人工气候环境下锈蚀混凝土梁的结构性能退化研究

Research on Structural Behavior's Deterioration of Corroded Reinforced Concrete Beams Under Man-Made Climate

在影响钢筋混凝土耐久性的众多因素中,钢筋腐蚀引起的混凝土结构过早破坏,已成为其中的一个主要原因.采用加速试验方法能在较短的时间内推测其几十年的性能.通过采用人工气候环境加速锈蚀方法,研究了锈蚀钢筋混凝土梁的承载力、延性及其结构性能退化机理.结果表明钢筋锈蚀特征与恒电流加速锈蚀情况存在很大不同,随着锈蚀率的增大,锈蚀钢筋混凝土梁的承载力和延性降低,裂缝分布越来越稀疏且分布趋于不均匀,但大部分构件的破坏形态仍为正截面破坏,而对应的锈蚀裂缝宽度为0.8 mm的恒电流加速锈蚀梁却发生了黏结撕裂破坏.

Among factors influencing the reinforced concrete＇s durability, structures destroying in an early period arose by rebar corrosion has become a primary factor. The deterioration of structural behavior can be studied using accelerated aging method in a short period. The carrying capacity, ductility and structural behavior＇ s deterioration of corroded reinforced concrete beams were studied by the accelerated corrosion methods under artificial climate. The results show that there are obviously different characteristics and behaviors on corroded bar between the galvanization methods and the accelerated corrosion methods under artificial climate. The bearing capacity and ductility of beams decreased and the cracks distributed more sparsely and non-homogeneous with the increasing of the corrosion rate. The failure modes of most beams were right section failure, while the beams with 0.8 m cracks are bonding tear failure by the galvanization method.