EXPERIMENTAL RESERCH ON SHEAR PROPERTIES OF RC BEAMS REINFORCED WITH FRP GRIDS AND EPOXY MORTAR
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摘要: 通过对7根试验梁进行了四点弯曲静力加载试验,研究纤维增强复合材料(FRP)网格-砂浆加固钢筋混凝土梁在其受剪过程中的界面机理和破坏模式,深入分析不同加固参数下此种加固方法的抗剪加固效果以及FRP网格的实际受力行为;并通过收集到的试验数据对五种现有计算模型进行分析对比。研究结果表明:FRP网格加固试件可抑制斜裂缝的发展,大大提高试件的极限承载力和变形能力,加固效果显著;当原混凝土梁的剪切斜裂缝宽度过大或出现剪压破坏时,FRP网格-砂浆与原混凝土梁间易产生不同程度的界面剥离破坏;在一定范围内,FRP网格的抗剪贡献与混凝土强度、剪跨比呈负相关,与FRP网格加固量呈正相关;并且混凝土强度或剪跨比越大,加固层出现界面提前剥离的可能性越高。Abstract: The four-point bending static loading tests of seven test beams were carried out to study the interface mechanism and failure mode of reinforced concrete beams strengthened with FRP grids and epoxy mortar in the shear process. The shear reinforcement effect of this method with different reinforcement parameters and the actual stress behaviors of FRP grids were analyzed. The five calculation models were analyzed and compared based on the collected test data. The results showed that the specimens strengthened with FRP grid could constrain the development of diagonal cracks, delay the formation of main oblique cracks, greatly improve the ultimate bearing capacity and deformation capacity of specimens, and the reinforcement effect was remarkable. When the width of the shear diagonal crack of the original concrete beam was too large or the shear compression failure occured, the interface between the reinforcement layer and the original concrete beam was easy to produce different degrees of peeling failure. In a certain range, the shear contribution of FRP grids was negatively correlated with the concrete strength or shear-span ratio, and positively correlated with the reinforcement amount of FRP grids, and the greater the concrete strength or shear-span ratio, the higher the possibility of interface peeling off in advance.
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Key words:
- FRP grid /
- epoxy mortar /
- reinforced concrete beam /
- shear porperty test
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