Le Huy-Viet, Kim Tae-Uk, Khan Suleman, Park Jun-Young, Park Jong-Woong, Kim Seung-Eock, Jang Yun, Kim Dong-Joo
Department of Civil and Environmental Engineering, Sejong University, 98 Gunja-dong, Gwangjin-gu, Seoul 143747, Korea.
Department of Civil Engineering, Hanoi University of Mining and Geology, Hanoi 100000, Vietnam.
Sensors (Basel). 2021 Sep 24;21(19):6386. doi: 10.3390/s21196386.
This study proposes the development of a wireless sensor system integrated with smart ultra-high performance concrete (UHPC) for sensing and transmitting changes in stress and damage occurrence in real-time. The smart UHPC, which has the self-sensing ability, comprises steel fibers, fine steel slag aggregates (FSSAs), and multiwall carbon nanotubes (MWCNTs) as functional fillers. The proposed wireless sensing system used a low-cost microcontroller unit (MCU) and two-probe resistance sensing circuit to capture change in electrical resistance of self-sensing UHPC due to external stress. For wireless transmission, the developed wireless sensing system used Bluetooth low energy (BLE) beacon for low-power and multi-channel data transmission. For experimental validation of the proposed smart UHPC, two types of specimens for tensile and compression tests were fabricated. In the laboratory test, using a universal testing machine, the change in electrical resistivity was measured and compared with a reference DC resistance meter. The proposed wireless sensing system showed decreased electrical resistance under compressive and tensile load. The fractional change in resistivity (FCR) was monitored at 39.2% under the maximum compressive stress and 12.35% per crack under the maximum compressive stress tension. The electrical resistance changes in both compression and tension showed similar behavior, measured by a DC meter and validated the developed integration of wireless sensing system and smart UHPC.
本研究提出开发一种集成智能超高性能混凝土(UHPC)的无线传感器系统,用于实时传感和传输应力变化及损伤情况。具有自传感能力的智能UHPC包含钢纤维、细钢渣集料(FSSA)和多壁碳纳米管(MWCNT)作为功能填料。所提出的无线传感系统使用低成本微控制器单元(MCU)和双探针电阻传感电路来捕捉自传感UHPC因外部应力而产生的电阻变化。对于无线传输,所开发的无线传感系统使用低功耗蓝牙(BLE)信标进行低功耗和多通道数据传输。为了对所提出的智能UHPC进行实验验证,制作了两种用于拉伸和压缩试验的试件。在实验室测试中,使用万能试验机测量了电阻率变化,并与参考直流电阻计进行了比较。所提出的无线传感系统在压缩和拉伸载荷下显示出电阻降低。在最大压缩应力下,电阻率分数变化(FCR)监测为39.2%,在最大压缩应力拉伸下每条裂缝处为12.35%。压缩和拉伸时的电阻变化表现出相似的行为,通过直流电表测量并验证了所开发的无线传感系统与智能UHPC的集成。