| dc.description.abstract | ABSTRACT
Cement is the primary binding material in concrete with over long history of production. Its production method and raw materials that have been used are the center of attention due to the carbon dioxide (CO2) emission into the atmosphere. Aside from this, the amount of carbon dioxide released by the cement industry is enormous due to the increase in global cement production. Furthermore, raw materials used in the cement industry significantly damage the environment. Therefore, countries have set emission reduction goals for the cement industry as a result. Using industrial byproducts as a supplementary cementing material or as a precursor to produce geopolymer concrete are strategies for reducing greenhouse gas emissions (GHG). Thus, this thesis research aims to characterize raw materials used as a precursor for geopolymer concrete.
The materials are mainly from different sources. Silicomanganese slag, ground granulated blast furnace slags are slag-based material, granite tailing from rock-based geopolymer material, and silica flour and microsilica, both silica-based materials. A particle size distribution, an X-ray fluorescence analysis, an X-ray diffractogram analysis, and a BET-surface area analysis were the laboratory methods used to investigate the particle size, phase identification, mineralogical composition, specific surface area, and microstructural characteristics of their materials. Laboratory findings show that all granite and silica flour exhibited pure crystalline phases while the slag-based materials GGBS and SiMn-slag exhibited amorphous to glassy phases. Microsilica exhibited a pure amorphous phase. The wet analysis was found to be the reproducible method for almost all materials. However, due to its high fineness, microsilica can form agglomerates. Analysis from x-ray fluorescence show that silica-based materials have a very low content of aluminum, and the slag-based raw materials showed higher content of calcium and magnesium oxides.
Generally, various factors influence the characteristics of precursors, such as the types of raw materials used in production, the methods of production, the location, and the weather conditions. Hence, this thesis research findings will provide a significant contribution for the geopolymer concrete development in characterizing materials that are used as a precursor of geopolymer concrete. | |