I own one with a 5 yard dump box on it. I weigh in at 11060lbs empty.
A tandem axle (ten wheel) dump truck can typically weigh between 20,000 and 25,000 lbs., depending on make, model, steel or aluminum dump body, etc.
GVW means Gross Vehicle Weight. That's the maximum permissible weight of the truck plus the trailer (in the case of a combination rig) plus the load. Therefore...if you take your dump truck, hook a 20,000-lb empty trailer to it and put a 25,000-lb backhoe on the trailer, the truck needs to weigh less than 25,000 lbs if you want to remain legal.
First set your Trailer brakes. unlock the back gate, and then engage your PTO. push lever forward to raise the trailer. the truck will be pulled towards the tandems as it rises.
Any vehicle towing a trailer or other vehicle is, in essence, a tractor. If the dump truck is towing another vehicle (trailer, etc.), then it is a truck tractor. If it isn't, then it's just a straight truck.
All things dependent, you'd probably be looking at 13,000 to 16,000 lbs. If you need a precise empty weight, my suggestion would be to scale out empty at your nearest truck stop.
The main differences in the dump truck and standard truck is the size. The dump truck you will be able to haul more stuff and it will be easier to off load.
A dump truck is simply a truck with a dump body - it could be a side dump, belly dump, or end dump. An end dump dumps out of the rear. "End dump" is generally used to refer to tractor-trailer end dumps, while single vehicle end dumps are generally just referred to as "dump trucks".