This paper presents the results of an experimental investigation on the fire response of steel beams and their bolted flange plate (BFP) connections. Using sub-frame assembly, full-scale steel beams with various BFP beam-to-column joints were examined under the ISO 834 standard fire condition. The failure modes, as well as the structural and thermal responses of the beam and the BFP connections were studied. The findings of the experimental studies indicate that the beam flexural failure occurs at the temperature range of 670–700°C when the mid-span deflection exceeds the limitation value specified in the BS-476. The BFP connections fail when the temperature exceeds 760°C, while the beam experiences deflections larger than span/20. The results also show that the bolt hole bearing and the bolt shear control the failure of the BFP connection in fire conditions. The BFP connection detail has a considerable effect on the fire response of the beam, e.g., increasing bolt shear strength in the BFP connection can improve the fire resistance and rating of the beam and its connections in steel moment-resisting frames.

本文介绍了对钢梁及其螺栓法兰板 (BFP) 连接的火灾响应的实验研究结果。使用副车架组件，在 ISO 834 标准火灾条件下检查具有各种 BFP 梁柱接头的全尺寸钢梁。研究了梁和 BFP 连接的失效模式以及结构和热响应。实验研究结果表明，当跨中挠度超过 BS-476 中规定的限制值时，梁弯曲破坏发生在 670-700°C 的温度范围内。当温度超过 760°C 时，BFP 连接失败，而梁的挠度大于跨度/20。结果还表明，螺栓孔支座和螺栓剪力控制了 BFP 连接在火灾条件下的失效。BFP 连接细节对梁的火灾响应有相当大的影响，例如，增加 BFP 连接中的螺栓剪切强度可以提高梁及其在钢抗弯框架中的连接的耐火性和等级。