Zhmagul Smagulovich Nuguzhinov’s research while affiliated with Karaganda State Technical University and other places

Scientometric analysis using the Scopus database and VosViewer program identified the critical directions of development of this or that field to identify promising technologies and to understand how these achievements affect the practice of design and construction. According to the analytics, the average number of articles per year on the topic of structural fire resistance and flame retardants increased by 18% compared to the previous period, and according to preliminary data, the trend will continue in 2024. Among the most cited papers, studies on composite materials and polymers dominate. Among the most productive researchers in the field of flame retardancy of materials are Hu, Yuan (54 papers), Wang, WeiYong (47 papers), and Jiang, Jian (39 papers). According to Scopus, research papers on this topic have been published in 2175 sources. The leading journal in terms of the number of published papers is Fire Safety with 250 publications, but journals such as Fire and Buildings of MDPI Publishing are strongly increasing the pace. Chinese researchers are actively studying various aspects of fire resistance of materials and have published 40% of all papers. Keyword analysis revealed a lack of papers on calculation of fire resistance of structures with fire protection means, calculation of fire resistance of composite structures, and 3D-printed structures compared to the number of articles on the reliability (strength calculation) of building structures.

The creep of concrete is one of the main problems threatening concrete structural development and the stability and safety of structures. However, the nonlinear theory is the key to solving the problem of taking into account the physical and mechanical properties of concrete creep in shell structures. To create such a theory, the original shell is replaced by a continuous equivalent elastic shell. To determine the stress–strain state of the structure, the equations of nonlinear creep and crack growth are derived, and a deformation model of the section is created. The behavior of the structure at all stages of the life cycle is investigated by solving the solving systems of differential equations of equilibrium, motion, and perturbation of the equivalent shell. The values of the ratios of dependence of long-term and short-term critical loads on deformations, forces, cracks, etc., are given. The accuracy of the solution of the developed nonlinear theory is compared with the linear theory of concrete creep as well as experimental data. The results show that, according to the linear theory, for the values for the short term and long term, up to 56% and up to 39% of critical loads are overestimated, respectively. The creep process in practical engineering can be effectively controlled by the results of the proposed theory.