模拟混凝土孔隙液中D-葡萄糖酸钠复合缓蚀剂对钢筋的阻锈作用

Effect of Sodium D-Gluconate-Based Inhibitor in Preventing Corrosion of Reinforcing Steel in Simulated Concrete Pore Solutions

应用电化学技术,结合扫描电子显微镜(SEM)观测,研究D-葡萄糖酸钠、钼酸钠和硫脲三组分复合缓蚀剂对模拟混凝土孔隙液中钢筋腐蚀行为的影响及其阻锈作用.结果表明:在含3.5%(w)NaCl的模拟混凝土孔隙液中,复合缓蚀剂具有协同效应,对钢筋有良好的阻锈作用.当D-葡萄糖酸钠、钼酸钠和硫脲浓度分别为750、250和500mg·L-1时,对钢筋的缓蚀效率可达到94.5%.应用软硬酸碱(HSAB)理论分析缓蚀机理,可认为三组分复合缓蚀剂在钢筋表面共同形成保护膜而阻止钢筋的腐蚀.

The corrosion behavior of reinforcing steel in simulated concrete pore solutions with and without corrosion inhibitors was studied by electrochemical techniques and scanning electron microscopy （SEM）. A combined inhibitive effect of sodium D-gluconate, Na2MoO4 and thiourea on restraining the corrosion of reinforcing steel immersed in the solution was observed. This result showed that there was a synergetic effect among the three agents in corrosion prevention. After adding the compound inhibitor （750 mg·L-1 sodium D-gluconate, 250 mg·L-1 Na2MoO4, 500 mg·L-1 thiourea） into the simulated concrete pore solution containing 3.5% （w） NaCl, the inhibition efficiency of the compound inhibitor was 94.5%. According to the Hard and soft acids and bases （HSAB） theory, the compound inhibitor worked by forming a protective film on the steel surface.