On the emergence of 3D printable Engineered, Strain Hardening Cementitious Composites (ECC/SHCC)

While interest in 3D printing of concrete (3DCP) and structures has been growing, a major obstacle for implementation of 3DP construction method is the need for steel reinforcement and the challenges this presents to the 3DP process. Engineered Cementitious Composites (ECC), also known as Strain-hardening Cement-based Composites (SHCC), hold promise to attain structural integrity, durability, reliability and robustness without steel reinforcement. This article surveys the state of the art on 3DP research with ECC and suggests needed research to direct future development. Research in Asia, Europe and the United States has demonstrated printability and buildability of 3DP-ECC that exhibits characteristic tensile ductility of cast ECC. Nonetheless, a number of outstanding research areas are identified, including those associated with more sustainable mix-design, rheology control, microstructure, filament/filament interface weakness, and long-term durability. Resolution of these challenges will better position the research community to addressing full scale construction, print speed, and print quality.