Experimental and analytical investigation for mechanical behaviour of vegetable fiber reinforced concrete

Abstract

The use of vegetable fibers in concrete has gained attention for enhancing material properties and promoting sustainable construction. This study evaluates the effects of three vegetable fibers—palm, luffa, and straw—on the mechanical properties of concrete, focusing on compressive, tensile, and flexural strengths. The experimental program varied the fiber types, lengths, and volume fractions in concrete samples. Results revealed that incorporating 1% palm fibers increased compressive strength by 1.6%, tensile strength by 2.7%, and flexural strength by 0.8% compared to plain concrete. Palm fibers cured in non-saline water exhibited the most notable improvements. In contrast, adding 1% luffa fibers resulted in approximately 10% increase in compressive strength but caused reductions in flexural (5.3%) and tensile (6%) strengths. Excessive fiber content adversely affected strength due to increased moisture absorption and air content. A generalized self-consistent model confirmed the relationship between fiber content and the modulus of elasticity, while morphological analysis highlighted the anisotropic properties of palm fibers, suggesting their potential for optimizing concrete performance. This research underscores the suitability of palm fibers as cost-effective, eco-friendly alternatives to synthetic fibers, contributing to improved mechanical performance and sustainable management of agricultural waste.