Particle Size Effects in Recycled Adobe and Bagasse Ash Composites

The use of recycled adobe soil to create new adobes presents challenges related to the quality and durability of the materials. The addition of ash was proposed as a possible solution to improve these properties and recover waste; however, the ash granulometry is a crucial factor to consider. This research evaluated the potential of using recycled adobe and sugarcane bagasse ash to develop new composite materials for construction. Various mixtures were prepared, varying the ash particle size (retained on the #100, #200, and bottom sieves). Subsequently, the physical (capillarity, water absorption by immersion, apparent density, and open porosity), mechanical (compressive and flexural strength), thermal, and acoustic properties of the mixtures were characterized. The ash addition percentage (2.5%) was defined based on another study. The results revealed that the composition of the mixtures significantly influences the materials' behavior. Although the ash-free mixtures exhibited the greatest strength, all mixtures exceeded the minimum requirements (1 MPa). Regarding thermal properties, no significant impact was observed from the ash particle size. However, the finest particles, less than 75 microns (retained at the bottom), improved sound insulation.