It is proposed the program and methodology of experimental researches of reinforced concrete constructions under the action torsion with bending, the main purpose of which is to check the calculation assumptions and the experimental determination of the design parameters of the proposed calculation method. Particular attention is paid to the determination of fracture levels and the width of the expansion of spatial cracks in reinforced concrete constructions under the action torsion with bending.

In article, advantages of circular pipe from the high-strength steel are studied. The behavior of these pipes as elements of the building constructions working for compression is considered. Examples of application of pipes in unique constructions are given. Expediency of application of high-strength steel with yield strength above 390 MPa is proved. Examples of calculation of pipes on the central compression with use of the technique presented in existing normative documents are given. Results of calculation with use of a FEA are also shown. In addition, the presented calculations are compared and conclusions are drawn.

The problem of calculating elastic torsion bars is one of the most important today’s problems in the field of structural mechanics. Many construction and engineering structures in the form of bar systems undergo torsional deformation. The geometric stiffness of its cross-sections is determined when calculating such structures in the first place. This physical parameter is used in assessing the stress-strain state of structural elements working on torsion. In the structural mechanics and the elasticity theory, only a few solutions for determining of the geometric stiffness of sections are known in the form of an ellipse, a rectangle, an isosceles triangle. Approximate methods of calculation are used at more complex cross-sections, mostly numerical ones. In the last two decades, in the study and solution of two-dimensional problems of the elasticity theory and the technical theory of plates, the geometric method, the interpolation method of the shape factor (IMSF), actively develops and uses, the basis of which are the isoperimetric properties of the integral geometrical characteristic of the region shape (plates, membranes, sections). This method is applicable for the task of elastic torsion of bars, but to date it has not received a decent development. In this article, with the help of IMSF, the reduced geometric stiffness of cross-sections for bars with sections in the form of figures intermediate between a circle and regular polygons is determined. A circular cross-section and sections in the form of a regular polygon are used as "reference" sections with known values of reduced geometric stiffness. A subset of sections between a circle and a regular polygon is obtained by successive synchronous clipping of its parts from the circle by straight lines, which are parallel to the sides of the regular polygon. Interpolation of "reference" solutions for any sections from the considered subset is carried out by the shape factor. Simple interpolation functions are constructed that allow one to find the desired solution for the considered subset of cross-section forms by elementary formulas using a single argument - the shape factor. The presented in the article graphical depiction of the dependencies "reduced geometric stiffness - the shape factor" makes it possible to visualize the place of the desired solution in the subset of the cross-section forms under consideration.

The work analyzes the seismic hazard in the Kerch Strait area using the probabilistic method. Foreign and domestic sources have been studied and a database of earthquakes has been compiled, including 176 events that occurred within a radius of 100 kilometers from the strait. The presence of foreshocks and aftershocks in the earthquake databases was taken into account. Five seismogenerating zones in the form of seismogenic surfaces uniformly distributed in depth and point sources are identified and their main characteristics are indicated. To assess the completeness of databases for each of the zones, the Step method is used. As a relationship between the number of earthquakes and the magnitude, the Gutenberg-Richter law was applied. The obtained values of peak accelerations on the surface are compared with the values calculated according to the maps OCP-2016 and SP 14.13330.2014 "Construction in seismic regions". The plots of the changes in the peak acceleration of the soil in depth are obtained using linear equivalent method.

Among tens of known ruled surfaces, which can be taken as middle surfaces of the shells, ruled surfaces of zero Gaussian curvature such as conic, cylindrical, and torse surfaces and also ruled surfaces of negative Gaussian curvature such as one-sheet hyperboloids, hypars, conoids find wide application. Circle and parabolic cylindrical and conic surfaces, hypars and one-sheet hyperboloid of revolution have the widest spread in modern design and building due to well-studied geometry of their form, existence of the methods of strength, buckling, and dynamic analyses, and due to their claiming for practical needs. But theoretical investigations of conoid shells, researches of their opportunities were not stopped. Some new information on strength analysis of right conoid shells, on the determination of their natural frequencies, examples of application of conoid shells for the shed roofs of industrial building, for the roofs of private villas and public buildings, summer theaters and museums, the application of them in modern sculptural complexes are presented in this review. It is shown that designing and building of conoidal shells is continued in 2000-2017 but on the lesser scales. All main presented references are dated the XXI ^st century.

