UTILIZATION OF ORGANIC RESIDUES IN SUSTAINABLE CEMENTITIOUS COMPOSITES

Abstract

The cement industry contributes significantly to global carbon emissions, accounting for nearly 8% of the total carbon dioxide (CO₂) emissions worldwide. The increasing demand for sustainable construction materials has encouraged the exploration of alternative supplementary cementitious materials that can partially replace cement without compromising mechanical performance. This study investigates the feasibility of utilizing agricultural organic wastes, namely Banana Leaf Ash (BLA) and Wheat Straw Ash (WSA), as partial replacements for cement in mortar. Mortar cubes of size 70.6 mm × 70.6 mm × 70.6 mm were prepared with varying replacement proportions of BLA and WSA. Compressive strength tests were conducted at curing periods of 7, 14, and 28 days to evaluate the mechanical behavior of the modified mortar mixes. The experimental results indicate that the incorporation of BLA and WSA influences the development of mortar. The mix containing 2% BLA and 3% WSA achieved the highest compressive strength of 13.88 MPa at 28 days, representing an increase of approximately 30% compared to the control mix. Moderate replacement levels demonstrated comparable or improved strength due to enhanced particle packing and pozzolanic reactions leading to the formation of additional calcium silicate hydrate (C–S–H) gel. However, higher replacement levels resulted in a gradual reduction in compressive strength due to the dilution of cementitious compounds. The findings demonstrate that agricultural wastes such as BLA and WSA can be effectively utilized as sustainable supplementary cementitious materials. Their utilization not only improves certain mechanical properties but also contributes to waste management and reduction of environmental impacts associated with cement production.