Microwave heating characteristics of cement mortar containing carbonyl iron powder applied to airport pavement deicing

To improve the microwave deicing efficiency of airport concrete pavement, carbonyl iron powder (CIP) was used as an absorbing material to prepare the microwave -absorbing cement mortar. Firstly, to characterize the microwave absorption ability of the mortar, its electromagnetic (EM) parameters and microwave reflection loss (RL) with different CIP content were investigated by using the coaxial vector network analyzer (CVNA) and arching reflected method, respectively. Then, the microwave heating rate and deicing efficiency of the mortar coated with ice was investigated under different icing temperature and ice layer thickness conditions with a microwave heating frequency of 2.45 GHz. Finally, the mechanical strength of mortar after deicing was tested to analyze the effect of an icing -deicing cycle on its engineering performance. The results showed that at the total frequency band, the mean RL and effective bandwidth of 10CCM was -2.8 dB lower and 1.6 GHz wider than that of the control group. Meanwhile, at 2.45 GHz, the RL of 10CCM was 1.31 times lower than that of the control group. When the icing temperature and ice layer thickness were - 10 degrees C and 1 cm, the heating rate of 10CCM was 1.34 times higher than that of the control group. Compared to the icing temperature, the changes in ice layer thickness on the mortar surface had less effect on its heating rate. After deicing, the CIP mortar still had favorable mechanical strength. Hence, the CIP was a favorable absorbing material that could be applied to cement mortar to improve the microwave deicing efficiency of the concrete pavement during long-term service.