Properties of alkali-activated clinoptilolite

Ortega, EA; Cheeseman, C; Knight, J; Loizidou, M

dc.contributor.author	Ortega, EA	en
dc.contributor.author	Cheeseman, C	en
dc.contributor.author	Knight, J	en
dc.contributor.author	Loizidou, M	en
dc.date.accessioned	2014-03-01T01:15:50Z
dc.date.available	2014-03-01T01:15:50Z
dc.date.issued	2000	en
dc.identifier.issn	0008-8846	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/13756
dc.subject	pozzolan	en
dc.subject	waste management	en
dc.subject	alkali-activated cement	en
dc.subject	compressive strength	en
dc.subject	zeolite	en
dc.subject.classification	Construction & Building Technology	en
dc.subject.classification	Materials Science, Multidisciplinary	en
dc.subject.other	ACCELERATION	en
dc.subject.other	MORTARS	en
dc.subject.other	ZEOLITE	en
dc.title	Properties of alkali-activated clinoptilolite	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/S0008-8846(00)00331-8	en
heal.identifier.secondary	http://dx.doi.org/10.1016/S0008-8846(00)00331-8	en
heal.language	English	en
heal.publicationDate	2000	en
heal.abstract	Materials made by hydrating the natural zeolite clinoptilolite with calcium hydroxide (Ca(OH)(2)) have been characterised and compared to other alkali-activated waste-derived and naturally occurring pozzolana. Compressive strength is dependent on the Ca(OH)(2) content, clinoptilolite particle size, and curing conditions. Optimising each of these factors has produced compacted materials containing 20 wt.% Ca(OH)(2) with average compressive strengths of 38.7 MPa. Capillary rise tests have been used to determine sorptivity coefficients of dry samples that range from 0.027 to 0.087 cm min(-1/2) depending on the alkali addition and the clinoptilolite particle size. Sorptivity depends on the Ca(OH)(2) content and reducing the clinoptilolite particle size reduces sorptivity but increases the level of water accessible porosity. X-ray diffraction (XRD) confirms that Ca(OH)(2) is consumed during curing and that it is not present in high strength, fully cured materials. Scanning electron microscopy combined with energy dispersive X-ray (SEM-EDX) analysis indicates the formation of hydration products with Ca/Si ratio in the range 0.8-1.2 and that a significant amount of unreacted clinoptilolite remains in optimised materials. (C) 2000 Elsevier Science Ltd. All rights reserved.	en
heal.publisher	PERGAMON-ELSEVIER SCIENCE LTD	en
heal.journalName	CEMENT AND CONCRETE RESEARCH	en
dc.identifier.doi	10.1016/S0008-8846(00)00331-8	en
dc.identifier.isi	ISI:000165977700017	en
dc.identifier.volume	30	en
dc.identifier.issue	10	en
dc.identifier.spage	1641	en
dc.identifier.epage	1646	en