The aim of present study was to study on Portland cement concrete using demolished aggregate and silica fume. The High Strength concrete has become more popular in recent years owing to the extraordinary advantages it offers over the conventional concrete but at the same time strong enough to be used for the structural purpose. The aim of the present work is to study the attitude of coarse aggregate replaced with demolished aggregates in volume percentages of 10%, 15%, 20%, 25% and 30% cement replaced with the silica fume in weight percentages of 5%, 10%, 15%, 20%, and 25 %. The conventional mix has been designed for M40 grade concrete. In this research, cubes, cylinders and beams of standard size have been cast and tested after 3 days, 7 days 28 days, 56 days of curing period.