后张无粘结PC平板-T形柱节点的试验研究

进行了6个足尺PC（预应力混凝土）平板-T形柱节点试件在竖直荷载作用下的冲切性能试验．其中，5个试件的平板中配有无粘结预应力筋，1个对比试件的平板中配普通钢筋．通过试验阐述了节点试件的破坏特征．结果表明：所有试件都产生弯曲冲切复合破坏特征；当接近极限荷载时，预应力筋的应力有较大幅度的增加，但未达到其极限强度；在保持一定的延性的条件下，平板中的预压应力可提高节点的冲切承载力和刚度．文中还根据试验结果给出了临界截面的形状和节点弯曲破坏的位置，最后采用美国ACI规范和我国规范所推荐的计算公式对上述节点的冲切承载力进行了验算．

Experimental Investigation into Unbonded Post-Tensioned PC Flat Plate-T-Shaped Column Connections

Six full-scale PC(Prestressed Concrete) flat plate-T-shaped column connections,of which five are post-tensioned with unbonded tendons and one is a parallel specimen constructed with normal bonded reinforcing bars,are experimentally tested to reveal their punching shear performances when being subjected to gravity loads.The failure modes of the connections are then investigated.The results show that a combined flexural and punching shear failure occurs for each connection,and that,when the applied load approaches the failure load,the tendon stress greatly increases but does not achieve the ultimate strength.Moreover,the pre-compression stresses in slabs can improve the ultimate strength and stiffness of the connection,with the ductility being fairly kept.The profile of the critical section and the location of the flexural failure are also presented based on the experimental results,and,finally,the experimental ultimate strengths of the six connections are compared with the results obtained according to the provisions in the ACI and the Chinese codes.