Abstract
3D concrete printing offers design freedom, eliminates formwork, reduces costs and waste, and accelerates construction, making it a powerful alternative to traditional methods. Reinforcing concrete during 3D printing remains a major challenge. Conventional reinforcement disrupts the extrusion process, while continuous methods using steel cables or wires face issues such as nozzle blockage, misalignment, and poor anchorage, limiting their effectiveness. Incorporating short, discrete fibers into 3DPCM provides self-reinforcement, simplifying the process while enhancing mechanical properties. However, including fibers affects the fresh state properties of 3DPCM, particularly the extrusion. This study reviews the effects of steel fibers addition on the fresh and hardened properties of 3DPCM by analyzing published literature results. Various journal articles are reviewed, and extracted data is summarized to identify the influence of steel fiber on flowability, static yield stress, dynamic yield stress, printability, buildability, compressive strength and flexural strength of 3DPCM. The effect of steel fibers orientational distribution in printed filaments is also analyzed, and efforts to control the distribution to obtain favorable changes in the properties of 3DPCM are also highlighted.