Investigation of elevated temperature on compressive strength and microstructure of alkali activated slag based cements

Abstract

This study investigated the high temperature resistance of alkali activated slag based cements. Different liquids-to-solids (L/S) and Na₂SiO₃/NaOH proportions have been used in mix proportions in addition. Ordinary Portland cement (OPC) was used by replacing it with Ferrochrome slag (FS) at different percentages from 0 to 30. As alkaline liquid, sodium hydroxide and sodium silicate were used. Various L/S ratios (1/3, 2/3 and 1) and Na₂SiO₃/NaOH solution proportions (2.0, 2.5 and 3.0) were used in the preparation of samples. The highest compressive strength obtained in the blends that liquid/solid ratio was 1/3 and the Na₂SiO₃/NaOH ratio was 3. The samples produced at this specified ratios were exposed to temperatures between 100 °C and 800 °C. Beyond 400 °C, the compressive strength of alkali activated cement specimens in elevated temperature increased compared to the compressive strength of samples unexposed to elevated temperature. Increases in alkali activated cement at 800 °C were 41.1%, 28.5%, 43.9% and 46.64%, respectively, for S0, S5, S10 and S15 specimens.

Keywords:

• Alkali activated cements
• alkali activation
• geopolymers
• slag

Disclosure statement

No potential conflict of interest was reported by the authors.