Mechanical and Microstructural Enhancement of Eco-friendly Cement Composites Using Treated Coir Fiber, Bagasse Pulp and Silicon Dioxide Nanoparticles

The research aims to improve and detail the characteristics of cement composite boards reinforced with recycled coir fiber, bagasse pulp, and nano-SiO2 for use in building projects in developing countries. Though it is easily accessible in many places, coir fiber (Cocos nucifera) has issues bonding strongly to the cement matrix. In order to modify the fiber characteristics prior to reinforcing, a mild treatment was implemented, which used varying alkali concentrations. Alkali (NaOH) treatment considerably enhanced the tensile strength of fibers, Young's modulus, thermal stability, thermogravimetric analysis and the single fiber tensile test. The laboratory-simulated Hatschek technique was employed to fabricate cement composite boards that contained varying proportions of treated and untreated coir fiber (5-15 wt %). The three-point bending tests were used to analyze the mechanical behaviour of the boards. Results demonstrated that treated fiber-reinforced composites had much higher flexural strength and ductility than untreated fiber-reinforced composites. Reinforced with treated fibers, the composites proved to be exceptionally strong, surpassing the minimum criteria of standards for fiber cement boards. The composite boards that contained 19 wt%, 1 wt %, and 5 wt % of bagasse pulp, nano-SiO2, and treated coir fibers, respectively, achieved an optimal flexural strength of 10.66 MPa. This investigation demonstrates that the mechanical performance and behavior of cement fiber composite boards can be improved by the effective augmentation and repurposing of recycled coir fibers as reinforcement.