Replacing steel stirrups with natural fiber reinforced polymer stirrups in reinforced concrete Beam: Structural and environmental performance

Abstract This paper comprehensively evaluates the feasibility of using the environmentally friendly natural fiber reinforced polymer (NFRP) stirrups in reinforced concrete structures. The evaluation is conducted in terms of structural performance and environmental impact. Flax fabrics impregnated in epoxy resin were wrapped around longitudinal reinforcement to form close-type stirrups. A total of eight specimens were prepared using NFRP stirrups, and then subjected to three-point bending load. The structural performance is presented in terms of load-deflection relation and the shear capacity contribution. The obtained structural performance indicated that the NFRP stirrups provided sufficient shear capacity and maintained satisfactory ductility. The optimum design of the NFRP stirrups used narrow and thick NFRP stirrups at large spacing. The environmental impact assessment using cradle-to-gate life cycle assessment (LCA) showed that the NFRP stirrups yielded slightly lower environmental impacts than the steel stirrups. The benign environmental impacts of the flax fibers were totally nullified by the negative effects of epoxy resin.