Acoustic emission activities and damage evaluation of reinforced concrete beams strengthened with CFRP sheets
Acoustic emission activities and damage evaluation of reinforced concrete beams strengthened with CFRP sheets
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DOI：
10.1016/j.ndteint.2010.06.006
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发表时间：
2010-10-01
影响因子：
4.2
通讯作者：
Seo, Soo-Yeon
中科院分区：
文献类型：
--
作者：
Yun, Hyun-Do;Choi, Won-Chang;Seo, Soo-Yeon
研究了声发射（AE）技术监测碳纤维增强聚合物（CFRP）布加固钢筋混凝土（RC）梁弯曲损伤演变的适用性。我们的目标是开始创建一个用户友好的健康监测系统的钢筋混凝土结构与碳纤维布加固使用AE技术。五个梁，200 mm x 300 mm的横截面，进行了测试，在三点弯曲超过1700 mm的跨度。其中一个梁进行了测试，在其原始状态作为参考，其余四个梁进行测试后，被加强与CFRP板粘结在张力面。在这项研究中调查的参数包括的量的CFRP片材和施工缺陷（CFRP片材是故意粘接没有粘合剂在最中心的10%和20%的粘接面积）。收集并分析所有标本的AE信号。根据初始裂纹、扩展、主筋屈服和CFRP板断裂或撕裂四个损伤级别，分析了声发射参数。利用声发射参数的频率-峰值分布确定了由古登堡-里希特关系定义的b值，用于评价CFRP布加固RC梁的损伤演化和断裂过程。从这项研究的结果，信号特性-事件，振幅与频率，振幅与持续时间-显示出明显的差异，在不同的加载阶段，这取决于主动损伤机制。b值与粘贴碳纤维布的钢筋混凝土梁的断裂过程和损伤局部化程度有关。声发射技术是一种有用的无损检测技术，用于监测钢筋混凝土梁的行为，外部加固在弯曲与碳纤维布。(C)2010爱思唯尔有限公司版权所有。
In this study, the applicability of acoustic emission (AE) techniques to monitor damage evolution in reinforced concrete (RC) beams strengthened in flexure with carbon fiber reinforced polymer (CFRP) sheets is investigated. The objective is to initiate the creation of a user-friendly health monitoring system for RC structures strengthened with CFRP sheets using AE techniques. Five beams, 200 mm x 300 mm in cross-section, were tested under three-point bending over a span of 1700 mm. One of the beams was tested in its virgin condition to serve as reference; the remaining four beams were tested after being strengthened with CFRP sheets bonded on the tension face. The parameters investigated in this study include both the amount of CFRP sheets and construction imperfections (the CFRP sheets were intentionally bonded without adhesive in the centermost 10% and 20% bonding area). The AE signals were collected and analyzed for all specimens. The AE parameters were analyzed for four levels of damage based on initial crack, propagation, yielding of main bars, and fracture or rip-off of the CFRP sheets. The frequency-peak magnitude distribution of the AE parameters was used to determine the b-value, defined by the Gutenberg-Richter relationship, for evaluating the damage evolution and fracture process of RC beams strengthened in flexure with CFRP sheets. From the results of this study, the signal characteristics - event, amplitude versus frequency, and amplitude versus duration - show clear differences in the different loading stages, depending upon the active damage mechanism. The b-value is correlated to the fracture process of the RC beams bonded with CFRP sheets and the degree of localization of damage. The AE technique is a useful nondestructive technique for monitoring the behavior of RC beams that are externally reinforced in flexure with CFRP sheets. (C) 2010 Elsevier Ltd. All rights reserved.