沿海服役混凝土结构氯离子质量分数检测和分析

Detection and analysis of chloride ions in marine concrete structures in service

为了弄清沿海服役混凝土的氯离子质量分数分布规律及影响因素,对江苏连云港码头部分泊位不同区域的氯离子进行了取样检测,分析了浸水时间、所处方位、开裂状态、维修历史等因素对混凝土内氯离子质量分数的影响。分析结果表明:水位变动区混凝土内的氯离子质量分数积累速度最快,且基本随高程增加而增大;开裂位置的氯离子质量分数明显大于相同环境下的非开裂位置;不同方位混凝土经历的光照时间不同,造成其内部氯离子质量分数有一定差异,其中向海侧混凝土内的氯离子质量分数峰值出现在混凝土浅层,背海侧的则出现在混凝土深层;混凝土表面维修后内部氯离子会向表面迁移,造成质量分数峰值出现在试件内部某一深度。

In order to understand the distribution and influence factors of chloride ions in the marine concrete structures in service,typical berths serving for different time periods in the Lianyungang port were sampled and the chloride ions in the marine concrete structures located in different regions were detected to find the influences of exposure zone,and the impacts of soaking time,locations and directions,cracking state and maintenance history on the chloride ions concentration of the marine concrete were analyzed in this study.The analysis results show that the accumulation rate of the chloride concentration in the concrete structures placed in the water level fluctuation zone is the fastest,which is larger than that in the atmospheric zone,and it increases with the increase of the elevation;the chloride ions mass fraction at the cracking position is obviously larger than that at the uncracked position in the same environment;the chloride ions’ingression rate is also influenced by the orientation which accepts the different illumination time,the peak value of the chloride ions mass fraction of the concrete to the sea side appears in the concrete cover,while the peak value of the chloride ions mass fraction of the back sea side appears in the concrete deep layer.The chloride ions in the concrete will transport from the inner to the surface when the surface layer of the concrete is repaired,which will make the peak value of the chloride profile appear at a certain depth of the concrete specimen.