Corrosion of re-bars is the main cause of performance reduction of seashore concrete structures. Many methods have been developed to predict concrete durability associated with corrosion of re-bars. Two tests are widely used in practice, namely immersion test and electrical test. There are several disadvantages of these tests. In immersion test, a lot of time is consumed and drilling of specimens is required to gather concrete powder. In electrical field test, expensive equipments are needed and the test procedure is complicated. In this paper, a new test method is proposed to overcome these disadvantages.
When a concrete specimen is immersed in the chloride containing solution, chloride concentration in the solution is decreased as time passes. The chloride concentration decrease depends on the diffusion of chloride in concrete specimen. Also we obtained an analytical solution which represents the chloride concentration change with time. We have developed a new method to estimate diffusion coefficient of chloride in concrete specimens by monitoring the chloride concentration in the immersing solution and the analytical solution. This approach makes it possible to get the diffusion coefficient of chloride in concrete specimen within couple days.