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dc.date.accessioned2021-08-04T11:07:52Z
dc.date.available2021-08-04T11:07:52Z
dc.date.issued2020-02-27
dc.identifierdoi:10.17170/kobra-202108044482
dc.identifier.urihttp://hdl.handle.net/123456789/13073
dc.language.isoengeng
dc.rightsNamensnennung 4.0 International*
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/*
dc.subjectUHPCeng
dc.subjectsuperplasticizereng
dc.subjectretardationeng
dc.subjectfluorescence microscopyeng
dc.subject.ddc660
dc.titleFluorescence Microscopic Investigations of the Retarding Effect of Superplasticizers in Cementitious Systems of UHPCeng
dc.typeAufsatz
dcterms.abstractThe adsorption of superplasticizer molecules to particle surfaces in cementitious systems is a very important aspect for the desired liquefaction of pastes and concretes. This way, the comb shaped polymers shield attractive forces between the particles and induce a well-dispersed, homogeneous suspension. These admixtures allow the usage of fine fillers even in combination with low amounts of mixing water, and thus, are the basis for modern high performance concretes. However, the adsorption does not cause beneficial effects only: The polymer covered particle surfaces, especially clinker, are hindered to interact with water, thus hydration is retarded. This is the reason for lower early strength and is very disadvantageous for certain applications. Today it is known that the molecular structure of the polymers, for instance the chain length and charge density, affects the retardation strongly. The complexity and diversity of cementitious systems is the main reason why research in this field is quite empiric and time as well as cost intensive. To investigate the adsorption of superplasticizers in various systems in-situ, a fluorescence microscopic approach was applied: By staining the polymers with fluorescent dye they become localizable and the adsorption quantifiable. This work shows the influence of molecular structure to adsorption characteristic of different polymers and the correlation to the retarding effect of superplasticizers, especially concerning the presence of silica fume, which is indispensable for ultra-high performance concrete (UHPC).eng
dcterms.accessRightsopen access
dcterms.creatorArend, Johannes
dcterms.creatorWetzel, Alexander
dcterms.creatorMiddendorf, Bernhard
dc.relation.doidoi:10.3390/ma13051057
dc.subject.swdUltrahochfester Betonger
dc.subject.swdBetonverflüssigerger
dc.subject.swdAdsorptionger
dc.subject.swdVerzögerungger
dc.subject.swdFluoreszenzmikroskopieger
dc.type.versionpublishedVersion
dcterms.source.identifiereissn:1996-1944
dcterms.source.issueIssue 5
dcterms.source.journalMaterialseng
dcterms.source.volumeVolume 13
kup.iskupfalse
dcterms.source.articlenumber1057


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