摘要
利用自制火灾试验炉及相关试验装置对足尺钢框架中6块(2?3)连续板格的受火行为进行了试验研究。简要介绍了整体结构模型、试验炉设计与试验方案情况,描述了相关试验现象及破坏特征,并对炉温、板格沿截面的温度梯度以及板格平面外与平面内位移、梁截面的温度梯度及竖向挠度等试验数据进行了分析。相关结论如下:升温阶段受火板格沿截面存在着显著的温度梯度并在降温阶段存在温度滞后现象;受火钢梁截面在升温阶段初期存在较大的温度梯度,在降温阶段趋于一致,并由于周边约束未发生断裂或局部屈曲,对比标准受火试验,抗火性能显著增强;不同位置的板格由于约束程度的差别,在火灾中的变形性能也不同;由于受火钢梁的反拱效应,受火板格的部分挠度曲线存在平稳段;对比相关文献结果,发现板格的裂缝特征与其受火强度和边界约束密切相关,与周围钢梁是否受火关系不大。
In order to further understand the fire behavior of concrete floor slabs, a fire test on six continuous panels(two by three) was performed in a full-scale steel-framed building via a self-made furnace and some experimental devices. The test building, the design of furnace and experimental contents are introduced, meanwhile relevant experimental phenomena and failure characteristics are recorded. The experimental data including the furnace temperatures, temperature distributions as well as vertical and horizontal displacements of panels and steel beams are also investigated. The experimental results indicate that the temperature gradient is large during the heat-up stage and a temperature lag appears during the cooling-down stage for the heated panels. For the heated steel beams, there is clear temperature gradient during the early heating-up stage but during the cooling-down stage the temperature tends to uniform. Furthermore, the steel beams in fire do not show partial buckling or failure due to the constraints provided by other structural elements. Therefore, the steel beams exhibit better fire-resistant performance in this test than in standard fire tests. In addition, the heated panels at different positions present distinctive deformations due to different boundary constraints. Due to the arc action of heated steel beams, some deflection curves of the heated panels appear plateau during the heating-up stage. Besides, cracking characteristics of the panels are concerned with the fire intensity and boundary constraints, but they do not depend on whether the steel beams around the panels are fired or not.
出处
《工程力学》
EI
CSCD
北大核心
2015年第1期145-153,共9页
Engineering Mechanics
基金
国家自然科学基金项目(51178143)
高等学校博士专项基金项目(20102302110043)
关键词
连续板格
炉温
变形
裂缝特征
钢梁
continuous panels
furnace temperature
deformation
cracking characteristics
steel beams