Research on electromagnetic properties and microwave deicing performance of carbon fiber modified concrete

Abstract

The electromagnetic properties of concrete have an important effect on the microwave deicing performance of concrete road. In this paper, the carbon fiber was added into the concrete matrix to prepare carbon fiber modified concrete (CMFC), aiming to improve the concrete’s microwave absorbing performance and enhance the efficiency of road microwave deicing. Moreover, a rectangular waveguide transmission/reflection method was used to test the electromagnetic properties of concrete, and a self-developed microwave deicing test system was employed to test the microwave deicing performance. The electromagnetic characteristics tests show that with the increase of carbon fiber content, the microwave energy storage performance of CFMC is firstly increased and then decreased, its performance of microwave energy loss increases gradually, and its reflection of microwave enhances gradually as well. When the microwave frequency is in the vicinity of 2.45 GHz, the real part of complex permittivity of CFMC with a carbon fiber content of 1‰ (CFMC-1), 3‰ (CFMC-2) and 5‰ (CFMC-3) are 1.59 times, 1.69 times and 0.94 times of that of plain concrete (PC), respectively. As for the imaginary part of complex permittivity, the ratios are 4.42 times, 36.38 times and 37.74 times, respectively. As for the reflection properties, CFMC-1 has the lowest reflectivity, which is −6.21 dB. In addition, the microwave deicing tests show that CFMC-3 has the fastest heating rate, which is 1.680 ℃/s, 4.46 times that of PC. However, considering the mechanical properties, deicing effect and economic cost, CFMC-1 has the best application prospects, whose heating rate is 1.289 ℃/s, 3.42 times that of PC. Above all, it can be concluded that the efficiency of concrete road microwave deicing can be effectively improved by adding carbon fiber, and the research in this paper can provide theoretical guidance for the road microwave deicing operations in some sense.