STUDY ON THE PHYSICO – CHEMICAL AND MECHANICAL PROPERTIES OF HARDENED ALKALI ACTIVATED SLAG PASTES

Abstract

Cement industry plays a very important role in the basic industries which used as the main building material. The Portland cement industry causes approximately 7% of global greenhouse gas production. The reduction of CO2 emissions can be done by using geopolymer cement. Geopolymer cement is alkali-activated slag composites which can be considered as a green material for construction to protect the environment. The thesis presents the preparation of alkali-activated slag (geopolymer cement) by mixing various amounts of NaOH and Na2SiO3 as a ratio by weight with ground granulated blast furnace slag (GGBS) which is the abbreviation of silicone-oxo-aluminate. Using GGBS reduce CO2 emission in comparison with Portland cement. GGBS is a by-product engendered during steel manufacturing and contains CaO-MgO-Al2O3-SiO2 oxides. The crystallinity of GGBS relies on the cooling method of slag melts. The GGBS is formed by cooling the molten slag rapidly using water which leads to formation of amorphous structure. The activation of slag by alkali leads to creation of CSH gel and calcium silicate aluminate hydrate (CSAH). So, in this study, ground granulated blast furnace slag is used to produce alkali activated slag pastes.