The article discusses the main approaches to conducting long-term tests to determine the creep of concrete, which are regulated by GOST 24544-81 applicable in the Russian Federation, as well as foreign standards ISO, ASTM and EN. The applied installations, measuring equipment, and sample parameters are considered. In the second part of the article, we will consider the controlled parameters of the test, and the processing of the results.

Data on the developed draft of the Set of rules ‘Monolithic structural systems. Design rules' are stated. The structure of the draft of the Set of rules is described and basic provisions on the design of constructive systems of buildings from monolithic reinforced concrete are given. When developing the draft of the set of rules experience of use of norms of the previous generation - the Set of rules 52-103-2007 ‘Reinforced monolithic concrete structures of buildings' - was considered.

SP 63.13330.2018 (Appendix B) on the calculation of embedded parts [1] based on the 1984 Recommendations [2] and does not take into account several important features of the embedded parts that have been identified in recent years. Besides, in recent years, anchors installed in a finished building base have been widely developed, the mechanism of operation of which is in many ways similar to the work of embedded parts. In this regard, to reduce regulatory requirements and their unification, there is a need to harmonize the basic provisions for calculating embedded parts with the domestic and foreign system of regulatory documents in the field of anchor fastening design. In the framework of the state standardization program in 2019, the department in the laboratory ‘Reinforced concrete structures and quality control' of the NIIZHB named after A. A. Gvozdev revised Recommendations [2] for the design of embedded parts. The article contains a description of the differences between the developed Calculation Manual from the previously valid regulatory documents and the reasons for which these differences were introduced.

Test methods for concrete are the basis for determining key characteristics in the design of concrete and reinforced concrete structures and their quality control. The ongoing updating of standards and regulatory documents in this area requires a systematic analysis of the entire regulatory framework in this area: there is a certain amount of requirements duplication in the international and national standards. At the same time, there are differences with international standards in the field of concrete testing methods, including non-destructive strength testing. This complicates the overall harmonization of the regulatory framework in terms of the design and construction of concrete and reinforced concrete structures. There are some gaps in the national regulatory framework, for example, on the test methods for fiber-reinforced concrete. The article presents the results of the monitoring and analysis of the national regulatory documents system in the field of concrete testing methods for the main characteristics of concrete. Priority areas for further research to develop test methods and standardize them formulated.

A new engineering model of shear resistance of beams of arbitrary cross-sections is proposed. Unlike the other models, the calculation is performed according to simple dependencies taking into account longitudinal reinforcement and without using the hypothesis of flat sections in the support zone. A comparison is made with experimental data and the results of numerical modelling. The accuracy and reliability of the proposed calculation method are confirmed.

The issues of calculation of concrete structures reinforced with polymer composite reinforcement are considered. The paper presents proposals for the normalization of relative deformations at the base point of a two-line diagram of concrete under axial tension, used for calculating reinforced concrete elements for the second group of limit States. Recommendations on a coefficient that takes into account the inelastic properties of concrete of the stretched section zone of elements when calculating the moment of crack formation are given. The paper presents proposals for calculating perforated structures of t-shaped or I-shaped cross-sections with a shelf in the narrow zone and for selecting the working armature of such structures.

The article deals with the application of optimal methods of environmental impact, the use of environmentally friendly products for reinforced concrete structures at each stage of their life cycle. The normative and technical base of the international organization for standardization ISO/TC 71 ‘Concrete, reinforced concrete, prestressed concrete' in the field of environmental activities is analyzed. A comparison of the international and Russian regulatory and technical base was made to further update and increase the level of harmonization of Russian and international standards in the field of construction of buildings and structures. Proposals for improving the regulatory and technical base of the Russian Federation have been developed.

The comparative analysis of domestic normative documents and the European standards containing technical requirements and operational characteristics of concrete, rules of their manufacturing is presented. Relations between technical requirements and an opportunity of direct application of the European standards in the Russian building industry are established. During work carrying out researches of qualitative characteristics of the concrete received by application of the European and domestic techniques. By results of the executed monitoring normative documents and laboratory researches the conclusion about necessity of carrying out of works to determine an opportunity of interrelation of requirements of GOST31384-2017 «Protection of concrete and reinforced concrete structures against corrosion The general technical requirements» on durability, water resistance and frost resistance with a part of recommended technology requirements on the limiting values appointed at selection of mixture of concrete in accordance with GOST Р 57345-2016/EN 206-1:2013 «Concrete. The general specifications» presented.

