Abstract
For investigating correlations among external and internal cracking of concrete as well as the stirrup damage caused by ASR deterioration, several specimens arranged by main reinforcement and stirrup are exposed under outdoor environment. The detailed observation and evaluation are performed for specimens with severe deterioration degree. As a result, it is noted that cracking in external concrete is perpendicular to surface and stagnate at the depth of stirrup; while, the internal cracking has the trend to generate with various direction and short length due to the constraint from stirrup. Further, it is considered that the stirrup confinement is effective when suffering deterioration without stirrup rupture; however, under the circumstance where stirrup rupture occurs, external cracking has the possibility to extend through the deeper position around the rupture location of stirrup, accompanied by acutely increasing width and differences in level on the surface.
