关键词: 混凝土, 氯离子, 干湿循环, 力学性能, 孔隙结构

Abstract: Concrete used in marine structures is corroded most seriously in tidal splash area caused by frequent dry-wet alternating environment. The influence of Cl^- invasion in seawater and continuous loading on the mechanical properties of the concrete was investigated by applying continuous stress to the dry-wet cycles test samples. By using the micro-CT technology, the influence of Cl^- invasion on concrete structure and uniaxial compressive strength under continuous loading was investigated from the micro-porous level. The results of mechanical property tests show that the continuous loading condition has a positive effect on maintaining the mechanical strength of the concrete, while the uniaxial compressive strength of concrete declines slowly with the increase of dry-wet cycles. Combined with pore size distribution analysis, it can be seen that Cl^- constantly invaded into concrete pores and deposited but has little influence on the mechanical property deterioration of concrete.

Key words: Concrete, Chloride Ions, Dry-Wet Cycles, Mechanical Properties, Porous Structure