碳纤维布加固钢筋混凝土梁受力性能的试验研究  

Experimental research on structural behaviour of RC beams strengthened with CFRP sheets

作　　者：董江峰[1] 王清远[1] 何东[1] 彭泽伟[1] 

机构地区：[1]四川大学,成都610065

出　　处：《应用力学学报》2011年第5期521-526,558,共6页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金(10772125);国家杰出青年基金(10925211)

摘　　要：通过对8根矩形截面钢筋混凝土梁的静力加载试验,研究了抗弯和抗剪两种加固方式对钢筋混凝土梁的破坏形态和力学性能的影响,对比分析了碳纤维加固率、试验梁的状态、混凝土强度对加固效果的影响。结果表明:经碳纤维抗弯和抗剪加固后加固梁相应的力学性能指标值明显提高;混凝土裂缝扩展得到了有效延缓,加固效果明显;抗弯加固后可显著提高混凝土梁的承载力和延性,但提高程度并不与加固率成正比;预裂梁抗弯加固后承载力和延性得到提高,但与其相同加固参数的梁相比,其承载力和延性有所降低;抗剪加固时混凝土强度越高,加固后混凝土梁的承载力和变形能力提高幅度越大,其中混凝土梁的变形能力受混凝土强度的影响较大。最后,对加固梁的极限承载力进行了理论分析与计算,建立了实用的理论计算公式,计算结果与试验结果吻合较好。This paper presents experimental research on eight reinforced concrete(RC) beams with rectangular cross-sections and strengthened by either flexural or shear reinforcing arrangements using carbon fibre reinforced polymer(CFRP) sheets.The structural behaviour and failure modes of the beams strengthened are studied.The main experimental parameters are the amount of CFRP sheets applied,the pre-loading conditions of RC beams and the concrete strength.The results show that the structural performance of RC beams strengthened by either flexural or shear reinforcing arrangements is enhanced greatly and the crack growth on the concrete is restrained effectively by CFRP.The load carrying capacity and the ductility of the RC beams strengthened in bending by externally bonded CFRP are significantly improved,however,the degree of improvement is not proportional to the amount of CFRP applied.The precracked beam gives the higher load carrying capacity and ductility in comparison to the reference beam due to the higher flexural resistance offered by CFRP reinforcement.However,preloading on the beam may result in a decrease in flexural strength and ductility when compare to the beam with the same reinforcing arrangement.The higher load carrying capacity and ductility are obtained for the beam with shear strengthening arrangement and cast by concrete with higher strength.However,the ductility of such the beam is influenced greatly by the concrete strength.In addition,the theoretical calculations of the ultimate strength of RC beams strengthened with CFRP sheets are undertaken.The results show that the theoretical results correlate reasonably well with the experimental data.

关 键 词：钢筋混凝土梁 承载力 力学性能 碳纤维布加固 试验研究 

分 类 号：TU375.1[建筑科学—结构工程]