Effect of sodium D-gluconate-Based inhibitor in Preventing corrosion of reinforcing steel in simulated concrete pore solutions

Abstract

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, Na 2MoO 4 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 Na 2MoO 4, 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. © Editorial office of Acta Physico-Chimica Sinica.