Abstract
Untill now, the agitating efficiency of the truck agitator has been estimated by quality of discharged concrete after agitating. Because directly we can't observe the flow of concrete in the agitator. In order to study about the agitating efficiency of fresh concrete, a new technique was discussed in this report. With help of visualization technique, it became possible to obtain the information about movements of coarse aggregates and mortar in fresh concrete model. As a result, it was cleared that there were three types of flow, which consist of surface layer flow, overflow and confined flow, of fresh concrete model mixed in it. In addition, the study also shows that the segregation of the fresh concrete consisting of coarse aggregate and mortar occurred at the interior in a truck agitator when amount of concrete was increasing.
