Effects of Different Types of Fibers on Fresh and Hardened Properties of Cement and Geopolymer-Based 3D Printed Mixtures: A Review

Abstract

Three-dimensional printed concrete (3DPC) is emerging as a new building material. Due to automation, this method dramatically decreases construction time and material wastage while increasing construction quality. Despite the mentioned benefits, this technology faces various issues. Among these issues, the inability to use steel bars for reinforcement and early age cracking because of the low water-to-binder ratio and high amount of binders can be mentioned. In this regard, due to the superior properties of fiber-reinforced concrete (FRC), such as high first crack strength, tensile strength, improvement ductility, and resistance to shrinkage cracking, one of the effective ways to reinforce the mixture of the 3DPC is to use fibers instead of steel bars. Regarding the mentioned issues, the effects of different fibers, such as steel, carbon fibers and so on, on fresh and mechanical properties and dimensional stabilities of hardened concrete have been reviewed. It is predicted that using fibers, especially hybrid fibers, not only covers the deficiencies of initial cracking of 3DPC, but also can be used instead of steel bars; therefore, this material can play a pivotal role in the construction industry’s future.