Experiments of Chloride Ingression in Loaded Concrete Members under the Marine Environment

This paper presents the results of an experimental investigation on the effect of load on chloride diffusion in concrete members in tidal zone and salt spray zone which were simulated by using a self-designed tidal circulation device and a salt spray chamber. The concrete members were loaded by using self anchoring at both ends. The load conditions were 0, 0.3, and 0.5 times of the member's flexural strength (f(f)). Chloride concentration profiles in concretes were determined after 35, 70, 120, and 180 days of exposure, respectively. Regression analysis of the experimental data was carried out by applying Fick's law of diffusion to determine the diffusion coefficient (D-c) and chloride concentration on the surface (C-s). The results show that chloride diffusion has a big difference between the two zones; diffusion coefficient (D-c) is time dependent and gradually reduces over time; loads have a certain impact on diffusion; and tensile stress promotes chloride diffusion whereas compressive stress inhibits chloride diffusion. Based on the results obtained, analytical expressions of chloride concentration considering loads and time in marine concrete are given. (C) 2014 American Society of Civil Engineers.