Cement Mixer

a truck that has a large container which turns when it is filled with wet cement so that the cement will not become hard.The mixer is similar, though larger in scale, than the smaller ones found on construction sites. A large motor, separate from the engine, rotates the drum on the truck body, and a series of blades or a screw powered by the same motor keeps the aggregate, water and cement in constant motion.Typically, a mix is about 10 to 15 percent cement, 60 to 75 percent aggregate and 15 to 20 percent water. Entrained air in many concrete mixes may also take up another 5 to 8 percent.