Evaluation of mechanical performance, durability behavior and texture characterization of OPC blended cement pastes modified with Nano Fumed silica

In this study, the influence of Nano fumed silica (NFS) addition on the examinations are exploring on the diverse blended cement pastes. The hardened blended cement pastes were prepared by using ordinary Portland cement (OPC) with supplementary cementitious materials as, Ground Granulated Blast Furnace Slag (GGBFS), Metakaolin (MK), Fly ash (FA) and Silica fume (SF). Single and double blended cement pastes were prepared. The water of consistency and setting time were measured, While, the performance of the specimens was explored by studying compressive strength, at various hydration ages. Moreover, the durability to sulfate ions attack and fire resistivity were measured. XRD and SEM techniques were utilized to study the phase compositions and morphology of the formed hydrates. The results revealed that the mixes contain 0.5% NFS with 9% SF exhibited more compressive strength values than other mixes. The blend mix contain 10% MK + 9% SF (M10MK + 9SF) showed the highest sulfate resistance than other mixes. Whereas, the addition of NFS to the blend pastes boosted the reading of compressive strength of pastes immersed in sulfate solution than those without nano fumed silica. In general, the cement pastes incorporating 0.5% NFS exhibited fire resistance at 500 °C.