The paper analyzes the effectiveness of strengthening techniques for masonry elements under central compression and compression combined with bending. Traditional and new strengthening techniques using composite carbon and fiberglass mesh (FRP) are given. The results of experimental investigations of reinforced and unreinforced masonry specimens under compressive loads are analyzed and their failure mechanisms are discussed. Furthermore, it discusses results of numerical analysis of reinforced masonry elements under eccentrically applied compressive loads. The fibre-reinforced polymer strengthening system is used, within which, epoxy adhesive is applied. The distribution of main compressive stresses in reinforced specimens with different sections (square, rectangular and circular) are analyzed and these stress concentration zones are determined.

Results of experimental and theoretical investigations of the coating of an industrial building, in which the ribbed plates are rigidly connected between themselves and the girder in the places of their bearing by welding the protruding bars of the steel reinforcement and monolithic concrete have been presented. Compatibility of the work of structures and the influence of such connection on the work of the girder and ribbed plates have been estimated. Vertical plate displacement as per the lines of longitudinal ribs has been determined. Theoretical definition has been made by means of the LIRA software package and the program developed at VlSU. In the first case, the solution has been obtained by step-by step iterative method using the exponential law of concrete deformation and a bilinear diagram of the state of the reinforcement. In the second case, the method of elastic solutions has been used, where the method of finite differences has been used for each iteration. The recommended norms trilinear deformation diagram has been adopted for the compressed concrete, and bilinear deformation diagram has been adopted for the reinforcement. Comparison and analysis of the results have also been presented.

The article presents methods of reliability analysis for existing steel beams with reduction of the rigidity of the support. In the reviewed methods is taken into account incompleteness of statistical information of controlled parameters in the design mathematical models of limit states. Information briefed for the method of evaluation the angular rigidity of the steel beams supports during the operation. The article presents the formulas for calculation the ultimate load on steel beams with various design schemes and rigidities supports by the strength criterion. The materials of this article can be useful to employees of the maintenance companies in the inspections and to identify the category of the technical condition of buildings and structures in accordance with the requirements of Interstate standard GOST 31937-2011 "Buildings and structures. Rules of inspection and monitoring". The algorithm of reliability analysis of steel beams considered in the example.

The use of the materials of proximity is imperative more and more in the traditional constructions and the house in rural areas. In numerous traditions, the dung of cow (DOC) is a basic material in the construction. However, the performances of the use of the dung of cow (DOC) in the construction are scientifically little proved. The present research project studied the influence of the use of the dung of cow on the compressive strength of mortars of bar ground for the usages of blocks in compressed ground (BCG) and/or blocks in stabilized ground (BSG). An analysis is led by comparing the compressive strength of reference mortars (simple bar ground and bar ground more 4 %, 8 % and 12 % of Portland cement) and mortars (simple bar ground and cement Portland) containing different proportions of BDV (2 %, 4 %, 6 %, 8 % and 10 %). The results mainly allowed to show that the addition of a small quantity (lower than 6 %) of DOC sawdust doesn’t decrease the compressive strength of the mortar of bar ground, it tends to improve it slightly. Beyond a 6 % content, the addition of the DOC decreases systematically the compressive strength of the mortar of bar ground.

The problem of improvement of transport and operational condition of bridge structures. It is noted that the indicator of the structural elements of bridges is the deterioration, reflecting the degree of decline in their functional qualities. It is found that increasing the operational reliability of the transport and operational condition of bridge constructions is advantageously carried out by applying the polymer composite materials. However, their use in construction is limited due to the complexity of predicting the stress - strain state over time in long-term and short-term loading. Examples of defects and damages of bearing structures of bridges identified in the field surveys. Describes methods of tests of endurance of concrete elements with a protective polymer coating. Presents the results of fatigue tests of concrete elements with protective coatings based on modified polymeric compositions intended for use in transport construction. The analysis of the experimental data of fatigue tests. Directions of practical implementation of research results.

