大气环境下预应力结构的耐久性设计理论

针对现代预应力混凝土结构耐久性失效的特点以及结构耐久性具体要求，详细论述了预应力结构耐久性设计的主要内容；随后就大气碳化环境这一指标，提出了预应力结构构件耐久性极限状态的定义形式，并给出了一种以结构耐久性能和可靠度理论为基础的结构耐久性设计方法，该方法与现行结构承栽力设计的可靠度设计方法相似，采用分项系数r（安全系数）来反映结构可靠指标；并在此基础上给出了一定设计使用年限、一定可靠指标下结构耐久性设计时保护层厚度的计算表达式．算例分析表明，该设计方法简单、实用，便于工程设计人员使用．

Design theory of durability of pre-stressed structure in atmospheric environment

Based on the characters of durability failure of modern pre-stressed concrete structure and requirements on structural durability,the primary contents about durability design are introduced in detail.Then,concerning the carbonation environment,the definition of durability limit for pre-stressed concrete structure is given,and a design method of durability which is based on structural durability performance and reliability theory is also provided.The method is similar to current reliability design of structural bearing capacity,and adopts subentry coefficient r to reflect structural reliability index.At last,some analytic results of example verify that our method is practical,simple and easy to use.