Durability Assessment of Expansive and Nonexpansive Calcium Sulfoaluminate Belite Cement Concrete in Chloride-Rich Environments

AbstractCalcium sulfoaluminate belite (CSAB) cement has gained prominence as a viable environmentally friendly substitute for conventional portland cement (PC). The current study investigates the relative performance of expansive and nonexpansive CSAB cement-based concretes, and PC-based concretes when subjected to chloride-rich conditions. Multiple testing methodologies, including surface resistivity measurements, chloride migration, rapid chloride penetration, long-term bulk diffusion, and water sorptivity, were employed to assess the durability of these concrete systems. Surface resistivity measurements indicated that CSAB systems exhibited significantly higher resistivity when compared with PC-based counterparts. Increased resistivity in CSAB systems was influenced by the conductivity of the pore solution, emphasizing that the formation factor provides a more accurate representation of the pore structure within the system. The expansive and nonexpansive CSAB cement–based concrete outperformed PC-based concrete in migration-based tests and rapid chloride penetration test (RCPT). In contrast, the CSAB and PC systems demonstrated similar performance in the long-term bulk diffusion-based test. Although CSAB systems exhibit finer pore structures than PC-based counterparts, their performance in chloride-rich environments is affected by their reduced binding capacity. The study emphasizes that the conclusions drawn from accelerated tests and resistivity measurements of CSAB cement–based concrete must be cautiously interpreted because these results may not indicate real-world performance.