Strength Behavior and Microstructure Characterization of Self-Consolidating Concrete with Sintered Fly Ash Coarse Aggregates

Self-consolidating concrete (SCC) made with sintered fly ash aggregates (SFAA) was investigated for its compressive strength and microstructural properties. Even with significant additions of mineral admixtures such as silica fume (SF) and metakaolin (MK) and 100% SFAA, the formulated SCC demonstrated compressive strength satisfying the minimum requirements for structural lightweight concrete, in accordance with established standards such as those recommended by the ACI 318-19, BS EN 206-1 and Eurocode 2 after 28 and 90 days of curing. Strength development was corroborated through SEM and EDS analysis, while non-destructive methods, including rebound hammer and ultrasonic pulse velocity (UPV), confirmed the enhancements in compressive strength.