Investigation on nano-silica blended cementitious systems on the workability and durability performance of self-compacting concrete

This paper manifests the performance of self-compacting concrete (SCC) together with the addition of nano-silica as supplementary cementitious material. For this study, nano-silica in different proportions of 1, 2 and 3% was used. The M40 grade of SCC with a total of four mixes inclusive of control concrete was prepared. The fresh state workability of SCC was assessed by conducting the slump flow, L-box test, V-funnel test, Orimet and J-ring tests. Hardened concrete test like tensile strength was also carried out. The durability tests on permeability properties like water absorption, porosity, sorptivity, rapid chloride penetration and sulfate resistance test were determined at the age of 7, 28, 90 and 180 days. The tensile strength showed 18.82% greater strength for 2% nano-silica compared to the control mix. The permeability tests exhibited a decrease from 378 coulombs to 99 coulombs and showed advancement in SCC with nano-silica. The scanning electron microscope study was conducted on SCC samples to determine the microstructural behavior of nano-silica. A dense matrix with better development of calcium silicate gel was observed for 2% nano-silica.