Status and Perspectives for Mechanical Performance of Cement/Concrete Hybrids with Inorganic Carbon Materials

The rapid advancement of modern infrastructure and construction industries demands cementitious materials with superior mechanical performance, durability, and sustainability, surpassing the limitations of conventional concrete. To address these challenges, carbon-based nanomaterials—including carbon nanofibers (CNFs), carbon nanotubes (CNTs), and graphene—have gained significant attention as next-generation reinforcement agents due to their exceptional strength, high aspect ratio, and unique interfacial properties. This review presents a critical analysis of the latest technological developments in carbon-enhanced cement and concrete composites, focusing on their role in achieving high-performance construction materials, as there is a shortage of reviews of cement concretes based on carbon nanoadditives. We systematically explore the underlying mechanisms, processing techniques, and structure–property relationships governing carbon-modified cementitious systems. First, we discuss advanced synthesis methods and dispersion strategies for carbon nanomaterials to ensure uniform reinforcement within the cement matrix. Subsequently, we analyze the mechanical enhancement mechanisms, including crack bridging, nucleation seeding, and interfacial bonding, supported by experimental and computational studies. Despite notable progress, challenges such as long-term durability, cost-effectiveness, and large-scale processing remain key barriers to practical implementation. Finally, we outline emerging trends, including multifunctional smart composites and sustainable hybrid systems, to guide future research toward scalable and eco-friendly solutions. By integrating fundamental insights with technological advancements, this review not only advances the understanding of carbon-reinforced cement composites but also provides strategic recommendations for their optimization and industrial adoption in next-generation construction.