According to Cooper Concrete, a 10 cubic yard capacity concrete mixing truck weighs over 26,000 pounds when empty. A similarly sized vehicle that is loaded may weigh as much as 66,000 pounds.
According to Wikipedia, Stephen Stepanian applied for the first concrete mixing truck’s patent in 1916. Because Stepanian’s truck design could not carry the concrete, which Cooper Concrete estimates weighs between 3,000 and 4,000 pounds per cubic yard depending on its composition, the initial application was turned down. Stepanian wasn’t deterred and reapplied for his invention, which was finally accepted in 1933.