Effect of colloidal nano silica (CNS) on high strength risk husk ash concrete

Abstract

Now a day mineral admixtures are use as replacement for cement in concrete because it reduces CO2 emission during hydration of cement. These mineral admixtures reacts with calcium hydroxide forms during cement hydration and this is called as pozzolanic action. The pozzolanic action of mineral admixture like Rice Husk Ash (RHA) would come into play at later stages. The Colloidal Nano Silica (CNS) which is nano material use in cement for accelerating pozzolanic action. In the present study, the mineral admixture RHA was used as 5, 10,15% replacement for OPC in M60 grade of concrete. The 10% RHA was taken as optimum dose on the basis of workability and compressive strength. To this 10% RHA concrete, effect of 1, 2, 4, 6% CNS addition were study by workability, compressive strength and split tensile strength. The workability decreases as CNS doses increases in 10% RHA replacement mix. The compressive strength of 2% CNS addition in 10% RHA replacement mix was increased by 8.44%, 9.5%, 13.21% at 3, 7, 28 days with respect to 10% RHA replacement mix without CNS. The split tensile strength of 2% CNS addition in 10% RHA replacement mix was decreased by 8.13%, 8.06%, 1.93% at 3, 7, 28 days with respect to 10% RHA replacement mix without CNS.