Influence of fibers on the mechanical properties of cementitious composites - a review

Abstract

Concrete is one of the major construction materials and it will possess sufficient compressive strength if properly designed and prepared. However, due to lower tensile strength and brittle nature, plain cement concrete tends to show sudden failure. Under this context, the different methods to improve the tensile strength of concrete have gained importance. The addition of fibers to concrete is considered to be an effective method to prevent brittle failure and improve the desirable characteristics of concrete such as tensile strength, impact resistance, abrasion resistance, shatter resistance, post-cracking ductility and strain capacity. Some types of fibers are also used in concrete for the repair, rehabilitation and retrofitting of structural members. The amount of fibers added to a concrete mix is based on volume fraction and aspect ratio. The past studies carried out on Fiber Reinforced Concrete (FRC) led to the development of more effective fiber mixing methods and performance-enhancing strategies. Among the various fibers, steel fiber is the conventional and most popular material. Several other natural and synthetic fibers also have been subjected to extensive research across the globe. In addition to all these, the effectiveness of recycled fiber reinforced concrete (RFRC) and fiber reinforced geopolymer concrete have been checked by several researchers and advancements in these materials are considered to be crucial steps towards the achievement of sustainable construction. This paper reviews the performance of various natural and synthetic fibers such as steel fiber, glass fiber, basalt fiber, jute fiber, and polymer fiber as a reinforcing material in concrete. The study is based on various fresh and hardened properties of FRC and parameters such as relative fiber matrix stiffness, volume of fibers, aspect ratio of fibers, orientation of fibers, workability and compaction of concrete, size of coarse aggregate and mixing.