Effect of chemical activation method and curing conditions on strength development of high PFA content mortars

M.R. Jones, E. Csetenyi, L.J. Csetenyi, Ravindra K. Dhir

    Research output: Chapter in Book/Report/Conference proceedingOther chapter contribution

    1 Citation (Scopus)

    Abstract

    Despite the proven economic, environmental and technical benefits, long-term strength development and durability performance, the utilisation of PFA (pulverised-fuel ash, fly ash) in many countries concrete remains at a moderate level. Wider use of PFA in concrete is inhibited by a number of factors, including its relatively slow initial strength gain. Activation of PFA has potential to enhance this by accelerating the early reaction rate. Mechanical, thermal and chemical methods may all be effective in promoting the pozzolanic reaction. In this study, grinding, calcination, and chemical activation of PFA with NaOH, Ca(OH)2 , CaSO4 ·1/ 2H2O, Na2SO4 , CaCl2 , and various combinations thereof were applied and compared. Breakdown of the glassy phase of PFA was found to be strongly influenced by the curing conditions applied. These included wet curing at 20°C or 50°C as well as a regime reflecting that used in some pre-cast concrete work, i.e. 50°C for 24 hours followed by wet curing at 20°C. The best results were obtained with simultaneous addition of gypsum and NaOH; and by a combination of lime, gypsum and Na2 SO4 , especially when pre-cast cured.

    Original languageEnglish
    Title of host publicationCement combinations for durable concrete
    Subtitle of host publicationproceedings of the International Conference on Cement Combinations for Durable Concrete
    EditorsRavindra K. Dhir, Thomas A. Harrison, Moray D. Newlands
    Place of PublicationLondon
    PublisherThomas Telford
    Pages293-298
    Number of pages6
    ISBN (Electronic)9780727740045
    ISBN (Print)0727734016 , 9780727734013
    DOIs
    Publication statusPublished - 1 Jan 2005
    Event2005 International Congress 'Global construction: ultimate concrete opportunities' - Dundee, United Kingdom
    Duration: 5 Jul 20057 Jul 2005

    Conference

    Conference2005 International Congress 'Global construction: ultimate concrete opportunities'
    CountryUnited Kingdom
    CityDundee
    Period5/07/057/07/05

    Fingerprint

    pulverized fuel ash
    mortar
    fly ash
    gypsum
    chemical method
    environmental economics
    grinding
    durability
    reaction rate
    lime
    effect
    method
    chemical

    Cite this

    Jones, M. R., Csetenyi, E., Csetenyi, L. J., & Dhir, R. K. (2005). Effect of chemical activation method and curing conditions on strength development of high PFA content mortars. In R. K. Dhir, T. A. Harrison, & M. D. Newlands (Eds.), Cement combinations for durable concrete: proceedings of the International Conference on Cement Combinations for Durable Concrete (pp. 293-298). London: Thomas Telford. https://doi.org/10.1680/ccfdc.34013
    Jones, M.R. ; Csetenyi, E. ; Csetenyi, L.J. ; Dhir, Ravindra K. / Effect of chemical activation method and curing conditions on strength development of high PFA content mortars. Cement combinations for durable concrete: proceedings of the International Conference on Cement Combinations for Durable Concrete. editor / Ravindra K. Dhir ; Thomas A. Harrison ; Moray D. Newlands. London : Thomas Telford, 2005. pp. 293-298
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    abstract = "Despite the proven economic, environmental and technical benefits, long-term strength development and durability performance, the utilisation of PFA (pulverised-fuel ash, fly ash) in many countries concrete remains at a moderate level. Wider use of PFA in concrete is inhibited by a number of factors, including its relatively slow initial strength gain. Activation of PFA has potential to enhance this by accelerating the early reaction rate. Mechanical, thermal and chemical methods may all be effective in promoting the pozzolanic reaction. In this study, grinding, calcination, and chemical activation of PFA with NaOH, Ca(OH)2 , CaSO4 ·1/ 2H2O, Na2SO4 , CaCl2 , and various combinations thereof were applied and compared. Breakdown of the glassy phase of PFA was found to be strongly influenced by the curing conditions applied. These included wet curing at 20°C or 50°C as well as a regime reflecting that used in some pre-cast concrete work, i.e. 50°C for 24 hours followed by wet curing at 20°C. The best results were obtained with simultaneous addition of gypsum and NaOH; and by a combination of lime, gypsum and Na2 SO4 , especially when pre-cast cured.",
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    Jones, MR, Csetenyi, E, Csetenyi, LJ & Dhir, RK 2005, Effect of chemical activation method and curing conditions on strength development of high PFA content mortars. in RK Dhir, TA Harrison & MD Newlands (eds), Cement combinations for durable concrete: proceedings of the International Conference on Cement Combinations for Durable Concrete. Thomas Telford, London, pp. 293-298, 2005 International Congress 'Global construction: ultimate concrete opportunities', Dundee, United Kingdom, 5/07/05. https://doi.org/10.1680/ccfdc.34013

    Effect of chemical activation method and curing conditions on strength development of high PFA content mortars. / Jones, M.R.; Csetenyi, E.; Csetenyi, L.J.; Dhir, Ravindra K.

    Cement combinations for durable concrete: proceedings of the International Conference on Cement Combinations for Durable Concrete. ed. / Ravindra K. Dhir; Thomas A. Harrison; Moray D. Newlands. London : Thomas Telford, 2005. p. 293-298.

    Research output: Chapter in Book/Report/Conference proceedingOther chapter contribution

    TY - CHAP

    T1 - Effect of chemical activation method and curing conditions on strength development of high PFA content mortars

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    AU - Csetenyi, E.

    AU - Csetenyi, L.J.

    AU - Dhir, Ravindra K.

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    AB - Despite the proven economic, environmental and technical benefits, long-term strength development and durability performance, the utilisation of PFA (pulverised-fuel ash, fly ash) in many countries concrete remains at a moderate level. Wider use of PFA in concrete is inhibited by a number of factors, including its relatively slow initial strength gain. Activation of PFA has potential to enhance this by accelerating the early reaction rate. Mechanical, thermal and chemical methods may all be effective in promoting the pozzolanic reaction. In this study, grinding, calcination, and chemical activation of PFA with NaOH, Ca(OH)2 , CaSO4 ·1/ 2H2O, Na2SO4 , CaCl2 , and various combinations thereof were applied and compared. Breakdown of the glassy phase of PFA was found to be strongly influenced by the curing conditions applied. These included wet curing at 20°C or 50°C as well as a regime reflecting that used in some pre-cast concrete work, i.e. 50°C for 24 hours followed by wet curing at 20°C. The best results were obtained with simultaneous addition of gypsum and NaOH; and by a combination of lime, gypsum and Na2 SO4 , especially when pre-cast cured.

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    M3 - Other chapter contribution

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    SN - 0727734016

    SN - 9780727734013

    SP - 293

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    BT - Cement combinations for durable concrete

    A2 - Dhir, Ravindra K.

    A2 - Harrison, Thomas A.

    A2 - Newlands, Moray D.

    PB - Thomas Telford

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    Jones MR, Csetenyi E, Csetenyi LJ, Dhir RK. Effect of chemical activation method and curing conditions on strength development of high PFA content mortars. In Dhir RK, Harrison TA, Newlands MD, editors, Cement combinations for durable concrete: proceedings of the International Conference on Cement Combinations for Durable Concrete. London: Thomas Telford. 2005. p. 293-298 https://doi.org/10.1680/ccfdc.34013