Figure 4-3. Typical on-site arrangement of mixing equipment and materials.
Site mixed. Method used for delivering plastic concrete by chute, pump, truck, conveyor, or rail dump
Central-plant mixed. Method used for delivering plastic ready-mix in either open dump trucks or mixer
Central-plant batched (weighed and measured). Method used for mixing and delivering "dry-batched"
ready-mix by truck.
Portable mixing plants. Method used for large building or paving projects distant from sources of supply.
Stationary mixers (including both on-site mixers and central mixers in ready-mix plants). They are
available in various sizes and may be tilting or nontilting, with open top, revolving blades, or paddles.
Mobile mixers (including both truck- and trailer-mounted mixers). A truck mixer may pick
up concrete from the stationary mixer in a partially or completely mixed state. In the latter
case, the truck mixer functions as an agitator.
Truck mixers generally deliver concrete
from a centrally located stationary mixer to the construction site or pick up