海洋环境下珊瑚混凝土的表面氯离子浓度规律

Surface Chloride Concentration Profiles of Coral Concrete Exposed to Marine Environment

采用自然扩散法研究了珊瑚混凝土在模拟海水环境中的氯离子扩散行为,探讨了养护龄期、暴露时间、强度等级和环境差异性对珊瑚混凝土表面氯离子浓度的影响。结果表明：在海洋环境中,珊瑚混凝土的表面氯离子浓度随着暴露时间的延长而呈乘幂的增长,随着养护龄期的延长而下降,随着混凝土强度等级的增加而下降;海水环境下,C50珊瑚混凝土的表面氯离子浓度比相同条件下的C50普通混凝土高出约3.5倍,且增长速率远远高于普通混凝土;在相同的养护龄期与暴露时间,我国南海实际岛礁环境中立方体试件的表面氯离子浓度比实验室数据要高出60%~90%,实际工程中珊瑚混凝土结构的表面氯离子浓度数值比较稳定,比实验室数据高出1.2~1.6倍。因此实际海洋环境下的珊瑚混凝土结构,为了保证结构强度并考虑氯离子扩散的影响,应尽量延长养护时间,有利于提高珊瑚混凝土的服役寿命。

The surface chloride concentration profiles of coral concrete exposed to substitute ocean water were investigated ,and influences of curing age, exposing time and strength grade of coral concrete on free chloride diffusion coefficients of coral concrete were discussed by using the natural diffusion method. Results show that surface chloride concentration profiles of coral concrete decreases with the passage of curing age and strength grade. However, that increases with the passage of exposure time and gradually tends to stabilize ？ The surface chloride concentration profiles of C50 coral concrete is 3.5 times higher of C50 normal concrete in the same conditions. Under the same curing age and exposure time, the surface chloride ion concentration of the south china sea island and reef actual enviroment cubic specimen is 6 0 % -90% higher than the laboratory data. The surface chloride ion concentration of coral in practical engineering concrete structure value is 1.2-1.6 times higher than the laboratory data. Therefore, in terms of concrete structures under the actual marine environment, in order to ensure the structural strength and considering the influence of the surface chloride ion concentration, we should prolong wet curing time and adopt approximately strength grade of coral concrete have such great influence on extending the service life of coral concrete.