Effect of Blending Micro and Nano Silica on the Mechanical and Durability Properties of Self-Compacting Concrete

The appropriate utilization of industrial waste materials like fly ash and silica particles from thermal power plants and ferrosilicon industries could be effectively used as partial supplementary cementitious materials. The fly ash was used as binary blends in the cement followed by micro silica and nano silica as ternary and quaternary blended materials in cement system of self-compacting concrete (SCC) respectively. As SCC possess high flowability, passing ability and resisting ability against segregation. The cement was replaced partially by weight from 5% to 15% by micro silica and 1% to 3% nano silica correspondingly. The behaviour of SCC at fresh state was determined using the following laboratory investigations (slump test, V-funnel and J-ring tests). The mechanical properties like compressive strength and flexural strength were analysed for different ages of concrete. The durability characteristics were identified by conducting the saturated water absorption test and the chloride penetration through rapid examination was carried out for all types of SCC mix proportions. The SCC mix containing 2% nano silica and the combination mix of 10% micro silica with 2% nano silica showed a comparable strength increase of 9.28% and 10.84% at 90 days. The addition of nanosilica enhanced the durability properties with less water absorption and decreased depth of chloride penetration.