The concrete mixer truck is a special truck used to transport concrete for construction; because of its shape, it is also often called a snail truck. This type of truck is equipped with a cylindrical mixing drum to carry the mixed concrete. During transportation, the mixing drum will always be kept rotating to ensure that the carried concrete will not solidify. After the concrete is transported, the inside of the mixing drum is usually washed with water to prevent the hardened concrete from occupying space and make the volume of the mixing drum less and less.