The Code of Rules SP 387.1325800.2018 'Spatial reinforced concrete structures of roofs and floors. Design requirements', which gives general rules for the calculation and design of spatial reinforced concrete structures, enacted. The need to accompany theoretical provisions with practical examples of calculating effective types of spatial reinforced concrete structures required to develop methodological materials (manual) for the calculation and design of such structures. The manual contains the necessary theoretical and practical recommendations, as well as examples of the calculation of the main types of reinforced concrete structures of buildings and structures for various purposes. Among the examples presented are spherical dome, diverse shells, and folded plates. The Manual includes recommendations for physical modeling of reinforced concrete spatial structures.

The article presents the results of testing of glass composite fittings in conditions of shortterm exposure to elevated and high temperatures. Based on the results obtained, as well as generalization of data on the influence of elevated temperatures on the change in the strength of FRP rebars, the possibility of its application for the reinforcement of concrete structures in terms of fire resistance and fire safety is determined.

Current issues of research and data of normative documents on such actual properties and qualities of cellular concrete as sorption humidity and vapour permeability are considered. The analysis of domestic and foreign normative documents on regulated indicators of sorption humidity and vapour permeability of cellular concrete is performed. Experimental data obtained from tests of cellular concrete to determine sorption humidity and the effect of gas and capillary porosity on it, as well as the water-solid ratio and density of cellular concrete, are presented. The analysis of calculation formulas for determining the vapor permeability coefficient in various regulatory documents is performed.

The article systematizes the main criteria necessary for service life determining the concrete and reinforced concrete structures, analyzes the state of the domestic and foreign regulatory framework in relation to the requirements for the service life of reinforced concrete structures, considers the main regulatory and technical documents in the field of reinforced concrete structures design of buildings and structures based on their life cycle. The types of corrosion damage to reinforced concrete structures and their determining factors are described, and internationally agreed models of durability for some degradation processes are given. On the basis of the work carried out, proposals have been prepared for the corrosion state assessing of operating reinforced concrete structures, their residual bearing capacity, serviceability, expected service life in given aggressive conditions and methods for service life determining of reinforced concrete structures. Proposals are given on the development and updating of a number of relevant regulatory, technical, organizational and methodological documents.

The results are given and the influence of technological factors on the rheological properties of self-compacting steel-fibre rein-forced-concrete mixtures is assessed, shortterm and long-term physical-mechanical and deformative characteristics of ultra-high-per-formance-fibre reinforced concrete are determined, including the determination of its actual frost resistance.

Contained in the design codes of reinforced concrete structures, since 1962 and to the present, the method of calculating the endurance was compiled taking into account the generalization and analysis of data from numerous experimental and theoretical studies. Subsequent use of this method in the practice of designing reinforced concrete structural members has shown that during the operation of structural members properly designed with the requirements for fatigue destructions did not occur. At the same time, the analysis showed the difference between the domestic method and the approaches of foreign standards in terms of fatigue verification for reinforcing and prestressing steel. Further research has shown some imperfections in the method of design for fatigue of steel (both reinforcing and prestressing steel). Taking into account the data of the conducted computational and theoretical studies, as well as in order to harmonize with the main provisions of the fatigue calculation adopted in the design standards of a number of leading countries, it is useful to take into account the ultimate stress range along with the maximum stress within the load cycle. In this regard, it is planned to update the existing methodology for calculating for fatigue, which will be supplemented with new provisions for calculating of reinforcing and prestressing steel for fatigue. When updating the methodology, it is most appropriate to take into account other provisions of the existing methodology as much as possible. In particular, the previous approach to determining the internal stresses in concrete and reinforcing steel, as well as the calculation of fatigue for concrete under compression, will be maintained.