Published Paper Details:

The amount of recycled aggregates produced was increased day by day leading to environmental affects. The disposal of the recycled aggregate is uneconomical and can be utilized in the construction activities. In this paper an attempt has been done to find the efficiency of replacing coarse aggregate with recycled aggregates. The influence of combination of silica fume with recycled aggregates on concrete for M45 grade with 0.4 W/C ratio and 0.75% superplasticizer by weight of the cement. Percentage of silica fume is varied as 25%, 30%, 35% and 40% by weight of natural aggregate and the silica fume by 10% and 20% by weight of cement to determine the fresh and hardened properties of the concrete. Compression, flexural, split tensile strength and modulus of elasticity tests are conducted to determine the influence of silica fume with recycled aggregates after 7, 28 and 56 days curing. Compressive strength of the concrete increases with increase in the amount of recycled aggregates up to 35% and then decreases with further increase in the amount of recycled aggregate. Optimum compressive strength of 72.64 Mpa and optimum flexural strength of 5.32 Mpa was obtained at 10% of silica fume and 35% of recycled aggregate. Modulus of elasticity of 34611 Mpa was achieved at 10% silica fume and 35% recycled aggregate.