Performance of Kenaf fiber reinforced concrete

Abstract

This experimental research presents a study on the mechanical properties of natural fiber reinforced concrete (FRC) which is made using the bast fibers of the kenaf plant. Appropriate mixture proportions and mixing procedures were tested to produce kenaf fiber reinforced concrete (KFRC) specimens with different chopped fiber volume fractions (0.5%, 1%, 1.5%, and 2%) and fiber lengths (10mm, 15mm, 20mm, 25mm, and 30mm). After finding the optimum percentage of the fiber volume fraction and fiber lengths several tests were conducted including workability, unit weight, compressive, flexural, and modified compressive tests of specimens were studied. Test results showed that the mechanical properties of KFRC are comparable to those of plain concrete control specimens, particularly when accounting for the effect of the increased w/c ratio is required producing workable KFRC. While KFRC increased the short term compressive strength of the specimens (7 days), it reduced the compressive strength of the specimens after 28 days. Further, KFRC generally exhibits more distributed cracking and higher flexural strength than plain concrete. This research indicated that KFRC is a promising ‘green’ construction material which could potentially be used in a number of different structural and non-structural applications.