Experimental Investigation on Mechanical and Durability Properties of Self-Compacting Concrete Incorporating Fly Ash And GGBS

Abstract

Selfcompacting Concrete is a innovative and high flowable concrete which can compact by its self-weight without the need for external vibration. This study investigates the Prehardened properties, mechanical properties, and durability characteristics of M30 grade SCC incorporating cosl Ash and Ground Granulated Blast Furnace Slag as partial replacement of cement. SCC mixes were developed respect to EFNARC guidelines using Ordinary Portland cement 53 grade cement, sand, coarse aggregate, superplasticizer, fly ash, and GGBS. 3 trial mixes are prepared by replacing 50% cementitious material with a fly ash-GGBS ternary blend in the ratios 40:60 (SCC M1), 60:40 (SCC M2) and 50:50 (SCC M3), and are compared with vibrated concrete. Pre hardened properties are evaluated with the Slump Flow and T50 test, L-Box test, and V-Funnel test; all SCC mixes satisfied EFNARC acceptance requirment for filling, passing ability and segregation resistance. Mechanical properties were evaluated through compression strength, tensile strength, and flexural strength tests for 3, 7 and 28 days of curing. Among all mixes, SCC M1containing 40% coal ash and 60% GGBS exhibited superior mechanical performance, achieving at 28-day compressive strength of 39.81 MPa compared to 32.25 MPa for CVC. Durability studies carried out using an Acid Attack Test with HNO3 and a Base/Chloride Attack Test with NaCl showed that SCC mixes experienced lower weight loss and strength loss than vibrated concrete, showing enhanced resistance for aggressive environmental conditions. The study concludes that SCC inclusion of flyash and GGBS provides improved workability, higher strength, and enhanced durability, while also promoting sustainable concrete production through reduced cement consumption.