Research On Durability Of Reinforced Concrete Structures Under Load

Nowadays, the durability damage and structure failure of reinforced concrete structures have become an important problem for the open high piles wharf located in marine environment. Although the durability of concrete structures has been studied by more and more researchers and engineers, load is not considered in the most studies. Actually structures always suffer from many forces. The paper made some explore on the durability of reinforced concrete structures with a lot of forces on it. It shows as follows:1. The diversified aspects of the chloride ion's diffusion in the concrete are researched. Combined with the examination, the influence which the load acts on the diffuse modulus of the chloride ion is chiefly analyzed. Also, the time-dependent model of the chloride ion concentration of concrete surface and the empirical formulas on the effect of the loads on the chloride diffusion are proposed. A new chloride diffusion model is developed from the Fick's second law; moreover, the parameters of the model are particularly analyzed.2. Based on the research of the erosion's mechanism and process of the reinforcing steel bar in the concrete, a rebar corrosion-rate model is presented. Also, the method to calculate the cracking time of the concrete covering layer and the time when the maximum apparent damage appears is analyzed and summarized.3. The method of calculating the bearing capacity of the reinforced concrete structure with corroded steel bars is presented. Based on the life-span rule of durability and carrying capacity, combined with the calculation theory of the reliability, the paper also brings up the method of evaluating the durability's life of the concrete construction.4. The system of assessing the life-span of the durability and bearing capability which adopts the computer language FORTRAN is weaved for the open type wharf. According to the example, the system primarily analyzes the capability change of the steel bar and the concrete under the construction of the open type wharf during its life-span.