单面受火预制复合保温墙体灾后轴压承载力研究

发布时间：2018-05-30 03:36

本文选题：预制复合保温墙体 + 单面受火　；参考：《东南大学》2015年硕士论文

【摘要】：随着我国国民经济的快速增长,能源短缺问题日益严重,节能工作已成为可持续发展的重要保证,其中建筑节能已成为提高社会能源使用效率的首要方面。预制复合保温墙体可实现预制、承重、保温节能于一体,符合当今我国大力开展建筑节能工作的政策,因而得到了广泛的使用。但是随之而来的建筑火灾隐患也增大,为了对此种新型墙体进行准确的损伤鉴定及火灾后的修复与加固工作,对其进行火灾后的力学分析显得尤为紧迫。基于此,本文进行了预制复合保温墙体的火灾后轴压性能的试验研究,并结合有限元软件对其灾后力学性能进行了理论分析。主要研究内容如下：(1)系统整理和归纳了高温后混凝土的残余抗压强度、残余抗拉强度、弹性模量、受压应力-应变本构关系和受拉应力-应变本构关系以及高温后钢筋的极限强度、屈服强度、弹性模量、延伸率和应力-应变本构关系。(2)分别进行了两榀常温预制复合保温墙体及两榀相应保温层厚度的火灾后墙体的轴压承载力试验研究,对四榀剪力墙的试验过程进行了描述,并将两组常温墙体和火后墙体的极限抗压承载力、荷载-位移曲线、荷载-混凝土应变曲线及荷载-钢筋应变曲线进行了对比分析。研究表明：保温层厚度为40mm和60mm的火灾后保温墙体的极限承载力分别比常温降低21.8%和16.8%；保温层厚度相同时,在相同荷载作用下,火灾后墙体的位移、混凝土应变及钢筋应变均大于常温墙体；无论是常温墙体还是火后墙体,在相同荷载作用下,由于墙体总厚度不变,有效的混凝土厚度随保温层厚度的增大而减小,故保温层厚度较大墙体的位移、混凝土应变及钢筋应变均稍大于保温层厚度较小的墙体。(3)利用通用有限元分析软件分析了各个墙体在轴压下的力学性能,并与试验结果进行对比分析,为理论分析提供了思路。(4)基于规范给出的剪力墙偏心受压承载力计算公式,采用三台阶模型作为钢筋和混凝土高温后强度计算模型,并考虑受火时间、轴压比及保护层厚度等因素对温度场分布的影响,对单面受火后预制复合保温墙体正截面偏心受压承载力计算公式进行了推导和分析。
[Abstract]:With the rapid growth of China's national economy, the problem of energy shortage is becoming more and more serious. Energy conservation has become an important guarantee of sustainable development, among which building energy conservation has become the most important aspect to improve the efficiency of social energy use. Prefabricated composite insulation wall can realize prefabrication, load bearing, heat preservation and energy conservation, which is in line with the policy of building energy conservation in our country, so it has been widely used. However, the hidden danger of building fire also increases, in order to accurately identify the damage of this new wall and repair and reinforcement work after the fire, it is particularly urgent to carry out mechanical analysis after the fire. Based on this, the axial compression performance of prefabricated composite insulation wall after fire is studied, and the mechanical properties of prefabricated composite insulation wall after fire are analyzed theoretically with the finite element software. The main research contents are as follows: (1) the residual compressive strength, residual tensile strength, elastic modulus of concrete after high temperature are systematically sorted out and summarized. Compressive stress-strain constitutive relation, tensile stress-strain constitutive relation and ultimate strength, yield strength, elastic modulus of steel bar after high temperature, The axial compression capacity of two prefabricated composite insulation walls at room temperature and two walls with corresponding thickness of insulation layer after fire were studied respectively. The experimental process of four shear walls was described. The ultimate compressive capacity, load-displacement curve, load-concrete strain curve and load-reinforcement strain curve of two groups of normal temperature wall and post fire wall are compared and analyzed. The results show that the ultimate bearing capacity of the fire insulation wall with the thickness of 40mm and 60mm is 21.8% and 16.8% lower than that of the normal temperature respectively, and the displacement of the wall after fire occurs under the same load when the thickness of the insulation layer is the same. Both the strain of concrete and the strain of reinforcing bar are larger than that of the wall at room temperature, and the effective thickness of concrete decreases with the increase of the thickness of insulation layer under the same load, whether the wall at room temperature or the wall after fire, because the total thickness of the wall remains unchanged. Therefore, the displacement, the strain of concrete and the strain of steel bar are slightly larger than those of the wall with smaller thickness of insulation layer. The mechanical properties of each wall under axial compression are analyzed by using the general finite element analysis software. Compared with the test results, this paper provides a train of thought for theoretical analysis. (4) based on the formula given in the code, the three-step model is used as the strength calculation model of steel bar and concrete after high temperature. Considering the influence of fire time, axial compression ratio and thickness of protective layer on the distribution of temperature field, the calculation formula of eccentricity compression bearing capacity of normal section of prefabricated composite insulation wall after single side fire is deduced and analyzed.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU398.9

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