Shota ANDO

Reconstruction and prospect of performance checking technology for concrete structures

Takumi SHIMOMURA

In this study, in order to realize a more rational performance checking system, considering the development of the current performance checking technology, the advantages of using advanced technologies such as 3D FEM analysis and flying salt simulation and the future technical issues were examined.
The benefits of setting the limit state to a more degraded state were quantitatively examined using the service life up to the limit state as an index. Calculations were performed using the existing salt damage deterioration models for RC sections with W / C = 0.45, c = 50mm, b = 100mm, d = 150mm, and As = 198.6mm2. The decrease in bending strength was calculated by calculation in accordance with the bending theory taking into account the reduction in cross section. As a result of the trial calculation, the service life up to "corrosion" was 62 years, "corrosion cracking" was 88 years, and "proof stress decreased by 20%" was 129 years. From these results, it was confirmed that the service life increased by setting the limit state to a more deteriorated state.
Next, the advantages of predicting corrosion distribution in beam members and structures were discussed. A beam specimen with local corrosion was prepared and a loading test was performed. As a result, the corrosion that occurred at the position where the sectional force was small did not affect the proof stress.
In addition, structural specimens with different ratios and arrangements of deteriorated members were fabricated and loaded tests were performed. As a result, it was confirmed that the load-bearing mechanism of the structure differs depending on the arrangement of the deteriorated members in the structure, and that the structural performance such as proof strength and bending stiffness differs.
It was considered that structural performance can be appropriately evaluated by predicting corrosion distribution in members and structures.