Based On The Monte Carlo Method Of Marine Concrete Structure Durability Reliability Analysis

At present, durability of concrete structures under chloride envinronment has become one of the problems widely concerned by the academic and engineer circles in civil engineerying. Due to the ingress of chloride,reinfaocements in concrete corrode,so the durability of structures declines gradually,which will destroy the carrying capacity and shaorten the service life of structures.Therefore,it is a very important task to evaluate the performance of degreded structures under chloride envinronment in order to predict their residual service life. Some problems of durability of reinforced concrete structures under chloride envinronment were studied ,and the main issues and results in this dissertation are as follows:Based on the current research achievement on durability under chloride environment,the relationship between the chloride diffusion coefficient of concreten marine concrete and the type of cement ,the w/c ratio, temperature and humidity of environment,time and so an is established. According to sum up the relationship between various parameters, based on the finite difference method, 1D and 2D diffusion programs for simulating the chloride concentration in concrete were made. The programs can simulate accumulation of chloride ions in the sea concrete of the complex conditions, by comparative and analysis, the calculation results are reasonable and meet the accuracy requirements. Based on the finite difference method for analysis the the chloride concentration of reinforced concrete structures with the service life ,on the basis of application of the Monte Carlo simulation method, the programs for accounting probability of the steelbar depassivation in sea concrete. The procedure can accurately calculate probability of the steelbar depassivation in sea concrete at the arbitrary moment, but also has to consider factors comprehensive, concise and simple interface advantages. Application of the software, a quantitative analysis about the reliability of the steel bars depassivation in marine concrete of different coverr thickness, water-cement ratio, cement mixing materials such as random variables eroded by the sea water So as to the durability of the concrete and durable design provides a simple life prediction methods and means.