Enhancing banana fibre to concrete adhesion through an optimised wood ash treatment process

The adhesion of high strength natural fibres with concrete matrix has often been put into question. In this perspective, natural fibre treatment serves as the ultimate approach to increase surface roughness and subsequently the bonding ability of the fibre. The aim of this study was therefore, to analyse the treatment effects of different wood ash concentrations on musa acuminata banana fibre. The peculiarity of using wasted wood ash for the treatment of waste-derived banana fibre was a key highlight of this research; fostering biomass valorization. Contact angle analysis gave favourable results for 16% wood ash treated fibre and the Young Dupre wettability method was adopted to determine the interfacial adhesion, represented as the ‘work of adhesion’. At the same fibre treatment, an increase of 50% was noted for the work of adhesion as compared to untreated fibres. This finding was indeed beneficial for adhesion of the treated fibre in concrete for the fibre had undergone much surface roughening as observed from the SEM image. A zero slump and highest VeBe time were obtained as in-situ parameters of the fresh treated fibre-based concrete. The crucial finding to validate the use of treated fibre in concrete, confirmed that indeed more physical adhesion was present between the interface of the treated fibre and concrete as compared with the untreated fibre. Such a statement revealed true with an increase of 27.1% in the compressive strength result of the treated fibre-reinforced concrete in comparison with the untreated fibre-based concrete. Thus, the effectiveness of treating banana fibres with wood ash solution was evidenced by the increase in adhesion ability of the fibre to the concrete for which an increase in compressive strength supported the results.