Evaluation of the durability and shielding properties of high-strength concrete incorporating locally available materials and carbon additives

Abstract

High-strength concrete (HSC) has been extensively studied for major applications, particularly in high-rise buildings and bridges. Furthermore, conductive concrete exhibits enhanced electrical properties, enabling its use in specialized applications such as heating, electromagnetic shielding, and antistatic systems. This study aims to combine these two types to produce conductive high-strength concrete (CHSC) using locally available materials. The proposed mixes' performance measurements include compressive strength, flexural strength, modulus of elasticity, long-term effects (like creep and shrinkage), and electromagnetic shielding. HSC with compressive strength up to 100 MPa and modulus of rupture of 8.96 MPa was successfully produced using locally available materials. The mix containing low dune sand achieved the best mechanical performance. The inclusion of steel fibers (FLDUNE) increased 28-day compressive and flexural strengths by 3.5 and 22%, respectively, and reduced shrinkage and creep by 25 and 10%. However, the addition of carbon materials along with steel fibers (FCLDUNE) decreased these strengths by 19.6 and 15%, and increased shrinkage and creep by 18 and 9%, respectively. The measured electrical properties of the proposed concrete mixes show resistivity of 33.3 Ω-m for FLDUNE and 25.7 Ω-m for FCLDUNE mixes and measured relative complex permittivity of 22.57-j2.22 with relative complex permittivity of 22.57-j2.22. Electromagnetic shielding showed an attenuation of -70 dBm using steel fiber, compared to -28.3 dBm for the control mix. Adding carbon material with steel fiber did not provide significant added value for shielding applications.