Mechanical characterization of mortar reinforced by date palm mesh fibers: Experimental and statistical analysis

Abstract As part of local agricultural date palm waste valorization, this work describes bio-composites made with a cement matrix reinforced with short Mesh date palm fibers for non-structural civil engineering applications. The study focuses in particular on investigating the influence of four parameters on the bending and compression properties of the bio-fiber reinforced mortar: the fiber content, length, NaOH concentration and immersion times of those fibers in the chemical solution. For this purpose, flexural and compression tests have been carried out. An experimental design representing 27 combinations of the above four parameters has been established to minimize the number of experimental trials and build a surface response methodology (SRM) using the design expert software 12 code. The results obtained show that the incorporation of mesh date palm fibers into the mortar improve the mechanical properties of the bio-fiber reinforced mortar. The bending stress of beams with the bio-based reinforcement increases 27.5% compared to the reference configuration; the bending modulus conversely improves by 18.9%. Compression stress and modulus showed increases around 46.6% and 36.3%, respectively. The objective function used to optimize the mechanical properties provides however an increase in bending stress and modulus around 50.0% and 20.0%, respectively, compared to the reference mortar case. The parametric design of the bio-composites that provided the best compression performance was very close to the one identified by the minimum of the objective function. Confirmatory experimental tests results compared to those from the objective function model developed show good agreement, with 3.3% and 3.8% differences for the bending stress and modulus, respectively.