Embedded smart sensor dipole antennas for real-time damage assessment, humidity, and temperature monitoring in reinforced and non-reinforced concrete structures

Abstract

In this study, a dipole antenna is designed for real-time damage assessment, humidity, and temperature monitoring in reinforced and non-reinforced concrete structures. The antenna-based sensor is embedded into reinforced and non-reinforced concrete beams to assess electromagnetic measurements. Reflection parameter S11 in dB values and resonant frequencies of the embedded antenna are evaluated to detect damage, humidity, and temperature changes. The exploratory results show that as deformation increases in reinforced concrete, resonance frequency values decrease and S11 values increase. The load and resonance frequency values showed very close trends as deformation increases in the beam. In water content sensing experiments, the S11 in dB values of the antenna decrease as the humidity increases for concrete specimens while the resonance frequency values increase as the humidity increases for the reinforced concrete specimen. Elevated temperature sensing experimental results show that the resonance frequency values of the antenna decrease as the temperature of the specimen increases for concrete specimens while the S11 in dB values increase as the temperature of the specimen increases for reinforced concrete specimen.

Capacitive compressive stress self-sensing behavior of cement mortar and its dependence on the thickness

“…Two different methods are used for the determination of stress/ strain in cement-based composites. The first is based on the principle of embedding the sensor with an electrical circuit into cement-based material or mounting it on it [24][25][26]. The latter is based on the principle that the cement-based material itself acts as a sensor without the need for a device.…”