The main objective of the present paper is to investigate the influence of recycled aggregate obtained from different demolished structures on the mechanical properties of concrete. The recycled aggregates are obtained from a demolished RCC slab of a 20 years old residential building and two RCC culverts of 15 years old of different locations. Four concrete mixes are prepared with recycled coarse aggregates obtained from each source. All mixes are designed for M25 grade concrete in accordance with Bureau of Indian Standards (BIS) IS: 10262-1982. The Physical and mechanical properties of natural and recycled coarse aggregates are studied. In addition, the properties like compressive strength and static modulus of elasticity of both normal and recycled aggregate concretes (RAC) are investigated. It is observed that irrespective of the source and type of structure, the recycled coarse aggregates obtained, are relatively finer and the surface texture is more porous and rough due to the adherence of old porous mortar to the recycled aggregates than natural aggregates. The recycled aggregate concretes show better improvement in compressive strength when it is air dried after seven days of wet curing compared to fully wet curing till the age of testing. In addition, it is observed that at an applied load the deformations are more than normal concrete. This attributes the presence of weaker interfaces and micro cracks in recycled aggregate concretes.