Investigating icing behavior in cementitious material during freeze-thaw using low-temperature low-field NMR

Low-temperature low-field nuclear magnetic resonance was applied to analyze the icing amount in water saturated white cement paste specimens at different temperatures during the freeze-thaw process. An innovative cylindrical specimen shape eliminated temperature gradients and enabled real-time monitoring of icing. The experimental results were compared with the results obtained using classical theory, showing good agreement from 0 degrees C to -8 degrees C but notable differences from -8 degrees C to -18 degrees C. Therefore, experimental data from specimens saturated with pure water, a 4 % salt solution, and an 8 % salt solution were analyzed to obtain the freezing probability according to pore size classification, and new equations were proposed on this basis to relate the volume of frozen water to temperature during the freezing and thawing of cementitious materials.

Automated summary

Low-temperature low-field nuclear magnetic resonance was used to analyze icing in water saturated white cement paste specimens during the freeze-thaw process at different temperatures. The experimental results were compared with classical theory, showing agreement at certain temperatures but discrepancies at others. New equations were proposed based on the analysis of specimens saturated with different solutions to relate the volume of frozen water to temperature during freezing and thawing of cementitious materials.