Chloride removal of calcium aluminate cements: Reaction and physicochemical characteristics

Abstract

The chloride removal characteristics of calcium aluminate cements in chlorinated solution were investigated in the present study. Furthermore, the reaction and the physicochemical characteristics of chloride-bearing calcium aluminate cement powders in the solutions were systematically investigated via leaching of reactive components from cement powders, X-ray diffraction, and BET tests. The independent variable is the content of Al2O3 in the cement powders. The test results showed that the chloride removal rate of calcium aluminate cements increased as the content of Al2O3 increased. The reaction route for the removal of chlorides was via the transformation of C2AH8 into hydrocalumite phases, which lead to an increase in the specific surface areas and mesopores volume in calcium aluminate cements. The obtained results provide information on the reaction and physicochemical characteristics to utilize calcium aluminate cements for chloride removal in a cementitious matrix.

Keywords

• Chloride removal
• Calcium aluminate cement
• Layered double hydroxide
• Hydrocalumite
• Physicochemical characteristics