摘要
利用自行研制的火灾试验炉,进行了足尺三层钢框架结构中钢筋混凝土双向板在恒载-升温工况下的火灾试验。介绍了钢框架足尺模型与火灾试验炉的设计以及试验观测内容和方法。描述和分析了试验中板的裂缝开展及破坏特征。研究了双向板在受火过程中沿板厚混凝土的温度分布、钢筋的温度变化以及板的平面外和平面内的变形。结果表明:火灾作用下,沿板厚存在非线性温度场及较大的温度梯度;在荷载和温度的耦合作用下,受火板顶沿板边出现密集裂缝,最终形成圆形塑性铰线,由于结构连续性及构件间的相互作用,与受火板相邻的未受火楼板板顶也出现了规则裂缝;火灾中受火板的平面外变形基本对称,最大平面外位移发生在板中心;周边相邻未受火构件对受火板有较强的侧向约束作用,导致板边未产生向外膨胀的平面内位移,而是随板挠度的增长一直向内收缩;整体结构中钢筋混凝土双向板具有较好的抗火性能。
The specially designed furnace was used,and the experiment of two-way concrete slabs in a full-scale three-storey steel-framed building under the combined effects of constant loading and fire were investigated.This paper introduces the design of the test building and furnace,measuring contents and methods.The cracking and failure characteristics of the slab are described.The distribution of temperature along the depth of the slab,the temperature variation of the steel reinforcement,vertical deflection and horizontal displacement are studied.It is shown that the distribution of temperature along the slab depth was nonlinear,and the temperature gradients were large.Under the combined effects of constant loading and fire,intensive cracks occurred on the top of the heated slab along the edges,and plastic hinge lines of circular shape appeared finally.Because of the structural continuity and interaction between structural members,regular cracks also occurred on the top of the adjacent unheated slabs.The vertical deflection of the slab was approximately symmetric during the test,and the largest vertical deflection occurred at the centre of the slab.Due to the high lateral restraint provided by the adjacent unheated structural members,the horizontal displacements at the edges of the slab were not outward but always inward with the increase of the vertical deflection of the slab.The test results indicate that the two-way concrete slab in a whole structure had a good fire performance.
出处
《工程力学》
EI
CSCD
北大核心
2013年第4期337-344,共8页
Engineering Mechanics
基金
国家自然科学基金项目(51178143)
关键词
整体结构
钢筋混凝土双向板
足尺抗火试验
温度场
变形
破坏模式
the whole structure
two-way reinforced concrete slab
full-scale fire test
temperature field
deformation
failure pattern
