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This work discusses the effectivity of using vegetal fibers as substitutes of synthetic ones on fiber - reinforced cementitious matrices (FRCM) and its potential as a solution for strengthening concrete structures. What is more, vegetal fibers are a potential substitute for synthetic fibers due to their lowcost, renewable and, lightweight composition. Two different fibers, cotton and hemp are selected based on their strength and deformation capacity. Pull-out tests were carried out to study the effect of epoxy resin coating on the adherence of the fibers to the matrix. Fibers coated with epoxy resin, yarns, and meshes, were tested under a tensile test. FRCM specimens were manufactured and tested in tension and numerical and analytical simulations were carried out. Coating vegetal fibers with epoxy resin, not also improved the interaction with the matrix, but also increased its strength, reaching similar synthetic fibers' strength. The deformation capacity of the vegetal fibers allowed the composite to present a more ductile behaviour, increasing the multi - cracking stage and delaying the failure point. Hemp specimens reached a higher strength and cotton specimens deformed more than 10 times hemp specimens. Both proved to be potential solutions for the strengthening of structures, especially in situations where dynamic loads are applied and a higher deformation is required. |
