Search

Among reinforcement methods for 3D concrete printing (3DCP) structures, steel cable reinforcement and reinforced concrete confined by 3DCP formwork (RC-3DPF) methods offer high design freedom and automation. However, the former lacks reinforcement in directions perpendicular to the printing direction, and the latter cannot satisfy constructional requirements. This paper proposed a hybrid approach: the steel rebar reinforced concrete column confined by the steel cable reinforced 3DCP permanent formwork (RC-SC-3DPF). Axial compression tests and theoretical analysis were conducted to study axial performances. Test results showed steel cables and fibres added to 3DCP formwork benefit RC-SC-3DPF structural performances. With a steel cable confinement ratio above 0.534%, RC-SC-3DPF outperforms the traditional case. Steel fibre, compared to PVA fibre, demonstrates greater potential for RC-SC-3DPF due to improved axial load resistance and reduced ductility loss. A theoretical model, based on experimental results, existing standards, and M&T model, was developed to effectively evaluate RC-SC-3DPF structural behaviour.