电场作用下早龄期混凝土内部离子的电迁特征试验研究

Experimental study on electrical characteristics of ions in concrete at early age under electric field

海洋环境下氯离子侵蚀、含氯盐建筑材料的使用或者浇筑时添加了含有氯盐的外加剂等工况下钢筋混凝土结构在早龄期便受到氯盐的腐蚀。早龄期的钢筋混凝土由于处于水化过程中,孔隙结构相对发达,离子迁移过程内部阻力小,因此在早龄期进行电迁除氯是一种有效的除氯措施。开展了基于电化学的早龄期除氯试验,针对电迁除氯后混凝土试件内部孔隙结构特征、化学元素分布特征、氯离子分布特征等三个方面,分别采用电子显微镜(SEM)、X射线荧光光谱仪(XRF)、快速氯离子含量检测仪(RCT)获取相应数据。结果表明:混凝土早龄期进行适当强度的电迁除氯处理可有效排除混凝土内部有害离子,同时钢筋周围区域的水化产物较其他区域丰富,孔隙结构得到改善。

Chloride penetration in marine environment,the use of building materials with chlorine salt,or the add of admixture contains chlorine salt.In these three kinds of conditions,the reinforced concrete structure will be corroded by chloride salt in the early age.In the process of hydration,the pore structure is relatively developed and the resistance of internal ions to transfer is weak.So it′s an effective way to remove chlorine of reinforced concrete structures in the early age.Through the method based on electrochemical dechlorination in early age.In the light of the three aspects as the internal pore structure,the distribution characteristics of chemical elements and the distribution of chloride ions after the electrochemical chloride extraction（ECE）,individually use electron microscope（SEM）,X ray fluorescence spectrometer（XRF） and fast chlorine ion content detector（RCT） to obtain the corresponding data.It shows that,in early-age a concrete-strength electrochemical chloride extraction treatment can effectively exhausts harmful ions,as the same time,the hydration products in the area around the steel bar are more abundant than those in other regions that improves the internal pore structure.