Properties of Steel Fiber Reinforced Concrete Dedicated for Casting Columns with Fractal Based Cross-Sections

The conducted research program was focused on the creation steel fiber reinforced concrete (SFRC) dedicated for casting columns with fractal based cross-sections. The columns in question were planned to be cast using 3D printed plastic formworks. Harnessing 3D printing of plastic enables easy creation of cross-sections which are not possible to be achieved using traditional formwork techniques. The mix had to be characterized by consistency enabling almost self-compacting behavior, reasonably high volume of fiber (volumes of fiber ranging from 0.5% to 2.0% were considered) and the maximum diameter of used aggregate of 2mm. Due to very complicated cross-sections of planned columns the mix had to be able to effortlessly penetrate very elaborate shapes of fractal formwork. All desired properties were achieved during the research program using two admixtures and micro steel fiber. The mix was tested using column specimens with circular, square and pentagon cross-sections.