ABSTRACT
This paper describes the works carried out in laboratory to investigate the possibility of using coarse bauxite residue (red sand >100 μm) aud its derivatives as a fine aggregate in concrete mixture designs. Alcoa World Alumina (Alcoa) has three refineries in Western Australia producing approximately 20,000 tonnes of mud and a similar level of red sand each day. Much research has been undertaken to establish a sustainable use for this residue. The main purpose of this research was to establish a scientific solution for the utilization of red sand and its derivatives as a replacement of natural fine aggregate (yellow sand) in concrete mixtures. The comparative analysis between normal mix proportions and the mix proportions utilizing red sand was achieved. For this project, the coarse bauxite residue obtained in the Bayer process was neutralized (carbonated) and washed to a by-product standard. Further processing was conducted using a magnetic separator to form different fractions such as Fligh Iron Red Sand and Fligh Silica Red Sand. Physical, chemical and mineralogieal properties of these materials have been tested and compared with that of natural sand. Several mixtures of concrete were then designed in order to verify their effects on strength and other properties. From the results obtained, it can be deduced that this material can be used in a wide range of concrete applications in Civil Engineering and Construction.
