LAUSR

Fibrous reinforcements, specifically those derived from agricultural sources, instead of steel make concrete more sustainable and provide unique properties to structures. Organic, inorganic and metallic fibers have been extensively studied as reinforcement and as aggregates for concrete. Steel, glass and carbon in fibrous forms have been used as reinforcement along with concrete or as a separate structure to improve performance or buttress dilapidated structures. Although these traditional materials provide good improvement in properties, they are derived from non-renewable and unsustainable sources. Recent focus has been to use renewable and sustainable materials in concrete instead of the traditional materials such as glass, carbon and steel. A plethora of fibers and fibrous materials, especially those derived from agricultural residues, have the potential to be used in concrete and make concrete structure more sustainable and environmentally friendly. In addition to the different types of fibers, various forms of the same fibers have also been used as reinforcement. Fibers, fabrics, tubes, rods and other structures have been used as reinforcement. In this review, we summarize the various types of fibers used in concrete and discuss the potential of using biofibers derived from agricultural residues as reinforcement and aggregates in concrete. We have broadly grouped the fibers into eight categories and further divided into sub-groups depending on the form of the reinforcement. Major focus has been to cover literature on natural fibers and agricultural residue-based reinforcements. Advantages of using fibrous materials including increase in performance properties have been reviewed. Limitations of the reinforcements and approaches to overcome the limitations have also been discussed.