TY - JOUR AU - Pristupyuk, Дмитрий Николаевич AU - Fedorov, Владимир Юрьевич AU - Danilov, Руслан Александрович PY - 2022/08/12 Y2 - 2024/03/29 TI - The study of the loss of fire resistance of the reinforced concrete crossbars and beams in operation JF - Journal of Civil Protection JA - JCP VL - 6 IS - 3 SE - Fire and industrial safety (technical sciences) DO - 10.33408/2519-237X.2022.6-3.278 UR - https://journals.ucp.by/index.php/jcp/article/view/686 SP - 278-293 AB - <p><em>Purpose.</em> The development of the theory of fire resistance of constructions, buildings and structures considering one of the directions of combined hazardous effects with the participation of fire – the assessment of fire resistance of reinforced concrete structures, having regard to the duration and conditions of their operation.</p><p><em>Methods.</em> To determine the operational limits of fire resistance, an analytical method for solving a static problem, a finite element analysis method for solving a heat engineering problem of fire resistance were used. The results of fire tests are applied to confirm the reliability of the data obtained by the simulation method.</p><p><em>Findings.</em> It has been found that already with a 25 % reduction in load-bearing capacity during use, reinforced concrete structures lose about 50 % of their original fire-resistance rating. It has been established that the dynamics of the loss of fire resistance of reinforced concrete crossbars and beams mainly depends on the category of technical condition, and not on their design parameters.</p><p><em>Application field of research.</em> The presented research results of fire resistance were obtained for reinforced concrete structures in operation and can be used to predict the behavior of operating reinforced concrete structures in fire, as well as to develop models and improve standards in the field of designing fire resistance of reinforced concrete structures.</p> ER -