Civil and Environmental Engineering, University of Strathclyde, Glasgow G1 1XJ, UK.
Sensors (Basel). 2021 Oct 26;21(21):7081. doi: 10.3390/s21217081.
Concrete infrastructure requires continuous monitoring to ensure any new damage or repair failures are detected promptly. A cost-effective combination of monitoring and maintenance would be highly beneficial in the rehabilitation of existing infrastructure. Alkali-activated materials have been used as concrete repairs and as sensing elements for temperature, moisture, and chlorides. However, damage detection using self-sensing repairs has yet to be demonstrated, and commercial interrogation solutions are expensive. Here, we present the design of a low-cost tomographic impedance interrogator, denoted the "ConcrEITS", capable of crack detection and location in concrete using conductive repair patches. Results show that for pure material blocks ConcrEITS is capable of measuring 4-probe impedance with a root mean square error of ±5.4% when compared to a commercially available device. For tomographic measurements, ConcrEITS is able to detect and locate cracks in patches adhered to small concrete beam samples undergoing 4-point bending. In all six samples tested, crack locations were clearly identified by the contour images gained from tomographic reconstruction. Overall, this system shows promise as a cost-effective combined solution for monitoring and maintenance of concrete infrastructure. We believe further up-scaled testing should follow this research before implementing the technology in a field trial.
具体的基础设施需要持续监测，以确保及时发现任何新的损坏或修复失败。监测和维护的经济有效的结合将对现有基础设施的修复非常有益。碱激活材料已被用作混凝土修复材料和温度、湿度和氯化物的传感元件。然而，使用自感修复进行损伤检测尚未得到证明，商业询问解决方案价格昂贵。在这里，我们提出了一种低成本层析电阻抗询问器的设计，称为“ConcrEITS”，它能够使用导电修复贴片检测和定位混凝土中的裂缝。结果表明，对于纯材料块，ConcrEITS 能够在与商业上可用的设备进行比较时以 ±5.4%的均方根误差测量 4 探针阻抗。对于层析测量，ConcrEITS 能够检测和定位粘贴在小型混凝土梁样品上并进行四点弯曲的贴片中的裂缝。在测试的所有六个样本中，通过层析重建获得的轮廓图像清楚地识别了裂缝位置。总的来说，该系统作为监测和维护混凝土基础设施的经济有效的综合解决方案具有很大的应用潜力。我们认为，在进行现场试验之前，应该在这项研究之后进行进一步的扩大规模测试。
