Influence of Nanomaterials on the Properties of Concrete: A Review

Abstract

Because nanoscale additions can alter hydration kinetics, pore structure, interfacial transition zones, fracture development, and transport characteristics, nanotechnology has grown in importance as a means of customizing cement-based materials. The effects of nanosilica (NS), nano alumina (NA), nano-TiO₂, nano -Fe₂O₃, nano-CaCO₃, nonclay (NC), nano metakaolin (NMK), carbon nanotubes (CNTs), and graphene oxide (GO) on the fresh, mechanical, microstructural, durability, thermal, and functional properties of concrete are summarized in this critical review. The review is based on a methodically assembled collection of peer-reviewed studies that were published between 2016 and 2025. These studies were found by searching major scientific databases like Scopus, Web of Science, and Google Scholar, as well as additional regional-language sources that covered similar nano-concrete applications. According to the reviewed literature, when utilized at an optimal dose, nanomaterials generally improve compressive, tensile, and flexural performance; however, excessive contents frequently result in agglomeration, increased water consumption, decreased workability, and strength loss. Improvements reported are highly depending on the substance and dosage. According to recent state-of-the-art research, regular concrete may increase its compressive strength by roughly 12–50%, its flexural strength by 2–22%, and its tensile strength by more than 50% in some systems. However, lightweight concrete can exhibit much greater relative improvements. It is not appropriate to consider these numbers as statistically pooled or meta-analytically determined estimates; rather, they are indicative ranges given throughout the analyzed research. Particle packing, pore refinement, nucleation, rapid hydration, pozzolanic consumption of Ca(OH)₂, extra C-S-H/C-A-S-H creation, interfacial transition zone densification, and nanoscale crack bridging are the main mechanistic advantages. Reduced capillary porosity, water absorption, and chloride transport are associated with durability advantages; however, not all studies indicate consistent benefits, particularly when dispersion is inadequate or dosage exceeds an optimal threshold. Workability loss, dispersion difficulty, uneven test methods, cost, occupational exposure, unclear life-cycle implications, and inadequate long-term field validation are some of the main obstacles to large-scale deployment. The review concludes that standardized dispersion and characterization protocols, life-cycle and techno-economic assessment, and performance-based design frameworks appropriate for field-scale construction should replace single-material laboratory optimization in the next phase of research on nano-modified concrete.