A Study on Prediction of Crack Appearance on RC Structure by Corrosion of Reinforcing Bars
By Katsuya Toda, Atsushi Ueno and Kimitaka Uji
Concrete Research and Technology
Vol.21, No.3, Sep 2010 (Issue 54)
- Synopsis:
- The residual life of a concrete structure can be estimated if crack appearance is accurately predicted. In the case, maintenance and life cycle cost can be reduced. However, it is very difficult to predict the residual life before crack appearance because the design sheets, especially for old structures, do not exist. Moreover, it is difficult to get data from the concrete structures by sampling tests on actual structures. In this study, the amount of corrosion when the crack appeared was predicted using electrical accelerated test and FEM analysis. The accuracy of the prediction by both methods was evaluated by comparing it with the actual amount of corrosion. The amount of corrosion measured in the electrical accelerated test was between 26 and 30 mg/cm2 when the area of corrosion on the reinforcing bar was 50%. For the verification of re-deterioration of repaired concrete, also the electrical accelerated test and FEM analysis methods were used. The corrosion mechanisms of repaired concrete were cleared by both the electrical accelerated test and the FEM analysis. In the FEM analysis, the condition, such as cover thickness and tensile strength were input and the residual life was accurately predicted. This prediction method is very useful in the case that the residual life of a reinforced concrete structures is cleared, and data from the FEM simulation can be directly used. With the FEM analysis performed in this paper, the amount of corrosion when the crack appeared and the re-deterioration between the concrete and the repair mortal were predicted.
- Keywords:
- Reinforcing bar, Corrosion, Electrical accelerated test, FEM analysis, Repair
