章庆学  李唐宁         （重庆大学土木工程学院 400045）

[提要]  对4个双向设有预应力筋孔道的框架柱(两个未灌浆和两个己灌浆，箍筋分别为 ф6.5@100,  ф6.5@75) 和一个没有留设预应力筋孔道的框架柱(箍筋 ф6.5@100)进行了轴心受压状态下极限承载能力的对比试验。试验结果表明预应力筋孔道面积不超过柱截面面积的25%时，在轴心受压状态下，双向留设的预应力筋孔道在灌浆饱满后对框架柱的极限承载能力影响不大。节点区箍筋加密到一定程度再提高配箍率，对框架柱极限承载能力的提高已没有多大效果。
[关键词]  预应力混凝土  框架柱  极限承载能力  双向留设预应力筋孔道

This paper illustrates the experiment on the contrast of the ultimate bearing capacity under the axes-pressure of both four frame columns with two-way placed ducts for tendons or strands( two filled with grout and the others without grout, the two frame columns' hooped reinforcement is  ф6.5@100, and the others' is  ф6.5@75) and one column( ф6.5@100 ) without any ducts. The result shows that it is not serious that the influence of those ducts is put on the ultimate bearing capacity of the weakened section of the frame column,when the total section area of the ducts is not beyond 25 percent of the cross-sectional area of the frame column under axes-pressure. It has little effect on the enhancement of ultimate bearing capacity of frame column that the ratio of the hooped reinforcement in the joint area is increased again after it is up to a certain degree.
Keywords: PPC; frame column; ultimate bearing capacity; two-way ducts; tendons; strands