Incorporating multi-walled carbon nanotubes in rubberized concrete: impact on physical, mechanical, and fire resistance properties

Abstract

In the current study, multi-walled carbon nanotubes (MWCNTs) were added to the crumb rubber concrete (CRC) to enhance its physical, mechanical, and fire-resistance properties. A comprehensive investigation into thirteen distinct concrete mixes incorporating rubber aggregate (RA) at levels of 5, 10, and 15%, combined with varying percentages (0, 0.1, 0.2, and 0.3%) of MWCNTs particles, evaluated workability, density, compressive strength, split tensile strength, and flexural strength of MWCNT-mixed CRC at ambient and elevated temperatures (200, 400, and 600 °C). The study demonstrated that MWCNTs, used as a partial substitute for cement in CRC, significantly improved concrete properties, enhancing density, flexural strength, split tensile strength, and compressive strength. Notably, adding 0.2% MWCNTs to CRC resulted in remarkable increases: 0.96% in density, 21.91% in 28-day compressive strength, 10.19% in split tensile strength, and 15% in flexural strength. The workability of CRC decreased with the inclusion of MWCNTs. Furthermore, results indicated that MWCNTs bolstered the residual compressive, tensile, and flexural strengths of rubberized concrete at elevated temperatures, with substantial improvements particularly evident at 200 °C. The present work was focused on the analysis of feasibility of MWCNT mixed CRC toward sustainable construction practices by comparing its physical, mechanical, and fire resistance properties with conventional concrete.