【作者】 郭丰哲；

【导师】 钱永久；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2005， 硕士

【摘要】 钢筋混凝土结构广泛应用于各类土木工程中。长期以来,由于“重强度轻耐久”设计思想的影响,大量的钢筋混凝土结构在使用期内就出现了由于耐久性失效而老化现象。钢筋混凝土结构的耐久性问题造成的负面影响和经济损失,引起了越来越多的学者和工程技术人员的关注。结构耐久性影响因素很多,并且各因素的关系错综复杂,相互耦合。因此,如何科学合理地评价现有结构并进行工程决策,已经成为当前钢筋混凝土结构耐久性研究的迫切任务。 本文结合高等学校青年教师教学科研奖励计划、四川省应用基础研究项目及实际工程结构的检测和评估项目,对钢筋混凝土结构的耐久性评估课题进行了一些研究。主要包括以下几个方面的内容: 1.从混凝土碳化、氯离子对结构的侵蚀、抗渗性与抗冻性、碱-骨料反应和钢筋锈蚀这几个方面入手,仔细分析了影响结构耐久性的因素,并重点介绍了钢筋锈蚀和混凝土碳化对结构耐久性的影响。 2.系统阐述了国内外混凝土耐久性各影响因素的研究现状,对已有的研究成果进行了评述,并结合最新的研究动态,指出混凝土各影响因素研究中存在的若干问题。 3.对混凝土结构耐久性检测的内容及过程进行了详细描述。采用现场量测法、回弹法、钻芯法等对结构进行材料性质检测,从而为耐久性的评定提供数据基础。 4.本文提出一种改进的三级综合评判方法。该方法的特点是:用类比法对非定量因素定量化,建立隶属函数;根据各因素之间的重要性,用层次分析(AHP)法确定因素权重;采用加权平均模型作为综合评判模型;用非对称贴近度法划分桥梁耐久性等级。 5.结合所建立的检测与评估体系,通过两个具体工程实例的检测评估实施,阐明实施的过程及系统的可行性,为今后相关项目研究提供一定的参考价值。更多还原

【Abstract】 R.C. (reinforced concrete) structures are widely used in civil engineering. The deficiency of durability appears in lots of existing R.C. structures. It causes many aging problems and has an ill effect on people’s productivity and life. It also brings people loss of money. So more and more scholars and engineering technical staff pay attention to the problem. The influencing factors relate intricately and interact complexly. So how to make an assessment of durability has become an urgent task in the research of R.C. structure durability.Supported by the Youth Teacher’s Teaching & Scientific Research Reward Plan in University, Foundation Application Research Program of Sichuan Province and some engineering examples, some subjects in structures durability are studied in this paper. The main contents are as follows:1. The paper carefully analyses the factors that influence the durability of concrete structure from some effects, such as carbonization, chloride, anti-freeze, anti-osmosis, alkali, erosion of reinforcing-bar, etc., especially introducting erosion of reinforcing-bar and carbonization in detail.2. The present research works of concrete durability are systematic elaborated. Combined with new programs in sthdy works, the problems existed in the research are pointed out.3. The contents and courses of durability detection for R.C. structure have been described in detail. The material of the structure has been tested by some means in order to provide some date for assessing the structure.4. An improved 3-grade fuzzy comprehensive evaluation method for reliability assessment of existing R.C. structures is presented in this thesis. The peculiarities of this method include the establishment of the membership functions of the non-quantitative factors by analogy method, determination of the weight value of each factor according to its significance by the analytic hierarchy process (AHP), use of the weighted average model in evaluation and classification of the grade of durability by the asymmetric approach degree method.5. The feasibility for this system was proved by the detection and evaluation oftwo different engineering examples. It is useful to draw experinence from the textual on the durability detection and evaluation of existing R.C. structures.更多还原