The problem of maintaining the exact ratio between the components in mixtures based on oxychloride cement is described. This problem is solved by the use of additives plasticizing or water-reducing action. The results of studying the effect of the type of additives on the mobility of mixtures and the strength of hardened oxychloride cement pastes are presented. The positive effect of the use of additives based on naphthalene and melamine sulfoformaldehyde was shown. The negative effect of additives based on lignosulfonates on the strength of oxychloride cement pastes has been established. Assumptions about the reasons for the low efficiency of additives based on polycarboxylate esters are indicated. The positive influence of the plasticizing effect of additives on the homogeneity of the microstructure of oxychloride cement pastes is shown. An assumption about the reasons for the increase in strength when using additives based on naphthalene and melamine sulfoformaldehyde is made.

Keywords: oxychloride cement, Sorel cement, plasticizer, water reduction, additive, modification, structure, strength

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

The article presents the opportunity to use bioengineering facilities for contaminated surface runoff treatment. Examples of existing technological solutions are given. For instance, in the Institute of hydrobiology NAS of Ukraine the use of bioplatos as post-treatment of water in channels through which water is transported from the Dnieper, was proposed and studied; in the Engineering research center (ERC) “Potential-4” various types of engineering and biological facilities based on the closed bioplate of hydroponic type used in wastewater treatment technologies as a water-protective structure that combines the main elements of treatment using microflora immobilized on an inert substrate and higher aquatic plants, were suggested; scientists of Khabarovsk Institute of Engineering Transport have developed a method for runoff treatment from an oil refinery using a "filter" from thickets of cattail and calamus. The authors of this article presented a technological scheme for treatment both acidic and weak acidic surface runoff in bioengineering construction using macrophyte plants as a complex of hydatophytes, hydrophytes, and helophytes. It is found out that runoff treatment in the proposed facility varies from 72 to 98%.

Keywords: biological pond, biocenosis, hydatophyte, hydrophyte, helophyte, heavy metal, contaminated runoff, filtration, phytophilter, sewage treatment plant