MECHANICAL AND DURABILITY PERFORMANCE OF CONCRETE MODIFIED WITH CARBON NANOTUBES: A REVIEW

Abstract

Carbon nanotubes (CNTs) have emerged as promising nanomaterials for enhancing the mechanical and durability properties of concrete. This comprehensive review synthesizes recent peer-reviewed literature on CNT-modified concrete, focusing on mechanical performance enhancement and long-term durability characteristics. The review examines optimal dosage ranges, dispersion techniques, strengthening mechanisms, and durability against environmental attacks. Results consistently demonstrate that CNT additions of 0.05–0.10 wt% of cement can increase compressive strength by 15–31%, flexural strength by 17–70%, and tensile strength by 20–45%, while simultaneously reducing water absorption, chloride penetration, and sulfate attack vulnerability. The microstructural analysis reveals that CNTs function as crack bridges and pore fillers, creating denser matrices with refined pore structures. Current challenges include achieving uniform dispersion, optimizing cost-effectiveness, and ensuring long-term durability. This review identifies critical research gaps in standardization protocols, large-scale production feasibility, and environmental impact assessment of CNT-modified concrete systems.