A study on alkaline dissolution and geopolymerisation of hellenic fly ash

Panagiotopoulou, Ch; Perraki, T; Tsivilis, S; Skordaki, N; Kakali, G

dc.contributor.author	Panagiotopoulou, Ch	en
dc.contributor.author	Perraki, T	en
dc.contributor.author	Tsivilis, S	en
dc.contributor.author	Skordaki, N	en
dc.contributor.author	Kakali, G	en
dc.date.accessioned	2014-03-01T02:51:56Z
dc.date.available	2014-03-01T02:51:56Z
dc.date.issued	2009	en
dc.identifier.issn	01966219	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/35753
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-62849090509&partnerID=40&md5=3b46df69e980d6729a2a11987e4863a0	en
dc.subject.other	Alkali ions	en
dc.subject.other	Alkaline dissolutions	en
dc.subject.other	Alkaline medias	en
dc.subject.other	Concentration of	en
dc.subject.other	Curing conditions	en
dc.subject.other	Curing temperatures	en
dc.subject.other	Curing time	en
dc.subject.other	Dissolution rates	en
dc.subject.other	Geopolymer	en
dc.subject.other	Geopolymerization	en
dc.subject.other	Geopolymers	en
dc.subject.other	Power stations	en
dc.subject.other	Si/al ratios	en
dc.subject.other	Surface crackings	en
dc.subject.other	Ceramic materials	en
dc.subject.other	Complexation	en
dc.subject.other	Compressive strength	en
dc.subject.other	Curing	en
dc.subject.other	Dissolution	en
dc.subject.other	Fly ash	en
dc.subject.other	Inorganic polymers	en
dc.subject.other	Raw materials	en
dc.subject.other	Synthesis (chemical)	en
dc.subject.other	Strategic materials	en
dc.title	A study on alkaline dissolution and geopolymerisation of hellenic fly ash	en
heal.type	conferenceItem	en
heal.publicationDate	2009	en
heal.abstract	This work concerns the use of fly ash (coming from the power station at Megalopolis, Greece), as raw material for the synthesis of geopolymers and it is part of a research project concerning the exploitation of Greek minerals and by-products in geopolymer technology. The experimental part comprises two parts: i) the dissolution of fly ash in alkaline media and the investigation of the effect of the alkali ion (K or Na), the concentration of the solution (2, 5 and 10M) and time (5, 10 and 24 hours) on the dissolution rate of Al+3 and Sr-4 and ii) the synthesis of fly ash based geopolymers and the investigation of the effect of curing conditions (T= 50, 70 and 90°C, t= 24, 48 and 72 hours) and the Si/Al ratio (Si/Al= 1.75-4.5) on the development of the compressive strength. The dissolution rate of the studied fly ash, in alkaline media, shows that this material can be considered as potential raw material for geopolymerization. The optimal curing conditions are 48 hours at 70°C. The increase in curing time leads to the decrease of compressive strength, while the increase in curing temperature causes a slight increase in compressive strength but it also favors the surface cracking of the specimens. The compressive strength of geopolymers is found to depend systematically on the Si/Al ratio, with the maximum being 45.5±2 MPa for a Si/Al ratio of 2.5.	en
heal.journalName	Ceramic Engineering and Science Proceedings	en
dc.identifier.volume	29	en
dc.identifier.issue	10	en
dc.identifier.spage	165	en
dc.identifier.epage	174	en