混凝土结构碳化耐久性的概率设计表达式  

The probability expression for concrete structure carbonization durability design

作　　者：姚继涛[1] 谷慧[1] 张义九 程凯凯[1] 

机构地区：[1]西安建筑科技大学土木工程学院,陕西西安710055

出　　处：《西安建筑科技大学学报（自然科学版）》2015年第1期1-5,共5页Journal of Xi'an University of Architecture & Technology(Natural Science Edition)

基　　金：国家自然科学基金项目(50678143;51278401)

摘　　要：随着施工工艺的不断改进和业主对可靠度的不同选择,现行耐久性设计方法在灵活性、通用性和可靠度控制精度上越来越表现出其自身的局限性.根据理论和经验相结合的碳化深度模型,选用最新统计数据,考虑保护层厚度,抗压强度以及混凝土结构碳化深度计算模型的不定性系数三个基本随机变量,提出结构关于时间的功能函数.依据设计值法和结构可靠度的基本理论,考虑基本变量的概率特性、结构设计的目标可靠指标以及其设计使用年限对设计结果的直接影响,用基本变量的基准值与分项系数的乘积来表达其设计值,在分项系数中全面反映了目标可靠指标的影响,建立了基于碳化寿命准则的混凝土结构耐久性概率设计表达式.该耐久性设计方法适用于一般大气环境下任意设计使用年限的不允许出现钢筋锈蚀的混凝土结构,根据表达式可直接确定新材料、新工艺在满足不同可靠指标和设计使用年限的耐久性要求下的保护层厚度和混凝土强度.With the development of the construction process and the different reliability options, the current method of durability design is increasingly showing its limitations on the side of flexibility, generality and accuracy for reliability control. According to the combination of theory and experience carbonation depth model, choosing the latest statistical data, considering the concrete protective cover thickness, compressive strength and carbonation depth calculation model uncertainty factor as the basic random variables, the paper puts forward the function of the structure about time. Drawing lessons from the basic idea of design-value method, with the basis of the existing structure reliability theory, considered directly of the influence of basic variables probabilistic properties, target reliability index and design working life to design result, and the design values are expressed as the product of reference design value and partial factor, it set up the probability expression of concrete structure durability design based on the rule of carbonation life. The influence of target reliability index roundly by each partial factors, which is benefit to reliability control. This durability design method is suitable for concrete structure design which not allowing the steel corrosion in any design working life under common atmosphere environment. Based on the expression, the protective cover thickness and concrete strength can be directly designed for the require of the durability with the new material, new technology to meet different reliability index and design working life.

关 键 词：碳化 耐久性设计 结构可靠度 概率设计 设计值法 

分 类 号：TU318.1[建筑科学—结构工程]