Deformation characteristics of dense and foamed mortars based on cement and gypsum-to-cement binders for 3D printing

Construction 3D printing is one of the revolutionary construction technologies, which involves the use of highly fluid cement and gypsum-to-cement mixes. However, this requires an additional study of the deformation characteristics of multicomponent materials. The article is devoted to the study of the own deformation char-acteristics of mortars based on cement and gypsum-to-cement binders, as well as fine-grained concrete for printing the contours of wall structures and foamed mortar for filling, monolithic and thermal insulation of their internal space. A wide range of cement and gypsum-to-cement materials has been studied, incl. foamed mortar. For these materials, comprehensive studies of deformation characteristics have been carried out, confirming the results obtained by X-ray diffraction analysis, SEM, heat of hydration, fresh and physical and mechanical properties. It has been established that in gypsum-to-cement materials, the revealed deformations of the expansion of gypsum overlap the negative deformations of air shrinkage. The resulting materials have a slump flow up to 226 cm, which allows the use of these materials for 3D printing of building structures. The high strength of the developed cement and gypsum-to-cement materials in all periods of hardening (above 50 MPa), as well as excellent thermal conductivity (0.10-0.13 W/(m & sdot;degrees C)), shows the promise of fine-grained mortars and foamed ones.