疲劳荷载作用下植筋梁蠕变性能的量化研究

The quantitative research of rebar-planting beam creep properties under fatigue load

为了研究混凝土植筋构件在疲劳荷载作用下的受力性能,本文对3根植筋深度分别为15d、20d、25d(d为植筋的直径)的混凝土植筋梁进行了静载试验,对2根植筋深度分别为15d、20d的混凝土植筋梁进行了疲劳荷载作用下的受弯试验研究。研究表明:植筋结构涉及3种材料、2个界面,由于粘结界面植筋胶的蠕变特性,更容易引发蠕变损伤对梁体造成的破坏;植筋胶粘结界面的蠕变在前10万次的循环过程中发展最快,在50万次循环之后增长量下降;增加植筋深度,可增加植筋胶、钢筋和混凝土的接触面积,使粘结界面植筋胶的蠕变变小,蠕变损伤变小。结合试验结果,提出了疲劳荷载作用下植筋梁蠕变、植筋深度和循环次数之间的关系式,为植筋梁的破坏分析提供了参考。

In order to research the bending behavior under fatigue loading, three anchorage bar beams were tested with the static load, the anchorage depth were respectively 15d,20d,25d （d was the diameter of steel bar）. Three anchorage bar beams were tested with the fatigue load,the anchorage depth of two beams were respectively 15d,20d. Research shows that rebar-planting structure involves three kinds of materials and 2 interfaces, the creep damage easily leads in the damage of beam because of the creep of planting bar glue on the bonding interface. The creep of planting bar glue on the bonding interface is mainly developed in the first 100 thousand cycles and the growth decline after 500 thousand cyciles. Increasing anchorage depth can improve the contact area of the planting bar glue, steel and concrete, reducing the creep of planting bar glue on the bonding interface, and can effectively reduce creep damage of the rebar-planting beam. The article put forward the relation between the creep of planting bar, anchorage depth and cycles according to the experimental result which provided the reference for the analysis of the destruction of the steel beam.