Erdem, YaseminKocak, Yilmaz2025-10-112025-10-1120260032-59101873-328Xhttps://doi.org/10.1016/j.powtec.2025.121545https://hdl.handle.net/20.500.12684/21306A great deal of research is still being carried out to determine the hydration reactions of silica fume-substituted cementitious composites. The changes in the structure of these composites due to complex hydration reactions vary according to the physicochemical properties of the materials. This study investigated the effectiveness of silica fume in combination with CEM I 42.5 R type Portland cement. For this purpose, the physicochemical properties of the raw materials and the development of hydration products determined by mineralogical, molecular, microstructural, and thermal analyses of silica fume substituted cement pastes at 28-day were monitored. In addition, the effect of the hydration products determined by these analyses on the compressive strength of cement mortars was discussed. The results showed that the compressive strength of the mortars could be improved by silica fume substitution at all hydration ages. Reason for this, silica fume with nano-sized particles and large surface area promotes the hydration of C<inf>3</inf>S and C<inf>2</inf>S and the formation of calcium silicate hydrate phase. Moreover, CH produced by cement hydration reacts with the amorphous silica in the silica fume to form an additional C–S–H gel, densifying the microstructure of cement-based composites and reducing voids. These findings indicate that the substitution of silica fume into Portland cement can provide an environmentally friendly, cost-effective and sustainable solution. Additionally, it is determined as a result of standard tests that cement produced with 10 % silica fume substitution meets all the requirements of 52.5 R type cement, which is the upper strength class. © 2025 Elsevier B.V., All rights reserved.en10.1016/j.powtec.2025.121545info:eu-repo/semantics/closedAccessMechanical PropertiesMicrostructureMineralogical AnalysisSilica FumeThermal AnalysisCalcium SilicateCarbon DioxideSilicateSilicon DioxideSodium ChlorideAmorphous MaterialsCompressive StrengthCost EffectivenessHydrationMaterials PropertiesMineralogyMortarParticle SizeParticle Size AnalysisPhysicochemical PropertiesPortland CementSilicate MineralsCement Based CompositesHydration ProductsHydration ReactionMechanicalMicrostructural CharacterizationsMineralogical AnalysisPhysicochemical PropertyPropertySustainable CementsThermalMicrostructureSilica FumeThermoanalysisCalcium SilicateCarbon DioxideCementCement Based CompositeChemicals And DrugsSilica FumeSilicateSilicon DioxideSodium ChlorideUnclassified DrugArticleBiocompatibilityBiomechanicsControlled StudyHydrationMicrostructureNonhumanStructure AnalysisTensile StrengthThermal AnalysisX Ray DiffractionArticle4672-s2.0-105013135080Q1