Assessment and Repair of Reinforced Concrete Structures Subject to Rust Damage.

(1)在对钢筋混凝土结构在使用和海洋环境中的损伤进行调查中，钢筋锈蚀形成的裂缝损伤较多。裂缝指数定义为混凝土与钢筋之间的平均应变之差，其应用是控制混凝土结构锈蚀的一种手段。研究发现，采用钢筋许用应力和高质量的覆层混凝土弹性应变对防腐蚀是有效的。(2)混凝土结构锈蚀后采用粘接板修补系统是维修作业中常用的修补方法。为了验证该系统的有效性和耐久性，对采用该方法修复的钢筋混凝土梁进行了力学性能和耐久性试验研究。该系统对混凝土结构的修复是有效的，但需要注意混凝土和焊接接头的含盐量。

(1) In surveying the damage of the reinforced concrete structures in using seasand and in a sea environment, there is much cracking damages due to the rust formation in reinforcing bars. The application of the cracking index, which is defined as the difference in the average strain between concrete and reinforing bar, is a means of controlling rust damage in the concrete structures. It is found taht the allowable stress for reinforcing bars and the high quality for the rensile strain of the cover concrete are effective in preventing corrosion.(2) The repair system by using bonding plate for the concrete structures subjected to rust damage is popular with maintenance operation. In order to establish the validity and durability of this system, the experimental studies on the mechanical and durable behaviour of the reinforced concrete beams repaired with this operation are carried out. The system is effective to repair the concrete structure, but it is necessary to attend to the salt content in conctere and welding joint.