Synergistic effects of latex and conductive additives in heavyweight concrete for EMI shielding

Electromagnetic interference (EMI) poses a significant challenge to modern electronic systems, necessitating effective shielding solutions. This study investigates latex-modified heavyweight concrete incorporating magnetite, activated carbon powder (ACP), and carbon nanofibers (CNF) to enhance both mechanical properties and EMI shielding effectiveness. Magnetite substitution of sand at 60 % provided optimal performance, achieving a compressive strength of 46.1 MPa and a flexural strength of 7.2 MPa at 28 days. The addition of 5 % latex further improved flexibility and durability, with reduced compressive and flexural strengths peaking at 35.49 MPa and 4.28 MPa, respectively. A control mix with 5 % latex and 60 % magnetite was selected for further evaluation, where additives such as CNF and ACP were incorporated to assess synergistic effects. For EMI shielding, the 60 % magnetite mix alone achieved a shielding effectiveness (SE) of 8 dB at 1.5 GHz, with absorption as the dominant mechanism. Incorporating 5 % ACP and 0.01 % CNF into the control mix enhanced performance further, achieving SE values of 7.5 dB and 6 dB, respectively, due to the formation of conductive networks and magnetic loss mechanisms. The composite containing 5 % latex, 60 % magnetite, and 0.01 % CNF achieved an optimal balance, maintaining a compressive strength of 37.07 MPa while delivering an SE of 7 dB at 1.5 GHz. This research highlights the synergistic effects of combining magnetite, latex, ACP, and CNF, resulting in improved structural strength and EMI shielding capabilities. These findings demonstrate the potential of latex-modified heavyweight concrete as a durable, high-performance material for EMI-resistant structures across various industries. • Latex-modified concrete boosts EMI shielding and mechanical performance. • 60 % magnetite replacement yields 46.1 MPa strength and 8 dB SE at 1.5 GHz. • 5 % latex improves durability but slightly lowers mechanical strength. • Adding CNF and ACP enhances shielding via conductivity and magnetic loss. • Optimized mix balances strength (37.07 MPa) and EMI SE (7 dB at 1.5 GHz).