Investigation of the Gas Breakthrough Properties of Mortar with Different Mixing Proportions of Silica Fume

Gas breakthrough behavior is an important parameter for evaluating the performance of cement-based materials in gas storage projects or radioactive waste disposal facilities. This study conducted gas breakthrough experiments using the step-by-step method on mortar samples to investigate the gas breakthrough properties of mortar. Mortar samples with three different mixing proportions of silica fume contents (0%, 5%, and 10% by weight) were selected for the experiments. The results showed that the incorporation of silica fume in the mortar samples significantly reduced both the intrinsic gas permeability and the water permeability, and increased the gas breakthrough pressure. The gas breakthrough pressures of the mortar samples with silica fume contents of 0%, 5%, and 10% were approximately 1.5, 3.7, and 5.4 MPa, respectively. Theoretical derivation and experiment data fitting indicated that on a double logarithmic scale the gas breakthrough pressure was linearly correlated with the intrinsic gas permeability and the water permeability, respectively.