Evaluation of the Durability of Dry Mix Compositions Based on Gypsum and Gypsum Cement for 3D Printing

The effectiveness of using 3D printing technology for the construction of exterior and interior walls, especially for low-rise residential and civil buildings of social purpose, is substantiated. The domestic experience in the construction of single-storey frameless buildings with load-bearing external walls printed on a 3D printer (with filling their internal space with inorganic insulation materials on a monolithic (foam concrete, foam gypsum) or backfill (expanded perlite, especially light expanded clay gravel) basis) is analyzed. The use of dry mixes on a gypsum and mixed basis for printing walls of low-rise buildings is justified for technological and economic reasons. On the basis of laboratory and field experiments to assess the durability of gypsum cement-pozzolan compositions (from dry mixtures) for 3D printing to change the temperature and humidity regime, it was established that the reason for the destruction and demolition of prototypes according to quantitative X-ray phase analysis was an increased content of ettringite during their hydration and hardening at a reduced temperature.