• Joshi Mihir Lalitkumar
• Kalpesh L. Kapadiya
• Prashant K. Bhuva
• Chirag R. Odedra
• Shekhar H. Parmar

Concrete is the most widely consumed construction material worldwide, but it suffers from limitations such as brittleness, low tensile strength, and high porosity in the interfacial transition zone (ITZ). These drawbacks reduce durability and restrict the performance of reinforced concrete structures under aggressive environments. Nanotechnology has emerged as a potential solution, with nano-silica (NS) gaining significant attention due to its pozzolanic reactivity and micro-filler effect. This study investigates the influence of nano-silica on the mechanical properties of M30 grade concrete. Ordinary Portland Cement (OPC) 43 grade was partially replaced with NS at 0%, 0.5%, 1.0%, 1.5%, and 2.0% by weight of cement. Experimental work included testing for slump (workability), compressive strength, split tensile strength, and flexural strength at curing ages of 7, 28, and 90 days. The results indicated that the addition of nano-silica decreased slump values due to higher water demand, but acceptable workability was maintained using a PCE-based superplasticizer. Compressive strength improved significantly, with a maximum gain of 16% at 1.5% NS replacement after 28 days. Similarly, split tensile and flexural strengths improved by approximately 12–15% at 1.5% NS. However, beyond 1.5%, the performance slightly declined due to particle agglomeration and reduced workability. Microstructural observations confirmed that NS refined the ITZ and reduced porosity, contributing to improved durability. The study concludes that an optimum NS dosage of 1.5% replacement of cement enhances the strength properties of M30 grade concrete, making it a promising material for high-performance and durable construction applications.

Nano-silica, Mechanical properties, High-performance concrete, Compressive strength, Flexural strength, Tensile strength

"INVESTIGATION OF MECHANICAL PROPERTIES OF CONCRETE BY USING NANO MATERIALS", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.12, Issue 10, page no.a246-a253, October-2025, Available :http://www.jetir.org/papers/JETIR2510031.pdf

"INVESTIGATION OF MECHANICAL PROPERTIES OF CONCRETE BY USING NANO MATERIALS", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.12, Issue 10, page no. ppa246-a253, October-2025, Available at : http://www.jetir.org/papers/JETIR2510031.pdf