Development and Characterization of Compressed Brick by Adding Ash Wood

With the aim of valorizing local materials and contributing to the reduction of construction costs and energy consumed for heating or air conditioning, wood ash was used to stabilize compressed earth bricks (CEB). The general objective of this work is to valorize wood ash in the stabilization of compressed earth bricks. The results of the geotechnical characterizations show that the particle size analysis of laterite falls within the optimum range as recommended by CRATerre; the Atteberg limits used to calculate the plasticity index reveal that the plasticity index of laterite is 13.2%, which complies with the Cameroonian standard NC 102-114 2002-2006. The results of the physico-chemical characterizations reveal that Fourier transform infrared spectroscopy analysis of the base materials (laterite and wood ash) revealed that the Si-O-Si, Si-O-Al and Ca-O functional groups present on the surface of laterite and wood ash respectively are responsible for the chemical bonds involved in brick production. These results show that the base materials can be used for the production of compressed and stabilized earth bricks. Optimization of the production of compressed and stabilized earth bricks through implementation of the mixing plan shows that wood ash and laterite are the governing factors during production, and the brick produced under optimum conditions at respectively 5ml water, 15g wood ash and 80g laterite for a compressive strength of 6.11MPa, a value within the range recommended by the Cameroonian standard for compressed earth bricks. (RC= 4MPa). Evaluation of the hydration behavior of BTCS obtained under optimum conditions shows that the blocks absorb water by capillarity and total immersion. However, water absorption remains below 0.1g/mm2 and below 15% for capillarity and total immersion respectively. They therefore comply with CRATerre recommendations for the use of a material in construction.