ARGAMASSAS DE REVESTIMENTO À BASE DE BIOCHAR DO BAMBU E AREIA ARTIFICIAL

Abstract

The growing concern with sustainability in the construction industry has driven to research aimed at replacing conventional materials by alternatives that have a lower environmental impact. In this context, the present study evaluated the performance of rendering mortars with partial replacement of Portland cement by bamboo biochar and river sand by manufactured sand derived from crushed stone dust. Five experimental mixes were produced, with gradual substitutions of cement by biochar and natural sand by manufactured sand at levels of 0%, 3%, 5%, 7%, and 10%. The tests performed included compressive strength, bond strength, and capillary water absorption. A systematic literature review revealed that incorporating biochar between 1% and 5% can improve the mechanical strength of mortars. Microstructural analyses indicated an increase in hydration products formation, contributing to the improvement in mechanical performance. Experimental results confirmed that replacing up to 5% of the cement by biochar leads to significant gains in compressive strength and adhesion, while maintaining satisfactory performance in terms of capillary absorption. On the other hand, mixes with substitutions above 7% showed a reduction in mechanical performance. Regarding the fine aggregate, manufactured sand demonstrated technical performance compatible with that of natural sand, proving to be a viable and sustainable alternative. It is concluded that combining biochar and manufactured sand, in appropriate proportions, can contribute to the development of more sustainable construction materials without compromising essential properties such as mechanical strength and durability.