预应力钢带加固钢筋混凝土梁抗剪性能试验研究

Experimental Study on Shear Performance of Reinforced Concrete Beams Strengthened with Prestressed Steel Strips

制作截面尺寸不同的3根未加固钢筋混凝土梁和3根预应力钢带加固钢筋混凝土梁,通过试验研究梁破坏形态、开裂荷载、抗剪承载力等。研究结果表明,随着荷载的增加,各试件最终均发生剪切破坏,破坏过程可分为初裂、裂缝发展、压溃破坏阶段;加固梁截面尺寸越小,钢带应变发展越快,对构件的约束作用越强;预应力钢带对加固梁弯曲开裂荷载的影响较小,但可提高8.89%~13.51%的斜裂缝开裂荷载,提高6.27%~7.50%的极限抗剪承载力。

Three unstrengthened reinforced concrete beams with different cross-sectional dimensions and three reinforced concrete beams strengthened with prestressed steel strips were fabricated.The failure modes,cracking loads,and shear bearing capacity of the beams were studied through experiments.The research results show that with the increase of the load,the shear failure of each specimen finally occurs,and the failure process can be divided into the stages of initial cracking,crack development and crushing failure.The smaller the section size of the strengthened beams,the faster the strain development of the steel strips,and the stronger the restraint effect on the components.The prestressed steel strip has little effect on the flexural cracking load of the strengthened beam,but it can increase the cracking load of diagonal cracks by 8.89%~13.51%,and increase the ultimate shear bearing capacity by 6.27%~7.50%.