Improving degradation resistance of ensete ventricosum fibre in cement-based composites through fibre surface modification

In recent years, natural fibre cementitious composites (NFCC) have gained popularity worldwide because of their potential application as low-cost construction materials. Despite the wide range of applications for NFCC, their long-term performance, i.e., durability under various exposure conditions, remains an open question. Natural fibres in a cementitious matrix may degrade over time as a result of the alkalinity of the cement matrix. In this study, Ensete ventricosum (Ev) fibre was treated with alkaline (NaOH) and hot-water to increase its resistance to alkaline attack. Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy (SEM), physical, and mechanical tests were performed on fibre bundles to evaluate the effect of surface treatment on fibre performance. After undergoing 0 and 25 wet-dry cycles, the composites reinforced with raw and treated Ev fibres were tested in a four-point bending configuration. In order to investigate cracking and failure behaviour, Digital Image Correlation and Acoustic Emission techniques were used. Using SEM, the microstructure of the Ev fibres was analysed. Raw Ev fibre reinforced cement composites completely lost their strength and ductility after 25 wet/dry cycles, whereas hot-water and alkali treated Ev fibre composites showed minimal degradation, demonstrating that hot-water and alkali treatment can reduce the degradation of natural fibres in cement-based composites. These findings are promising for the development of an Ev fibre reinforced cement-based green composite.