Cooper Concrete estimates that an empty concrete mixing truck with a 10-cubic-yard capacity weighs about 26,000 pounds. A similarly sized loaded truck can weigh up to 66,000 pounds.
According to Wikipedia, Stephen Stepanian filed a patent for the first concrete mixing vehicle in 1916. The initial application was denied due to the inability of Stepanian’s truck to securely transport the concrete, which Cooper Concrete claims weighs between 3,000 and 4,000 pounds per cubic yard, depending on its composition. Stepanian, undeterred, reapplied for his patent and was granted final permission in 1933.