Gradual intrusion of deleterious liquids, e.g. chloride ions, through capillary pores in reinforced concrete structures accelerates steel corrosion and results in boundless durability issues. For this reason, it is required to measure and characterize pore structure in concrete to guarantee its long-term durability. There are four categories of pore size in concrete, interlaminar pores (1–3 nm), capillary pores (10 nm to 1 µm), micro-pores (1 mm to 10 µm), and air voids (more than 10 µm), of which capillary pores are responsible for moisture ingress in concrete, which is of interest (Mehta and Monteiro 2006).