Structural performance, reliability and service life prediction of concrete beams subject to pitting corrosion

摘要

Corrosion of reinforcing steel due to chloride attack is one of the major causes of deterioration ofconcrete structures.This paper describes the development of probabilistic models to predict the spatial distributionof maximum depths of pitting corrosion for reinforcing bars and prestressing strands.The pitting corrosion modelwas developed using accelerated corrosion tests in a chloride-concrete environment. The model is then combinedwith appropriate failure criteria to calculate the reduced strength of prestressing strands under pitting corrosionattack. The models are applied to reinforced and prestressed concrete beams in flexure. The influence of pittingcorrosion on structural strength, mean time to failure and structural reliability can then be estimated. It wasalso found that significant increases in 50-year probabilities of failure were observed if spatial variability ofpitting corrosion are included in the analysis. This allows for a more realistic representation of service lifeprediction.