Title:
Effects of Limestone Powder on Chloride Concentration of Cement Paste (Prepublished)
Author(s):
Xuefang Wang, Wenhui Deng, Qizhi Zhang, Xuxiu Jia, Rong Chen, Ming Wang, Ran Chen, Lincheng Weng, Dehui Wang
Publication:
Materials Journal
Volume:
Issue:
Appears on pages(s):
Keywords:
carboaluminate; chloride concentration; Friedel’s salt; limestone powder; supplement cementitious materials; synergistic effect
DOI:
10.14359/51749271
Date:
10/29/2025
Abstract:
The concentration of chloride ions involves both chemical binding and physical adsorption. This study investigated how limestone powder and supplementary cementitious materials (SCMs) synergistically affect chloride concentration in cement paste, using analyses of corrosion products, pore structure, and chloride concentration coefficient. Cement pastes with 0 to 50% limestone powder and fly ash or slag were tested. Results showed that the synergy between limestone powder and fly ash or slag promoted carboaluminate formation, which completely converted to Friedel’s salt in chloride environments. This enhanced chemical binding and increased physical adsorption of chloride ions, while reducing porosity and the most probable pore diameter. When limestone powder was 5 to 25% with fly ash less than 10%, or both limestone powder and slag were 20 to 30%, the chloride concentration coefficient reached its peak. Thus, proper limestone powder content improves chloride resistance by enhancing both chemical and physical chloride binding.