Delayed ettringite formation (DEF) in mortars of white cement

Katsioti, M; Patsikas, N; Pipilikaki, P; Katsiotis, N; Mikedi, K; Chaniotakis, M

dc.contributor.author	Katsioti, M	en
dc.contributor.author	Patsikas, N	en
dc.contributor.author	Pipilikaki, P	en
dc.contributor.author	Katsiotis, N	en
dc.contributor.author	Mikedi, K	en
dc.contributor.author	Chaniotakis, M	en
dc.date.accessioned	2014-03-01T01:35:29Z
dc.date.available	2014-03-01T01:35:29Z
dc.date.issued	2011	en
dc.identifier.issn	0950-0618	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/21073
dc.subject	Delayed ettringite formation (DEF)	en
dc.subject	External sulphate attack	en
dc.subject	Limestone cement	en
dc.subject	Mortars	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	Controlling factors	en
dc.subject.other	Delayed ettringite formation	en
dc.subject.other	Ettringite formations	en
dc.subject.other	Ettringites	en
dc.subject.other	High temperature	en
dc.subject.other	SEM-EDAX	en
dc.subject.other	Sulphate attack	en
dc.subject.other	Sulphates	en
dc.subject.other	Sulphates attack	en
dc.subject.other	Thermogravimetry	en
dc.subject.other	White cement	en
dc.subject.other	Compressive strength	en
dc.subject.other	Computational electromagnetics	en
dc.subject.other	Limestone	en
dc.subject.other	Mortar	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	Cements	en
dc.title	Delayed ettringite formation (DEF) in mortars of white cement	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.conbuildmat.2010.06.095	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.conbuildmat.2010.06.095	en
heal.language	English	en
heal.publicationDate	2011	en
heal.abstract	In this study white cement CEM I-52.5 and white limestone cement CEM II-LL, A and B, with 15% and 25% limestone substitution, were studied. The way delayed ettringite forms, due to exposure to high temperatures (50 degrees C) and external sulphate attacks, was examined in the mortar samples. The mortars were immersed at 50 degrees C for 180 days in: (a) a saturated Ca(OH)(2) solution and (b) a 5% Na2SO4 solution. During the experiment's duration, the mortar samples were being observed visually on a regular basis while their expansion was estimated on a weekly basis by measuring the change of length with a micrometer. At the end of the experiment, the mortar samples' compressive strength was determined and the deterioration products were identified through means of X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM-EDAX), Thermogravimetry (TG) and Infra-Red Spectroscopy (FT-IR). Concluding it is evident that the amount of ettringite is proportional to the C(3)A content of cement. Sulphates amount in cement is the controlling factor for heat induced ettringite formation since when they are consumed the reaction stops. On the other hand in the case of external sulphate attack another important controlling factor is the compressive strength of the cement; the higher compressive strength the lower the risk of expansion. Finally, in the case of external sulphate attack, limestone, when added to cement, was proved to enhance the durability against sulphates attack when compared to a cement of the same class. (C) 2010 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.2010.06.095	en
dc.identifier.isi	ISI:000285893300061	en
dc.identifier.volume	25	en
dc.identifier.issue	2	en
dc.identifier.spage	900	en
dc.identifier.epage	905	en