Electrochemical behavior of steel bars in magnesium phosphate cement

TY - JOUR

T1 - Electrochemical behavior of steel bars in magnesium phosphate cement

AU - Tang, Hao

AU - Qian, Jueshi

AU - Qin, Jihui

AU - Li, Zhen

AU - Jia, Xingwen

AU - Yue, Yanfei

AU - Dai, Fumin

N1 - © 2023 Elsevier Ltd. All rights reserved.

PY - 2023/7

Y1 - 2023/7

N2 - The electrochemical characteristics of steel bars in magnesium phosphate cement (MPC) are crucial when applying MPC to reinforced concrete. In this study, the electrochemical behaviors of steel bars in MPC were investigated via electrochemical tests combined with surface analyses. The results indicated that the steel bars in the simulated MPC pore solution could effectively passivate, forming films that mainly consisted of FePO4. In the MPC matrices, the continuous precipitation of phosphates led to the accumulation of passive films, which were responsible for the superior corrosion protection of MPC compared to traditional cement materials. MPC exhibited a self-healing corrosion feature after the depassivation of steel bars, which could be characterized by the dramatic recovery of passive film resistance and charge transfer resistance. Furthermore, the corroded steel bars in MPC with a low magnesia-to-phosphate ratio could re-passivate and stabilize for long periods of time.

AB - The electrochemical characteristics of steel bars in magnesium phosphate cement (MPC) are crucial when applying MPC to reinforced concrete. In this study, the electrochemical behaviors of steel bars in MPC were investigated via electrochemical tests combined with surface analyses. The results indicated that the steel bars in the simulated MPC pore solution could effectively passivate, forming films that mainly consisted of FePO4. In the MPC matrices, the continuous precipitation of phosphates led to the accumulation of passive films, which were responsible for the superior corrosion protection of MPC compared to traditional cement materials. MPC exhibited a self-healing corrosion feature after the depassivation of steel bars, which could be characterized by the dramatic recovery of passive film resistance and charge transfer resistance. Furthermore, the corroded steel bars in MPC with a low magnesia-to-phosphate ratio could re-passivate and stabilize for long periods of time.

KW - Magnesium phosphate cement (MPC)

KW - Steel bars

KW - Electrochemical impedance spectroscopy (EIS)

KW - Passivation

KW - Self-healing corrosion

U2 - 10.1016/j.cemconres.2023.107167

DO - 10.1016/j.cemconres.2023.107167

M3 - Article

SN - 0008-8846

VL - 169

JO - Cement and Concrete Research

JF - Cement and Concrete Research

M1 - 107167

ER -