Effects of Nanomaterials on the Fresh and Hardened Properties of Concrete: A Review.

Insufficient tensile strength, low abrasion resistance, and inadequate consistency in the fresh state led to fractures and decreased the durability of the concrete. Tensile stress resistance is the most challenging, resulting in the formation of microcracks that propagate to a macrolevel. Nanomaterials, with dimensions ranging from 0.1 to 100 nanometers, represent an innovative class of materials that can enhance the mechanical properties of concrete through the nano-core effect. These materials play significant roles in the formation of calcium-silicate-hydrate (C-S-H) gels, contribute to seeding effects, and augment cement hydration reactions. Given the above, the addition of nanomaterials makes concrete exhibit exceptional mechanical strength and improved durability performance. The primary objective of this review is to identify the potential nanomaterials suitable for the development of high-performance concrete. This article reviews the literature on the effects of nanoparticles, such as nano-calcium carbonates (NCCs), iron oxide (NI), nano-aluminum oxide (NA), graphene oxide (GO), nano-silica (NS), and nano-titanium oxide (NT) on the fresh and hardened properties of the material. The study identifies a promising nanomaterial for enhancing concrete, highlights research gaps, and suggests future research directions for its optimal application in future concrete constructions.