Recycling untreated sugarcane bagasse ash and industrial wastes for the preparation of resistant, lightweight and ecological fired bricks

In order to mitigate environmental damage and reduce the exploitation of clay banks caused by the production of fired brick, research on the effect of the partial replacement of clay (CLAY) by industrial waste is under development. It has been reported that in brickmaking the partial substitution of clay with sugarcane bagasse ash (SCBA) affects the physical and mechanical properties by increasing absorption and reducing compressive strength. SCBA is a waste material produced in large quantities by the sugar industry and is generally discarded in open dumps. This research evaluates the effect of the partial replacement of CLAY with agricultural and industrial waste on the strength and durability properties of fired bricks. In the first phase of this study, CLAY was partially replaced by untreated sugarcane bagasse ash (UtSCBA), and in the second phase by combinations of UtSCBA plus fly ash (FA) and UtSCBA plus silica fume (SF). Binary and ternary mixtures were elaborated and characterized. The plasticities of all mixtures were evaluated, and bricks were fabricated at 900 and 1000 °C for the binary mixtures and at 900, 1000 and 1100 °C for the ternary mixtures. The fired bricks were tested for linear shrinkage, apparent density, apparent porosity, water absorption, initial rate of absorption, compressive strength and flexural strength. It was found that the bricks made with 70CLAY + 20UtSCBA + 10SF mixture fired at 1100 °C are only 2.08% more resistant to compression, 84% more resistant to bending, and only 7.03% lighter than the control bricks; nevertheless, with this mixture the use of clay is reduced by up to 30%.