsurfacesandbetweentheadjacentwalls.Onthe

freshEPORIP,formfilletswithMAPEGROUTBMtwo-componentmortar

withalowmodulusofelasticity.Aftercompletingthecycle,applytwo

coatsofMAPELASTICFOUNDATIONwithabrushor rolleronall the

vertical and horizontal surfaces to form a layer at least 2 mm thick.

90

Fig.8.8c–ApplicationofEPORIPinthefilletjointsbetweenhorizontalandverticalsurfacesandbetweenadjacentwalls

Fig.8.8a–Oneofthephasesoftheinstallationofwaterproofcoatingwithwater-repellentIDROSILEXmortaronthehorizontalsurfaceandMAPELASTICFOUNDATIONontheverticalandhorizontalsurfaces:spreadingonbondingslurry

Fig.8.8b–Screedmadefromsand,cementandIDROSILEX

Fig.8.8e–VerticalwallsandhorizontalsurfaceswaterproofedwithMAPELASTICFOUNDATION

Fig.8.8e–ApplicationofMAPELASTICFOUNDATION

Fig.8.8d–MakingfilletsontheEPORIPwhilestillfreshwithMAPEGROUTBM

Technical Notebook


Approximately4hoursafterapplyingthefirstlayer,andinallcasesonly

whenthefirstlayerhasdried,thesecondlayermaybeapplied.

8.2.3 WATERPROOFING WITH A COMBINED BENTONITE-FLEXIBLE CEMENTITIOUS MORTAR SYSTEM

-Afterpreparingthesubstrateasdescribedabove,applytwocoats

of MAPELASTICFOUNDATION on thehorizontal surfaceanda strip

at least30cmwideontheverticalsurfaceswithabrushorrollerto

formalayeratleast2mmthick.Approximately4hoursafterapplying

thefirstlayer,andinallcasesonlywhenthefirstlayerhasdried,the

secondlayermaybeapplied.

- Line the horizontal surfaces with MAPEPROOF by positioning the

underside (the dark side) of the geo-textile fabric on the substrate

andon theverticalwallsand theuppersideof the fabric (thewhite

side) facing upwards so it is visible. The edges must overlap by at

least10cm.Fastenthesheetsinplacetothesubstratewithnailsand

MAPEPROOFCDpolyethylenewashersapproximatelyevery50cmon

horizontalsurfacesandevery30cmonverticalsurfaces.Whenlaying

theproductaroundthroughelements,thesheetsmustbecuttoshape

sotheyfitperfectlyaroundtheelements,whichmustalsobesealed

withIDROSTOPB25(incertaincases,itmaybenecessarytoextrude

MAPEPROOFSWELLover the IDROSTOPB25).Makesure thereare

absolutelynocreaseswhenlayingthesheets.

-JointsbetweenMAPEPROOFandMAPELASTICFOUNDATIONmust

be sealed with IDROSTOP B25 hydro-expanding bentonite jointing

material,fixedtothesurfacewithnailsevery25cm.Asanalternative,

IDROSTOPhydro-expandingrubberprofileforwaterproofingworking

jointsuptoapressureof5atmmayalsobeused.

-Tojointhesteelreinforcementinthenewreinforcedconcretefloor

slabwith the reinforcement in theoldone, theMAPEPROOF sheets

93

mustbeperforatedaccordingtotheresultsofstructuralcalculations.

Apartfromthethicknessofthenewfloorslab,thestructuralanalysis

mustalsoindicatethenumberpersquaremetreanddiameterofthe

metallicconnectorswhichmustbeusedon thehorizontalsurfaces.

Theconnectorsmust thenbecast inplacewithEPOJETsuper-fluid

epoxy resin. The points in which the connectors pass through the

sheetsmustbegroutedwithMAPEPROOFMASTIC.







thicknessofwhichmustbesufficienttoresistthehydraulicliftfromthe

groundwater.

Bibliography1. P. Colombo, F. Colleselli: "Elements of Geotechnics". Third edition. 2004. Printed by Zanichelli.

2. Varisco Wellpoint, "Draining ground with the wellpoint system".

92

Fig.8.9-DetailedlayoutofreliningtheinsideofaliftwellbyapplyingMAPEPROOFonthehorizontalsurfaceandMAPELASTICFOUNDATIONontheverticalsurface:filletjointbetweenthefloorslabandretainingwall

1

2

3

4



MAPEPROOF MASTIC

Connectors


IDROSTOP B25

MAPEPROOF


Ground

6

7

8

9

5

CENTRAL STATIONMilan - Italy

Waterproofingtheformerundergroundcar-parkarea,nowusedasanarchive,withMAPEPROOFandIDROSTOPB25

NIKE STORESan Benedetto del Tronto

Italy

WaterproofingstructuresbelowgroundlevelwithMAPEPROOF,

MAPELASTICFOUNDATION,IDROSTOPB25,MAPEPROOF

SWELLandLAMPOSILEX

Technical Notebook


9594

Technical Notebook


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NOTES

Waterproofing structures installed below ground level

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