Assessment of Residual Life of Coastal Concrete Structures

本文介绍了海岸混凝土结构的寿命评估与控制，以维护基础设施的安全和改善。通过腐蚀加速试验、实测试验和疲劳试验，得出以下结论：裂缝指标可用于控制混凝土结构的锈蚀损伤。结果表明，钢筋的许用应力与覆盖层厚度相对应，高质量的混凝土覆盖层拉应变能有效防止腐蚀。在严重腐蚀环境下，钢筋应力小于（36C+8）MPa （C为覆盖厚度，单位为cm）时，很少发生锈蚀。同样，在普通腐蚀环境下，当应力小于（56C+8）MPa时，混凝土不容易锈蚀。得到了钢筋混凝土因锈蚀损伤产生纵向裂纹的疲劳强度和数量，并对锈蚀损伤的钢筋混凝土梁的剩余寿命进行了估算。

This paper describes the assessment and control of life for coastal concrete structures to maintain the security and improvement for infrastructure. Based on the accelerated test for corrosion,surveying field and fatigue test,the following results may be drawn.The cracking index may be applied to control rust damage in the concrete structures. It is found that the allowable stress for reinforcing bars corresponds to the cover thickness and the high quality of the tensile strain of the concrete cover is effective in preventing corrosion.In a severe corrosive environment,the rust damage occurs rarely if the stress in reinforcing bars is less than (36C+8)MPa (C is the cover thickness in cm).Similarly in an ordinary corrosive environment,the concrete is not susceptible to rust damage if the stress is less than (56C+8)MPa.The fatigue strength and number of reinforced concrete beans with longitudinal crack due to rust damage are obtained and the residual life of reinforced concrete beams damaged by corrosion is estimated.