Resistance of alkali-activated slag to sulphate attack and elevated temperatures

Mahmoud, Ayaallah; Kishar, Essam A.; Ahmed, Doaa A.

doi:10.21608/jsrs.2018.25530

Resistance of alkali-activated slag to sulphate attack and elevated temperatures

Document Type : Original Article

Authors

¹ Chemistry Dep., Faculty of Girls, Ain Shams University, Cairo, Egypt.

² Professor of inorganic chemistry, 2 Assistant prof. of inorganic chemistry, 3 Assistant lecture of inorganic and analytical chemistry

³ Chemistry Dep., Faculty of Girls, Ain Shams University, Cairo, Egypt

10.21608/jsrs.2018.25530

Abstract

Thermal stability as well as sulphate resistance of alkali activated slag (AAS) pastes prepared from Ground Granulated Blast Furnace Slag (GGBFS) and 5% fly ash (FA)are examined. AAS pastes are accelerated using alkaline solution of sodium hydroxide with concentration 1, 1.5 and 2 M and sodium silicate with fixed concentration (0.28 mol/Kg).AAS pastes exposed to 5% MgSO₄ solution and to high temperature (200, 400, 600 and 800 ^oC). The compressive strength, bulk density, total porosity, chemically combined water content and phase composition are determined in this study. Concentration of 2M NaOH with 5% FA promotes the best properties of AAS pastes that exhibit the highest resistance to firing up to 400^oC by achieving the greatest compressive strength. However, AAS pastes activated by 2M NaOHgive a high sulphate resistance.

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