High-calcium fly ash as the fourth constituent in concrete: Problems, solutions and perspectives

Tsimas, S; Moutsatsou-Tsima, A

dc.contributor.author	Tsimas, S	en
dc.contributor.author	Moutsatsou-Tsima, A	en
dc.date.accessioned	2014-03-01T11:44:40Z
dc.date.available	2014-03-01T11:44:40Z
dc.date.issued	2005	en
dc.identifier.issn	0958-9465	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/37077
dc.subject	Compressive strength	en
dc.subject	Concrete	en
dc.subject	Fly ash treatment	en
dc.subject	High-calcium fly ash	en
dc.subject.classification	Construction & Building Technology	en
dc.subject.classification	Materials Science, Composites	en
dc.subject.other	Composition	en
dc.subject.other	Compressive strength	en
dc.subject.other	Construction	en
dc.subject.other	Data acquisition	en
dc.subject.other	Grinding (comminution)	en
dc.subject.other	Hydration	en
dc.subject.other	Industrial applications	en
dc.subject.other	Strength of materials	en
dc.subject.other	Concrete	en
dc.subject.other	Fly ash treatment	en
dc.subject.other	High-calcium fly ash	en
dc.subject.other	Mineralogical composition	en
dc.subject.other	Cements	en
dc.title	High-calcium fly ash as the fourth constituent in concrete: Problems, solutions and perspectives	en
heal.type	other	en
heal.identifier.primary	10.1016/j.cemconcomp.2004.02.012	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.cemconcomp.2004.02.012	en
heal.language	English	en
heal.publicationDate	2005	en
heal.abstract	Even though Hellenic high-calcium fly ashes of different origin are widely used by the cement industry for the production of several CEM II types of cements according to EN 197-1, their systematic use in concrete still presents some difficulties. This inhibits the establishment of specifications for their addition. Main problems concerning the quality, are focused on variations in chemical and mineralogical composition, necessity for supplementary grinding, high proportion of free-CaO and periodically high proportion of SO3 content. These problems as well as the solutions, for every day use by the concrete industry, applied during the construction of a dam. are discussed, in this paper. To overcome these problems, untreated fly ash was cheaply upgraded by grinding at a specially designed ball mill, with simultaneously hydration, for the reduction of free-CaO. Details also (i) for fly ash variations in relation to their origin, (ii) the grinding plant and (iii) the industrial production of fly ash. are given. Finally, in a separate chapter of this paper, aiming to explain the treatment of fly ashes followed during their industrial production, data of the mechanical strength of mixtures of cements incorporating fly ashes with different treatment, concerning their free-CaO and their fineness, are given. (C) 2004 Elsevier Ltd. All rights reserved.	en
heal.publisher	ELSEVIER SCI LTD	en
heal.journalName	Cement and Concrete Composites	en
dc.identifier.doi	10.1016/j.cemconcomp.2004.02.012	en
dc.identifier.isi	ISI:000226478000012	en
dc.identifier.volume	27	en
dc.identifier.issue	2	en
dc.identifier.spage	231	en
dc.identifier.epage	237	en