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章慶學(xué)  李唐寧         （重慶大學(xué)土木工程學(xué)院 400045）

[提要]  對(duì)4個(gè)雙向設(shè)有預(yù)應(yīng)力筋孔道的框架柱(兩個(gè)未灌漿和兩個(gè)己灌漿，箍筋分別為 ф6.5@100,  ф6.5@75) 和一個(gè)沒有留設(shè)預(yù)應(yīng)力筋孔道的框架柱(箍筋 ф6.5@100)進(jìn)行了軸心受壓狀態(tài)下極限承載能力的對(duì)比試驗(yàn)。試驗(yàn)結(jié)果表明預(yù)應(yīng)力筋孔道面積不超過柱截面面積的25%時(shí)，在軸心受壓狀態(tài)下，雙向留設(shè)的預(yù)應(yīng)力筋孔道在灌漿飽滿后對(duì)框架柱的極限承載能力影響不大。節(jié)點(diǎn)區(qū)箍筋加密到一定程度再提高配箍率，對(duì)框架柱極限承載能力的提高已沒有多大效果。
[關(guān)鍵詞]  預(yù)應(yīng)力混凝土  框架柱  極限承載能力  雙向留設(shè)預(yù)應(yīng)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