Brick Wall
Here you can see the brick wall I have made out the 3 textures under it. All I did for this was trim the textures a bit and change the colour of the splat.
Concrete Wall
To create the concrete wall all I had to do is separate the cracks and rust and put them where I wanted it.
Metal Wall
To create the metal wall I have added some rust at the top and selected the cracks in the metal to make them look like rust.