The rapid industrialization and urbanization in the country leads lot of infrastructure. This process leads to several problems like shortage of construction materials, increased productivity of wastes and other products. This project deals with the reuse of waste plastics as 20% replacement of coarse aggregate in M20 grade concrete. Usually M20 grade concrete is used for most constructional works. In our project we are going to replace about 20 % of natural coarse aggregate to recycled plastic aggregate. Tests were conducted to determine the properties of concrete with 20% replacement of coarse aggregate with the plastic aggregate under the temperature variation. We apply the temperature on coarse aggregate cubes, 20% replaced Plastic aggregate and Heat resisting paint applied cubes and place in furnace under certain interval (2000C, 3000C, 5000C) temperature. Then after 24 hours remove the cubes from furnace and take the compressive strength test on cubes.