Effect of fly ash on sulphate attack in controlled environment

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dc.contributor.advisorDay, Robert L.
dc.contributor.authorKonecny, Jana
dc.date.accessioned2005-07-21T19:37:38Z
dc.date.available2005-07-21T19:37:38Z
dc.date.issued1989
dc.descriptionBibliography: p. 146-153.en
dc.description.abstractSulphate attack of concretes and mortars is a very complex process which is not yet fully understood. It was the purpose of this thesis to evaluate the influence of two western North American fly ashes on sulphate durability. In this work care was taken to eliminate sources of experimental variability by controlling the quality of (a) the attacking environment and (b) the material composition. The attacking environments were (a) combined sulphate solution (0.176 Mol Na2so4 + 0.176 Mol Mgso4·7H20) and (b) water. Both were kept at pH 7, pH 9.5 and pH uncontrolled. Sulphuric acid (H2so4) was added once daily to keep pH constant. Mortar bars were exposed to experimental conditions when they reached (a) constant strength (21 ± MPa) or (b) constant calcium hydroxide content (15% plain mortars,10.5± 0.5% blended mortars). Ordinary Portland cement (Type 10) and sulphate resistant cement (Type 50) were employed. Sundance and Laramie fly ashes (sub-bituminous ashes) were used in two levels of replacement, 35 and 50% by volume. Water/cement ratio by mass of 0.47 was used. The extent of attack was evaluated by linear expansion measurement. At the end of the testing period (6, 9 or 12 months) compressive and tensile strength measurements were performed and micros true ture of mortars was examined by means of x- ray diffraction and thermogravimetric analyses. Laramie fly ash reduced sulphate resistance at both levels of ash replacement. Sundance fly ash improved sulphate durability of ordinary Portland cement as measured by linear expansion. Increased rate of expansion was displayed by bars exposed to sulphate solution at pH 7 after 250 days of immersion. Generally, though, consistent dependency of extent of attack on the pH of the solution was not detected.
dc.format.extentxv, 158 leaves ; 30 cm.en
dc.identifier.citationKonecny, J. (1989). Effect of fly ash on sulphate attack in controlled environment (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/24036en_US
dc.identifier.doihttp://dx.doi.org/10.11575/PRISM/24036
dc.identifier.isbn0315503211en
dc.identifier.lccTP 884 A3 K66 1989en
dc.identifier.urihttp://hdl.handle.net/1880/21623
dc.language.isoeng
dc.publisher.facultyEngineering
dc.publisher.institutionUniversity of Calgaryen
dc.publisher.placeCalgaryen
dc.rightsUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subject.lccTP 884 A3 K66 1989en
dc.subject.lcshConcrete - Deterioration
dc.subject.lcshFly ash
dc.titleEffect of fly ash on sulphate attack in controlled environment
dc.typemaster thesis
thesis.degree.disciplineCivil Engineering
thesis.degree.grantorUniversity of Calgary
thesis.degree.nameMaster of Science (MSc)
ucalgary.item.requestcopytrue
ucalgary.thesis.accessionTheses Collection 58.002:Box 703 520541625
ucalgary.thesis.notesoffsiteen
ucalgary.thesis.uarcreleaseyen
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