Experimental and Analytical Study on Strength Properties of Fibre Reinforced Quaternary Blended Concrete (Hybrid Fibres)

The quest for enhanced performance and sustainability in concrete technology has led to extensive research into the incorporation of supplementary cementitious materials and fibers. Among various potential advancements, quaternary blended concrete reinforced with hybrid fibers has emerged as a promising solution that can potentially yield superior mechanical properties and long-term durability. In this paper, an experimental and analytical study is presented to evaluate the strength properties of fiber-reinforced quaternary blended concrete, incorporating a combination of hybrid fibers. The research explores the respective roles of different supplementary cementitious materials—such as fly ash, ground granulated blast furnace slag (GGBS), silica fume, and metakaolin—in addition to the influence of steel and polypropylene fibers (in hybrid form), on compressive, split tensile, and flexural strengths. A systematic series of laboratory tests were conducted on a set of controlled samples and quaternary blended mixes at various curing ages. The outcomes unveil considerable improvements in mechanical performance and microstructural characteristics when compared to conventional ordinary Portland cement (OPC) mixes. The paper concludes with a discussion on optimal mix proportioning and the synergistic effects of supplementary cementitious materials and hybrid fibers. The results indicate that adopting this quaternary blend coupled with hybrid fibers can significantly improve energy absorption, crack resistance, and overall structural capacity in concrete, thereby offering a viable path forward for modern construction practices.