Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Assessment of the Pozzolanic Reactivity of Calcined Kaolinitic Clays by a Rapid Alkaline Solubility Test
Abstract Given the availability of clay deposits in several geographical areas of the Cuban territory and the use of calcined clays as a source of Supplementary Cementitious Materials (SCM), it is necessary to evaluate the pozzolanic reactivity of its calcination products and because of the complexity in the chemical - mineralogical characteristics of the pozzolans. This work introduces a new rapid method to predict the potential character pozzolanic of these materials by alkaline solubility and presents the possible correlation with isothermal calorimetry in lime-pozzolan pastes following the R3 protocol. The raw materials were characterized by XRF, XRD and TGA. The clayey materials contain more than 70% of SiO2 + Al2O3 + Fe2O3, which guarantees its pozzolanic character after its thermal activation. The process of the dihydroxylation of the clay minerals happens between 350 °C and 650 °C, and for the deposit of Yaguajay the decomposition of the calcite is between 650 °C and 750 °C. Alkaline solubility test is a viable test to assess the pozzolanic reactivity of calcined kaolinitic clay due a good and directly correlation between the content of soluble aluminum and the total heat released (R = 0.995) and there is not a significant dispersion of the obtained data for each clay deposit (CV% between 0.01 and 2.80). The pozzolanic reactivity of its calcination products determined by isothermal calorimetric follows the sequence CG > LS > LL > YG and matches with Alkaline Solubility test.
Assessment of the Pozzolanic Reactivity of Calcined Kaolinitic Clays by a Rapid Alkaline Solubility Test
Abstract Given the availability of clay deposits in several geographical areas of the Cuban territory and the use of calcined clays as a source of Supplementary Cementitious Materials (SCM), it is necessary to evaluate the pozzolanic reactivity of its calcination products and because of the complexity in the chemical - mineralogical characteristics of the pozzolans. This work introduces a new rapid method to predict the potential character pozzolanic of these materials by alkaline solubility and presents the possible correlation with isothermal calorimetry in lime-pozzolan pastes following the R3 protocol. The raw materials were characterized by XRF, XRD and TGA. The clayey materials contain more than 70% of SiO2 + Al2O3 + Fe2O3, which guarantees its pozzolanic character after its thermal activation. The process of the dihydroxylation of the clay minerals happens between 350 °C and 650 °C, and for the deposit of Yaguajay the decomposition of the calcite is between 650 °C and 750 °C. Alkaline solubility test is a viable test to assess the pozzolanic reactivity of calcined kaolinitic clay due a good and directly correlation between the content of soluble aluminum and the total heat released (R = 0.995) and there is not a significant dispersion of the obtained data for each clay deposit (CV% between 0.01 and 2.80). The pozzolanic reactivity of its calcination products determined by isothermal calorimetric follows the sequence CG > LS > LL > YG and matches with Alkaline Solubility test.
Assessment of the Pozzolanic Reactivity of Calcined Kaolinitic Clays by a Rapid Alkaline Solubility Test
Cabrera, E. (Autor:in) / Almenares, R. (Autor:in) / Alujas, A. (Autor:in)
28.10.2017
7 pages
Aufsatz/Kapitel (Buch)
Elektronische Ressource
Englisch
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