临海滩涂环境下混凝土中氯离子侵蚀破坏试验研究

混凝土的材料组成、工作环境等因素对其耐久性有很大的影响。通过对不同配合比、不同保护层厚度长期暴露于临海滩涂环境的钢筋混凝土试件表面裂缝规律、钢筋锈蚀程度、力学性能等方面的试验研究,表明:直接暴露于临海环境中的钢筋锈蚀最为严重;钢筋锈蚀越明显,其强度下降趋势越显著,锈蚀率越大,延性越低;混凝土保护层的厚度、裂缝宽度跟钢筋锈蚀之间是相互影响的,保护层厚度越小,裂缝宽度越大,钢筋锈蚀率越高,当裂缝宽度为小于或等于0.2mm的细微裂缝时,钢筋锈蚀率≤2%,当裂缝宽度0.5 mm时,钢筋锈蚀率与裂缝之间可能存在线性正向关系。

Experimental Study on Erosion Damage of Chloride Ion in Concrete under the Coastal Beach Environment

The factors of concrete such as the material composition and working environment have great influence on the durability of concrete. Based on the experimental study on the surface crack law, the corrosion degree and the mechanical properties of the reinforced concrete specimen exposed to the different mix proportions, the thickness of the different protective layers and the long-term exposure to the coastal beach, the results show that directly exposed to the coastal environment, the corrosion of rebar is the most serious. The more obvious the corrosion of steel bar, the more obvious the trend of its strength decrease. The greater the corrosion rate, the lower the ductility. The thickness of concrete protective layer, the width of crack and the corrosion of rebar are mutual influence. The smaller the thickness of the protective layer, the greater the crack width, the higher the corrosion rate of the rebar will be. Specifically, when the crack width is less than or equal to 0. 2 mm of fine cracks, the corrosion rate of rebar is less than or equal to 2%. When the crack width is more than 0. 5mm, there may be a linear positive relationship between the corrosion rate of rebar and the crack.