Enhancement of electromagnetic shielding and piezoelectric properties of White Portland cement by hydration time

Abstract

Effect of hydration time on the structural and physical properties of White Portland Cement (WPC) is considered to be a critical and essential factor. In this study effect of hydration time (360, 720, 1260, and 1450) min on the dielectric, electromagnetic shielding and piezoelectric properties of WPC at room temperature were investigated. Amorphous crystal structure of WPC has been detected by X-ray diffraction. Meanwhile dielectric and permeability properties of the present samples were investigated from frequency 9–11.5 GHz in X- band at room temperature (RT). At lower hydration time (360 min), the permittivity increases rapidly with frequency, however an anomalous peak has been observed at (720–1450 min) owing to the relaxor behaviour. The dielectric properties are explicitly improved by hydration time due to the enhancement of the mechanical properties. Furthermore, scattering parameters (Reflection coefficient (S11) and Transmission coefficient (S12)) in addition to electromagnetic shielding have been studied for the present samples. The transmission coefficient tends to decrease significantly with hydration time due to enhancement of the sample consolidation. The shielding effectiveness increases with increase in hydration time which indicates internal consolidation of WPC sample. Moreover, the hydration time shows an enhancement both of leakage current and piezoelectric properties of WPC at room temperature.