Durability Assessment And Residual Service Life Prediction Of Existing Reinforced Concrete Structures

With the increasing of existing reinforced concrete structures' service life, the aging problem of structures is more and more prominent. How to assess the durability and predict the residual service life of existing reinforced concrete structures has become an urgent problem. This paper bases on background 'The Sixth Research Subject of National Concrete Code Project [GBky6001]' and 'The Research fund of HuaQiao University's high-level Person [BS05303]'. Build on the existing durability study of reinforced concrete structures, the main research of this paper is the durability assessment and durable service life prediction of reinforced concrete structures on the basis of a number of factors. The main content is as follows:Firstly, based on the research of the durability influence due to concrete carbonation, chloride ion ingress and sulfate attack combined with the load-carrying capacity, the paper synthetically studied the correlation of all failure models, and advanced the durable reliability model of reinforced concrete members analyzing by systematic reliability method, which are influenced by a number of factors; then applied this model to the analysis of reinforced concrete structures.Secondly, by taking advantage of all existing identification standard for reliability, this paper gave the assessment standards of all qualitative and quantitative index. Based on analytic hierarchy process (AHP) and attribute recognition theoretical model, this paper set up a synthetically durability assessment model which can assess reinforced concrete members and structures. The result of the model can be the basis of the durability assessment of the existing reinforced concrete members and structure.Thirdly, the durability assessment index was divided into deterioration degree index and deterioration rate index. Based on attribute recognition theoretical model, this paper got the two assessment results of the deterioration degree and deterioration rate, then took deterioration degree which reached 10% as the failure standard. At last, based on the assumption that deterioration varies with time exponentially, the residual service life is yielded.Finally, based on the analysis model of structural dynamic reliability which took account of load-carrying capacity decaying, the cost of building maintain and reinforcement, and economic benefit (including direct and indirect economic benefit), this paper put forward an assessment criterion for remaining service lives of existing concrete structures based on the theory of reliability and economic optimization. And also, an optimum model to predict the remaining lives is provided.In this paper, three durability assessment models of existing concrete structures were found, that were the reliability analysis model of structure durability model...