既有钢筋混凝土桥梁碳化可靠度评估方法

Method of Carbonization Reliability Assessment for Existing Reinforced Concrete Bridges

讨论了钢筋混凝土结构的混凝土碳化机理及碳化深度模型 ,给出了适合于既有钢筋混凝土桥梁可靠度分析的混凝土碳化深度表达式 .以混凝土碳化至钢筋表面作为结构的耐久性失效极限状态 ,建立了以现时刻为分析时间起点的混凝土碳化可靠度分析及剩余碳化寿命预测模型 ,并研究了其实用近似计算方法 .以一座实际钢筋混凝土桥梁为例 ,对其碳化可靠度及剩余碳化寿命进行评估 。

The mechanism of concrete carbonization and the mo de l of carbonization depth of reinforced concrete structures were discussed, and a formula of concrete carbonization depth suitable for reliability analysis of exi sting reinforced concrete bridges was given. Then, taking the state while concre t e carbonization develops to the surface of the reinforcement as the durability l imit state, and taking the present time as the analysis starting point, models o f reliability analysis and residual lifetime prediction of concrete carbonizatio n are established, and their practical approximate calculation methods are prese nted. Finally, taking a actual reinforced concrete bridge for example,the reliab ility of carbonization and residual carbonization lifetime of the bridge were es timated. Reference basis for maintenance decision of the bridge was provided.