The investigation of calcined red mud effects on pozzolanic activity and colouring, mineralogical and physical properties of concrete

Red mud is an industrial waste of the Bayer process which is used for the production of alumina from bauxite ore. In the world, a large amount of red mud accumulates depending on the production of aluminium, becoming a problem for environment and human health. Generally, the production of 1 ton alumina or 0.5 ton aluminium metal generates approximately 1 ton red mud waste. The aim of this thesis is to utilize red mud from Eti Aluminium Company as a colourant pigment, filler or pozzolanic material in construction industry. Primarily within the scope of the thesis; mineralogical, microstructural, grain size, surface area, density, thermal, colouring, radioactivity, alkali-silica reaction and environmental compliance properties of waste red mud were determined. In the second stage of the thesis; mechanical, mineralogical, microstructural and thermal properties of 2., 7., 28. and 90. days standard mortar specimens that prepared with red mud replaced cement in the amount of 10 wt%. In the final stage of the thesis; red mud was used as colourant pigment in paving stone, curb stone and as aggregate in city furniture prototypes. Colouring and mechanical properties of produced concretes were compared with traditional pigment and aggregate containing concrete products. Besides, environmental compliance tests of red mud containing colourant products and mortar specimens were performed. Research and development studies of utilization of red mud in different industries are focused on ceramic and tile productions in our country. The utilization of red mud as a pozzolanic pigment or aggregate in coloured concrete production, investigation of colouring properties, development of paving stone, curb stone and city furniture prototypes has been an important pilot study for recycling an industrial waste to commercial product in our country.