三面受火小偏压SRC柱耐火极限试验

摘要

Locating in different positions, columns in structures may be heated from l-,2-,3- or 4-side, which will lead to a different fire behavior because of different heating situation. To discover the behavior of steel reinforced con-crete (SRC) columns subjected to 3-side heating, two tests on fire resistance of eccentrically loaded SRC (steel rein-forced concrete) columns under ISO-834 standard fire are conducted. Temperature distribution, axial and lateral de-formations as a function of time, damage mode, fire resistance and related mechanisms are observed. From the results we can see, spalling or of concrete has visible influence on the temperature distribution and fire resistance. Load ratio and eccentricity are key factors to deformation and fire resistance of 3-side heated SRC columns. Test results can be taken as a reference to fire resistance design of SRC columns subjected to 3-side heating.%由于所处位置不同,结构中的柱有可能处于非四面均匀受火状态,受火边界的差异将导致柱耐火性能存在一定的差异.为认识三面受火型钢混凝土(SRC)柱的耐火性能,进行了两根ISO-834标准火灾作用下、三面受火(受拉侧不受火)SRC柱在小偏心荷载作用下的耐火极限试验,观察了试件破坏过程,获取了截面温度场分布、轴向变形-时间关系曲线、侧向变形-时间关系曲线及构件的耐火极限,分析了有关规律及机理.试验结果表明,混凝土爆裂(崩落)对截面温度场及构件耐火极限均有影响；荷载比和偏心率是影响高温下SRC偏压构件变形特征及耐火极限的重要因素.试验结果可供三面受火SRC柱耐火设计参考.