Flexural performance of RC beam strengthened with highstrength steel wire mesh and polymer mortar overlay
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摘要: 分析了钢绞线网-复合砂浆加固钢筋混凝土梁的荷载-挠度曲线, 研究了加固层与本体梁界面的粘结机理。将钢筋混凝土梁的受力性能分为未裂阶段、裂缝阶段和破坏阶段, 在平截面假定的基础上, 建立了高强钢绞线网-复合砂浆加固梁的截面弯矩-跨中挠度分析模型。采用换算截面法对加固梁在集中荷载作用下的抗弯性能进行全过程受力分析, 并通过10根加固梁的试验数据对模型进行验证。分析结果表明: 截面屈服弯矩和极限弯矩试验值与模型计算值的平均比值分别为1.027、1.094, 屈服跨中挠度和极限跨中挠度试验值与模型计算值的平均比值分别为1.286、0.918, 因此, 截面弯矩-跨中挠度模型可行。Abstract: The load-deflection curves of RC beam strengthened with high-strength steel wire mesh and polymer mortar overlay were analyzed, and the bond mechanism between concrete surface and polymer mortar was studied. The overall flexural behaviour of strengthened beam could be divided into precracking stage, cracking stage and failing stage, and an analysis model of section moment and mid-span deflection for RC beam was developed based on plane assumption. The overall flexural behaviour of strengthened beam subjected to concentrated load was analyzed by using transformed section method, and the model was verified by using the test data of 10 strengthened beams. Analysis result shows that the average ratios between the test values and computation values of yielding moment and ultimate moment of beam section are 1.027 and 1.094 respectively, the average ratios between the test values and computation values of yielding mid-span deflection and ultimate mid-span deflection are 1.286 and 0.918 respectively, so the model is feasible.
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Table 1. Parameters of test specimens
Table 2. Comparison between experimental and predicted moments
Table 3. Comparison between experimental and predicted deflections
Beam Yielding deflection/mm Δyt /Δyp Ultimate deflection/mm Δut /Δup Test value Δyt Predicted value Δyp Test value Δut Predicted value Δup B11 26.5 19.3 1.373 81.7 83.6 0.977 B14 23.0 18.3 1.257 104.6 106.7 0.980 B19 34.0 18.2 1.868 84.1 88.6 0.949 BSC-B1 7.2 6.0 1.200 10.3 11.8 0.873 BSC-B2 8.2 6.1 1.344 15.7 14.9 1.054 BSC-B3 6.3 6.0 1.050 10.0 11.9 0.840 BSC-B4 6.4 5.9 1.085 9.8 11.0 0.891 B10 6.7 5.7 1.175 15.8 16.7 0.947 B12 7.6 5.6 1.357 10.0 12.0 0.833 RCBF-4 9.9 8.6 1.151 117.0 140.3 0.834 -
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