预应力碳纤维布加固钢筋混凝土梁力学性能试验

Experimental study on mechanical behavior of reinforced concrete beam strengthened with prestressed CFRP sheets

基于预应力碳纤维布加固钢筋混凝土梁能够提高其承载能力的理论,进行了6根外贴预应力碳纤维布(CFRP)加固钢筋混凝土梁的力学性能试验。研究了在不同预应力和不同端部锚固方式下加固后的钢筋混凝土梁的预应力损失、开裂荷载、跨中挠度、极限荷载及抗弯抗剪性能。结果表明:碳纤维布预应力在一定范围内能够决定钢筋混凝土梁的加固效果,同时在梁端部采取锚固方式能有效阻止预应力碳纤维布在放张过程中的预应力损失;预应力碳纤维布加固后梁的开裂荷载随着预应力的增大而增大,最大增大幅度达到81.8%;极限荷载在一定范围内随预应力的增大先增大后减小,极限荷载最大增大幅度为41.07%。

Based on the theory that reinforced concrete beams strengthened with prestressed CFRP sheets can improve its bearing capacity, the mechanical behavior test of six reinforced concrete beams strengthened with prestressed CFRP was performed. The prestress loss, cracking load, mid-span deflection, ultimate load and bending and shear behavior of reinforced concrete beams strengthened under different prestresses and different end anchoring methods were studied. The results show that the prestress of CFRP sheets can determine the strengthening effect of reinforced concrete beams within a certain range. At the same time, anchoring methods at the end of the beam can effectively prevent the prestress loss of the prestressed CFRP sheets during the relaxation process. The cracking load of the beam strengthened with prestressed CFRP sheets increases with the increase of prestress, and the maximum increase is 81.8%. The ultimate load increases and then decreases with the increase of prestress within a certain range, and the maximum increase range of ultimate load is 41.07%.