In-line activation of cementitious materials for 3D concrete printing

Development of a calcium sulfoaluminate-Portland cement binary system for twin-pipe 3D concrete printing

“…3D concrete printing (3DCP) technology is revolutionizing the construction industry with many merits over traditional construction methods, such as higher design freedom, raised construction efficiency, less material consumption, reduced labor force, and improved worker safety [1,2]. For example, a recent report showed that 3DCP technology has the potential to increase the construction speed by 50-80% with reducing material consumption by 30-60% [3]. Different types of methods have been proposed including extrusion-based printing, powder-bed printing, and shotcrete-based printing [4][5][6].…”

“…For the former, the accelerator can be stored in an encapsulated form with the initial mixture followed by activating at the print head, i.e. heating above the melting temperature of the shell material to dissolve the capsules [3].…”

Effect of Nanostructured Silica Additives on the Extrusion-Based 3D Concrete Printing Application

“…The corresponding comparison can be summarized as follow. Even though Ramakrishnan et al [17] reported that the encapsulated accelerator could improve 500% and 220% strength and modulus of 3D printed filament with excellent pumpability, it can lead to the rapid development of hydration temperature and shrinkage cracks [18]. Opposite to the accelerator, the effect of the superplasticizer is mainly to enhance material pumpability by reducing the dynamic yield stress [19].…”