Chemical and Mechanical Characterization of Treated and Untreated Woven Fique Fiber Textiles as an Alternative External Reinforcement for Concrete

The growing demand for eco-friendly construction materials has increased interest in vegetable fibers, like fique, as composite reinforcement. However, chemical and physical characterization of fibers, yarns, or woven textiles is required to understand the composite response. This study characterizes woven fique textiles from Colombia with varying warp/weft configurations (24/21 and 2 × 24/20) and surface treatments (untreated, alkalinization, and hornification) and provides a preliminary examination of their use as external reinforcement for concrete in compression. The textiles were analyzed using FTIR (Fourier Transform Infrared Spectroscopy), SEM (Scanning Electron Microscopy), and tensile tests. Compressive tests on confined and unconfined concrete cylinders assessed the effect of textiles on the maximum compressive strength and failure mode. FTIR and SEM results revealed that alkalinization and hornification altered the cross-sectional area (−49% and −23%), tensile strength (+48% and + 4%), and stiffness (+28% and + 14%) of the untreated textiles. These effects result from lignin/hemicellulose removal when using alkalinization or due to the enhanced hydrogen bonding in the hornified textiles. Incorporating a single layer of treated woven fique textiles increased the compressive strength of concrete cylinders by up to 19%. This underscores the potential of treated woven fique-textiles as a more sustainable reinforcement solution for structural applications.