Please use this identifier to cite or link to this item: http://hdl.handle.net/1822/39097

TitleCarbonation front progress in mortars containing fly ash considering the presence of chloride ions
Author(s)Malheiro, Raphaele Lira Meireles Castro
Camões, Aires
Ferreira, Rui Miguel
Meira, Gibson
Amorim, M. T.
Reis, Rui
KeywordsCarbonation
Chloride
Diffusion
Durability
Fly ash
Interaction
Permeability
Issue date2015
PublisherTrans Tech Publications
JournalKey Engineering Materials
CitationMalheiro R., Camões A., Meira G., Ferreira R. M., Amorim M. T., Reis R. J. A. C. Carbonation Front Progress in Mortars Containing Fly Ash Considering the Presence of Chloride Ions, Key Engineering Materials, Vol. Volume 634, pp. 214-221, doi:10.4028/www.scientific.net/KEM.634.214, 2014
Abstract(s)The incorporation of fly ash (FA) in cementitious matrices have been frequently used in order to make the matrix more resistant to the action of chlorides. On the other hand, it is known that Ca (OH)2 existing in the matrix is partially consumed by the pozzolanic reactions, which facilitates the advancement of carbonation. Given that the combined action between carbonation and chloride penetration is a fact little known, we speculate about the behaviour of the matrix in this context. This study investigates the influence of the presence of chlorides on the carbonation in mortars with FA. Samples with 0% and 40% replacement of cement CEM I 42.5 R for FA were molded with water/binder 0.56 and 0.52 respectively. After 90 days of curing the specimens were subjected to cycles of immersion/drying for 56 days. Half of the samples was subjected to the following cycle: two days in a solution containing NaCl (concentration equal to 3.5 %); 12 days in the carbonation chamber (4% of CO2). The other half was: two days in water; 12 days in the carbonation chamber. Then, the development of carbonation was evaluated. The results indicate that the presence of chlorides influences the carbonation. The specimens submitted to the exclusive action of CO2 showed a greater depth of carbonation compared to that presented by the specimens subjected to combined action. This may be related to changes in properties of the matrix which may lead to further refinement of the pores and related to the presence of the salt that can lead to partial filling of the pores and the increase in moisture content.
TypeConference paper
URIhttp://hdl.handle.net/1822/39097
DOI10.4028/www.scientific.net/KEM.634.214
ISSN1662-9795
Publisher versionhttp://www.scientific.net/KEM.634.214
Peer-Reviewedyes
AccessRestricted access (UMinho)
Appears in Collections:C-TAC - Artigos em Revistas Internacionais

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