冷弯薄壁槽钢-混凝土组合梁受火试验研究  

Experimental research on cold-formed thin-walled channel steel concrete beam exposed to fire

作　　者：高轩能[1] 黄文欢[1] 朱皓明[1] 

机构地区：[1]华侨大学土木工程学院,福建厦门361021

出　　处：《建筑结构学报》2012年第5期141-149,共9页Journal of Building Structures

基　　金：国家自然科学基金项目(51008133);福建省自然科学基金项目(2011J01319);中央高校科研业务费专项基金项目(JB-JC1005)

摘　　要：对5个冷弯薄壁槽钢-混凝土组合梁试件进行在ISO-834标准火灾下的受火试验。试验中考虑了荷载水平、防火涂层厚度和槽钢截面高度等参数的影响。试验结果表明:荷载水平、防火涂层厚度和槽钢截面高度是影响组合梁抗火性能的主要因素,其他因素影响很小;在ISO-834标准火灾下,以跨中挠度δ=l/25作为组合梁达到耐火极限的判别标准是合适的;填充混凝土可有效提高组合梁的整体刚度和延性,使其在高温下直至破坏仍可保持完整性,没有出现高温局部屈曲现象;在槽钢上直接涂刷防火涂层不能保证其与槽钢表面的紧密结合,需要改进组合梁的防火涂层施工工艺;试验结果验证了有限元分析结果的正确性。The experiments of five cold-formed thin-walled channel steel concrete beam specimens exposed to the ISO- 834 standard fire were carried out. Different influencing factors such as loading level, fire protection coating thickness and channel steel height were considered and analyzed in the fire resistance tests of the specimens. The experimental investigation shows that the loading level, the fire protection coating thickness and the channel steel height are the main influencing factors on the fire-resistant behavior of the composite beams. Under the ISO-834 standard fire, the midspan deflection of δ= 1/25 can be a suitable criterion to determine the fire resistance of the composite beam. The experimental results also show that the filled concrete can greatly improve the overall stiffness and ductility of the composite beams, so that the composite beams can retain the integrity till the loss of functions at a high temperature. The filled concrete can also avoid the local buckling and collapse of the composite beams at high-temperatures. The results also indicate that brushing fire protection coating directly on the cold-formed channel steel cannot ensure the coating to paste on the surface of the channel steel firmly, and that it is necessary to improve the painting technique of fire protection coating on the composite beam. The experimental results verified the correctness of the theoretical calculations.

关 键 词：组合梁 冷弯薄壁槽钢 受火试验 受火性能 耐火极限 

分 类 号：TU352.5[建筑科学—结构工程] TU398.9