混凝土植筋受冲击后粘结性能试验研究

Experimental research on bonding behavior of concrete bonded rebars after impact loading

进行了混凝土植筋在落锤冲击荷载作用后的粘结锚固性能试验。试件按植筋深度的不同分为4组,每组试件分别进行了静力拉拔试验和5种冲击加载工况试验,冲击荷载峰值为同组试件静力极限拉拔力的0.6-1.5倍,试件在承受冲击力作用后再进行静力拉拔试验。结果表明,植筋深度小于临界锚固长度的试件,承受较大冲击荷载后试件的承载力即完全丧失,承受较小冲击荷载后试件的承载力虽未完全丧失,但延性大幅度降低;对于植筋深度相当于临界锚固长度的试件,承受冲击荷载后试件仍有较大的抗拉拔承载力,但延性降低较大;当植筋深度大于临界锚固长度时,试件在承受冲击荷载后仍有良好的抗拉拔承载力和延性。

After the drop-hammer impact loading,the bonding anchorage behavior test for concrete bonding rebars was conducted. Specimens were divided into four groups according to the embedded depths. The static pullout test and impact loading test for each group were carried out. The peak value of impact load was 0. 6 ~ 1. 5 times as large as the ultimate static pullout force of the specimen in same group. Static pullout test on specimens was conducted after impact loading. The results show that the specimens with the embedded depth less than the critical anchorage length would completely lose the bearing capacity after suffering large impact loading,and the ductility of the specimens reduces significantly,although the impact loading on specimens is not so large and the bearing capacity is not completely lost. For specimens with the embedded depth equivalent to the critical anchorage length,the specimens still have large pullout capacity after bearing impact loading,but the ductility decreases significantly. While the embedded depth is larger than the critical anchorage length,the specimens still have good pullout capacity and ductility after bearing impact loading.