【作者】 傅军；

【导师】 金伟良；

【作者基本信息】 浙江大学 ， 结构工程， 2010， 博士

【摘要】 新型墙体在我国得到了广泛应用,取得了极大的社会效益和经济效益,但是墙体的开裂渗漏问题也日益凸显,这不仅带来了建筑功能的下降和保温节能的失效,而且导致建筑物使用寿命的降低。为了更好地推广使用新型墙体材料,解决新型墙体工程应用的抗裂抗渗问题已成为迫在眉睫的问题。本文从产品生产、施工工艺、设计计算、构造措施、检测技术等多个环节,结合文献阅读和专家咨询,沿着“工程实践”主线,对新型墙体材料抗裂抗渗调研、不同龄期混凝土砖墙体收缩试验、框架填充墙干缩开裂数值模拟、新型墙体表层渗透性能现场测试、墙体表层裂缝图像处理几个方面开展了系统、深入的研究,主要研究内容及成果如下：1)对新型墙体材料在浙江地区工程中的工程应用情况进行了广泛的调查研究,并采用样本数据进行了统计分析,调研表明：行业管理部门没有详细的技术实施导则、生产企业内部的管理制度及保证体系不完善,是引起质量缺陷的“源头”2)采用“半分离-整体式”计算模型和二层单跨框架填充墙结构模型,进行了干缩开裂过程的数值模拟,对不同柱刚度、开洞率、连接刚度下结构的变形、应力、裂缝规律做了详细的描述,对相关因素做了定量分析,包括自重和竖向荷载作用的影响、干缩带来的变形和裂缝问题等。3)采用均匀化(匀质化)代表单元RVE(representative volume element)对砌体结构进行了分析,主要进行了弹性阶段的一些有限元模拟试验,包括构建的单元在单轴受压、单轴受拉情况下的强度模拟、等效弹性常数的模拟、对单元进行累叠、整体结构算例等,用以验证RVE单元从单个扩充到整体时的合理性。4)通过试验研究了不同龄期混凝土砖块体和墙体的收缩变形规律,得出了墙体初期收缩率、应变状态的变化情况,拟合了初期应变与时间的关系,采用数值模拟进行了对比,并在此基础上提出了工程限制措施建议。5)采用GWT透水测试仪以及相关的试验方法对烧结页岩砖墙、混凝土多孔砖墙的表层渗透性进行了现场测试,分析了不同材料、不同位置、不同试验措施等对渗透系数的影响,同时以测试成果为基础对墙体渗透性进行了评价。6)将数字图像处理技术应用于墙体浅层裂缝测量上,提出了一种基于神经网络进行图像分割的方法,应用该方法对墙体裂缝图像进行提取,通过实例说明了获取数字化裂缝信息的可行性。7)结合上述研究成果和相关文献的总结,制定了一个基于抗裂抗渗性能的新型墙体材料工程应用技术导则。上述各个研究点对应于新型墙体抗裂工程应用的各个阶段和环节。新型墙体抗裂抗渗性能工程应用研究是一个复杂和渐进的过程,本文通过研究取得了阶段性成果,为后续工作提供了一定的基础。更多还原

【Abstract】 New-type wall materials are widely used in our country, which have brought much social and economic benefits. But the crack and leakage problems of new-type walls are obviously serious, these problems can bring harmful influence on the building, such as reducing the building function, making the insulation and energy saving invalidation, and losing the service life. In order to extend the using of new-type wall materials, it is extremely urgent to solve the problems of new-type walls’crack and leakage.By combining literature readings and expert consults, Researchs on the engineering application of new-type walls’crack and leakage resistance are systematically and deeply carried out. Researchs are based on many aspects, such as product productions, construction technologies, design and calculations, structural measures, detecting techniques. This thesis includes:Investigation of new-type walls’crack and leakage resistance, Experimental investigation of shrinkage of Concrete perforated brick(CPB) walls at different ages, Numerical simulation of wall-infilled frame’s shrinkage, New-type walls’in-field test of surface permeability, Image processing of wall crack etc. Research contents are listed as follows:1) Applications of new-type wall materials in Zhejiang province have been widely investigated, and the sample data are statistical analyzed. Results show that being no detailed guideline of professional management and being imperfection of manage and guarantee system of production occupations cause the original quality defects.2) Numerical simulation analysis of cracks’development by shrinkage effect has been carried out on a practical meeting two-storey and single span wall-infilled structure, using FEM models as whole-type and semi-discrete type. Different column rigidity, opening size, and connection rigidity are described with deformation, stress, and crack development results. Relevant factors are qualitative analysed, including the influences of dead load and problems of deformation and crack by dry shrinkage.3) Masonry structure is analysed using RVE(representative volume element), mainly in elastic stage. Including:RVE simulation of uniaxial tensile and compression strength test, simulation of equivalent elastic constants, element build-up and a whole structure calculation example etc. The feasibility of element expansion from single to whole is validated. 4) Experimental investigations of shrinkage of Concrete perforated brick(CPB) walls at different ages have been carried out. The walls’ shrinkage rate and strain variation at early age are concluded. Relationship between instantaneous strain and age is fitted. Experimental results are compared with numerical simulation. Basing on the achievement, engineering treatment measures are proposed.5) Penetration instrument (GWT) and its method are used at in-field testing of agglomeration shale brick and CPB walls’ surface permeability. Influence of different materials, locations, test methods to the permeability coefficient are analysed, then the walls’ permeability is assessed basing on the results.6) Digital image processing technology for shallow cracks measurement in walls is used. A new method of image segmentation basing on neural network is presented. By this method, cracks images are extracted. The experimental results on project examples show that this method is feasible to gain digital crack information.7) By summarizing above research results and documents readings, a technical guideline has been made for the application of crack and leakage resistance.Above contents correspond to each stage and link the crack-resistance practice. Engineering application research of new-type walls’ crack and leakage resistance is complex and progressive, above researches have some stage achievements, which lay a ground for further works.更多还原