Properties and microstructures of 3D printable sulphoaluminate cement concrete containing industrial by-products and nano clay

Owing to its sound/thermal insulation and the elimination of the conventional moulds, 3D printable foam concrete (FC) has gained increasingly attention among researchers. In this study, the producibility of calcium sulphoaluminate cement-based foam concrete (CSA-FC) through concrete extrusion was confirmed, which also contains nano-clay (NC) and industrial by-products. The fresh and hardened properties, microstructures as well as extrudability of prepared samples were investigated. The initial results highlight the benefits of using appropriate amount of NC and desulfurized gypsum (FGD gypsum) for the hydration acceleration and extrudability improvement of samples. Meanwhile, the use of NC could alleviate the performance degradation owing to the use of industrial wastes in samples due to its nucleation and pozzolanic effects. Further, through the extrusion technology, a suitable mix design of CSA-FC with satisfactory performance, low carbon footprint and cost was proposed, which eliminates the conventional moulds during its production.