Probability Prediction And Evaluation Method Of Durability Of Reinforced Concrete Highway Bridges And Corresponding Program System

There are millions of bridges in Zhejiang Province, and many of them were built in earlier time. Due to the neglect of the durability of concrete structures in construction periods, serious problems exist now in many reinforced concrete highway bridges which are still in use. Based on the scientific project from Zhejiang Provincial Communication Department named 'Research on the durability evaluation of reinforced concrete highway bridge (2004H44)', which is taken on by Zhejiang University and Highway Administration Bureau of Zhejiang Province, this study conducts the research on the durability evaluation and prediction of reinforced concrete highway bridges and makes a computer application from the results of this research. The method and the technique used here are innovative to a certain extent, and they must be valuable and referencable for engineering practices.The main contents researched in this paper are as follows:On the basis of a large number of data from investigation and the researches conducted by earlier people, this paper puts forward a path probability method and presents a judgement rule about corrosion initiation considering the associated action of chloride contamination and carbonation of concrete, by which the condition of chloride contamination or carbonation of concrete or the combination of both can be considered.A three-level-multi-index evaluating model and an improved weighted mean-based fuzzy evaluation method are proposed here. Attribute index is given in allusion to correlative environment attribute, and an evaluation method is present by the combination of engineering experience and surveyed data, qualitative evaluation and quantitative evaluation, component analysis and structure system analysis.Based on the theory on prediction and evaluation proposed above, an analysis computer application is made and then applied in several typical projects. The interface of the application is friendly, the operation is convenient, and the results are so exact that they are coincident with surveyed data. Therefore, a widely extended value will be shown in the design and maintenance management of concrete bridge structure.