Counterplan for earthquake disaster of concrete structures deteriorated due to reinforcement corrosion and alkali-aggregate reaction

研究了混凝土碳化、氯离子钢筋锈蚀或碱-骨料反应膨胀对混凝土结构抗震性能的影响。得出以下结论：(1)即使对PC梁进行海水淡化，也能获得足够的强度和变形。在反向荷载作用下，钢筋混凝土梁的抗剪强度下降。(3)钢筋混凝土梁的疲劳破坏模式由主筋疲劳断裂向混凝土压碎转变。当碱-骨料反应劣化程度较大时，钢筋混凝土梁的疲劳强度会降低。(4)采用连续纤维布加固劣化钢筋混凝土梁，得到与正常钢筋混凝土梁相同的抗剪加固效果。(5)提出并发展了损伤单元、钢筋与混凝土或钢筋与混凝土之间的粘结单元，并利用这些单元对钢筋混凝土桥墩的损伤、修复或加固进行了有限元分析。

Earthquake resistance of concrete structures deteriorated by carbonation of concrete, reinforcement corrosion due to chloride ion or expansion due to alkali-aggregate reaction was examined. The following results can be drawn.(1) Sufficient strength and deformation were obtained, even when desalination was applied to PC beams. The brittle failure such as the breaking of prestressing bar due to the hydrogen enibrittlement was not observed.(2) Shear strength of concrete decreased, when RC beams deteriorated due to alkali-aggregate reaction were applied to the reverse loading.(3) The pattern of fatigue failure of RC beams deteriorated due to alkali-aggregate reaction changed from fatigue breaking of main reinforcement to crushing of concrete. Fatigue strength of RC beam will decrease, when the deterioration due to alkali-aggregate reaction is large.(4) Same effect of shear reinforcement as the sound RC beam was obtained, when deteriorated RC beams were reinforced by using continuous fiber sheet.(5) The damage elements, bond elements between steel and concrete or reinforcements and concrete were proposed and developed, and RC pier damaged, repaired or strengthened were analyzed by the FEM using these elements.