Assessment of Residual Life of Coastal Concrete Structures

本文阐述了沿海混凝土结构的寿命评估和寿命控制，以维护基础设施的安全和改善。通过腐蚀加速试验、现场勘察和疲劳试验，得出以下结论：开裂指数可用于控制混凝土结构的锈蚀损伤。结果表明，钢筋的许用应力与保护层厚度相对应，混凝土保护层的高质量拉应变对防腐是有效的；在严重腐蚀环境中，当钢筋应力小于(36C+8)Mpa(C为保护层厚度)时，几乎不会发生锈蚀损伤；同样，在普通腐蚀环境中，如果应力小于(56C+8)Mp，混凝土不容易发生锈蚀损伤。通过计算得到了钢筋混凝土梁因锈蚀损伤而产生纵向裂缝的疲劳强度和钢筋混凝土梁的数量，并估算了锈蚀损伤钢筋混凝土梁的剩余寿命。

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.