暴露和浸泡混凝土氯离子结合能力相关性研究

Correlation Study of Concrete Chloride Ion Binding Capacity between Exposure and Immersion

在盐湖现场暴露和长期浸泡环境下进行了混凝土腐蚀试验,分别测定了不同试验环境下混凝土构件在不同深度的总氯离子含量(Ct)和自由氯离子含量(Cf),运用了回归法分析盐湖卤水浸泡和盐湖现场暴露环境下混凝土氯离子结合能力的相关性系数KR与其扩散深度、混凝土抗压强度的相关性。分析结果表明:氯离子结合能力相关性系数KR随着混凝土抗压强度的增加而降低;对于混凝土抗压强度小于58.6 MPa时,其KR值均大于1.2且随着氯离子扩散深度的增加而增大,当混凝土抗压强度为80.6 MPa时,其KR值仅为0.8且随着氯离子扩散深度的增加而降低。因此,为了更准确的预测盐湖现场环境下的实体结构的寿命,需要利用RE=2.687e-0.0142fc+(0.0111-0.0002fc)xRI将室内环境下的氯离子结合能力换算成现场环境下的氯离子结合能力。

Concrete corrosion test under long term immersion and field exposure environment was done. The total and free chloride ion content of concrete sample was measured at different depth under different environment. With regression method, the concrete chloride binding capacity KR between diffusion depth or concrete compressive strength was analyzed. The results show that Kn （ correlation of concrete chloride binding capacity） decreased with the increasing of concrete compressive strength. The KR are much larger than 1.2 when the concrete compressive strength is less than 58.6 MPa and increased with the increasing of chloride diffusion depths, the value of Ka is just 0.8 when the concrete compressive strength is 80.6 MPa and increased with the increasing of chloride diffusion depths. In order to predict the service life of field concrete structure more accutate, concrete concrete binding binding capacity under immersion condition is converted into capacity under field environment based on the equation RE=2.687e^-0.0142fc＋（0.0111-0.0002fc）x RI.