Comparison of dielectric properties, radiation shielding, and electrical resistivity of alkali-activated blast furnace slag and Portland cement binders

Alkali-activated materials (AAMs) are increasingly explored for sustainable construction, yet their electromagnetic and radiation-related properties remain largely unknown. This study explored the radio wave propagation, gamma-ray shielding efficiency, and electrical resistivity of alkali-activated blast furnace slag (BFS-AAM) compared to hydrated Portland cement (PC). BFS-AAM demonstrated superior relative permittivity (εr ≈ 7.6 at 2.4 GHz) and loss tangent (∼0.33) at lower radio frequencies (0.02–10 GHz), leading to enhanced signal attenuation compared to PC (εr ≈ 5.6, loss tangent ≈ 0.07). BFS-AAM showed similar performance to PC at frequencies between 10–20 GHz, while its characteristics below 10 GHz make it suitable for secure signal environments. In terahertz spectrum (0.2–2 THz), relevant for 6G wireless communication, both materials displayed comparable permittivity (∼5.3 and ∼4.2) and loss tangent (∼0.09 and ∼0.04), indicating compatibility with residential and commercial applications. Simulations at 0.7, 2.4, and 6.0 GHz confirmed higher signal attenuation by BFS-AAM. Additionally, BFS-AAM exhibited higher resistivity (26–110 Ω·m), greater compressive strength (60 MPa), and lower porosity (∼11 %), contributing to its favorable dielectric properties. Although BFS-AAM demonstrated slightly lower gamma-ray shielding efficiency (at 0.661 MeV) than PC, its multifunctional properties position it as promising material for advanced electromagnetic and radiation shielding technologies.