Legal capacities will vary by state. In North Carolina, 16 - 17 tons was typical. In some of the northeastern states, they'll let a triaxle gross in the 70 - 72k range on secondary roads.
12 or 14. Depends if lift axle has dual tires or not.
17 tons
You'd have to be more specific. Dump trucks come in many sizes, and there is no "one size fits all" answer.
Three - the two drive axles, and the steer axle.
25-28
Which weight? Gross weight? Tare weight? What configuration? 1 ton pickup? Single axle Class 7/8 truck? Tandem axle truck? Tri-axle truck? Quad axle truck? Quint axle truck? Centipede? "Superdump" quint with Strong Arm? Transfer truck? Tractor-trailer end dump, or belly dump, or side dump? Try to narrow down the variables a bit. There's really no way of knowing what an "average" dump truck is without knowing statistics of how many single axle, tandem, tri-axle, quad, quint, centipede, and superdump dump trucks are out there - to the best of my knowledge, no such statistics have been compiled. At the company I work for, our tandem axle dumps (with steel dump bodies) weigh between 23,000 and 24,500... the 23,000 lbs. trucks are the Peterbilt 330s, and the 24,500 lb. trucks are the Kenworth T800s with "rock tub" steel bodies, high lift gates, and split gate beds. These are the tare (empty) weights, not the loaded weights.
Dump trucks come in many sizes and configurations. Additionally, vehicle weight laws vary greatly between countries. We would have to have some idea of what configuration and jurisdiction you had in mind. Configurations of dump trucks would include single axle, tandem axle, tandem axle with twin steer, tri-axle, quad axle, quint axle, centipede, tractor-trailer end dump, etc.
It varies from state to state, and will also be dependent on the tare weight of the truck. I can tell you that, in North Carolina, 13 to 15 tons is the norm for a tri-axle dump truck.
Dump truck specifications vary greatly- too much so for a "one size fits all" type of answer. A better idea of what type of dump truck, how many cubic yards the bed can hold, etc would be needed here.
Dump trucks typically don't haul liquid commodities, unless you're thinking of snow removal operations where they'll be outfitted with prewet or calcium chloride tanks. Even with that in mind, you need to remember that there are many different sizes of dump truck out there. 15 cubic yards is "typical" for a tandem axle dump truck.
Varies by state. In North Carolina, a tri-axle is generally good for 15 - 17 tons, depending on the tare weight of the vehicle.
it depends on how big the dump truck is