Enhancing the mechanical properties of blended cements by utilising the coarser fraction of high-calcium fly ash

Antiohos, S; Vouros, V; Tsimas, S

dc.contributor.author	Antiohos, S	en
dc.contributor.author	Vouros, V	en
dc.contributor.author	Tsimas, S	en
dc.date.accessioned	2014-03-01T02:50:04Z
dc.date.available	2014-03-01T02:50:04Z
dc.date.issued	2005	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/34886
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-33645290940&partnerID=40&md5=d9fa6be6709d124a3538eb1e851e9ad7	en
dc.subject	Fixed lime	en
dc.subject	Fractionation	en
dc.subject	High-calcium fly ash	en
dc.subject	k-value	en
dc.subject	Reactive Silica	en
dc.subject.other	Fixed lime	en
dc.subject.other	High-calcium fly ash	en
dc.subject.other	Reactive Silica	en
dc.subject.other	Calcium	en
dc.subject.other	Concrete additives	en
dc.subject.other	Fly ash	en
dc.subject.other	Fractionation	en
dc.subject.other	Silica	en
dc.subject.other	Cements	en
dc.title	Enhancing the mechanical properties of blended cements by utilising the coarser fraction of high-calcium fly ash	en
heal.type	conferenceItem	en
heal.publicationDate	2005	en
heal.abstract	Despite their great availability and relative low cost, fly ashes are still utilized in the construction sector with extreme cautiousness. This is the outcome of their inherent variability, but also of the diversity characterizing the processing methods applied globally. The majority of the processing procedures aim at removing the coarser fractions of fly ash since these are usually rich in undesired residual carbon and furthermore they are considered less reactive (or even chemically inert) in cement environment. However, the same fractions are usually enriched in silica which when located in the glass phase of the ash comprises the main carrier of the pozzolanic reactions. In the work presented herein, a bulk high-calcium (ASTM class C) fly ash was fractionated into two new ash samples using the 45-micron sieve. The coarse fraction was then ground to reach similar particle size distribution with the finer one and they were both used to replace moderate (20%) and high (40% by weight) volumes of cement in mortar and paste systems. Evidence included in this investigation reveal that when properly treated, the coarser fraction of fly ash can play a crucial role in improving both the early and later age performance of blended cements. Excess of active silica ascertained in the coarse fraction of the bulk ash was held responsible for its superiority throughout the curing period.	en
heal.journalName	Proceedings of the International Conference on Cement Combinations for Durable Concrete	en
dc.identifier.spage	241	en
dc.identifier.epage	250	en