Nowadays, the importance of the durability in concrete structures is more than the other factors like the compressive strength. Reinforced concrete structures, which are exposed to harsh environments are expected to last over long periods of time. For that important reason, a durable structure needs to be produced. Especially for reinforced concrete structures, one of the major forms of environmental attack is chloride penetration, which leads to corrosion of the reinforcing steel and a subsequent reduction in the strength, serviceability of the structure. This may lead to early repair or replacement of the structure. The ability of chloride ions to penetrate the concrete must then be known for design and quality control purposes.