Jiang Jian, Hei Chuang, Feng Qian, Jiang Jinwei
Key Laboratory of Earthquake Geodesy, Institute of Seismology, China Earthquake Administration, Wuhan 430071, China.
Wuhan Institute of Earthquake Engineering Co., Ltd., Wuhan 430071, China.
Sensors (Basel). 2019 May 6;19(9):2096. doi: 10.3390/s19092096.
Anchored steel bars have been widely used in retrofitting of existing concrete structures. The bonding strength between the anchored steel bar and the concrete is critical to the integrity of the strengthened concrete structure. This paper presents a method to monitor epoxy-grouted bonding strength development by using a piezoceramic-enabled active sensing technique. One concrete beam with an anchored steel bar was involved in the monitoring test, and two concrete beams with six anchored steel bars were used in the pull-out test. To enable the active sensing, a Lead Zirconate Titanate (PZT) patch was bonded to the surface of the exposed end, and piezoceramic smart aggregates were embedded in each concrete specimen. During the monitoring experiment, signals from PZT sensors and smart aggregates were acquired at intervals of 0, 20, 40, 60, 80, and 100 min. In addition, a pull-out test was performed on each of the remaining six anchored steel bars in the two concrete beams, while the signal was recorded in the test. Furthermore, a wavelet packet analysis was applied to analyze the received signal energies to investigate the bonding strength development between the concrete and the anchored steel bar during the epoxy solidification process. The test results demonstrate the effectiveness of the proposed method in monitoring the bonding strength development between the anchored steel bar and the concrete, using the PZT-enabled active sensing.
植筋已广泛应用于既有混凝土结构的加固改造中。植筋与混凝土之间的粘结强度对于加固后混凝土结构的整体性至关重要。本文提出了一种利用基于压电陶瓷的主动传感技术监测环氧灌浆粘结强度发展的方法。监测试验采用了一根带植筋的混凝土梁，拔出试验采用了两根带六根植筋的混凝土梁。为实现主动传感，在外露端表面粘贴了锆钛酸铅（PZT）片，并在每个混凝土试件中埋入了压电陶瓷智能骨料。在监测试验过程中，每隔0、20、40、60、80和100分钟采集一次来自PZT传感器和智能骨料的信号。此外，对两根混凝土梁中其余六根植筋分别进行拔出试验，并在试验过程中记录信号。此外，应用小波包分析对接收到的信号能量进行分析，以研究环氧固化过程中混凝土与植筋之间粘结强度的发展情况。试验结果表明，所提出的利用基于PZT的主动传感监测植筋与混凝土之间粘结强度发展的方法是有效的。
