Incorporation of Coconut Fibers Into Clay‐Based Mortars: A Study on Mechanical and Microscopic Behavior

ABSTRACT Amid growing environmental concerns and the search for sustainable building materials, this study investigated the mechanical and microstructural behavior of clay‐based mortars reinforced with coconut fibers. Mixtures were produced in which natural sand was replaced by sand and clay residues, with fiber additions of 2.5% and 5% by weight of cement. The mortars were evaluated in fresh and hardened states, compressive and flexural strengths, and through scanning electron microscopy (SEM), energy dispersive x‐ray spectroscopy (EDS), and x‐ray diffraction (XRD) analyses. The clay residue produced compressive strength values comparable to the reference mixture. The incorporation of 5% coconut fibers resulted in a statistically significant increase in flexural strength compared to the non‐reinforced mortar, despite the formation of shrinkage‐induced microcracks. The analysis confirmed the presence of quartz, kaolinite, orthoclase, and calcium aluminum silicate. The results highlight the potential for applying waste and natural fibers in eco‐efficient mortars, emphasizing the importance of curing and moisture control.