Effects of Ca(OH)2 on the reinforcement corrosion of sulfoaluminate cement mortar

This study aims to explore the effects of different Ca(OH)2 contents on the mechanical performance and corrosion behaviors of steel in Calcium sulfoaluminate (CSA) cement, where compressive strength, corrosion potentials of reinforcements, corrosion current density, pH of pore solution as well as mortar resistivity of CSA/Ca(OH)2 mortar were researched, and the corrosion behaviors were further interpreted by the clarification of hydration phases through microstructural analyses. The initial results highlighted the positive effects of using adequate Ca(OH)2 (~ 6%) in CSA mortar in terms of strength, yet its excessive addition could delay the subsequent hydration reaction of CSA. Meanwhile, with an increased quantity of Ca(OH)2, the amount of some hydration phases, such as Al(OH)3 reduced, resulting from their reaction with Ca(OH)2. Finally, the corrosion current density increased with the reduced mortar resistivity when the reinforcement in CSA/Ca(OH)2 system was corroded, and their relationship was also provided in this study.