爆裂对偏心受压柱抗火性能的影响研究

发布时间：2018-06-16 18:25

本文选题：爆裂 + 偏心受压柱　；参考：《华北理工大学》2017年硕士论文

【摘要】：研究抗火性能的重要方法是足尺抗火试验,目前关于不同养护周期下含水率差异的普通混凝土柱抗火试验研究成果还很少。含水率越高,高温作用时易发生爆裂,而爆裂对于混凝土柱抗火性能会有严重影响。在一些临海地区发生火灾时,特别是受海风、潮水作用影响大的建筑物,此类结构混凝土由于经常受潮湿环境影响,内部含水率较高,发生火灾时极易爆裂、对结构造成更严重影响。综上,设计了三种不同养护周期下的含水率、两种受力形式共计6根足尺混凝土试件,通过抗火试验对构件的破坏形式、内部温度变化、耐火极限等进行了详细研究:1)归纳整理了钢筋混凝土柱抗火研究现状和结论,针对高温爆裂存在的问题提出并设计了火灾试验方案。2)全面总结了混凝土内部钢筋和混凝土高温作用下的力学性能,分析了其中较好的研究成果。3)设计三类条件养护下的三根轴压普通混凝土柱和三根偏压普通混凝土柱分别进行抗火试验对比,分析含水率和受力形式受高温影响的差异性。4)火灾试验现象描述方面对高温后混凝土表面颜色、爆裂发生的严重区域、构件产生的裂缝特征等试验内容进行了归纳,总结了不同含水率导致的爆裂程度及不同受力形式导致的裂缝特征等规律。5)温度数据处理分析方面包括试验炉内温度、内部及表面混凝土温度、内部钢筋温度等试验前布置的所有热电偶反馈的信息,得出了混凝土和钢筋温度升高趋势、最高温度,及混凝土内部水蒸气高温产生的“烘干效应”等结论。6)位移和耐火极限对比方面对六组火灾试验位移变化进行比较,研究了火灾试验中不同构件竖向位移变化规律及爆裂和受力形式对耐火极限的影响等内容。
[Abstract]:The important method to study the fire resistance is the full-scale fire test. At present, there is little research on the fire resistance of ordinary concrete columns with different moisture content under different curing periods. The higher the moisture content is, the easier it is to burst at high temperature, and the burst will have a serious effect on the fire resistance of concrete columns. When fire occurs in some coastal areas, especially in buildings which are greatly affected by sea wind and tide, the concrete of this kind of structure is prone to burst when fire occurs because it is often affected by wet environment and has high internal moisture content. Have a more serious impact on the structure. In summary, three kinds of moisture content under different curing periods are designed. Six full-scale concrete specimens are subjected to two kinds of stress. The damage form and internal temperature of the member are tested by fire resistance test. The fire resistance limit of reinforced concrete columns is studied in detail. (1) the current situation and conclusion of fire resistance of reinforced concrete columns are summarized and sorted out. Aiming at the problem of high temperature burst, the fire test scheme. 2) summarizes the mechanical properties of reinforced concrete and concrete under high temperature. In this paper, three axially compressed ordinary concrete columns and three eccentric compression ordinary concrete columns under three kinds of curing conditions are designed and compared with each other. Analysis of the difference between moisture content and stress form affected by high temperature. 4) in terms of description of fire test phenomenon, the color of concrete surface after high temperature, the serious area of crack occurrence, the crack characteristics of members and so on are summarized. In this paper, the cracking degree caused by different moisture content and crack characteristics caused by different stress forms are summarized. 5) the temperature data processing and analysis include the temperature inside the test furnace, the internal and surface concrete temperature, etc. The internal steel bar temperature and all the thermocouple feedback information before the test, obtained the rising trend of the temperature of concrete and steel bar, the highest temperature, And the "drying effect" caused by high temperature water vapor in concrete. 6) the displacement and fire resistance limit of six groups of fire test displacements are compared. The variation law of vertical displacement of different components in fire test and the influence of burst and force form on fire resistance are studied.
【学位授予单位】：华北理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU352.5;TU375.3

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