Investigation on the Corrosion Behavior of Steel Embedded in Basic Magnesium Sulfate Cement Concrete: An Attempt and Challenges.

Basic magnesium sulfate cement is a type of green high-performance cementitious material. In order to exert its performance advantages and expand its application field, it is urgent to study the problem of steel corrosion in basic magnesium sulfate cement concrete (BMSCC). In this paper, linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS) were used to study the corrosion behavior of steel bars in different strength grades of BMSCC in seawater. Based on the relationship between the corrosion current density and the immersion time, the corresponding time-varying model was obtained. The LPR and EIS results show that the corrosion potential and polarization resistance of steel bars in BMSCC decreased with the immersion time in the seawater environment. The fitting analysis indicated concordance between the corrosion rates with the logarithmic function time-varying model. Furthermore, the cracking time of the protective layer of BMSCC was analyzed based on the cracking time prediction model of Portland cement concrete and the mechanical properties of BMSCC.