Studies were conducted using varying proportions of granite powder in canal lining concrete to determine the effect on compression resistance, impermeability and freeze–thaw cycling. The concrete microstructure was assessed using mercury intrusion porosimetry, scanning electron microscopy, and other methods. The data indicate the appearance of pore throats and demonstrate that a granite content of 10%–20% reduces the concrete strength, frost resistance, and impermeability based on changes at the microscopic level. An equation describing the relationship between the granite powder content and pore structure parameters (porosity, 20‐ to 200‐nm pore volume, and fractal dimension) was established.