Effect of Sodium β-Glycerolphosphate on Corrosion Resistance of HRBF500 Steel Bar in Simulated Concrete Pore Solution

Abstract

To improve the corrosion resistance of the fine-grained high-strength steel bar (HRBF500 steel bar) and the durability of the corresponding marine concrete structures，sodium β-glycerolphosphate (BG) was added to the simulated concrete pore solution (SCP solution)containing 3.5%NaCl.The effect of BG content on the electrochemical corrosion behavior of HRBF500 steel bar was investigated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS).Mott-Schottky curves were employed to study the semiconductor characteristics of the corrosion product film on the HRBF500 steel bars’surface.Additionally，the corrosion morphology on the surface of steel bar was observed using scanning electron microscopy (SEM)，and it was compared with ordinary carbon plain round steel bar (HPB235).Results showed that BG acted as an anodic corrosion inhibitor，facilitating the passivation of steel reinforcements.With the increase in BG content，the corrosion current density of HRBF500 steel bar initially decreased significantly and then rose slightly.The carrier density of the passivation film reduced，and the impedance value notably increased.The optimal corrosion inhibition effect was observed with 1.0 g/L BG.Without an inhibitor，the corrosion resistance of HPB235 steel bar was superior to that of HRBF500 steel bar.However，the addition of 1.0 g/L BG corrosion inhibitor made their corrosion resistances very similar.By adding an appropriate corrosion inhibitor to concrete environment containing chloride ions，the durability and safety of HRBF500 steel bars could be enhanced，which was advantageous for their application and popularization in engineering.

Keywords

• steel bar|hrbf500|corrosion resistance|sodium β-glycerolphosphate corrosion inhibitor|simulated concrete pore (scp) solution