The effects of ZnO powder and different fiber types used in tuff/calcite-based geopolymers on electromagnetic shielding effectiveness

Abstract

Electromagnetic (EM) shielding has become increasingly important in our modern world due to the growing use of electronic devices, which poses risks of EM pollution and its adverse effects on humans. Many studies have explored the incorporation of various additives into geopolymer mixes to enhance their EM shielding properties. This study investigates the impact of tuff/calcite-based geopolymers reinforced with three different types of fibers (Polypropylene, Steel, and Carbon) and varying percentages (2.5 %, 5 %, and 10 %) of ZnO powder on EM shielding effectiveness. Compressive strength, flexural strength, water absorption, length change tests, and EM shielding (900–6000 MHz at every 100MHz step) measurements were performed on geopolymer samples. Optimal shielding performance was achieved by the addition of 10 % ZnO by volume alongside carbon fiber. This combination resulted in a total shielding value of −78.92dB at a bandwidth of 2800MHz.