The article discusses the history and stages of development in Russia of a unique type of architectural structure - Memorial-Museum complex. This is a complex object, that usually integrates the memorials, monuments, museums and parks into coherent ensembles. Memorial architecture is one of the most important basis of the spiritual identity of every society and type of governmental system. Its main target is to strengthen the identity of a particular ethnic group or their Union by means of architectural, spatial and artistic influence, in which the main are image and symbol. Despite some similarities with foreign counterparts, the domestic practice of creation of the Memorial and Museum complex has several unique features and differences, which has not been studied before comprehensively in the professional press. The author highlights in this historical process four periods, which are discussed in two parts of the article. Their origins and impact factors are analyzed and the main representatives are considered.

Process of receiving highly effective construction materials sets a number of tasks among which development of structures, compoundings, technological modes and many others for researchers. Mathematical models allow to describe rather fully structure of composite material, considering the natural nature of distribution of structural elements in volume of material that proves approach to his studying from positions of the theory of dimension and topological spaces. In the paper the main regularities of formation of optimum grain structure of construction composite materials on a cement basis with mineral fillers are considered and generalized. The complex way mathematical reconstruction of grain structure and calculation of optimum compositions of raw mixes, the wide range of parameters and to estimate derivative properties of disperse systems, and also to select optimum particle size distribution of mixes allowing to vary is offered.

The research presented below is about the polymer concrete based on polyvinyl chloride modified by silane supplements. Developed material is an environmentally friendly and durable coating for floors, finishing and insulating materials. An experiment has been carried out including the analysis and data processing for the material. The composites were examined for impact strength, wear capacity, compressive strength, density, burning quality, absorption of water, freeze-thaw resistance.Box-Benkin plan has been used in order to carry out the experiment, which resulted in building surfaces of response for physical and mechanical properties. While researching, a polymer concrete with excellent physical and mechanical properties has been created, which can be used as floor coverings in industrial and civil engineering,quadrel, piping,gauge material building purpose, chemically - oil - gasoline-resistant flooring for livestock ranches, manhole cover, high-abrasion-resistant coatings galvanizing plants, oil - gasoline-resistant paving flags for filling station and petrochemical industry, finishing wall materials, not removable cast formwork for cast-in-place construction. This material is promising for release in the construction market in Russia and abroad.

The influence of macroeconomic conditions on the total value of potentially achievable monetary savings due to the planning of large-scale programs for thermal retrofit of groups of residential buildings is described. Various combinations of the discount rate and bills rates for thermal energy, which are representative of different economic conditions, have been studied. The expediency of optimizing the thermal retrofit of groups of residential buildings is estimated. Economic criteria for cost-efficiency of the implementation of such programs are shown and the conditions for their profitability are found. Optimum values of thermal performance factors corresponding to different combinations of economic conditions were obtained. Optimal ranking of thermal retrofit of residential buildings for the studied values of the discount rate and bills rates have been found. The influence of the considered conditions on the optimal parameters of thermal performance and the rule of ranking of thermal retrofit of the residential group buildings are found.

In a wide interval of concentrations, the influence of nanopowders of zirconium dioxide on the deformation-strength, adhesion, tribological and thermophysical properties of epoxy polymers based on industrial resin ED-20. As nanopowder used several types of zirconium dioxide with different thermal histories, different particle sizes and specific surface area, phase composition and the presence of a dopant is yttrium oxide. Installed the sharp dependence of properties on temperature calcination of the injected powder. Higher values of strength properties, elastic modulus, work of fracture and resistance to abrasion when using powders with the calcination temperature of 500 ºc are associated with smaller particle size and greater specific surface area compared to powders obtained at 700 ^о С. Alloying of powder of zirconium dioxide with yttrium oxide provides an increase in modulus and compressive strength.