Low-carbon, expansive engineered cementitious composites (ECC) in the context of 3D printing

Shrinkage and high carbon footprint are two significant challenges in the application of printable cementitious materials. To address these concerns, low-carbon, expansive, printable engineered cementitious composites (ECC) with appropriate mechanical properties were designed and validated. Limestone calcined clay cement (LC3)-based ECC combined with calcium sulfoaluminate cement (CSA) was adopted to design printable mixes with appropriate open times. The length deformation monitoring of cast and printed ECCs revealed that wet curing at an early age could effectively promote expansion. Regarding environmental sustainability, the CSA-ECC mix has a carbon footprint of merely 69% of concrete. Considering ECC's ability to reduce element size and material consumption, the environmental friendliness of printable CSA-ECC can be further enhanced. In addition, mechanical tests confirmed that the proposed ECCs demonstrated comparable or superior performance to their cast counterparts.