Effect on mechanical, durability and micro structural properties of high strength self compacting concrete with inclusion of micro and nano silica

The aim is to study the strength, durability and microstructural properties of high strength self compacting concrete (SCC). 25% cement is replaced by fly ash (10%) and Ground granulated blast furnace slag (GGBS) (15%) for all the mixes except control mix (M1). Micro silica (MS) and Nano silica (NS) were added at different percentages to make high strength SCC. As a cost reduction and to promote renewable material Manufactured Sand (M-Sand) used as a fine aggregate instead river sand. To determine the fresh properties of SCC followed the EFNARC 2002 guidelines. The Compressive strength test was conducted to find strength properties of SCC. The results showed that addition of MS and NS drastically decreases the fresh properties but increases the strength properties of SCC. Ultrasonic pulse velocity test was conducted to find dynamic modulus of SCC. To find the resistance of chloride ingress in to concrete by conducting Rapid chloride permeability test (RCPT). Further microstructure of SCC studied using SEM images. Finally cost analysis was performed for each mix and its results indicated as ratio of strength/cost. The combination of MS and NS in a mix (M7) showed the optimum compressive value, optimum durability and improved micro structure among all the mixes. But in ratio of strength/cost a mix M2 showed optimum result.