用丝束电极模拟研究混凝土中钢筋的锈蚀

用丝束电极模拟混凝土中钢筋表面的不同位置，研究了浸于pH=12，浓度为10％的NaCl溶液中直至9d的混凝土中钢筋的锈蚀状况．通过测量丝束电极的自然腐蚀电位、极化电阻、腐蚀电流，以及在丝束电极探头附近混凝土的密实性、孔溶液的pH值和Cl^-含量的取样分析，研究了由于混凝土的不均匀性造成Cl^-在其中扩散的不均匀性所致的钢筋锈蚀状况．结果表明：混凝土保护层越厚，则电极自然腐蚀电位越高，钢筋实际锈蚀状况也越轻；在混凝土密实性较高区域的孔溶液PH值相对较高，Cl^-含量较低，由于该区域电极的自然腐蚀电位较高，因而电极的实际腐蚀状况较轻，而在混凝土密实性较低的区域，情况则刚好相反．

Simulating Research on the Corrosion of Steel Bar in Concrete by Wire-Beam Electrode

The corrosion conditions of rebar embedded in the concrete which was immersed in 10% sodium chloride solution(pH=12) for 9 d was studied by using the wire-beam electrode.Through measuring the natural corrosion potential,polarization resistance and polarization electric current,and analyzing the compactness of the concrete near the wire-beam electrode,the pH value of solution and the content of chloride ion,the corrosion conditions of reinforcing steel bar which was caused by heterogeneity in diffusion of chloride ion due to heterogeneity of the concrete was studied.The result shows that the thicker the protective layer of the concrete,the higher the natural corrosion potential of wire-beam electrode,which could alleviate the corrosion of the rebar.It is also found that the pH value is relatively higher and that the content of chloride ion is lower in dense areas of the concrete where the natural corrosion potential is higher,therefore the corrosion of reinforcing steel bar in this area is rather slight.While the other areas where the concrete is not dense,the things are opposite.