Valorization of wood sawdust in making porous clay brick

Abstract

This paper studies the application of a variety of sawdust materials in the production of lightweight insulating bricks. First, the mineralogical and chemical composition of clays was determined. Next, ceramic bricks were fabricated with different quantities of materials (3 to 6 and 9 wt. % for sawdust, 65 wt. % for grey clay, 24 to 27 and 30 wt. % for yellow clay and 2 wt. % of tuff). These bricks were fired at 800 and 950°C. The effect of adding this sawdust on the technological behaviour of the brick was assessed by drying and firing shrinkage, water absorption, porosity, bulk density and compressive strength. The results have shown that the optimum sintering temperature is 950°C. Below this temperature, at 950°C, increased open porosity was observed, which decreased the compressive strength of the bricks. Based on the results obtained, the optimum amounts of waste were 9 wt. % sawdust of eucalyptus, 24 wt. % shaping moisture and 1.6 particle size diameter. These percentages produced bricks whose mechanical properties were suitable for use as secondary raw materials in ceramic brick production. Key words: Clay brick, absorption, porosity, sawdust, mechanical properties.