Assessment of fly ash Nagan Raya as a sustainable supplementary cementitious material

The by-product produced by the coal-fired power plant in Nagan Raya, Aceh, Indonesia, is referred to as fly ash Nagan Raya (FANR).Based on available characterization data, the particles of FANR exhibited a misty surface texture and contained several key chemical constituents, including Si, Fe, Al, and Ca.Owing to this composition, which closely resembles that of ordinary Portland cement, FANR was a pozzolanic material capable of participating in secondary cementitious reactions that contributed to strength development when combined with a calciumrich environment.However, FANR absorbed mixing water, leading to reduced consistency and workability of the fresh mortar.The misty surface of the material increased water demand, which in turn influenced the mortar's physical and mechanical properties.As a result, the unique surface characteristics of FANR significantly altered the physical and mechanical properties.The purpose of this study was to assess the qualities of FANR as a cement substitute in mortar.This study examined w/b ratios of 0.55 and 0.50 with FANR incorporated at levels of 5%, 10%, 15%, 20%, and 25%.The study analyzed chemical composition, surface features, setting time, workability, and compressive strength.It found that FANR had a misty surface, spherical particles, and containing Si, Fe, Al, and Ca.In fresh mortar, these properties shortened the setting time and reduced workability.The 28-day compressive strength peaked at a w/b ratio of 0.50 with 5% FANR, and higher FANR levels continued to gain compressive strength beyond 28 days, demonstrating its impact on mortar performance.