Arif, MohammedAl-Hagri, Mohammed GamalShariq M.Rahman I.Hassan, AmerBaqi, Abdul2020-03-262020-03-2620202250-2149https://dx.doi.org/10.1007/s40030-019-00411-whttps://hdl.handle.net/20.500.12395/38686The present study focuses on the effect of cement replacement with micro-silica fume (SF), nano-silica fume (NS) and fly ash (F) individually and in a combination of two additives, on the mechanical properties (split, flexural tensile and compressive strengths) of 22 modified concrete mixes. The microstructure analysis and chemical microanalysis of the mixes have also been undertaken. The addition of micro- and nano-silica fume alone enhances the strength of concrete. However, the addition of fly ash causes a reduction in the strength properties for all replacement percentages. The combination of micro- and nano-silica fume improves the mechanical properties of concrete for all percentages of replacement. The microstructure and chemical analysis of modified concrete show enhancement in the morphological properties of concrete owing to pore filling with dense and compact structure and C–H crystals reduction and denser structure in pastes due to the incorporation of micro- and nano-silica fume. The present experimental research shows that the concrete modified with industrial by-products establishes extra functionalities, thus well addressing the environmental sustainability issues. © 2019, The Institution of Engineers (India).en10.1007/s40030-019-00411-winfo:eu-repo/semantics/closedAccessMechanical propertiesMicro-additivesMicrostructure analysisModified concrete compositesNano-additivesArticle101189104Q2