Strength and durability of unary and binary nano particle blended cement composites

Numerous studies have explored the enhancement of concrete properties using nanomaterials. This research investigates the influence of nano-sized cement (NC) and nano metakaolin (NMK) on the performance of cementitious composites. Cement was partially replaced with NC, NMK, and a hybrid blend (1:1) at varying levels. Nano cement was produced by high intensity ball grinding. Both mortar and concrete mixes were evaluated for physical, mechanical, and durability characteristics. Compressive strength of mortar cubes was measured on 3, 7, and 28 days, showing notable improvement with nano particle incorporation. 10% unary and 20% binary replacement using NC and NMK resulted in 31.56% and 46.27% increase in compressive strength of mortar mixes. Concrete mixes were tested for workability, compressive strength, water absorption, electrical resistivity, chloride permeability, and sulphate resistance. Workability improvement of fresh concrete mixes with NC demonstrates the surface morphology changes in NC due to the high intensity ball milling process. Results revealed that both unary and binary nano replacements significantly enhanced strength and durability of concrete mixes. 20%, 10% and 15% replacements with NC, NMK and hybrid combination resulted in best outcome. Microstructural analysis using X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) confirmed a denser matrix and refined pore structure in nano-modified specimens. Findings of the study demonstrate that nano cement and nano metakaolin can effectively improve the performance of cement-based materials, offering promising potential for advanced concrete applications.