Assessment of the rheological and mechanical properties of palmyra fruit mesocarp fibre reinforced eco-friendly concrete

Concrete's poor tensile strength has led to the extensive use of artificial fibre reinforcements throughout history. However, the environmental impacts associated with the production of these fibres have raised concerns, spurring interest in sustainable alternatives, including natural fibres. The untreated fibre extracted from the mesocarp region of full-grown palmyra fruit is a promising natural substitute. This study investigates the effects of adding palmyra fibre (PF) into concrete as a partial replacement for cement. Four fibre concentration levels of 0.5%, 1%, 1.5%, and 2% were considered without any fibre treatment. The addition of PF decreased the workability of fresh concrete mixtures, but it improved compressive strength by 10% and split tensile strength by 21% at an optimal PF concentration of 1%. Higher fibre concentrations led to lower mechanical strength but increased ductility as the compression-to-tension ratio was increased by 35% with incorporation of 2% fibre. Furthermore, fibre-reinforced concrete mixtures had lower production costs and carbon dioxide emissions than conventional concrete mixtures. Overall, this study suggests that palmyra fibre has significant potential for producing sustainable concrete structures.