Concept of Using 3D Printing for Production of Concrete-Plastic Columns with Unconventional Cross-Sections

A concept of concrete-plastic columns was presented in the paper. As a proof of concept, a research program was conducted. Seven different cross-sections of columns formwork were 3D printed using plastic. The cross-sections represented three types of columns' shapes: most common, rare, and impossible to be realized using traditional formworks (based on fractals). Prepared plastic formworks were filled with cement mortar playing the role of ordinary concrete. After 28 days of curing, the load-strain characteristics of all the concrete columns were tested. Achieved results were discussed. It was proven that concrete-plastic columns were characterized by quasi-plastic behavior while being ultimately destroyed. Columns with fractal-based cross-sections sustained the largest strains while maintaining a significant part of the maximum load. The achieved results proved that it is possible to completely omit traditional steel rebar-stirrup reinforcement. The future direction of needed research should cover larger columns and other concrete-plastic elements. Using fiber-reinforced concrete for the creation of concrete-plastic elements should be also tested.