The results of studies of the influence of various hardening conditions, incl. simulating conditions in the center of massive monolithic structures, for compressive and tensile strength, initial modulus of elasticity, hardening kinetics of self-compacting concrete of classes from B25 to B55. A classification of concretes according to the hardening kinetics is proposed, using as a criterion the time to reach a certain level from the design compressive strength under normal hardening conditions. The invariance of the dependence of the initial modulus of elasticity of the investigated concretes on the compressive strength on the age and type of concrete is established. A certain difference between the dependence "initial modulus of elasticity - ultimate compressive strength" and a lag in the rate of increase in tensile strength from the rate of increase in compressive strength of the studied concretes in the early period of hardening relative to traditional concretes of vibration compaction were revealed. It is shown that in the early period of hardening the studied concretes are characterized by a higher level of the conditional crack resistance criterion E0/Rt, which indicates to a certain extent a higher fragility of the studied concretes in this period.

Keywords: self-compacting concrete, compressive and tensile strength, hardening kinetics, modulus of elasticity, crack resistance criterion

In the Russian Federation, there are settlements that can only be reached by special equipment: swamp walkers, SUVs. Permanent access to such settlements is hindered by swamps, rivers, etc. Temporary winter roads "autozymniki" are laid to such settlements in winter. The construction of "autozymers" includes several stages: the preparatory stage, the main stage of construction, operation of the autozymer and disposal. If a temporary winter road passes through swamps, then it is advisable to push such soils with tractors with widened tracks or tracked tractors. The article proposes the design of a articulated pneumatic roller for the construction of winter highways, and also carried out a design calculation including: calculation of resistance to movement, hydraulic calculation, selection of hydraulic equipment.

Keywords: winter road, machinery, automobile winter road, pneumatic roller, washing of swampy grounds, calculation

The construction of a Polar gas turbine power plant is carried out on permafrost soils. Features of the construction of reinforced concrete structures of foundations and other elements in the permafrost zone implies high requirements for strength, density and frost resistance. A new composition of the concrete mixture with improved physical and mechanical properties is proposed. Superplasticizing additives and production waste are used in the composition of the concrete mixture.

Keywords: foundation, permafrost, borehole piles, superplasticizer, sulfuric acid sludge, concrete mix, strength, frost resistance

The article discusses the features of pipeline construction in permafrost conditions. Classical technical methods of design and construction are economically unprofitable. It is necessary to introduce new design solutions that can significantly reduce the anthropogenic impact of the pipeline on permafrost soil with a minimum of construction and subsequent operation costs.

Keywords: pipelines, permafrost, special supports, thermal insulation of the pipeline, thermal stabilization