Freeze-thaw resistance performance of alkaline residue-blast slag based low carbon binder material: Supplementary study

Abstract

The freeze–thaw resistance performance of mortar is crucial for its engineering applications. This study provides supplementary research on the freeze–thaw resistance of AR-CCS activated GGBS-FA cementitious system. Cyclic freeze–thaw experiments were conducted considering factors such as mix proportion as well as curing methods. The results show that after 50 rapid freeze–thaw cycles, the strength loss and mass loss of this system fluctuated between approximately 16–24% and 2.0–4.5%, respectively. Microscopic analysis indicates that excessively high temperatures and curing time can lead to temperature-cracks, deteriorating its freeze–thaw resistance. The addition of FA will decrease the system's strength and degrade pore structure, resulting in decreased freeze–thaw resistance. However, FA promotes the formation of tobermorite and C-A-S-H in the system, reducing the sensitivity of strength loss to temperature. Through statistical analysis, established a predictive equation for freeze–thaw resistance based on compressive strength and Cl-electric flux, with a strong correlation, having R2 ranging from 0.989 to 0.994. Overall, while this cementitious system may have slightly lower freeze–thaw resistance compared to traditional Portland cement with similar strength, but still meets engineering application requirements. It shows a significant engineering application potential in products without steel reinforcement like pavement bricks.