Strength and microstructural analysis of nano-silica based cement composites in presence of silica fume

Abstract Replacement of cement with pozzolanic materials has addressed numerous inquiries identified with impact of these materials on the microstructural and other properties of cement composites. On the other hand, because of the absence of technique and pertinent supporting information, an appraisal of general execution of such admixtures is hard to be completed. The utilization of pozzolanic materials as cement substitution in mortar has enhanced the execution of their physico-chemical and mechanical properties. In this study, the composition of silica fume (SF) was differed as 3%, 6%, 9% and 12% at a fixed composition of nano-silica (NS) as 0.5% by weight for substitution of cement. The fresh and hardened properties of cement mortars were analyzed and microstructural analysis was performed. The specimens were found to exhibit better developed microstructure and enhanced compressive strength with inclusion of optimized dosage of SF in presence of NS. The study has confirmed that the simultaneous replacement of cement with the optimized dosage of pozzolanic materials brings improvement in the properties of the cement mortar and can be used to partially substitute cement for the beneficiary effects.