配箍率对高强钢筋RPC梁抗剪性能影响研究

Study on the influence of stirrup ratio to shear performance of RPC beams with high strength reinforcement

为了研究HRB500级高强钢筋活性粉末混凝土简支梁的抗剪性能,通过改变箍筋配筋率,对4根在集中荷载下的RPC简支梁进行受剪破坏试验,比对分析不同配箍率对试验梁的斜裂缝发展、受剪承载力及最大斜裂缝宽度的影响。试验结果表明:高强箍筋和活性粉末混凝土具有良好的协同工作性能,抗剪延性得到改善;高强钢筋活性粉末混凝土梁的临界斜裂缝一般由腹剪型斜裂缝发展而成;配箍率大小对试验梁的斜向开裂荷载并无明显影响,但是配箍率越高,斜裂缝宽度越小,抗剪承载力越高;桁架-拱理论模型公式比较适用于高强钢筋RPC有腹筋梁抗剪承载力的计算。

In order to study the shear performance of reactive powder concrete simply supported beams with HRB500 level high strength reinforcement,four RPC beams＇shear failure experiment was carried out under con-centrated load by changing the stirrup ratio.The influence of different stirrup ratio on diagonal cracks develop-ment,bearing capacity of the testesd beams,and the maximum diagonal crack width shear are compared and an-alyzed.Test results show that high-strength stirrups and reactive powder concrete can work coordinately,and the shear ductility is improved.Generally,critical diagonal cracks of reactive powder concrete beams with high strength reinforcement are formed by the development of abdominal shear diagonal cracks.Stirrup ratio of the tested beams had no obvious effect on the diagonal cracking load.With the increase of stirrup ratio,the diagonal crack width becomes smaller,and the shear bearing capacity becomes higher.Truss-arch theory model formula is suitable for the shear bearing capacity calculation of high strength reinforced RPC beams with stirrups.