配置无粘结预应力筋的板柱节点抗冲切性能试验

Test study on punching shear behaviors of unbonded pre-stressed reinforced concrete slab-column connections

通过理论分析和试验研究,阐述了配置无粘结预应力筋的混凝土板的破坏形态和特征,并讨论了预应力钢筋的不同布置方式对节点冲切承载力和变形的影响.结果表明合理配置预应力钢筋的板既能提高冲切承载力,又能改善板柱节点的延性;预应力钢筋的配置位置和有效预应力的大小,对节点的承载能力和变形能力的影响较大,可有效提高承载能力.笔者提出了配置预应力筋的板柱节点构件抗冲切强度公式,计算结果与试验结果符合良好.

The slab-column structure system has a broad future of application with the development of unbonded pre-stressed reinforced concrete technology in civil engineering.However the punching shear performance of the slab-column connection has been changed because of the use of the unbonded pre-stressed reinforcement.The failure mode and property of the connection are developed in the paper by theoretical and test investigation.The punching shear capacity and deformation property of the joint with various unbonded pre-stressed reinforcements are also discussed.The results show that reasonable utilizing of the unbonded pre-stressed reinforcement can increase not only the punching shear ultimate capacity but also deformation of the member;the location and effective pre-stress of the reinforcements have great influence on bearing capacity and deformation of the connection.A new formula of calculating the ultimate punching shear force of the member is put forward,which can be validated by the test results.