This article presents the results of a study of the tendency of composites based on magnesium oxychloride cements to deformation changes. The dependence of the degree of deformation of light magnesian concretes on the conditions of their hardening has been determined. The main factors influencing the deformation of light magnesia concretes have been established. The influence of hardening conditions on the intensity of deformation changes is shown. Revealed the reasons causing uneven deformation of light magnesia concrete. A method for the manufacture of light magnesia concretes has been determined, which prevents their uneven deformation and subsequent violation of the geometry of the structure. It has been established that the introduction of modifier additives, such as cellulose ethers, helps to reduce the delamination of concrete magnesia mixtures, improve their homogeneity and reduce the unevenness of deformation changes over the sample volume.

Keywords: magnesium oxychloride cement, volumetric deformations, shrinkage, expansion, warpage, hardening conditions