| 预应力TRM加固混凝土梁最优预应力计算方法 |
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| 引用本文： | 任伟,黄平明,李晓路,赵煜,刘贺.预应力TRM加固混凝土梁最优预应力计算方法[J].中国公路学报,2022,35(9):311-320. |
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| 作者姓名： | 任伟 黄平明 李晓路 赵煜 刘贺 |
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| 作者单位： | 1. 长安大学 旧桥检测与加固技术交通运输行业重点实验室, 陕西 西安 710064;2. 广东省交通运输规划研究中心, 广东广州 510101;3. 济宁市鸿翔公路勘察设计研究院有限公司, 山东济宁 272000 |
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| 基金项目： | 国家重点研发计划项目(2021YFB1600300);陕西省自然科学基础研究计划项目(2021JM-171) |
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| 摘 要： | 为了扩大纤维织物网增强水泥聚合物砂浆加固技术(TRM)在钢筋混凝土梁加固上的应用范围，深入研究预应力TRM的力学机理，探索纤维预应力的合理取值范围，提高加固设计计算精度。基于预应力TRM加固混凝土梁模型试验与非线性损伤数值试验交互验证，对比分析了原结构和加固结构承载全过程力学机理，在参数影响规律研究的基础上，建立了分析模型，提出了计算方法，得到以下结论：预应力TRM可以有效改善被加固梁截面的受力状态，提高纤维材料强度的利用率；随着纤维预应力的增大，被加固梁承载力存在一个极值点，此极值点对应的纤维预应力即为最优预应力。最优预应力率并非定值，它随纤维加固量的增大而增大，随混凝土强度的增大而减小，初始荷载对其影响可以忽略。以受拉钢筋屈服、受压混凝土压溃、TRM达到设计强度，即3种材料强度均得到发挥，为最优破坏模式，给出的预应力TRM加固混凝土梁正截面承载力的计算方法及其参数优化后的简化计算公式，并进行了精确性验证，可直接应用于设计计算。研究揭示了TRM加固混凝土梁最优预应力的力学机理，提出了可直接应用预应力TRM加固混凝土梁的计算分析方法。
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| 关 键 词： | 桥梁工程 预应力TRM 模型试验 最优破坏准则 最优预应力 计算方法 |
| 收稿时间： | 2021-08-19 |
Calculation Method for Optimal Prestressing of Reinforced Concrete Beams Strengthened with Prestressed TRM |
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| REN Wei,HUANG Ping-ming,LI Xiao-lu,ZHAO Yu,LIU He.Calculation Method for Optimal Prestressing of Reinforced Concrete Beams Strengthened with Prestressed TRM[J].China Journal of Highway and Transport,2022,35(9):311-320. |
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| Authors: | REN Wei HUANG Ping-ming LI Xiao-lu ZHAO Yu LIU He |
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| Affiliation: | 1. Key Laboratory of Transport Industry of Bridge Detection Reinforcement Technology, Chang'an University, Xi'an 710064, Shaanxi, China;2. Guangdong Provincial Transport Planning and Research Center, Guangzhou 510101, Guangdong, China;3. Jining Hongxiang Highway Survey and Design Institute Co. Ltd., Jining 272000, Shandong, China |
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| Abstract: | To broaden the application range of textile-reinforced mortars (TRMs) in reinforced concrete (RC) beams, the mechanism of RC beams strengthened with prestressed TRMs was examined, the reasonable value range of fiber prestress was explored, and the calculation accuracy in reinforcement design was improved in this study. Based on an interactive verification of the model test and nonlinear damage numerical test of RC beams strengthened with prestressed TRMs, the mechanisms of the original structure and the reinforced structure during the entire bearing process were compared. Based on an investigation of the influence of parameters, an analysis model was established and a calculation method was proposed. The following conclusions were drawn: prestressed TRMs can effectively improve the stress state of the reinforced beam section and the utilization rate of fiber material strength. With increasing fiber prestress, the bearing capacity of the reinforced beam can reach an extreme point, corresponding to the optimal prestress. The optimal prestress ratio is not constant, it increases with increasing fiber reinforcement and decreases with increasing concrete strength, and the effect of an initial load can be ignored. The optimal failure mode is that the strength of the three materials are utilized, that is, the tensile reinforcement yield, concrete crushing in a compression zone, and TRM fracture. The calculation method and simplified calculation formula for the normal section bearing capacity of RC beams strengthened by prestressed TRMs are determined after parameter optimization, and the accuracy is verified, demonstrating that the model can be directly applied for design and calculation. This paper presents the optimal prestress of RC beams strengthened with prestressed TRMs, and the proposed calculation and analysis methods, which can be directly utilized for the design of RC beams strengthened with prestressed TRMs. |
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| Keywords: | bridge engineering prestressed TRM model test optimal failure criterion optimal prestress calculation method |
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