تحلیل هزینه سازه ای در چرخه عمر برای تغییرات ظرفیت خمشی تیرهای بتن آرمه در معرض خوردگی میلگرد

Abstract

This paper presents an approach for evaluating structural resistance degenerate due to reinforcement corrosion and for predicting future structural performance during the service life of the deteriorating reinforced concrete beams due to corrosive environments. a finite element method is adopted for envisioning the nonlinear flexural behavior of intact and corroded RC beams based on Ultimate strength design method and Load and resistance factor design method approaching this aim, the impact of corrosion of embedded reinforcing element on the flexural capacity of corroded reinforced concrete structures is estimated. A stochastic degeneration model based on gamma process is utilized to assess the probability of failure of structural flexural capacity over the lifetime. Optimal repair planning and maintenance strategies throughout the service life are circumscribed by evaluating the cost for maintenance and the risk of structural failure. Based on the conclusions from the numerical model including two RC beams subjected to reinforcement corrosion the following results are drawn: The permissible deterioration limits that describe the thresholds of the deterioration for the safety and repair requirement, held major effects on the probability of failure. The results from the worked example show that the proposed method can afford reliable predictions for structural strength deterioration and efficiently implement a risk-cost-benefit optimized repair procedure through the service life of the structure affected by bar corrosion. The lifetime distribution increases 5years for LRFD method and 3.5 years for USTD method while allowable limits enlargement 10%. The lifetime distribution extends 5years for LRFD method and 3.5 years for USTD method while allowable limits increase 10%.