Application potential of combining strain hardening cementitious composites and helical reinforcement for 3D concrete printed structures: Case study of a spiral staircase

Abstract

Despite 3D Concrete Printing having the potential to advance the construction industry through material savings, design flexibility, and a more efficient workflow from design to construction, the challenge of reinforcing the layers of created structures remains unresolved. Recent developments within reinforcement techniques for 3D concrete printing, such as helical reinforcement and strain-hardening cementitious composites, have shown promise to work as potential solutions. To demonstrate the effectiveness of these techniques on a load-bearing structure, an automated production of spiral staircase elements is presented combining automated placement of helical reinforcement and strain-hardening cementitious composites. A design study is presented and different staircase elements were produced, experimentally tested in bending and compared to analytical results. The findings of the study reveal that the strengths and weaknesses of each reinforcement concept are evident when examined individually. However, when integrated together, these concepts complement each other, resulting in a successful and efficient reinforcement method for printed concrete.