Comparison of tensile properties between natural fibres and inorganic fibres for strengthening timber structures

Fibre-reinforced polymers (FRPs) have been successfully applied to the strengthening of reinforced concrete structures and a similar methodology is adopted by researchers in order to strengthen timber structures using synthetic fibres such as carbon, glass or aramid fibres. This paper explores the viability of using fibres from botanical sources for the reinforcement of timber structures. In this study, two natural fibre materials, namely kenaf and ramie, in combination with a polymeric matrix, are tested for their tensile properties in accordance with ASTM D 4018-99. The results indicate that kenaf fibres exhibit average ultimate tensile strength value at rupture of 750 MPa and Young’s modulus of 58 GPa. The test results also show that the corresponding parameters for ramie fibres average at 810 MPa and 36 GPa respectively. These values are closer to those of timber as opposed to analogous values for carbon and glass fibres. The strength and elastic moduli compatibility of both kenaf and ramie fibres with timber and contrast with carbon and glass fibres is further discussed in relation to the viability of using these natural fibres as reinforcement for timber