Carbonation Of Concrete Durability Test. Stress State

Prestressed concrete carbonation is a major factor of steel corrosion in prestressed concrete.How to predict carbonation and service life of prestressed concrete accurately is a important problem to be solved. Combined with the research on fatigue and durability of unbonded prestressed concrete structure supported by the national natural science foundation of china,quantitative analysis on concrete carbonation in stress status was carried out.Through the analysis of test and theory,the predic -tion modle of concrete carbonation in stress status was obtained.Then provide a grounds for sequent work on design and evaluation of PC concrete carbonation.The main contents of this thesis include:1. Taking domestic and overseas correlative development as reference. Based on concrete carbonation test combined with different stress status, experimental research and theoretical analysis were adopted for analysing change relation of concrete carbonation depth in stress status as time changes to obtain the mechanism and law of concrete carbonation in stress status and unstressed status.2. Influence factors of concrete carbonation and carbonation mechan -ism shall be analysed and summarized.The computing mathematical model of concrete carbonation depth in stress would be fitted according to the experimental results and the carbonation coefficient calculation formula would be obtained . Analyz the calculated value from the modle and the data from the experiment to verify the accuracy of the modle.3. Analyzing the prediction formula of concrete carbonation which is in stress states,calculate structure's sevice life in the natural environment and calculate out the reliability of carbonation durability.Then derive the carbonation durability limit-state design method of prestressed structure.