Effect of Internally Propagated Crack in Concrete due to Corrosion of Reinforcing Bar on Behavior of Surface Crack

Abstract

Concrete structure is usually inspected by appearance at the periodical inspection. However, highly skilled engineers are necessary for this preliminary and qualitative inspection. Considering decrease in expert and increase in deteriorated concrete structures, more quantified inspection method is needed to evaluate the performance more accurately and easily. Previous researches have presented the relationship between corrosion mass loss of reinforcing steel bar in concrete and surface crack width. These studies were often conducted by using reinforced concrete specimen which includes single longitudinal rebar. On the other hand, on-site structures include not only longitudinal rebar also transverse rebar which is located with larger cover thickness. For this reason, the accelerated corrosion test using the specimens and inspection at an on-site corroded structure were conducted to evaluate the effect of the transverse rebar and its corrosion on the behavior of surface crack. As a result, it was revealed that internally propagated crack would have a large influence on the surface crack and the index of the surface crack density could bring more accurate evaluation of the corrosion mass loss of rebar than only the crack width.