碳纤维布加固二次受力下剪弯段开双孔RC梁受力性能

Mechanical properties of RC beams with double holes on shear-bending region reinforced by CFRP under second-loading systems

基于剪弯段开双孔RC梁受力的特点,考虑不同的初始荷载,对碳纤维布(CFRP)加固二次受力条件下剪弯段开双孔梁的受力性能进行了试验研究。研究结果表明,未加固开孔梁的承载力随初始荷载的增大而降低,破坏时梁的底部钢筋没有发生屈服,呈剪压破坏状态;与未开孔RC梁相比,二次受力下各开孔梁的承载力随着初始荷载的增大有明显下降的趋势,当初始荷载分别为未开孔梁极限承载力设计值的20%,40%和60%时,其极限承载力分别降低了26.1%、30.9%和35.5%。初始荷载不超过未开孔梁极限承载力设计值的40%时,开孔梁碳纤维布加固后的极限承载力与未开孔梁相比下降幅度不超过8%,加固效果明显;初始荷载低于未开孔梁极限承载力设计值的60%时,开孔加固梁的底部钢筋屈服,与未开孔梁一样呈受弯破坏形态。

It had focused on the mechanical properties of beams with double holes under second- loading systems,which were reinforced with CFRP on shear- bending region,and considering the different initial load.The result indicates that with the increase of the initial load the bearing capacity of the beams with double holes and no reinforced is lower,and the bottom steel of beams does not yield,but cut bending damage happened.Compared with RC beam with no opening,with the increase of the initial load the bearing capacity of the beams with double holes under second- loading systems declines significantly.When the initial load was 20%、40%、60%of the ultimate bearing capacity of beams with no hole,its ultimate bearing capacity decreased by 26.1%,30.9%,35.5%.When the initial load is not over 40%of the ultimate bearing capacity of beams with no hole the ultimate bearing capacity of beams with double holes reinforced with CFRP does not decline over 8 percent compared with beam with no opening.The reinforcing effect is obvious.When initial load is less than 60%of the ultimate bearing capacity of beams with no hole the bottom steel of beams with holes and reinforced yields,and is in the bending failure status which is the same as the beam with no hole.