Experimental Investigation on Properties of High Strength Self Compacting Concrete

Self-Compacting Concrete (SCC) is an advanced concrete technology capable of flowing and consolidating under its own weight without mechanical vibration, making it suitable for heavily reinforced and complex structural elements. This study presents an experimental investigation on the fresh, hardened, and non-destructive properties of High-Strength Self-Compacting Concrete (HSSCC) of grade M60 incorporating fly ash and silica fume as supplementary cementitious materials. Ordinary Portland Cement (OPC) 43 grade was partially replaced with fly ash at 0%, 10%, 15%, 20%, and 25%, while silica fume content was kept constant at 8%. A polycarboxylic ether-based superplasticizer was used to achieve the required workability, and mix design was carried out as per IS 10262:2019 and IS 456:2000. Fresh properties were evaluated using slump flow, V-funnel, and L-box tests, while hardened properties were assessed through compressive, split tensile, and flexural strength tests at 7 and 28 days. Ultrasonic Pulse Velocity (UPV) testing was conducted to evaluate internal quality. Results indicated that increasing fly ash content enhanced the workability and flowability of SCC without compromising stability. The mix with 25% fly ash achieved the highest performance, with 28-day compressive strength exceeding 70 MPa and improved tensile and flexural strengths. UPV results confirmed better density and homogeneity. The study concludes that the combined use of fly ash and silica fume is effective in producing sustainable and high-strength SCC suitable for structural applications.