活性粉末混凝土连梁抗震性能试验研究

Experimental study on seismic behavior of reactive powder concrete coupling beams

连梁是联肢剪力墙重要的组成部分,对结构的抗震性能具有重要影响。文章以活性粉末混凝土(RPC)小跨高比连梁为研究对象,对其进行了拟静力试验,分析了跨高比和配箍率对其受力性能和破坏形态的影响。结果表明:跨高比较小(l/h=0.8)的连梁发生了斜压破坏;随着跨高比增加(0.8<l/h≤1.5),连梁呈现出弯剪破坏特征,且延性稍好于跨高比较小的连梁;随着配箍率在一定范围内的增加,可以更有效地控制连梁的裂缝发育;连梁进入塑性后,滞回曲线无法恢复至原点,存在残余应力;随着连梁跨高比的进一步增大,其刚度退化变慢。

Coupling beams are important elements in reinforced concrete coupled shear walls.They are key components to assure seismic behavior of commonly used structural system in tall buildings.This paper takes the seismic properties of the small span-to-depth ratio beams of reactive powder concrete(RPC),as the object of study.The effects of span/depth and stirrup content on shear failure modes and aseismic capacities of RPC Beams were analyzed.The test results indicate that RPC beams with relatively small span-to-depth ratio(l/h=0.8)are damaged by diagonal compressive failure.Beams,with the increase of the span-to-depth ratio(0.8<l/h≤1.5),are showing a clear bending-shear failure characteristics,and the ductility of beams,with the increase of the span-to-depth ratio,are better than beams with relatively small span-to-depth ratio.With the increase of the stirrup ratio in a certain range,beams can effectively control the development of cracks.The hysteretic curves of beams can not be restored to the original point after beams entered into plasticity stage,and the residual stress exists in beams.With the increase of span-to-depth ratio,the stiffness degradation of beams becomes slower.