Improving the Electromagnetic Properties of Bitumen Using SiC-Fe3O4 Composites: Fid-Bau Portal

Improving the Electromagnetic Properties of Bitumen Using SiC-Fe3O4 Composites

Liu, Xiaoming / Wei, Ziqi / Zhao, Yu / Yan, Daxiong

It is important to further improve the microwave absorption capacity of bitumen to promote the application of microwave heating in pavement maintenance. $SiC - {Fe}_{3} O_{4}$ composites were prepared as microwave-enhanced materials based on the impedance matching theory and the limitation of traditional single-phase microwave absorber. A network analyzer was used to measure the electromagnetic parameters. The rheological properties were evaluated and the morphological characteristics of $SiC - {Fe}_{3} O_{4}$ composites were studied. The process of microwave-heating of bituminous concrete was simulated and the heating rate and heat distribution were analyzed intensively. The results showed that the reflection loss of bitumen containing $SiC - {Fe}_{3} O_{4}$ composites reached $- 21.82 dB$ (the microwave reflectivity was only 1%), which is 13.4 dB lower than that of the bitumen containing SiC. The average heating rate of the bituminous concrete containing optimum $SiC - {Fe}_{3} O_{4}$ composites was $0.322 ° C / s$ , which is 1.88 times of that of pure bituminous concrete, and higher than that of bituminous concrete containing either SiC or ${Fe}_{3} O_{4}$ . $SiC - {Fe}_{3} O_{4}$ composites improved the thermal conductivity of bituminous concrete, as well. The rheological properties of bitumen did not decline. The microstructure of $SiC - {Fe}_{3} O_{4}$ composites contributed to microwave absorption. It can be concluded that the bitumen containing $SiC - {Fe}_{3} O_{4}$ composites has stronger microwave-absorption ability compared with the bitumen containing a single-phase absorber. The bituminous concrete with composites had a greater microwave heating effect, and the optimum mass ratio of SiC to ${Fe}_{3} O_{4}$ was $1 ∶ 2$ .