Recent Approaches to Modify the Interaction between Cement-based Materials and Electromagnetic Waves: Effectiveness of Functional Fillers and Structural Modifications

This study aims to provide a review of how electromagnetic waves, primarily frequency bands in telecommunications networks, interact with cement-based materials and presents recent approaches, including the integration of functional fillers or structural components into the materials, to modify these interactions. Based on a dataset comprising experimental results from various previous studies, the study provides a comprehensive evaluation of the effectiveness of approaches on not only shielding capability but also the reflection and transmissivity of electromagnetic waves when interacting with cement-based materials, and the mechanisms behind these effects. The use of metal- and carbon-based fillers with high conductivity is a fundamental approach to increase the wave shielding of the material through dielectric losses. Conversely, approaches using materials with low electrical conductivity, such as quartz, rice husk ash, expanded polystyrene, or glass, can increase the transmissivity of waves. However, the effectiveness varies and depends on the type, shape, and the fraction of fillers, as well as the frequency of waves. Furthermore, structural modifications, such as increasing thickness, applying coating layers, using a multi-layered structure, or embedding a metal sheet into the material, are also effective ways to enhance absorption, leading to a reduction in the transmissivity of waves.