Mechanical and durability characteristics of gypsum-free blended cements incorporating sulphate-rich reject fly ash

Antiohos, SK; Papageorgiou, D; Chaniotakis, E; Tsimas, S

dc.contributor.author	Antiohos, SK	en
dc.contributor.author	Papageorgiou, D	en
dc.contributor.author	Chaniotakis, E	en
dc.contributor.author	Tsimas, S	en
dc.date.accessioned	2014-03-01T01:26:36Z
dc.date.available	2014-03-01T01:26:36Z
dc.date.issued	2007	en
dc.identifier.issn	0958-9465	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/18150
dc.subject	Active silica	en
dc.subject	Chloride binding capacity	en
dc.subject	Gel/space ratio	en
dc.subject	Gypsum-free blended cement	en
dc.subject	k-value	en
dc.subject	Reject fly ash	en
dc.subject	Sulphate resistance	en
dc.subject.classification	Construction & Building Technology	en
dc.subject.classification	Materials Science, Composites	en
dc.subject.other	Coal	en
dc.subject.other	Compressive strength	en
dc.subject.other	Construction industry	en
dc.subject.other	Energy efficiency	en
dc.subject.other	Fly ash	en
dc.subject.other	Sulfur compounds	en
dc.subject.other	Active silica	en
dc.subject.other	Chloride binding capacity	en
dc.subject.other	Gel/space ratio	en
dc.subject.other	Gypsum-free blended cement	en
dc.subject.other	Reject fly ash	en
dc.subject.other	Sulphate resistance	en
dc.subject.other	Cements	en
dc.title	Mechanical and durability characteristics of gypsum-free blended cements incorporating sulphate-rich reject fly ash	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.cemconcomp.2007.04.006	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.cemconcomp.2007.04.006	en
heal.language	English	en
heal.publicationDate	2007	en
heal.abstract	To accommodate the wide variations among the different types of fly ash and the growing need for its greater utilization in the construction sector, relevant standards have been established that differentiate the appropriate qualities from the unacceptable ones. Unfortunately, potentially reject fly ashes (rFA), which do not comply with standard requirements, comprise a significant part of the total amount produced in coal or lignite burning stations. High-sulphate fly ash (HSFA) is a typical example of reject material, since all relevant standards (both European and ASTM) clearly define that sulphur trioxide should be kept under a certain low limit (approximately 3-5% depending on the standard) or else concrete's durability may be threatened. The aim of this work was to design, produce and monitor the properties of a series of blended cements prepared by mixing clinker with a fly ash of high-sulphate content. No gypsum was added in the mixtures, since it is believed that sulphate ions necessary for the prolongation of the setting process (commonly provided by gypsum) could be provided by fly ash enriched in sulphates. All samples tested exhibited satisfactory initial and final setting times as well as decent compressive strength values when compared to the reference specimen containing only gypsum and no fly ash. Additionally, this paper reports on the performance aspects of blended pastes exposed to chloride binding tests and aggressive (a) 2% H2SO4 and (b) simulated marine environment solutions. Results revealed that waste materials not up to relevant standards could still contribute to the production of quality products of energy and economical efficiency. (C) 2007 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.2007.04.006	en
dc.identifier.isi	ISI:000248605300004	en
dc.identifier.volume	29	en
dc.identifier.issue	7	en
dc.identifier.spage	550	en
dc.identifier.epage	558	en