框架填充墙裂缝机理与控制研究

发布时间：2018-05-09 11:05

本文选题：体积变形 + 使用阶段干燥收缩率　；参考：《长沙理工大学》2015年硕士论文

【摘要】：框架填充墙尤其是新型墙体材料填充墙体虽然具有很多优点,但其干缩性大会导致框架填充墙容易产生裂缝,裂缝一旦出现,会影响降低墙体的各种性能,本文针对框架填充墙裂缝问题进行了研究并提出有效的裂缝控制方法。首先,本文对砌体裂缝产生机理进行了分析总结,主要分析形变引起的开裂机理,填充墙的体积形变包括干燥收缩、温度形变、碳化、徐变以及其它因素产生的变形,分别对这几个机理进行探讨研究,并综合比较国内外关于形变因素系数的取值,提出在诸多形变因素下,框架填充墙形变主要因素是干燥收缩。其次,使用阶段的干燥收缩才是导致框架填充墙变形和开裂的主要原因,通过使用阶段干燥收缩率和标准法测得的干缩率之间的公式关系定量求出框架填充砌体使用阶段的干燥收缩率,最后综合比较使用阶段的干燥收缩率、砌体试验干缩值以及各国规范取值,提出框架填充墙干燥收缩率取值建议。第三,假设墙体三种不同的柔性边界条件,并选择三种典型代表性框架填充墙材料,应用ANSYS有限元分析软件分析框架填充墙体不同材料、不同边界条件以及不同墙体尺寸对墙体应力大小及分布的影响,定性研究墙体在上述不同情况下的开裂规律。第四,根据强度理论推导出墙体极限干燥收缩率公式,分析不同边界条件、不同墙体尺寸情况下,干燥收缩当量温差下降一度时墙体应力大小以及方向,结合ANSYS软件分析得到的砌体主应力大小和推导公式计算得到墙体开裂极限干燥收缩值,最后结合填充墙使用阶段干燥收缩率以及极限干燥收缩率回归公式,计算出不同材料不同强度等级砌体的伸缩缝间距,定量分析裂缝控制措施。
[Abstract]:Although the frame-filled wall, especially the new-type wall material, has many advantages, its dry-shrinkage will lead to cracks in the frame-filled wall. Once the crack appears, it will affect the performance of the wall. In this paper, the crack problem of frame infilled wall is studied and an effective crack control method is proposed. First of all, the mechanism of masonry cracks is analyzed and summarized in this paper. The volume deformation of filled walls includes drying shrinkage, temperature deformation, carbonization, creep and other factors. These mechanisms are discussed and compared with the values of deformation factor coefficients at home and abroad. It is pointed out that the main deformation factor of frame infill wall is drying shrinkage under many deformation factors. Secondly, the drying shrinkage in the use stage is the main cause of deformation and cracking of the frame filling wall. The dry shrinkage of frame filled masonry is calculated quantitatively by the formula relation between dry shrinkage and dry shrinkage measured by standard method. Finally, the drying shrinkage of frame filled masonry is compared synthetically. The dry shrinkage value of masonry test and the values of national specifications are proposed, and some suggestions on the dry shrinkage ratio of frame infilled wall are put forward. Thirdly, three kinds of flexible boundary conditions are assumed, and three kinds of typical frame infilled wall materials are selected. The ANSYS finite element analysis software is used to analyze the different wall materials filled with frame. The effects of different boundary conditions and different wall sizes on the stress size and distribution of the wall are studied qualitatively. The cracking law of the wall under the above different conditions is studied qualitatively. Fourthly, according to the strength theory, the paper deduces the formula of the ultimate drying shrinkage rate of the wall, and analyzes the stress magnitude and direction of the wall when the equivalent temperature difference of drying shrinkage drops by one degree under different boundary conditions and different wall sizes. Combined with the main stress and deduced formula of masonry analyzed by ANSYS software, the ultimate drying shrinkage value of wall cracking was calculated. Finally, combined with the regression formula of dryness shrinkage rate and limit drying shrinkage rate in the use stage of infilled wall, The expansion joint spacing of masonry with different materials and different strength was calculated and the crack control measures were quantitatively analyzed.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU398

【相似文献】