Predicting the deterioration of concrete durability in various environments

The maintenance in infrastructure has been improving. Many concrete structures play important roles. It is important that such structures are maintained and managed rationally to ensure use of limited resources and finance. However, systematic management and maintenance requires accurate predictions of performance changes of structures and members. The purpose of this study is to examine a modeling method for predicting the deterioration of concrete structures and members using a nonlinear exponential function model with our database which has accumulated change-in-time data of RC model specimen. The following conclusions can be drawn from this study :1) The deterioration prediction equation, which is an exponent function with three population parameters, is able to express nonlinear changes with age by a curve which has form with a peak. The equation is fitted well as the characteristics of strength increases with age at an early stage and decreases at a late stage.2) The three population parameters of the nonlinear exponential function are made up with the population parameters which are expressed as an intercept of an deterioration indicator (coefficient B), an internal factor based on water-cement ratio, type of cement, etc.(coefficient A) and an external factor depending on exposure conditions and so on (coefficient C)