基于服役寿命的海工结构耐久性评定

Durability service life assessment of concrete structures in marine environment

根据某海港泊位码头及引桥结构构件的使用要求,将混凝土表面出现可接受最大外观损伤作为待估结构构件的耐久性极限状态,提出采用现场实测数据进行海工结构耐久性服役寿命评估。分析海洋环境下影响结构服役寿命的因素,采用现场检测数据推算各构件的耐久性参数(混凝土表面氯离子浓度、钢筋处氯离子浓度、氯离子扩散系数等)。耐久性寿命评估结果与现场调查检测结果一致。保护层厚度、保护层中氯离子浓度及混凝土等级的实测,混凝土表面氯离子浓度、钢筋表面氯离子浓度及钢筋锈蚀临界氯离子浓度等的推算与选取是耐久性寿命评估的关键因素。

According to the function of a seaport berth wharf and approach bridge,the most acceptable appearance of injury in concrete surface was to be assessed as the durability limit state.The methodology for the assessment of marine structures＇ durability service life using the field investigation data was presented.The influencing factors of durability service life of concrete structure in marine environment were analyzed.Field investigation data were used to calculate the durability parameters（chloride concentration of concrete surface,chloride concentration at steel-concrete interface,chloride diffusion coefficient）.The assessment results of the durability service life reveal a good agreement with that of field investigation.The concrete cover thickness,chloride concentration on concrete cover,concrete strength,chloride concentration at steel-concrete interface,chloride concentration on concrete surface and critical chloride concentration are the key elements for the assessment of the durability service life.