【作者】 蒋建华；

【导师】 袁迎曙；

【作者基本信息】 中国矿业大学 ， 结构工程， 2011， 博士

【摘要】 气候环境作用是钢筋混凝土结构耐久性设计和使用寿命预计的重要影响因素。为了使气候环境作用能与荷载作用一样,采用定量方法进行耐久性设计和使用寿命预测,本文试图将气候环境作用与混凝土微环境响应结合起来,并建立与混凝土微环境相关的耐久性退化模型。恒定人工气候环境下,基于混凝土内部温度响应和相关基本物理量的试验研究,分析了混凝土微环境的温度响应规律,并结合传热过程的基本理论,建立了人工气候环境下混凝土微环境温度响应预计模型。恒定人工气候环境下,基于混凝土内部相对湿度响应规律以及混凝土湿质扩散系数的研究,并结合传质学基本理论,建立了人工气候环境下混凝土微环境相对湿度响应预计模型;同时,研究了混凝土微环境相对湿度、温度与含水量关系。开展了自然气候环境下混凝土微环境响应的长期试验研究,基于试验结果,分析了自然气候环境下混凝土微环境的滞后响应规律;同时,鉴于自然气候环境有遮挡条件与无遮挡条件下混凝土微环境响应的差异,开展了日照、降水对混凝土微环境的影响研究。基于自然气候环境温度和相对湿度的变化,采用一定数学处理方法,提出了自然气候环境温度和相对湿度作用谱构筑方法;基于气候环境作用谱,利用人工气候环境下混凝土微环境响应预计模型,计算自然气候环境下混凝土微环境响应值;基于混凝土微环境响应的变化及其对耐久性退化的影响规律分析,提出混凝土微环境响应谱的概念和构筑方法。通过分析混凝土内钢筋锈蚀速率的控制因素,利用金属腐蚀动力学方程和钢筋锈蚀的电化学原理,建立了混凝土内钢筋锈蚀速率的电化学基本模型;借助基本模型,并基于一系列试验研究和理论推导分析,最终建立了考虑混凝土微环境影响的钢筋锈蚀速率时变预计模型。开展了自然气候环境下混凝土内钢筋锈蚀速率的长期试验,得到了自然气候环境下混凝土内钢筋锈蚀速率的真实发展规律,并对其进行机理分析;基于气候环境作用谱、混凝土微环境响应谱以及钢筋锈蚀速率预计模型的研究结果,提出了自然气候环境下混凝土内钢筋锈蚀速率的预计方法。阐述了钢筋混凝土结构使用寿命的全过程,并给出各阶段使用寿命的相关计算模型。最后,综合上述研究结果,提出混凝土材料与结构的使用寿命预计策略,包括新建混凝土结构耐久性设计的使用寿命预计和基于寿命预计的耐久性试验设计。该论文有图276幅,表41个,参考文献186篇。更多还原

【Abstract】 Actions of climate environment are important factors influencing durability design and prediction of service life of reinforced concrete structures. To make the actions of climate environment, with the similar to load, being used for durability design and prediction of service life by quantitative methods, this dissertation attempts to link the actions of climate environment and the responses of concrete’s micro-environment together, and establish the durability degradation model related to concrete’s micro-environment.In artificially controlled constant climate environment, based on the experimental studies of the internal temperature response of concrete and corresponding basic physical parameters, the temperature response laws of concrete’s micro-environment were analyzed, and combined with the basic theory of heat transfer process, the prediction model of concrete’s micro-environmental temperature response under artificial climate environment is established.In the artificially controlled constant climate environment, based on the researches of the response laws of relative humidity inner concrete and the concrete’s humidity diffusion coefficients, and combined with the basic theory of mass transfer, the prediction model of concrete’s micro-environmental relative humidity response under artificial climate environment is established; at the same time, the relationship of relative humidity, temperature and moisture content in concrete’s micro-environment was studied.The long-term experimental study of concrete’s micro-environmental responses under natural climate was carried out, based on testing results, then the hysteretic laws of concrete’s micro-environmental response under natural environment were analyzed; at the same time, considering the difference of concrete’s micro-environmental responses under between shelter and open-air conditions of natural environment, the effects of sunlight and rainfall on the concrete’s micro-environment were studied.The methods for building climatic action spectra of temperature and relative humidity are proposed using certain mathematical treatment, based on the natural climate environmental changes in temperature and relative humidity; based on the climatic action spectra, the theoretical values of concrete’s micro-environmental response under natural climate were calculated using the prediction models of concrete’s micro-environmental responses under artificial climate environment; based on the analysis of the changes of concrete’s micro-environmental responses and their effects on durability degradation, the concepts and building methods of response spectra in concrete’s micro-environment also are proposed.Through the control factors of steel corrosion rate in concrete being analyzed, a basic electrochemical model of steel corrosion rate in concrete is founded using the kinetics equations of metal corrosion and the electrochemical principles of steel corrosion; with the basic model, and based on a series of experiments and theoretical derivation, the prediction model of time-variation corrosion rate of reinforced bars in concrete is established ultimately considering the impacts of concrete’s micro-environment.The real development of steel corrosion rate in concrete under natural climate environment was obtained by the long-term test, and its mechanism analysis also was carried out; based on the research results of climatic action spectra, concrete’s micro-environmental response spectra and prediction model of steel corrosion rate, the prediction method of corrosion rate of reinforced bars in concrete under natural climate is presented.The whole process of service life of reinforced concrete structure is expounded, and the relevant calculation models of service life in different stages are proposed. Finally, combining the above results, the strategies for predicting the service life of concrete materials and structures are presented, including the prediction of service life in the durability design of new concrete structures and the design of durability testing based on the life prediction.更多还原