Kenaf fibrous concrete: mechanical properties with different fiber volume fraction

Abstract

Kenaf fiber comes from Kenaf plant which grows thrivingly in hot and humid temperature. The origin of Kenaf comes from a few different countries that have similar characteristics such as Africa, China, and India. Kenaf or its scientific name, hibiscus cannabinus is a beneficial crop where the seeds and stems can be used in various industries such as medicine, paper production and composite material. Kenaf core and bast fiber can reach up to 3 meters long and this is an essential reason to corporate Kenaf with other composite material like polymer and concrete. This paper indicates the investigation of finding an optimum value of Kenaf Fibrous Concrete with fiber volume of 0%, 0.5%, 0.75%, 1% and 1.5% in the mix proportions. The mechanical properties of fresh and hardened samples were tested during 7th and 28th day of curing in water. Compressive strength, splitting tensile and flexural strength tests were executed in accordance of BSEN 12390-3:2009, ASTM C496M-06 and BSEN 12390-5:2009 respectively, with different volume fractions in finding an optimum value of Kenaf Fibrous Concrete. The result shows that kenaf fiber has the hydrophilic characteristic that influences more water absorption in the mix proportions. The capability of this fiber improves the tensile strength and ductility because of the inclusion of fiber. However, it decreases the concrete compressive strength.