Steel-concrete composite structures have been widely used in multi-story, long-span, and heavy-load buildings due to their advantages of high strength, high stiffness, excellent seismic performance, and construction efficiency. With the rising frequency of building fires, which pose significant threats to life and property, investigating the fire resistance of these structures is imperative. This necessitates developing fire-resistance design methods that consider overall structural performance and implementing corresponding protective measures. The ultimate goal is to ensure the integrity of critical structural components and prevent the collapse of the overall structure, which is of great significance in ensuring the overall fire safety of structures and reducing fire protection costs in construction.This paper summarized the fire resistance of steel-concrete composite structures, focusing on fire experimental studies on steel-concrete composite beams, reinforced concrete (RC) two-way slabs, concrete-filled steel tubular (CFST) columns, as well as the steel-concrete composite planar and spatial frames. Additionally, various fire resistance analysis models were discussed and compared. Based on the review, key issues and future directions were proposed.The main findings were as follows: 1) Experimental studies demonstrated that steel-concrete composite restrained beams exhibited significantly better fire resistance than simply-supported beams, owing to the catenary effect under high temperatures and large deformations. RC two-way slabs showed excellent fire resistance, with observed cracking on the top surface while the bottom remained relatively intact. The fire resistance of conventional CFST columns was found to be limited, requiring protective measures. Moreover, composite spatial frames demonstrated superior performance compared to planar frames, as they maintained structural integrity without collapse, whereas planar frames were prone to beam or column failure. 2) Numerical analysis indicated that the shell-solid element model effectively simulated the local and torsional buckling of steel beams observed in tests of steel-concrete composite continuous and restrained beams. The solid element model accurately reproduced the expansion deformation in reinforced concrete two-way slabs resulting from non-uniform temperature distributions across their thickness. When solid or shell-solid element models were applied to CFST columns, they successfully captured the interface void, slippage, and constraint effects between the steel tube and concrete. Furthermore, modeling concrete with solid elements incorporating its thermo-mechanical-time constitutive relations satisfactorily represented the phenomenon where the top of the RC two-way slabs cracked while the bottom remained largely intact. Similarly, modeling steel using solid or shell elements with its thermo-mechanical constitutive relations, which implicitly incorporated high-temperature creep into the stress-induced strain, the finite element calculated values of deformation for steel-concrete composite beams and CFST columns under fire showed good agreement with experimental values. 3) Due to the limitations of experimental conditions, structural fire tests seldom achieved the collapse stage, leaving the failure mechanisms of structural systems inadequately understood. It was essential to employ shell-solid finite element models combined with thermo-mechanical-(time) constitutive relationships of materials to conduct fire resistance analysis of composite spatial frames and establish the correlation between component failure and structural system failure. Furthermore, the current fire protection design methods based on component testing or calculation, as stipulated in existing codes, still need to be thoroughly investigated to determine whether they meet the requirements for structural fire protection design.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |