Paper Contents
Abstract
The incorporation of nanotechnology into cementitious systems has emerged as a transformative approach in modern concrete engineering, enabling enhancements in mechanical performance, durability, and microstructural refinement. Among various nanomaterials, nano-magnesium oxide (nano-MgO) has garnered increasing interest due to its high surface reactivity and its ability to influence cement hydration dynamics and pore structure densification. This study explores the effects of nano-MgO on the performance of concrete through an experimental investigation involving 150150150 mm cube specimens. Five concrete mixes were designed with nano-MgO incorporated at varying dosages0%, 0.5%, 1.0%, 1.5%, and 2.0% by weight of cement. The specimens were evaluated at 7, 14, 28, and 90 days of curing to assess mechanical behavior (compressive strength, split tensile strength, and flexural strength), durability (via water absorption), and microstructural development (using SEM and XRD techniques). Results demonstrated a marked improvement in strength and durability properties with nano-MgO incorporation up to an optimal dosage of 1.5%, beyond which a decline was observed. The enhancement in performance is attributed to the formation of additional magnesium silicate hydrate (MSH) gels, refinement of the interfacial transition zone, and reduced porosity. SEM images revealed a denser matrix with reduced microcracks and better hydration characteristics at the nano-scale. XRD patterns confirmed the reduced presence of portlandite and the emergence of brucite and secondary silicate phases, indicating active pozzolanic reactions involving nano-MgO. However, at 2.0% dosage, performance decreased slightly due to nanoparticle agglomeration, which limited effective dispersion and reactivity. This study confirms that nano-MgO, when used at an optimal concentration, can serve as a highly effective additive in producing high-performance concrete with improved strength, reduced water permeability, and enhanced microstructural stability. The findings support the sustainable use of nano-engineered materials in concrete and provide a practical framework for the integration of nano-MgO in future construction applications where long-term durability and structural reliability are critical.Keywords: Nano-magnesium oxide, Concrete durability, Acid attack, SEM, EDS, XRD, Long-term performance.
Copyright
Copyright © 2025 Shivam Singh. This is an open access article distributed under the Creative Commons Attribution License.
