Effect of silicon carbide powder on temperature field distribution characteristics and microwave deicing efficiency of cement concrete containing magnetite (Fe3O4) powder
Heping Qiu, Yongchang Wu, Huaxin Chen, Ruiyang Wang, Zhiyu Han, Zhenmin Wan
Abstract
To improve the temperature field distribution characteristics and overall deicing efficiency of magnetite (Fe 3 O 4 ) powder concrete during microwave heating at the extremely low-temperature condition, the silicon carbide (SiC) powder with favorable heat transfer ability was added to the concrete system. The microwave heating characteristics and thermal conductivity of concrete were studied to analyze its heating rate and heat transfer ability, respectively. Meanwhile, the thermal response changes of the concrete surface were recorded during the microwave heating, and the temperature difference (TD) and standard deviation (St.d) were used to characterize its surface temperature field distribution characteristics. In addition, the ice layer shedding time (ILST) of the concrete surface was used to evaluate the overall deicing efficiency of the concrete coated with ice. The results showed that in the microwave-absorbing concrete, the Fe 3 O 4 content was the main factor affecting its microwave heating rate. The SiC could effectively improve the thermal conductivity of concrete. When the SiC content was 6 wt%, the heat transfer ability of concrete was improved by 69.2%. Therefore, after adding the SiC, the temperature field distribution characteristics of the concrete surface were tending to be uniform during microwave heating. After heating 120 s, the SiC content with 6 wt% could effectively reduce the TD by 23 °C and the St.d by 5.6 °C of surface temperature field of concrete containing Fe 3 O 4 . When the mass percentage of Fe 3 O 4 and SiC was 1:1, the ILST of concrete coated with ice was the shortest at the icing temperature of −30 °C and the ice layer thickness of 20 mm. It was 55.5 and 24.3 s shorter than that of concrete without absorbing materials and thermal conductivity materials, respectively, and its deicing efficiency was 1.51 and 1.22 times higher than theirs.