AN EXPERIMENTAL STUDY ON THE EFFECT OF ALKALI TREATMENT ON PROPERTIES OF KENAF FIBER FOR REINFORCED CONCRETE ELEMENTS

Abstract

Kenaf fibers are coming into interest to use in reinforced concrete elements in recent years due to its attractive properties such as non-abrasive, lightweight and renewable. However, the properties of kenaf fiber such as high moisture absorption and weak in interfacial adhesion make the use of kenaf fiber in reinforced concrete elements become less attractive. Alkali treatment is one of the best used chemical treatment for natural fibers. It help to increase the fiber surface roughness by chemically modify and clean the fiber surface. The purpose of this research is to do a fundamental study on the effects of alkali solutions to the kenaf fiber. There are a lot of researchers conducted study on the effects of different concentrations of NaOH on kenaf fiber. However, there is no information about the study of alkali treatment of kenaf fiber with different pH. Therefore, this study seeks to determine the effects of alkali pH on the properties of kenaf fiber. By theoretically, the pH of concrete is around 13, so it is important to have a better understanding on the effects of alkaline to the kenaf fiber especially pH 13. The finding of the research can help to develop an effective use of fiber in cementitious materials. The problem of water absorption of kenaf fiber could appear if fibers are directly introduced in concrete. For these reasons, in this study, different pH of NaOH (pH 8 to 14) were used and the effects on the colour of fiber, weight loss and water absorption of treated kenaf fibers were evaluated.