The influence of addition of treated kenaf fibre in the production and properties of fibre reinforced foamed composite

•Treatment of fibre on the durability properties.•Durability properties of kenaf fibre reinforced lightweight foamed concrete.•Better adhesion of treated kenaf fibre with matrix and lower ductility. This paper describes the investigation of the influence of treatment of fibre on the durability properties includes drying shrinkage test, water absorption test, initial surface absorption test (ISAT), and accelerated weathering test (wet/dry cycling). Additionally, scanning electron microscopy with energy dispersive X-ray (SEM/EDX) analysis was carried out to study the surface morphology under magnified graphics of lightweight foamed concrete with the inclusion of both treated and untreated kenaf fibres. The foamed concrete mixture was set to a target density of 1250 kg/m3 with a tolerance of 75 kg/m3. The cement, sand and water ratio used was 1:1.5:0.45 with 0.45% volume fraction of kenaf fibre inclusion. Correspondingly, the most optimal condition to perform such treatment was studied based on previous researchers, in which the alkaline medium used was 6% sodium hydroxide (NaOH), followed by 12 h immersion period. The study on durability properties of kenaf fibre reinforced lightweight foamed concrete (KFLFC) helps to determine the suitable application for various industrial products in term of lifespan and functionality. The advantageous properties such as low in density and light in weight can reduce the self-weight of structure, by all means, lowering the project cost and time. In this project, the durability tests of the kenaf fibre reinforced lightweight foamed concrete (KFLFC) were conducted according to American Standard Testing Method (ASTM), British Standards (BS EN), and Eurocodes (EC EN). The results showed that alkaline treatment could clean and chemically modify the kenaf fibres surface morphology, rendering to increase in surface roughness which gives better surface adhesion between fibre and cement matrix in terms of adhesion, hydration process, and internal curing process. Similarly, SEM analysis indicating better adhesion of treated kenaf fibre with matrix and lower ductility.