The problems of competitiveness of construction organizations and ways to solve them investigated. The factors limiting the business activity of construction organizations are highlighted and evaluated based on statistical data. Three main categories and corresponding specific factors of competitiveness of construction organizations analyzed. The method of expert assessments revealed the degree of their influence on the competitiveness of the organization. The ways of increasing the competitiveness of construction organizations, taking into account these factors, proposed.

Keywords: competitiveness, increasing competitiveness, factors of influence, construction organization, statistical methods, the method of expert assessments

The properties of fiber-vermiculite concrete composite are investigated. Analysis of the results showed that reinforcement with basalt fibers of the matrix increases the flame retardant properties. The presence of basalt fibers in the composite significantly increases the strength and flame retardant properties of the initial matrix and reduces the thickness of the flame retardant layer. The highest values of bending strength are achieved with a 0.9% reinforcement percentage and a ratio of fiber length to diameter equal to 1444.

Keywords: composite, basalt fiber, reinforcement, vermiculite concrete, dispersed, strength, bending, flame retardant properties, compression, matrix, thickness, percentage of reinforcement

The article deals with the actual problem of minimizing the negative impact on the environment of the construction process. The concept of sustainability in the construction industry is defined. The main factors contributing to the formation of sustainability in the construction industry are identified. Practical recommendations for solving environmental problems in the construction industry have been developed.

Keywords: sustainability, construction, ecology, energy conservation, sustainable materials, resource conservation, efficiency, ecological balance

Operational characteristics of reinforced concrete bending elements under low-cycle impact are considered. The residual deformations and deflections of partially prestressed structures exposed to repeated static loads are investigated, the dependences for estimating the residual deformations and deflections of partially prestressed structures under the action of low-cycle loads are Given. On the basis of the analysis, the dependence of the relative increase in deflections on the coefficient of partial prestressing with repeated application of static loads was established.

Keywords: partially prestressed elements, repeated loads, residual deformations, non-stressed reinforcement, low-cycle impact, residual deformations and deflections

The article considers the urgent problem of minimizing the negative environmental impact of the construction process. The values ​​of maximum and gross emissions into the environment during the construction of the facility are calculated, a set of measures is proposed that reduce the level of negative environmental impact during the implementation of the construction project. Practical recommendations on the organization of construction production taking into account environmental indicators have been developed.

Keywords: ecology, assessment, environmental impact, optimization, construction production, monitoring, measures to reduce emissions

The deformation model is considered in relation to the bending elements most characteristic of partially prestressed reinforced concrete structures. The bearing capacity and deformability of partially prestressed structures are investigated. Given the criteria of strength of compressed concrete that meets the attainment of the ultimate strain in the compressed concrete, as well as stretched in the longitudinal reinforcement, characterized by the achievement of the ultimate strain either in stressed or non-stressed reinforcement. The analysis of the calculation results of the strength and deformability of partially prestressed structures under short-term and long-term effects of the load on the deformation model and the norms. It is shown that the deformation model accurately estimates partially prestressed reinforced concrete elements with different types of loading for any combination of tensioned and non-tensioned reinforcement by strength and deformation.

Keywords: partially prestressed elements, deformability, strength, non-stressed reinforcement, state diagrams, deformation model

Studied the technical condition of the housing Fund of the Republic and its energy saving potential. The analysis of the impact of energy saving measures on the thermal parameters of residential buildings. Shows a practical illustration of the economic effect from implementation of energy saving technologies.

Keywords: housing, energy conservation, energy upgrading, energy saving technologies, economic efficiency, optimization

The structure and content of the energy renovation of the housing stock. Algorithms of calculation of economic efficiency of energy saving measures. The analysis of the impact of energy saving measures on thermal parameters of residential buildings. The practical illustration of the economic effect from implementation of energy saving technologies in the process of complex modernization of the housing stock.

Keywords: housing, energy conservation, energy modernization, energy-saving measures, economic efficiency, overhaul, optimization

A new approach to solving the problem of evaluation of strength of concrete in torsion. The basic idea of this theory is that the torsion causes the bending element in a plane 45 ° angle. Solved the problem of assessing the strength of rod reinforced concrete elements in torsion. Development of methods of calculation of durability of reinforced concrete elements in torsion has allowed to pass to the decision of problems of strength under twist with torsion.

Keywords: Research, reinforcement, strength, crack, twist, torsion, reinforced concrete, element, hole, beam

Cracking of reinforced-concrete elements with holes is examined. Comparison of theoretical and experiment moments of crack’s  formation during torsion, and during intensive torsion with twist. Formula for practical calculations of cracking of reinforced-concrete elements with holes during torsion and formula for estimate of cracking of reinforced-concrete elements with holes during intensive torsion with twist is suggested.

Keywords: Crack, twist, torsion, reinforced-concrete, elements, hole, beam