Simulated C3A Effects on the Chloride Binding in Portland Cement with NaCl and CaCl2 Cations

C3A contents of Portland cement have significant role in chloride ion binding in chloride-contaminated environments. Cations release due to NaCl and CaCl2 in chloride environments, are the most common and aggressive agents. In this research, various simulated pure C3A made using calcium hydroxide and aluminum hydroxide including 5%, 8%, 10%, and 12%. Moreover, the different concentrations of sodium and calcium cations in NaCl and CaCl2 in the simulated Portland cement paste were added the bonding performances were investigated. X-ray diffraction (XRD) of prepared C3A samples identified for major phases of specimens. Thermo-gravimetry analysis (TGA) was used to quantify the simulated C3A. Standard test methods including ASTM C1152 and ASTM C1218 were utilized to measure the acid-soluble and water-soluble chloride in prepared specimens respectively. The results showed that the amount of acid-soluble and water-soluble chloride for NaCl and CaCl2 cations decreased with an increase of the C3A, which indicates that the better chloride ion binding potential. Moreover, it was concluded that CaCl2 cations have more chloride binding capacity than NaCl. For calcium cations in CaCl2, the increase of C3A is distinguished in water-soluble chloride in comparison with NaCl cations. Then, in areas contaminated with NaCl ions, it is recommendable to use more C3A content in the Portland cement.