Cement&ConcreteComposites25(2003)

737–749

/locate/cemconcomp

In uenceofmixproportionsonrheologyofcementgrouts

containinglimestonepowder

LucieSvermova,MohammedSonebi*,PeterJ.M.Bartos

DepartmentofCivilEngineering,AdvancedConcreteandMasonryCentre,UniversityofPaisley,PaisleyPA12BE,UK

Received27May2002;accepted30September2002

Abstract

Inthispapertheparametersofcementgrouta ectingrheologicalbehaviourandcompressivestrengthareinvestigated.Factorialexperimentaldesignwasadoptedinthisinvestigationtoassessthecombinede ectsofthefollowingfactorson uidity,rheologicalproperties,inducedbleedingandcompressivestrength:water/binderratio(W/B),dosageofsuperplasticiser(SP),dosageofviscosityagent(VA),andproportionoflimestonepowderasreplacementofcement(LSP).Mini-slumptest,Marshcone,Lombardiplatecohesionmeter,inducedbleedingtest,coaxialrotatingcylinderviscometerwereusedtoevaluatetherheologyofthecementgroutandthecompressivestrengthsat7and28daysweremeasured.Atwo-levelfractionalfactorialstatisticalmodelwasusedtomodelthein uenceofkeyparametersonpropertiesa ectingthe uidity,therheologyandcompressivestrength.Themodelsarevalidformixeswith0.35–0.42W/B,0.3–1.2%SP,0.02–0.7%VA(percentageofbinder)and12–45%LSPasreplacementofcement.Thein uencesofW/B,SP,VAandLSPwerecharacterisedandanalysedusingpolynomialregressionwhichcanidentifytheprimaryfactorsandtheirinteractionsonthemeasuredproperties.Mathematicalpolynomialsweredevelopedformini-slump,platecohesionmeter,inducingbleeding,yieldvalue,plasticviscosityandcompressivestrengthasfunctionofW/B,SP,VAandproportionofLSP.Thestatisticalapproachusedhighlightedthelimestonepowdere ectandthedosageofSPandVAonthevariousrheologicalcharacteristicsofcementgrout.

Ó2002ElsevierLtd.Allrightsreserved.

Keywords:Compressivestrength;Grout;Inducedbleeding;Limestonepowder;Mini-slump;Rheology;Superplasticizer;Viscosityagent;Water/binder

1.Introduction

Cement-basedgroutsarewidelyusedininjectiongroutingofcracksinmassivestructuressincetheirphysicalandmechanicalpropertiescanbeeasilycon-trolled.Therheologicalbehaviourofspecialcementgroutsintendedfortheunderwatersealingofcracksindams,o shorestructures,massivefoundations,or s-suresinrockcanbeenhancedbytheincorporationofviscosityagent(VA)[1,2].GroutscontainingVAarealsousedfor llingpost-tensioningducts,whereitisimportanttoensurehighresistancetosedimentationandbleeding,henceensuringcorrosionprotectionofstressedtendons[3].Admixturesmainlya ectthe owbehaviourofthecementpastewithoutalteringthecomposition.Therefore,itseemsreasonabletotryto

Correspondingauthor.Tel.:+44-141-849-4216;fax:+44-141-848-3275.

E-mailaddress:mohammed.sonebi@paisley.ac.uk(M.Sonebi).0958-9465/$-seefrontmatterÓ2002ElsevierLtd.Allrightsreserved.doi:10.1016/S0958-9465(02)00115-4

*

studythee ectofwater/binderandadmixtures,chemi-calandmineral,byonlytestingthecementpaste.Therheologicalmeasurementsoncementpastewereusedtoassessthefreshproperties.Viscosityagentsarealsousedingroutsfortherepairofdeterioratedstructuresbyinjection.

Viscosityagentsarerelativelynewadmixturesusedtoenhancethecohesionandstabilityofcement-basedsys-tems[4–10].SuchVAsarewater-solublepolysaccharidesthatenhancethewaterretentioncapacityofpaste[4,5,7–10].Theuseofviscosityagentincreasestheyieldvalueandplasticviscosityofcement-basedgrout,thusneces-sitatingincreaseinwater/binderorsuperplasticiserdos-agetoinsurealowyieldstressnecessaryforproperpenetrability,spreadingandcontrolsedimentation[4,10].Severalresearchershaverelatedtheimprovementinrheologicalpropertiesandtheperformanceofcement-basedgrouttotheadditionofsuperplasticiser(SP)andVA[4–10].Forexample,forunderwatercement-basedgrout,mini-slump,washoutresistanceandresidual