【作者】 吕清芳；

【导师】 金伟良；

【作者基本信息】 浙江大学 ， 结构工程， 2007， 博士

【摘要】 本文依托国家自然科学基金课题和863计划项目等，以混凝土结构耐久性环境区划标准(Durability Environmental Zonation Standard，简称DEZS)为研究对象，对耐久性区域划分和分区耐久性规定进行了研究，提出了建立混凝土结构耐久性环境区划标准的基本方法，在建立基于结构全寿命周期成本(Structural Life-Cycle Cost，简称SLCC)理论的混凝土结构耐久性定量设计方法的发展方向上迈出了关键一步。本文主要进行了以下研究：1、进行了浙江省内的公路桥梁、沿海码头、沿海地下工程等的耐久性状况普查，并选择有代表性的工程进行详细检测，明确了耐久性劣化存在显著区域性差别，确定了DEZS研究的必要性，初步提出了东南沿海地区混凝土工程的设计施工维护建议，为浙江省混凝土公路桥梁结构耐久性设计、施工与检测的地方规定提供了参考；2、在SLCC的理论基础上，提出了DEZS的定义，阐述了该标准的主要内容、基本原则、适用范围与实际意义，提出了根据SLCC理论，以结构工作环境对结构的严酷程度为标准，以平面版图区域划分的方式，给出对应区域的耐久性规定的标准形式，并确立了以结构的使用寿命为中心，处理环境作用效应与结构抵抗环境作用的能力这一对关系的基本研究方法；3、从混凝土碳化、氯盐侵蚀以及冻融破坏三种混凝土耐久性劣化机理出发，分析讨论了影响混凝土结构耐久性的两方面因素，即影响环境作用效应的因素和影响结构抵抗环境作用能力的因素，从而初步确定了DEZS中的耐久性区划指标和结构耐久性指标；4、首先分别讨论碳化、氯盐侵蚀与冻融破坏三种劣化作用对应的结构耐久性极限状态，然后选择适用于DEZS的碳化深度预测模型、氯离子扩散深度模型和冻融破坏模型，最后根据各自对应的耐久性极限状态和目标可靠指标，采用设计使用寿命模式，确定结构耐久性寿命预测的概率方法；5、DEZS的编制从两方面着手进行：选定结构材料条件作为标准内部条件，根据耐久性寿命预测方法，合理简化环境条件分布参数，预测满足可靠指标的结构耐久寿命，并以最小寿命的区域分布进行耐久性环境区域划分；以划分完成的区域代表性环境条件分布为标准外部条件，根据耐久性寿命预测方法，在满足耐久可靠指标的使用寿命条件下，试算出各区域内的结构材料条件组合，提出各分区耐久性规定。最后将区划方法应用于浙江省范围作为建立DEZS的实例，并为建立浙江省以及东南沿海地区的区划地方标准提供了蓝本。本文得到国家自然科学基金课题——“氯盐侵蚀环境的混凝土结构耐久性设计与评估基础理论研究”(50538070)、国家高技术研究发展863计划“沿海重大混凝土桥梁耐久性试验方法与寿命评估技术”(2006AA04Z422)、浙江省科技计划重点项目“浙江沿海重大工程安全耐久性的关键技术研究”(2003C23024)、浙江省交通厅科技项目“浙江公路桥梁混凝土结构耐久性调查与评估研究”和交通部西部交通建设科技项目“混凝土桥梁耐久性指标体系、检测方法与评价标准的研究”(200631822302-06)等的支持。更多还原

【Abstract】 Durability Environmental Zonation Standard (DEZS) of concrete structure isstudied from durability zonation and durability stipulations to put forward the basicmethodology of DEZS. It makes a mighty advance towards the quantitative durabilitydesign of concrete structures based on the theory of Structural Life-Cycle Cost (SLCC).The research contents are as follows:1. The durability conditions of the highway bridges, coastal quays and coastalunderground constructions are investigated inside Zhejiang province. Somerepresentative projects are detected in detail. The results indicate the remarkableregional difference in the durability degradation, which confirms the necessity of DEZSresearch. Some suggestions are proposed for the design and construction of the concretestructures in the southeast coastal area, offering reference for local stimulations ofZhejiang Province;2. First, the definition of DEZS is proposed. Second, the main content and thebasic principles are explained. Third, the scope of application and the significance ofDEZS are presented. Fourth, the criterion is established according to the severity ofenvironment effect on concrete structures. Fifth, the canonical representation ofmapping zonation correspondingly with durability regulations is confirmed. And Sixth,the basic methodology of DEZS is put forward, which is to dispose the environmentaleffects and the structural resistivity with focus on service life;3. The influencing factors of the environmental effects and the structural resistivityare discussed from three deterioration mechanisms: carbonation, chloride erosion andfreeze-thaw cycles. Thus the durability zonation indexes and the structural durabilityindexes in DEZS are identified initially;4. Following with the discussion of the limit states under the actions of carbonation,chloride erosion and freeze-thaw damage, the carbonation depth model, the chloridediffusion model and the freeze-thaw damage model are identified for DEZScorrespondingly, which are then applied in service life mode to form a probabilisticmethod of durability service-life prediction, according to the limit states respectivelyand the target reliability index;5. DEZS is established on two aspects. One is durability zonation determined bythe distribution of the minimum service life, which is predicted with normal inside conditions(given distribution of construction and material conditions) and varioussimplified outside conditions(various regional distribution of environmental conditions)by durability service life models on request of the reliability indexβ. The other isregional durability regulation presented in the form of combinative inside conditions,which are worked out through pilot calculation with normal outside conditionsrepresenting the zoned region, also by durability service life models on request of thereliability indexβ. At last, an example of DEZS is set in Zhejiang Province, whichcould be a reference to local standard for the southeast coastal area.This research was supported by the project of National Natural Science Fund"Fundamental Research on Durability Design and Assessment of Concrete Structures inChloride Erosive Environment" (50538070), 863 program of National Hi-TechResearch Development "Durability Test Method and Assessment Technology ofImportant Coastal bridges" (2006AA04Z422), the major project of Zhejiang Scientificand Technical Program "Research on the Key Technique of Safety and Durability ofImportant Coastal bridges in Zhejiang Province" (2003C23024), the West TrafficConstruction Project of National Traffic Ministry "Study on Durability Index System,Test Methodology and Assessment Standard of Concrete Bridges"(200631822302-06),the projects of Zhejiang Traffic Office "Survey and Assessment Research on Durabilityof Concrete Highway Bridge Structures in Zhejiang". Their support is gratefullyacknowledged.更多还原