Improvement of shear behavior of masonry using natural fibers: Experimental evaluation of external reinforcements based on TRM with cabuya fibers

Fired brick masonry is a common construction material used in housing for both structural and non-structural elements. However, it is particularly sensitive to shear stresses, such as those induced by seismic events. Textile-reinforced mortar (TRM) has been successfully used to reinforce masonry structures externally, thereby increasing their load-bearing capacity and ductility. While most research on this topic has focused on synthetic fiber fabrics, natural fiber fabrics have also been used in some cases. This study investigates the potential applications and effectiveness of cabuya fibers in TRM for masonry reinforcement. To obtain more sustainable solutions, this study uses local materials typical of traditional construction, including handmade bricks and natural cabuya fibers. The research objectives included the mechanical characterization of cabuya fibers (cords, ropes, and fabrics); the evaluation of the tensile behavior of TRM with cabuya fiber fabrics; and the assessment of the diagonal compression behavior of masonry walls externally reinforced with mortar and cabuya fibers. To protect the cabuya fibers embedded in the cement mortar, two treatments were evaluated: coating the fibers with alkyd or polyester resins. TRM specimens with polyester resin-coated fibers exhibited better mechanical performance. Using bricks from different brickworks resulted in notable dispersion in mechanical strength and failure modes during diagonal compression tests. However, walls reinforced with TRM exhibited significantly higher shear strength values ranging from 0.72 to 0.89 MPa regardless of brick strength. Additionally, DIC analyses showed the ability of the TRM-reinforced walls to control cracking, resulting in more ductile failures. • Natural cabuya fibers were used for sustainable retrofitting of masonry walls. • Polyester coating of fibers increased strength and stiffness of cabuya fabrics. • TRM with cabuya fibers improved shear performance of masonry walls. • TRM with cabuya fibers and polyester resin doubled shear strength and stiffness. • Inelastic shear strain above 1 % for 30 % stress loss was achieved with cabuya TRM.