In cement and concrete, pore size distribution is a critical factor that influences the material’s permeability, strength, and durability. Pores in concrete can range from nanometers to millimeters and are created during the mixing, setting, and curing phases. The distribution of these pores affects how the material interacts with environmental conditions such as moisture, chemicals, and mechanical stress. Smaller pores can hinder the movement of water and ions, enhancing durability and reducing permeability, while larger pores tend to decrease the mechanical strength and durability by allowing more aggressive agents to penetrate the material.