Textile Concrete in Adverse Conditions 2018 Tomá? Bittner.pdf

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ISSN:1662-9795,,pp59-65Revised:2018-05-04
doi:.net/:2018-05-09
©2018TransTechPublications,SwitzerlandOnline:2018-08-23
TextileConcreteinAdverseConditions
,a*,á1,b,ý1,c,áč1,,e
1KloknerInstitute,CzechTechnicalUniversityinPrague,Šolínova7,16608Praha6
a*tomas.******@,bmichaela.******@,cpetr.******@,
dMiroslav.******@,epetr.******@
Keywords:Textileconcrete,ARglass,fine-grainedUHPC,deflection
(TRC)isamodernmaterialthathasbeenthesubjectofmanyscientific
-grainedcement-basedmatrix,
fiberreinforced,fabricofacrylic-resistantglass,
thismaterialarethin-walledelements,whichcanbeused,forexample,forfacadecladdings
elements,lostformwork,shellstructures,gardenarchitectureorforstrengtheningorrepairof

textileconcreteduringexposuretoroadsalts,underloadofbendingmoment,atlong-termloading
atelevatedtemperatures,andassessmentofglassfiberresistanceduringexposuresimulating
concreteporesolution.
Introduction
Althoughthisconstructionmaterialismadeusingaverymoderntechnology,itspractical


needstobecompensatedforbymorelight-weightconstruction,andalsobysignificantlyhigher
utilityvalue,namelyresistancetocorrosiveenvironments[1,2,3,4].
Aninvestigationwascarriedoutunderlaboratoryconditionsonthinelementsmadefromultra-high
performance,concretereinforcedwitha2Dacrylic-resistanttextileglassmat().Theconcrete
hadafine-
propertiesofthematrixandoftheglassreinforcementsweredeterminedbyanumberof
accompanyingtests.
TextileConcrete
AnextensiveexperimentalprogramwascarriedoutinthelaboratoryoftheKloknerInstitutein
ordertooptimizetheUHPCmix[5,6,7,8,9].Aprograminvolvingseveraldozensofdifferent
mixtureswasaimedatoptimizationofthecompositionofthefine-grainedUHPCmatrixand
achievementofhighertensileandcompressivestrengthandbetterresistancetoaggressive

theamountofingredients,productiontechnology,andthestorageandtreatmentoftheresulting
.
Theconcretemixturecontainedperm3:
-standardsandwithamaximumfractionof2mm(1267kg),
-(690kg),
-microsilica(100kg),
-slag(80kg),
-Gleniumsuperplasticizer(40kg),
-water(160l).
Thestrengthcharacteristicswereverifiedon40/40/160mmspecimens(28days):
-tensilestrength12-14MPa,
-compressivestrength120-140MPa,

TechPublications,.(#110124100,UCONNHomerBabbidgeLibrary,Storrs,USA-21/10/18,10:28:28)
60RehabilitationandReconstructionofBuildings
-modulusofelasticity41-43GPa,
-fractureenergyGf130-150N/m.
TheUHPCmatrixmixedintheKloknerInstitutevariesslightlyatlowercompressiveandtensile
,anumberofresistancetestswerecarriedoutontheresistanceofthe
concretesurfacetowateranddefrostingchemicals,methodC,resultinginmaximumwasteafter
400cyclesofabout19g/m2(+5/-20°C),andfrostresistancetests,inwhichtherewereno
changesinthephysicalpropertiesofthematerialafter400cycles.
TheexperimentallyinvestigatedstructuralelementswerereinforcedusingAR(alkali-resistant)
glass,atextile2Dglassreinforcement(mesh20x20mm,)thatwasprovidedwithprotection
againstanalkalineenvironment.
Loaddisplacementdiagram:Threethin-walledelements-plates()madefromfine-grained
concrete-weresubjectedtoafour-pointbendingloadingtest().Thecourseoftheload-
,
initialstageoftheloadingprocess,noglassreinforcementofanykindwasapplied,andthefirst
,theloadingforce
decreased,thentheglassreinforcementwasactivated,andtheloadgraduallyincreaseduntilthere
,theloadingcontinued,more
cracksgraduallydevelopeduptomaximumdeflection,
showthatthereisadifferencebetweenthetensilestrengthoftheaccompanyingbodiesandthe

.
Long-termloadingintheexperiment,threethinplatesweresubjectedtoalong-termloadingunder
-levelloading,approximately75%of

loadedplatescollapsedundertestingafter105days(*).Thiswasduetothelocallowerstrengthof
theUHPCmatrix,,aproblem
thatneedstobeinvestigatedinthefutureistofindouthowtoattaintheglassreinforcementtobe
placed/positionedpreciselyalongthecrosssectionoftheelement.
::Load-displacementdiagram(threesamples)
:Dimensionsofspecimens

LengthSpan
Specimensectionb/hforceslayerincross
[mm]section
SP1,2,321/1211100100020036
SL1,2,332/25020001900650413
ST1,2,321/1211100100020036

