Enhancing Self-Compacting Concrete Performance by Substituting Fine Limestone with Wood Ash

Abstract

This work falls within the scope of waste valorization and reuse, specifically agricultural and vegetal waste, in the formulation of self-compacting concrete (SCC) which mainly consist of limestone fines. The production of these fines requires energy consumption and negatively impacts the environment. Partial replacement of these fines with wood ash, which is generated in large quantities from forest incineration, combustion of vegetal waste, and charcoal preparation, becomes a solution to reduce the production cost of these fines and preserve the environment. The study involved creating reference SCC with no wood ash, then replacing the fine limestone with wood ash in volumes of 6.12%, 18%, and 24%, and analyzing the properties of the resulting concrete in both fresh and hardened states. Tests included density, slump flow, L-Box, segregation resistance, V-funnel, air content, compressive strength, flexural tensile strength, sclerometer resistance, ultrasonic pulse velocity, and elastic modulus, as well as analysis by DRX and FTIR. The findings indicate that partial replacement of fine limestone with wood ash improves the compactness and stability of the concrete, and reduces spreading, particularly in a confined environment. Additionally, the study shows that the SCC with wood ash substitution meets the European standard EFNARC and exhibits acceptable mechanical performance.