How sulfates and increased temperature affect delayed ettringite formation (DEF) in white cement mortars

Adamopoulou, E; Pipilikaki, P; Katsiotis, MS; Chaniotakis, M; Katsioti, M

dc.contributor.author	Adamopoulou, E	en
dc.contributor.author	Pipilikaki, P	en
dc.contributor.author	Katsiotis, MS	en
dc.contributor.author	Chaniotakis, M	en
dc.contributor.author	Katsioti, M	en
dc.date.accessioned	2014-03-01T01:35:48Z
dc.date.available	2014-03-01T01:35:48Z
dc.date.issued	2011	en
dc.identifier.issn	0950-0618	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/21204
dc.subject	DEF	en
dc.subject	Limestone	en
dc.subject	Mortar	en
dc.subject	Sulfates	en
dc.subject	White cement	en
dc.subject.classification	Construction & Building Technology	en
dc.subject.classification	Materials Science, Multidisciplinary	en
dc.subject.other	Change of length	en
dc.subject.other	DEF	en
dc.subject.other	Delayed ettringite formation	en
dc.subject.other	Ettringites	en
dc.subject.other	Increased temperature	en
dc.subject.other	Saturated solutions	en
dc.subject.other	SEM	en
dc.subject.other	Sulfate attack	en
dc.subject.other	Sulfates	en
dc.subject.other	Type II	en
dc.subject.other	White cement	en
dc.subject.other	Cements	en
dc.subject.other	Compressive strength	en
dc.subject.other	Computational electromagnetics	en
dc.subject.other	Curing	en
dc.subject.other	Expansion	en
dc.subject.other	Limestone	en
dc.subject.other	Scanning electron microscopy	en
dc.subject.other	Sodium	en
dc.subject.other	Thermogravimetric analysis	en
dc.subject.other	X ray diffraction	en
dc.subject.other	X ray diffraction analysis	en
dc.subject.other	Mortar	en
dc.title	How sulfates and increased temperature affect delayed ettringite formation (DEF) in white cement mortars	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.conbuildmat.2011.03.051	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.conbuildmat.2011.03.051	en
heal.language	English	en
heal.publicationDate	2011	en
heal.abstract	In this study, white cement CEM I and white limestone cement CEM II-LL A and B with 15%, 25% and 35% limestone substitution were studied. The way delayed ettringite is forming due to exposure to increased temperature (50 degrees C) and external sulfate attack was examined in mortar samples which were immersed for 90 days in three different solutions: (a) saturated solution Ca(OH)(2) at 50 degrees C, (b) saturated solution of Ca(OH)(2) at 20 degrees C and (c) 5% w/w Na2SO4 solution at 50 degrees C. During this period mortar samples were visually observed regularly while their expansion was estimated on a weekly basis by measuring the change of length with a micrometer. At the end of the 90-days period the compressive strength of the mortars was determined and the deterioration products were identified through means of X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and thermogravimetric analysis (DTG). The results of this study show that DEF occurred in two forms. Samples cured at increased temperature contained DEF type I, which caused mediocre expansion and damage. Samples cured at increased temperature in the presence of sulfates produced DEF type II, which caused significant damage on the surface and exhibited high expansion. (C) 2011 Elsevier Ltd. All rights reserved.	en
heal.publisher	ELSEVIER SCI LTD	en
heal.journalName	Construction and Building Materials	en
dc.identifier.doi	10.1016/j.conbuildmat.2011.03.051	en
dc.identifier.isi	ISI:000291411200050	en
dc.identifier.volume	25	en
dc.identifier.issue	8	en
dc.identifier.spage	3583	en
dc.identifier.epage	3590	en