:LoadcapacityofTRCboards
Deflection[mm]Force[N]
Specimenatcrackatcrack
atfailureatfailure
initiationinitiation
S12,172,8296,6810,1
S22,574,2364,7819,3
S32,771,4308,0799,7
:Long-termloading
Deflection[mm]
SpecimenMaxload[kN]
immediateafter225days
L16,478,521017,9
L26,55*/75,0
L37,079,671106,7
:Testingoftemperatureinfluence
Deflection[mm]Permanent
Specimenaftercoolingdeformation
at75°C
20°C[%]
T16,936,120,88
T25,705,040,88
T36,505,760,89
::Increaseofdisplacement
after225daysafterheatingintemperaturechamber
TemperatureeffectonTRC:Theeffectoftheelevatedtemperatureonthedeformationofthe
,.
about30%°Cfor22hours,after
cooling,permanentdeformationremainofapproximately12%ofthetotaldeflection(Tab4).This
permanentdeformationaffects,ononehand,theeffectofthedifferentcoefficientofthermal
expansionofthefibreandthematrix,aswellastheinfluenceoftheprotectivelayeroftheresin.
62RehabilitationandReconstructionofBuildings
:Glass-:Long-termloadingtest
DegradationofTRCinModelPoreConcreteSolutions
Inscopeoftestingthephysicalandchemico-physicalpropertiesthe2Dglassfabric

from2Dfabricfirsttypeofsample(rectangularsegmentofdimensions110×110mm)wasusedin
-longitudinalthread400m

solution,twosamplesoffabricwereexposedintotal:thefirstonetoanalysetheextentof
degradation,–10
.
ThealkalinityofmodelporesolutionsoffreshconcretewasadjustedtopH=(theoretical
modelconcrete;concretewithoutalkalimetaloxides;saturatedsolutionofCa(OH)2),pH=
(realconcrete;cementwithhighamountofalkalimetaloxides;saturatedCa(OH)2solution
representingrealconcrete;cementwithhigheramountofalkalimetals,saturatedCa(OH)2solution
withtheadditionofKOH).Thetensiletestscomparedthedifferencesbetweenreferenceand

theconstantdisplacementrateregime–theratewas0,05mm/,the
,thetypeofseparationandelongationwasrecorded

allowedtoevaluatethechangeinelasticpropertiesofthesample.
AccordingtotheFT-IRspectrometrytheglassfibresarefixedinthenetshapewhenusingthe
polyesterfibres(withnofurtherspecification).Polyesterfibresarequitepopularintextileindustry

strongacidsandstrongalkalisonlyattacktheirouterlayer[13].Forprotectivecoatingonglass
fibres,themelamin-formaldehyde,melamin-ureaor(urea-)
confirmedbythebythepresenceofcharacteristicabsorptionbandsat3460-3100cm-1wavelengths
(characteristicforprimaryamines)andbandsat2900cm-1(aliphatichydrocarbonsC-H),1530cm-1
(C=N–triazinyle)andapproximately813cm-1(triazine)[10,11].Thespectraofunagedsamples
alsoshowcharacteristicabsorptionbandsat1200-800cm-1wavelengths(silicavibration).Specific
absorptionbandsforalkali-resistantglass(“AR”)areinthewavelengthrangeof895-900and950-
979cm-1(Si-O-Zrvibration)[12,13].Thethicknessoftheaminoresincoatingonthefibresisvery
unevenassuggestedbythedifferentheightsofpeakscorrespondingtothedetectionofSiO2from
-IRspectrumofthealkali-

resistantglasswillnotcompletelymatchthespectrumofcrystallineSiO2,sincetheglassmaterialis



theformationofpores.
Thesignificantdegreeofdegradationofprotectiveorganiccoatingisevidentafterexposurein
(5weekexposure–
3500-3100cm-,thealiphaticchain
absorptionband(approximately2900cm-1)
1550-1510cm-1occurs,suggestingformationofCO-NHbond–hydrolysisofresinmacromolecule.
Thereisalsoasignificantshiftofbandsaround1000cm-1rangetowardslowerwavelength
+
Ca(OH)2,CaCO3formedbyreactionofcalciumhydroxidewithCO2orpresenceofcalcium
silicates–
pronouncedinthespectraforsamplesafter5-
().Asinthethepreviouscase,themostdistinctaretheabsorptionpeaksofCa2+
richproducts.
Theeffectofaggressiveenvironment(–always5-weekexposure)ontensile

-IRspectraclearlyshowthatthedegradationoftheglassfibre
networkiscausedbylocalizedporosityofprotectivecoatingfromaminoresin.
Summary
ThispaperpresentssomeofthebasicfeaturesofTRCaspartoftheresearchconductedatthe
KloknerInstitute,suchasexposuretode-icingsalt,underloadofbendingmomentandlong-term

-conventionalreinforcementwasexposedto
solutionssimulatingtheaggressivenessofmodelconcrete()andveryaggressiveconcrete
().QualitativeanalysisofaprotectiveorganiccoatingonglassfibresusingtheFT-IR

weeksofexposureusingtheFT-,

,itexhibitedan
-conventional
glassfibrefabricreinforcem