...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Composites for Construction >Repair Effects and Acoustic Emission Technique-Based Fracture Evaluation for Predamaged Concrete Columns Confined with Fiber-Reinforced Polymers
【24h】

Repair Effects and Acoustic Emission Technique-Based Fracture Evaluation for Predamaged Concrete Columns Confined with Fiber-Reinforced Polymers

机译：纤维增强聚合物约束的预损伤混凝土柱的修复效果和基于声发射技术的断裂评估

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

During the last two decades, the use of fiber-reinforced polymer (FRP) in the retrofitting of concrete structures has been widely studied. However, there is limited research on the effect of initial concrete damage on the retrofitting effect of FRP on concrete columns, especially when the initial damage is severe. For FRP-confined concrete columns, the fracture process inside the concrete is covered by FRP and is not visible to inspectors during the service period. This paper investigates these problems through an experimental study of 28 100 x 100 x 300 mm concrete columns using axial compression tests and acoustic emission (AE) fracture monitoring. Prior to FRP wrapping, three different damage levels were assigned to the concrete columns. The stress-strain results showed that the predamage levels had a small effect on the ultimate strength of the FRP-confined predamaged concrete columns, even when the predamage was severe, whereas the axial/lateral strains were more affected by the predamage levels. AE parameter analysis showed that at the early loading stage, AE signals generated from FRP-confined predamaged concrete columns contained less energy than those from the FRP-confined intact concrete columns. The fracture processes of unconfined and FRP-confined concrete columns were also studied through concrete failure modes, b-value and improved b-value (Ib-value) analyses, and fractal analysis. The following conclusions were drawn from the analyses: (1) during compression of the FRP-confined concrete columns, the concrete failure modes shifted from cracking type to cracking-crushing mixed type; (2) the fracture process of the confined concrete columns could be divided into three stages, which are different from those for unconfined concrete columns and reinforced concrete beams; (3) the fractal dimension of the crack network had a relationship with the b-value and decreased from a value between 3 and 2 to a final value of 2 during the fracture process for unconfined and FRP-confined concrete columns.
机译：在过去的二十年中，对纤维增强聚合物（FRP）在混凝土结构翻新中的用途进行了广泛的研究。但是，关于初始混凝土破坏对FRP加固混凝土柱的影响的研究有限，特别是在初始破坏严重的情况下。对于FRP约束的混凝土柱，混凝土内部的断裂过程由FRP覆盖，并且在服务期内检查人员看不到。本文通过对28 100 x 100 x 300 mm混凝土柱进行轴向压缩试验和声发射（AE）断裂监测的实验研究来研究这些问题。在FRP包裹之前，对混凝土柱分配了三个不同的损坏级别。应力应变结果表明，即使预应力严重，预损伤水平对FRP约束的预损伤混凝土柱的极限强度影响很小，而轴向/横向应变受预损伤水平的影响更大。声发射参数分析表明，在加载的早期阶段，由FRP约束的预损坏混凝土柱产生的AE信号所包含的能量要比FRP约束的完整混凝土柱所产生的能量要少。还通过混凝土破坏模式，b值和改进的b值（Ib值）分析以及分形分析，研究了无约束和FRP约束混凝土柱的断裂过程。分析得出以下结论：（1）在FRP约束混凝土柱受压过程中，混凝土破坏模式由开裂型转变为开裂-混合型。 （2）承压混凝土柱的断裂过程可分为三个阶段，与非承压混凝土柱和钢筋混凝土梁的断裂过程不同。 （3）裂缝网络的分形维数与b值有关系，并且在无限制和FRP限制混凝土柱的断裂过程中，裂缝网络的分形维数从3到2减小到最终值2。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号