Durability and Microstructure Analysis of Sugarcane Bagasse Ash-Based Self-Compacting Concrete: A State-of-the-Art Review

Durability is a critical factor governing the long-term performance and service life of self-compacting concrete (SCC). Sugarcane bagasse ash (SCBA) has emerged as an effective strategy to enhance the durability of SCC. Numerous experimental studies have investigated the influence of SCBA on individual durability properties and reported promising results. However, understanding of the mechanisms linking durability performance with microstructural characteristics remains limited. This review critically synthesizes the durability performance and microstructural characteristics of SCBA in SCC. We conducted a systematic literature review of peer-reviewed publications. The review evaluates the effects of SCBA on density, mercury intrusion porosimetry, water absorption, sorptivity, sulfate and sulfuric acid resistance, ultrasonic pulse velocity, corrosion resistance, electrical resistivity, and chloride penetration. It also evaluates heat of hydration, SEM, and EDS. The reviewed studies mostly indicate that 10 to 15% gives favorable durability performance. However, this range should not be considered a universal optimum because performance depends on SCBA characteristics, replacement role, and mix composition. Furthermore, SCBA reduces the heat of hydration and improves resistance to chloride ingress, sulfate attack, reinforcement corrosion, and water transport. SCBA also produces a denser, more homogeneous microstructure. However, durability performance deteriorates at higher replacement levels because of cement dilution, increased water demand, and unreacted SCBA particles. The review also identifies major research gaps, including the lack of standardized SCBA processing methods, limited long-term field validation, and insufficient quantitative correlations between microstructural evolution and durability performance.