| 铝合金/GFRP筋近表面嵌入式增强钢筋混凝土梁抗弯性能试验 |
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| 引用本文： | 苟海刚,邢国华,武名阳,张蓬瑶,常召群,于晓光.铝合金/GFRP筋近表面嵌入式增强钢筋混凝土梁抗弯性能试验[J].中国公路学报,2019,32(8):125. |
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| 作者姓名： | 苟海刚 邢国华 武名阳 张蓬瑶 常召群 于晓光 |
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| 作者单位： | 1. 长安大学 建筑工程学院, 陕西 西安 710061;2. 长安大学 基建处, 陕西 西安 710064 |
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| 基金项目： | 国家自然科学基金项目（51868073）；陕西省重点研发计划项目（2017KJXX-37）；中央高校基本科研业务费专项资金项目（300102288302，300102218510） |
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| 摘 要： | 为研究铝合金/玻璃纤维增强复合材料（GFRP）筋近表面嵌入式加固混凝土梁的抗弯性能，以加固方式、加固筋类型和加固量为变量，设计了5根钢筋混凝土梁试件进行单调静载试验，重点分析了混凝土加固梁的破坏模式和破坏特征。研究结果表明：采用铝合金筋或GFRP筋嵌入式加固后混凝土梁的受弯承载力均显著提高；加固量相同时，GFRP筋加固梁、铝合金/GFRP筋混合加固梁和铝合金筋加固梁的极限荷载比未加固梁分别提高了105.8%、45.7%和17.5%，但混凝土梁采用GFRP筋加固后延性降低、脆性突出，而采用铝合金/GFRP筋混合加固或铝合金加固后混凝土梁的延性则与对比梁相当；GFRP筋嵌入式加固梁和铝合金筋嵌入式加固梁分别发生了混凝土保护层剥落破坏和加固筋屈服后混凝土压溃破坏，而铝合金/GFRP筋混合加固梁则先是GFRP筋与混凝土保护层发生剥离，之后随着作用跨中位移的持续增大，受压区混凝土发生压溃，破坏过程有两重防线。在试验研究基础上，采用截面分析法给出了嵌入式加固梁抗弯强度的理论计算模型与工程实用模型，计算结果表明：加固梁极限弯矩的试验值与理论预测值之比及与实用模型计算值之比的平均值分别为1.081和1.063，方差分别为0.003和0.005，吻合较好。
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| 关 键 词： | 桥梁工程 铝合金 混合加固 混凝土梁 破坏模式 延性 |
| 收稿时间： | 2018-10-14 |
Experiment on the Flexural Behavior of Reinforced Concrete Beams Strengthened with NSM Aluminum Alloy/GFRP Bars |
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| GOU Hai-gang,XING Guo-hua,WU Ming-yang,ZHANG Peng-yao,CHANG Zhao-qun,YU Xiao-guang.Experiment on the Flexural Behavior of Reinforced Concrete Beams Strengthened with NSM Aluminum Alloy/GFRP Bars[J].China Journal of Highway and Transport,2019,32(8):125. |
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| Authors: | GOU Hai-gang XING Guo-hua WU Ming-yang ZHANG Peng-yao CHANG Zhao-qun YU Xiao-guang |
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| Affiliation: | 1. School of Civil Engineering, Chang'an University, Xi'an 710061, Shaanxi, China;2. Infrastructure Projects Office, Chang'an University, Xi'an 710064, Shaanxi, China |
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| Abstract: | To study the flexural behavior of reinforced concrete beams strengthened with near-surface mounted (NSM) aluminum alloy/glass fiber reinforced polymer (GFRP) bars, five concrete beam specimens with several main variables including strengthening manner, NSM reinforcement type, and NSM reinforcement ratio were designed for a monotonic static loading test. This study investigated the failure modes and failure characteristics of strengthened concrete beams. Test results show that reinforced concrete beams strengthened with NSM aluminum alloy or GFRP bars can increase the flexural strength. Compared with the reference beam, under same NSM reinforcement amount, the increases in the ultimate loads of beams strengthened with NSM GFRP, aluminum alloy/GFRP, and aluminum alloy bars are 105.8%, 45.7%, and 17.5%, respectively. The ductility of NSM GFRP bars strengthened beams considerably decreases and brittle failure modes are observed, but the ductility of the beam specimens strengthened with NSM aluminum alloy and/or GFRP bars is equal to that of the reference beam. The specimens strengthened with NSM GFRP and aluminum alloy bars fail by concrete cover separating and concrete crushing after yielding of the tension reinforcement, respectively. However, the beam specimen strengthened with NSM aluminum alloy/GFRP bars initially exhibits debonding between GFRP bars and the concrete cover and is followed by concrete crushing with increasing the mid-span displacement, the process of failure is shown to have two safeguards. Based on the test results, the theoretical calculation model and engineering practical model for the flexural capacity of NSM strengthened beams are presented using the section analysis method. The calculation results show that the predicted values have good agreement with the test results for the ultimate bending moment of NSM strengthened beams, where the mean ratio of experimental results to theoretical predicted values and engineering practical predicted values is 1.081 and 1.063, respectively, with a variance of 0.003 and 0.005. |
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| Keywords: | bridge engineering aluminum alloy hybrid strengthening concrete beam failure mode ductility |
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