Abstract
Improvement in mechanical properties of non-cement mortar using ASTM Class C fly ash (FA) containing high amounts of CaO produced from a fluidized bed-type boiler and blast furnace slag (BS) was studied. This type of FA is used to carbonate non-cement mortar under supercritical conditions for CO2 fixation, and it cannot be recycled and reclaimed easily because of the presence of high amounts CaO. Specimens of non-cement mortar with varied mixing ratios of BS and FA, distilled water, and alkali activators were prepared, aged for 3, 7, and 28 days, and subsequently, supercritically carbonated in a CO2 atmosphere. As a result, an improvement in the mechanical properties of non-cement mortars was expected. CaCO3 was produced in the specimens as a result of carbonation under supercritical conditions. The weight change rate, carbonation rate, phenolphthalein test, and mechanical compressive strength tests were performed on the specimens. In the case of the specimens with only distilled water added, the high pH of the FA increased the reactivity of the BS, thereby enhancing the mechanical properties of the specimen. In the case of the alkali-activated non-cement mortar specimen, the compressive strength increased by 11.2%, to 52 MPa after carbonation under the supercritical condition.
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Abbreviations
- Supercritical CO2 :
-
shows the characteristics of both the liquid and gaseous states of CO2
References
Ahn, S. H., “An Evaluation of Green Manufacturing Technologies based on Research Databases” Int. J. Precie. Eng. Manuf.-Green Tech., Vol. 1, No. 1, pp. 5–9, 2014.
Kang, H. J., Ryu, G. S., Koh, K. T., Kang, S. T., Park, J. J., and et al., “Effect of Alkaline Activator and Curing Condition on the Compressive Strength of Cementless Fly Ash Based Alkali-Activated Mortar” Journal of the Korean Institute of Resources Recycling, Vol. 18, No. 2, pp. 39–50, 2009.
Hong, S. H., Lee, B. D., and Han, S. H., “Application of Fly Ash Concrete in the Pavement” Journal of Korea Concrete Institute, Vol. 20, No. 1, pp. 701–704, 2008.
Ahn, N. S., Lee, J. H., and Lee, Y. H., “Sulfate Attack According to the Quantity of Composition of Cement and Mineral Admixtures” Journal of the Korea Institute of Building Construction, Vol. 11, No. 6, pp. 547–556, 2011.
Park, J. Y., Kim, Y. T., and Kim, H. J., “Carbonation of Coal Fly Ash for Construction Materials” Journal of the Korean Crystal Growth and Crystal Technology, Vol. 22, No. 3 pp. 147–151, 2012.
Sim, J. S., Lee, K. G., Kim, Y. T., and Kang, S. K., “Hydration Characteristics of Coal-Fly Ash Containing High CaO Compound” Journal of the Korean Ceramic Society, Vol. 49, No. 2, pp. 185–190, 2012.
Kim, W. S., Kang, T. K., Paik, M. S., Kim, S. S., and Jung, S. J., “The Experimental Study on Carbonation Properties of High Volume Fly-Ash Concrete” Journal of the Korea Architectural Institute, Vol. 23, No. 1, pp. 207–210, 2003.
Short, N. R., Purnell, P., and Page, C. L., “Preliminary Investigations into the Supercritical Carbonation of Cement Pastes” Journal of Materials Science, Vol. 36, No. 1, pp. 35–41, 2001.
Kim, I. T., Kim, H. Y., Park, G. I., Yoo, J. H., and Kim, J. H., “Effect of Carbonation Reaction of Portlandite with Supercritical Carbon Dioxide on the Characteristics of Cement Matrix” Applied Chemistry, Vol. 5, No. 1, pp. 60–63, 2001.
Hartmann, T., Paviet-Hartmann, P., Rubin, J., Fitzsimmons, M., and Sickafus, K., “The effect of supercritical carbon dioxide treatment on the leachability and structure of cemented radioactive waste-forms” Waste Management, Vol. 19, No. 5, pp. 355–361, 1999.
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Park, J., Kim, Y. Improvement in mechanical properties by supercritical carbonation of non-cement mortar using fly ash and blast furnace slag. Int. J. Precis. Eng. Manuf. 15, 1229–1234 (2014). https://doi.org/10.1007/s12541-014-0461-3
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DOI: https://doi.org/10.1007/s12541-014-0461-3