应力状态下混凝土碳化耐久性试验研究

【作者】 施清亮；

【导师】 罗小勇；

【作者基本信息】 中南大学 ， 结构工程， 2008， 硕士

【摘要】 预应力混凝土碳化是预应力混凝土中钢筋锈蚀的一个主要因素,如何对预应力混凝土的碳化深度及其寿命进行准确的预测是急待解决的问题。本文结合国家自然科学基金项目“无粘结预应力混凝土结构的疲劳与耐久性研究”,对应力状态下的混凝土碳化进行了定量的分析。通过试验与理论分析得到混凝土在应力状态下碳化深度的预测模型,为以后预应力混凝土碳化的设计与评估提供一个可供的参考依据。研究的内容主要有:1.参考国内外相关研究成果,基于已有的混凝土碳化试验,采用试验研究和理论分析相结合的方法,深入分析不同应力状态下混凝土试件中碳化深度随时间的变化关系,探索应力状态下混凝土碳化机理与规律。2.对混凝土碳化的影响因素、碳化机理进行分析总结,根据实验结果拟合混凝土在应力状态下碳化深度的计算数学模型。并得出在拉压应力状态下混凝土碳化的碳化系数计算公式。将拟合模型的计算值与试验数据进行对比分析,验证模型的准确性。3.对应力状态下混凝土碳化深度预测公式进行分析,计算自然环境状态预应力混凝土结构的碳化寿命,同时计算出构件碳化耐久性的可靠度,并进一步推导出预应力结构碳化耐久性极限状态设计与评估方法。更多还原

【Abstract】 Prestressed concrete carbonation is a major factor of steel corrosion in prestressed concrete.How to predict carbonation and service life of prestressed concrete accurately is a important problem to be solved. Combined with the research on fatigue and durability of unbonded prestressed concrete structure supported by the national natural science foundation of china,quantitative analysis on concrete carbonation in stress status was carried out.Through the analysis of test and theory,the predic -tion modle of concrete carbonation in stress status was obtained.Then provide a grounds for sequent work on design and evaluation of PC concrete carbonation.The main contents of this thesis include:1. Taking domestic and overseas correlative development as reference. Based on concrete carbonation test combined with different stress status, experimental research and theoretical analysis were adopted for analysing change relation of concrete carbonation depth in stress status as time changes to obtain the mechanism and law of concrete carbonation in stress status and unstressed status.2. Influence factors of concrete carbonation and carbonation mechan -ism shall be analysed and summarized.The computing mathematical model of concrete carbonation depth in stress would be fitted according to the experimental results and the carbonation coefficient calculation formula would be obtained . Analyz the calculated value from the modle and the data from the experiment to verify the accuracy of the modle.3. Analyzing the prediction formula of concrete carbonation which is in stress states,calculate structure’s sevice life in the natural environment and calculate out the reliability of carbonation durability.Then derive the carbonation durability limit-state design method of prestressed structure.更多还原