Early and Long-Term Assessment of High-Performance Concrete Contained Nano-Silica Exposed to Sulfate Attack

Abstract

This research aims to study the influence of using the Nano-silica in high-performance concrete subjected to external sulfate attack with different levels. Four concrete mixes were prepared by using two types of Portland cement: ordinary and sulfate resistant cement. From each mix, cubic concrete specimens were cast and subjected to different exposure conditions. The concrete cubes were immersed in sodium sulfate (Na2SO4), magnesium sulfate (MgSO4) and calcium sulfate (CaSO4) solutions with concentrations of (1.5, 10 and 15) %. The specimens were tested for compressive strength at (3, 7, 14, 28, 90, 180, 270, 365, and 545) days and the values of sulfate penetration in concrete samples were determined. It can be found from the results that high-performance concrete containing Nano-silica gave a relatively good sulfate resistance compared to the reference sample. Moreover, results indicated that the strength deterioration was reduced after incorporating nano-silica.