STUDY ON THE ELECTROMAGNETIC WAVE SHIELDING CAPABILITY OF CEMENTITIOUS GYPSUM WALL TILES CONTAINING BIOCHAR AND IRON SALTS

Abstract

Electromagnetic interference caused by gadgets that generate EM waves is becoming a significant problem as technology advances, and the 5G network is being deployed in Singapore as one of the most frequently used building materials. Cementitious materials should improve their characteristics to provide more significant EMI shielding. Furthermore, to customise the EM SE of wall tiles to control or restrict EM transmittance through walls to enhance data security.

This study investigates the electromagnetic shielding effect of cement mortar containing gypsum, biochar, iron salts (Fe2O3 and Fe3O4) with different amounts of water to the matrix. Results obtained shows a marginally significant between inclusion gypsum, biochar, Fe2O3 and Fe3O4 with a quantity of initial mixing water and total shielding effectiveness between 2.60 GHz to 3.95 GHz aligned with Singapore 5G network frequency. BC20Fe3T25, 20 wt% gypsums, 20 wt% biochar, 25 wt% Fe3O4 and marginally workable water was found to be the optimal combination, with the greatest EMSE values of SE 23.87 dB, Absorption 12.55 dB and Reflection 11.06 dB. Compared to plain mortar SE 5.57 dB, A 2.75 dB, R 3.67 dB and SE 7.13 dB, A 3.81 dB, R 4.17 dB for marginally workable and high water respectively. While the addition of Fe2O3 does improve EMSE values, Fe3O4 still outperforms Fe2O3 in EMSE values. Although high water has a greater frequency due to the workability of the mortar, moderately workable water is still recommended and has been demonstrated to have superior EMSE values than HW in the most optimum combination.