What is the capacity of a concrete truck?

"capacity of a concrete truckis,the large usual sixe is 9 yards,the smaller are about 3 yards"

Actually over the years the size of mixer drums has increased

You will notice the large the drum the more axles the truck has plus it depends on what make a mixer it is 1) London 2) Jaeger 3) Rex

The early 3 axle trucks with a rex mixer carried 5 cu yards

That increased to 7 cu yards

London and Jaeger drums carried 8 cu yards

On trucks with 3 axles and a tag (4th axle that trails the truck) carried 12 yards or 10m3

The newer 5 axle trucks usually hold 14-16 cu yards

Please understand that 1 m3 = 1.3 cu yards

1 cu yard/27 cu ft of 20 mpa concrete at a 3" slump weights - 3400 lbs

Hope this helps you