混凝土结构抗火研究综述与建议

To promote the development of research of fire resistance of concrete structures, the four aspects of the development process were systematically summarized. Accordingly, the development of the temperature field of fire, fire resistance performance and fire resistance design of concrete structures, damage assessment and repair reinforcement of structures after fires, improvement of the fire resistance of structures, and some issues for each aspect that still need to be investigated were discussed, and the development trend of the research was also prospected. Among them, the research methods of the fire temperature field were summarized from the perspectives of air and structural temperature fields. The effects of different parameters on the high-temperature resistance performance of concrete materials, members, and structures were also summarized. Further, the application, advantages, and disadvantages of existing fire-resistance designs for concrete structures were analyzed, and the general process of structural damage assessment after a fire was examined. Engineering damage assessment and reinforcement repair cases after fires were also analyzed, and existing detection and repair methods after fires were summarized. Finally, methods for improving the fire resistance of structures were listed in terms of materials and construction. The results show that the mechanical properties of concrete structures deteriorate seriously at high temperatures. Adding fibers, adjusting raw materials, and construction measures can improve structural fire resistance. Further, adding polypropylene fibers can effectively prevent spalling of high-performance concrete. The following main subjects need further study, such as the temperature field distribution of large concrete structures under high temperature, the influence of the randomness of a material's high-temperature performance on mechanical properties of members, the influence of different temperature-load paths, the effects of repeated lifting and lowering temperatures on the high-temperature performance of structures and members, the establishment of a scientific evaluation system for structures subjected to high temperatures, a theoretical study on structural fire resistance reliability design, and a high-performance concrete structure fire resistance design method. 3 tabs, 5 figs, 50 refs.