Steel Fiber Links in 3D Printed Concrete

Abstract

3D concrete printing exhibits the potential to proliferate the industrialization of the concrete construction sector, which is notoriously conservative and indolent towards change. This emerging technology is propitious given its advancements in geometric design freedom, reductions in construction time, waste and material usage through formwork-free construction. However, when 3D concrete printing is fastidiously compared to current methods of concrete construction, a detrimental disadvantage, the absence of effective steel reinforcement is evident. Therefore, the amelioration of the brittle interlayer interface is the focus of several 3DCP research and industry endeavors. Steel reinforcement is favored as most modern concrete structures rely on the compressive and tensile strength of concrete and steel, respectively. However, a significant technical challenge is posed by the addition of reinforcement during the automated 3DCP process. Thus, the post-crack behavior of specimens reinforced during the printing process with straight steel fibers orthogonal to the interlayer interface is experimentally evaluated through four-point flexural tests in this research. The brittle interfacial failure is ameliorated through the addition of steel fibers that link consecutively deposited layers.