WITHDRAWN: Utilization of waste coffee ground ash as fine aggregates in concrete: Enhancing shear strength through activated carbon reinforcement

Abstract

This study addresses burgeoning environmental concerns amid rising global coffee consumption amid rising global coffee consumption by exploring the viability of utilizing waste coffee ground ash (SCG) as a sustainable fine aggregate in concrete production. Significant improvements are noted by investigating the impact of SCG on the shear strength of standard concrete and enhancing properties through activated carbon reinforcement derived from SCG via physical activation. Experimental results reveal that incorporating up to 1.5% activated carbon by weight markedly boosts early shear strength. Moreover, composites with a small inclusion of activated carbon demonstrate superior shear power during curing compared to conventional mixes. The study employs Teaching-Learning Optimization (TLBO) and Extreme Learning Machine (ELM) techniques to forecast shear strength accurately. ELM emerges superior, showcasing heightened accuracy, lower RMSE, and superior r and R2 values compared to TLBO. Conclusively, leveraging waste coffee ground ash as a fine aggregate in concrete not only presents an effective method for enhancing shear strength but also underscores a promising pathway toward sustainable waste management and reduced environmental impact, reflecting a pivotal stride in harmonizing concrete performance enhancement with eco-friendly practices.