摘要
针对某高层建筑结构低合金盘圆变形钢筋混凝土楼板火灾后板底混凝土大面积脱落的情况,现场采用超声回弹综合法确定楼板温度场,钻取芯样测试火灾后混凝土强度,截取钢筋试件通过拉伸试验检测火灾后钢筋力学性能。火灾后高强混凝土和低合金盘圆变形钢筋强度降低,而钢筋屈服强度比极限强度降低更为明显。采用 DIANA 有限元软件分析了火灾后材料强度损失、板底混凝土剥落对楼板抗弯承载能力的影响。计算结果表明,火灾后板底混凝土剥落是导致楼板抗弯承载能力降低的重要因素,其对楼板承载力的影响比材料强度损失的影响更为显著。
It was found in a high-rise building structure after fire that large-area concrete spalled at the bottom of slabs reinforced with low-alloy deformed steel bars. Temperature field of slabs during fire was determined by the uhrasonie-rebound combined method, and post-fire mechanical performance of concrete and steel bars were inspected by drilled cores and intercepted steel bars respectively. Strength of high-strength concrete and lowalloy deformed steel bars decrease after fire, and the yielding strength of the steel bars decreases more evidently than the ultimate strength. The effects of strength loss of concrete and steel bars, as well as concrete spalling on bending resistance of slabs after fire were analyzed by DIANA finite element software. It was shown that concrete spalling is the main factor to influence the bending resistance of slabs after fire.
出处
《结构工程师》
2009年第6期128-132,共5页
Structural Engineers
基金
国家科技支撑计划(2006BAJ04A03)
关键词
钢筋混凝土
低合金盘圆变形钢筋
楼板
剥落
火灾
安全性评估
reinforced concrete slab, low-alloy deformed steel bar, concrete spalling, fire, safety assessment
