Effects of coconut fibers on flexural and tensile strengths of concrete maintaining uniform workability

Abstract

Concrete, the most commonly utilized building material, possesses a high compressive strength but has very low tensile and flexural strength. Steel is the most popular type of flexural and tensile strength enhancer in Cement concrete, however due to the rapid increase in the cost of steel as a result of the financial crises experienced in several countries, research is currently being done to use other affordable and easily accessible material to decrease the quantity of  reinforcement steel, as Tensile as well as flexural reinforcement. Coconut fiber, also known as coir fiber, Due to its thread-like structure has previously been shown to help boost concrete's flexural and tensile strength, having said that it negatively affects the workability of fresh concrete. So we can use a workability enhancer to overcome this negative effect while getting optimum benefits in terms of enhancement of flexural and tensile strength. The goal of the study is to discover how coir fiber affects concrete's flexural and tensile strength under uniform workability, with the help of a super plasticizer. It also attempts to find the ideal content of fiber to be used in concrete. The methodology is that with the assistance of a hit-and-trail procedure, we find out the amount of plasticizer needed for each fraction of fiber percentage, to create a constant range workability of 40±5mm for every proportion. Beams and cylinders were cast, curing was done for 28 days, and then their flexural capacity and tensile strength were analysed for each fraction of coconut fiber: 0%,0.4%,0.8%,and1% (by WT of cement )in comparison to plain concrete, the flexural strength improved by 21 percent,25 percent,and15.24 percent at fibers proportions of 0.4%, 0.8%, and 1%, respective, while the tensile strength increased by 29.66 percent, 38.66 percent, and 22.81percent. The best outcomes were discovered at 0.8%. It's determined that the addition of coir fiber results in a considerable improvement in flexural strength and Tensile strength meanwhile plasticizer proves to be good cure against workability loss due to  fibers.