大连港服役50年混凝土的力学性能与耐久性

Mechanical Properties and Durability of Wharf Concrete after 50 Years′ Service in Dalian Port

本文分别研究了大连港服役11年和50年的某码头大气区、浪贱区和潮汐区混凝土的外观破坏情况和物理力学性能,测定了不同深度混凝土的氯离子含量分布以及混凝土电阻率和RCM氯离子扩散系数(DRCM)等耐久性参数,探讨了部分耐久性参数之间的相关关系。结果表明,两个年代海洋码头的潮汐区混凝土都存在剥落现象,其中服役50年码头的大气区和浪溅区混凝土还存在裂缝现象。综合文献数据研究发现,海洋混凝土结构的表面自由氯离子含量随着暴露时间的延长呈指数函数或幂函数的增长关系,且服役早期增长较快,服役后期增长速度减缓。海洋混凝土结构的表观氯离子扩散系数随暴露时间的延长呈现经典的幂函数衰减关系。

This paper studied the appearance damage,physical mechanical properties of atmospheric zone,splash zone and tidal zone of one wharf which have been in service for 50 years and 11 years in Dalian Port,respectively.Besides,the durability parameter of chloride content distribution in different depth of concrete,electrical resistivity and RCM chloride diffusion coefficient（DRCM）were measured.And the correlation between the different durability parameters was also discussed.The results show that spalling was observed on the concrete surface of two wharfs in tidal zone.And cracks were found on the surface of concrete after 50 years in atmospheric zone and splash zone.Based on the test data of literatures,it is found that the surface free chloride contents（cs）shows exponential or power growth with the prolongation of exposure time,and growth of csis faster in the early service time,the slower in the later service time.Apparent chloride diffusion coefficient of marine concrete structure exhibits a classical power attenuation function with the extension of exposure time.