Study on Fresh and Mechanical Properties of Coconut Fiber Reinforced Self Compacting Concrete Enhanced with Steel Fibers

Abstract

In Earth quake-prone regions, the ductile behavior of structures is a basic requirement. Among the natural fibers, coconut fibers have the highest toughness. In low-cost concrete structures, coconut fibers can possibly be utilized as reinforcement. Self-compacting concrete has a high flowability that under its own weight without any vibration or impact fills all the parts and chinks of the formwork. In this research, the effect of coconut fibers and hybrid combination of coconut fibers and steel fibers keeping low steel fiber content i.e., 0.5%by volume fraction on the fresh and hardened properties of Self Compacting Concrete is studied. Mix design strength of 20MPa is considered. Steel fiber reinforced self-compacting concrete at a volume fraction of 0.5% is produced for comparison. Slump flow diameter and time, and V-Funnel time tests were performed to look for the fresh properties. Mechanical properties such as compressive strength, split tensile strength and flexural strength were determined using cube specimen of 150mm, cylinder specimen of 150mm X 300mm and prism specimen of 100mm x 100mm X 500mm respectively. The experiment revealed that workability decreased with increase in fiber content. The hybrid fiber reinforced self-compacting concrete mixes showed congestion in flow section. Coconut fiber reinforced self-compacting concrete showed increase in compressive strength and flexural strength with increment in fiber content compared to normal self-compacting concrete and hybrid combinations. The hybrid mixes showed the increment in split tensile strength with increase in fiber content compared to coconut fiber reinforced self-compacting concrete and normal self-compacting concrete.