Reinforced concrete (RC) structures account for a significant portion of the world’s infrastructure. However, many RC structures, especially in hazard-prone countries like the Philippines, are old and may be deficient in the current design standards, which may necessitate strengthening and retrofitting. Strengthening structures to extend their lifespan is one strategy for promoting sustainable construction; hence, this study investigates the effectiveness and limitations of alternative nature-based materials as strengthening materials. Textile-reinforced mortar (TRM) is a developing strengthening technique combining the properties of conventional and modern materials in an innovative system of using textile grids embedded in an inorganic cementitious mortar matrix. However, the textile reinforcements used are synthetic and unsustainable; hence, there is a need to develop sustainable alternative materials. Natural fibers, particularly residual abaca (Musa textilis Nee) fibers, which are abundant in the Philippines, maybe a potential strengthening material. This study aims to characterize the physical and mechanical properties of the raw and treated abaca fibers and the abaca textile’s geometrical and mechanical properties with an experimental thickness (single-ply and double-ply) and varying grid spacing through direct tensile testing and scanning electron microscopy. The mechanical properties obtained for the tensile strength and strain of abaca twined fibers and abaca textiles show a potential for the development of an abaca TRM for structural strengthening and other applications, considering the potential and limitations of the composite material.