实验梁尺寸对简支梁内嵌CFRP板条弯曲性能影响  

Size Effect on Flexural Properties of Simple Supported Beam Near-surface Mounted CFRP Laminate

作　　者：王兴国[1] 郑丹丹[1] 朱坤佳[1] 李力[1] 

机构地区：[1]河南理工大学,河南焦作454003

出　　处：《铁道工程学报》2014年第3期72-75,116,共5页Journal of Railway Engineering Society

基　　金：国家自然科学基金青年基金(5110816);河南省教育厅科研计划项目(2008A560004)

摘　　要：研究目的:针对外贴碳纤维增强聚合物(Carbon fiber reinforced polymer,简称CFRP)片材加固混凝土梁易剥离等缺点,本文首先在混凝土梁表层开槽并嵌粘CFRP板条,继而开展单调加载的弯曲性能试验,分析了不同试验梁尺寸(缩尺模型梁尺寸与原型梁尺寸的比值为1/2)对混凝土梁特征荷载、裂缝分布及其间距、钢筋及CFRP板条应变等的影响。研究结论:结果表明:(1)实验梁尺寸对嵌入式加固效果有一定影响,特别是对持续荷载作用下混凝土梁加固后的性能影响更为明显;(2)同荷载下,模型梁的挠度大致为原型梁挠度的1/2,接近几何相似系数;(3)持续荷载作用下的混凝土内嵌CFRP片材加固效果也相对较好,承载力提高幅度均小于无初始荷载作用下的混凝土加固梁,与实验梁几何相似系数无线性关系,且模型梁加固后裂缝间距相对更大,设计时应注意;(4)本研究结果可供桥梁加固研究及应用参考。Research purposes： For the shortcomings of external bonding carbon fiber reinforced polymer （CFRP） laminate reinforced concrete beam, such as easy debonding, in this article first slot in the surface layer concrete beam and stick embedded CFRP strip, and then carry out the flexural properties test of monotonic loading. Effect of different size of RC bridge beams （scale model beam size to prototype beam size ratio is 1/2 ） on typical load, distribution and spacing of cracks, strain of FRP laminate and steel bar is analyzed. Research conclusions：Results show that： （1） Beam size impacts on the embedded strengthening effect, especially on performance of the concrete beam after reinforcement under sustained load. （2） Deflection ratio is close to geometric similarity coefficient for scale model and prototype beams under the same load. （3） Under sustained loading, the concrete embedded CFRP sheets have good reinforcement effect, bearing capacity is improved less than the strengthened beam without initial load, and the improved value is nonlinear relationship with geometric similarity coefficient. Crack spacing of model beam is relatively larger after reinforcement, and it should be paid attention to in design. （4） The results can be references for the bridge reinforcement study and application.

关 键 词：混凝土梁桥 表层嵌入 碳纤维板条 尺寸效应 

分 类 号：TU378.2[建筑科学—结构工程]