Effect of variegated biosolids incorporation on the technological properties of fired clay bricks using Taguchi method

Green routes to effectively mitigate the extensive generation of variegated biosolids (VB) from the artisanal basketry sector has been specially constrained with traditional waste management practices. In this investigation, VB is used as a pore forming material in the development of fired clay bricks. Three compositional different bricks formulated with different dosages of VB (i.e., 0, 6 and 12 wt%) inclusion in brickmaking clay (BC) were fired at 900, 1000 and 1100 degrees C temperatures, and assessed for their physico-mechanical and thermal properties. Weight loss (WL) results showed the bricks WL increased with elevated firing and high addition VB admixed proportion. The highest 12.8% WL was observed among the BS12-1100 bricks. Fired shrinkage (FS) values were within recommended limits of 2.4-7.6%. Apparent Porosity (AP) results ranged from 19.3% to 38.6%. AP increased by 52.3% with VB addition but decreased up to 23.83% due to improved firing. Water absorption (WA) results were mostly found within the quality standards of 9.1 - 19.8%. Bulk density (BD) variations were observed between 1.3 g/cm3 and 2.2 g/cm3. Compressive strength (CS) reductions were in the acceptable range of 25.0 - 9.1 MPa. The thermal conductivity (TC) test results of the bricks showed a 28.59% improvement in the thermal insulation properties of the bricks. The Taguchi method revealed BS12-900 brick series as best optimized products due to its acceptable 9.1 MPa CS and least TC (0.452 W/mK). Thus, the usage of VB for brick production has an important contributory role to the economy and ecology of Ghana.