PRELIMINARY STUDY OF CONCRETE WITH ADDITION OF SUGARCANE BAGASSE ASH: INFLUENCE ON AXIAL COMPRESSION

Abstract

Concrete is recognized as the leading global construction material, but the manufacture of Portland cement is energy-intensive and responsible for high annual carbon dioxide emissions, exceeding 2.5 billion tons. The scarcity of traditional supplementary cementitious materials (SCM) is driving the search for agro-industrial byproducts, such as sugarcane bagasse ash (SCBA), whose global ash production reaches approximately 11.9 million tons annually. The potential of SCBA lies in its silica-rich composition, which makes it a pozzolanic material. This preliminary literature review evaluated the viability of SCBA as a partial cement substitute, focusing on its influence on axial compressive strength. The analyses indicate that viability depends on processing, as only fly ash demonstrated a high amorphous content and adequate pozzolanic activity. In contrast, dense ash exhibited high crystallinity and was inert. Grinding was essential to refine the material, producing fly ash with a particle size similar to that of cement. Partial replacement of cement with this processed fly ash, at levels up to 25%, provided axial compressive strength similar to or higher than the reference. The strength gain is explained by the continued pozzolanic effect at advanced ages, avoiding the detrimental dilution effect observed with inert dense ash. The processed lightweight SCBA thus meets the technical requirements for pozzolan for use in construction.