These machines are called Earthmoving Equipment. Below is a list of webpages showing photos and describing each of of these major roadwork equipment.
As for the scarifiers and blades, these are attachments that are used on Graders. Blades are used to do final leveling of the earth before the rood bases or asphalt is placed. Scarifiers on the other hand 'scratch' the ground (like plowing) in order to prepare the earth to be mixed with the correct of amount of water.
Major Earthmoving Equipment:
Hope this helps. If you need further information please feel free to ask.