Sustainable Resilience for 3D Concrete Printed Homes in New Zealand (2024-11)¶

3D Concrete Printing (3DCP) in construction is a novel technology that has the potential to disrupt the current construction industry as well as bring numerous benefits. These include reduced construction time, waste minimisation, higher accuracy, fewer CO2 emissions, geometrical freedom, and site safety improvements. Research in 3DCP materials and structures has been investigated for more than a decade. However, the implementation of this technology in New Zealand is still limited due to the seismicity of the country, the availability and the cost of the raw material, some mechanical characteristics of the 3DCP material such as anisotropy and durability, and unknowns regarding reinforcement solutions for structural elements. The Ministry of Business, Innovation and Employment has funded the “Low-carbon and seismically resilient solutions for 3D concrete printed home”, a project aimed at investigating the feasibility of 3DCP in New Zealand. The project aims to develop low-carbon novel 3DCP materials as well as to develop and test steel-reinforced 3DCP structural elements for seismic-cyclic loading. This article presents the results and plans of the ongoing research at the University of Canterbury as well as some case studies of 3DCP homes in New Zealand. At a material level, two novel binders have been developed using local and waste materials: limestone, calcined clay, zeolite, wastepaper sludge and mussel shell powder. Results in terms of fresh and mechanical properties including durability are presented. At a structural level, the plans for experimental tests of vertical 3DCP adopting post- tensioning bars and conventional reinforcement will be overviewed. The paper concludes by discussing two case studies of residential 3DCP homes built in New Zealand's low-seismic areas.