Study on the Microwave Absorption Properties of Double-Layer Structured Fiber-Reinforced Electromagnetic Wave-Absorbing Ceramsite Concrete

Single-layer electromagnetic wave-absorbing ceramsite concrete exhibits poor reflection loss and insufficient effective absorption bandwidth in the 8 to 18 GHz frequency range. To address this, expanded perlite (EP) and polypropylene fiber (PF) were used as wave-transparent agents in the matching layer, while carbon fiber (CF) and basalt fiber (BF) were used as wave-absorbing agents in the absorption layer, to prepare double-layer structured fiber-reinforced electromagnetic wave-absorbing ceramsite concrete. The arch method testing system was used to analyze its electromagnetic wave absorption properties in the 8 to 18 GHz frequency range. The experimental results indicate that the double-layer structured specimens exhibit enhanced microwave absorption properties compared to their single-layer counterpart, with improved low-frequency electromagnetic wave reflection loss and broadened effective absorption bandwidth. The microwave absorption properties vary with the changes in fiber types and volume fractions in the matching and absorption layers: when EP is incorporated into the matching layer, the absorption layer with CF achieves optimal microwave absorption parameters at 0.6% CF volume fraction, while with BF, the properties improve as the BF volume fraction increases; when PF is incorporated into the matching layer, higher PF volume fraction than CF or BF in the absorption layer yields lower minimum reflection loss and wider effective absorption bandwidth.