A Wireless, Passive Embedded Sensor for Real-Time Monitoring of Water Content in Civil Engineering Materials
A Wireless, Passive Embedded Sensor for Real-Time Monitoring of Water Content in Civil Engineering Materials
复制标题
DOI：
10.1109/jsen.2008.2007681
复制
发表时间：
2008-11-01
影响因子：
4.3
通讯作者：
Ong, Keat Ghee
中科院分区：
文献类型：
--
作者：
Ong, Justin B.;You, Zhanping;Ong, Keat Ghee
应用无线无源嵌入式传感器对砂土、路基土、混凝土等土木工程材料中的水分进行实时监测。该传感器由一个平面电感-电容(LC)电路组成，嵌入在测试样品中，通过跟踪传感器谐振频率的变化，可以使用环形天线远程测量样品的内部水分含量。由于水的介电常数比测试样品高得多，样品中水的存在增加了LC电路的电容(电容器的电容与其电极之间介质的介电常数成正比)，从而降低了传感器的谐振频率。利用该传感器对不同粒度砂样的干燥速率进行了研究。还进行了一项研究，以测量波特兰水泥混凝土板在浇注过程中的养护速度，以及在水中浸泡后的干燥速度。所描述的传感器技术可用于长期监测土壤和沙子中的局部水分含量，以了解这些介质中的环境健康状况。此外，该传感器还可用于监测混凝土支架和路面内的水分含量。水含量的测量对土木工程基础设施很重要，因为过量的水可能会加速它们的退化。
A wireless, passive embedded sensor was applied for real-time monitoring of water content in civil engineering materials such as sands, subgrade soils, and concrete materials. The sensor, which comprised of a planar inductor-capacitor (LC) circuit, was embedded in test samples so that the internal water content of the samples could be remotely measured with a loop antenna by tracking the changes in the sensor's resonant frequency. Since the dielectric constant of water was much higher compared with that of the test samples, the presence of water in the samples increased the capacitance of the LC circuit (capacitance of the capacitor was proportional to the dielectric constant of the medium between its electrodes), thus decreasing the sensor's resonant frequency. Using the described sensor, a study was conducted to investigate the drying rate of sand samples of different grain sizes. A study was also conducted to measure the curing rate of a portland cement concrete slab during casting, and its drying rate after it has been soaked in water. The described sensor technology can be applied for long-term monitoring of localized water content inside soils and sands to understand the environmental health in these media. In addition, this sensor will be useful for monitoring water content within concrete supports and road pavements. The measurement of water content is important for civil engineering infrastructure since excess water may hasten their degradation.