Transport of Concrete by Belt Conveyors:

Within this method, the belt used has a covering of rubber of width 60 cm and speed not exceeding 1 m/s. The slump of concrete combine should not be more than 6 cm in any case. A line of the conveyors should not have any marked breaks in plan. An angle of inclination of the conveyor must not exceed 18° for 4 cm slump and 15° for 4 to 6 cm slump. Flat belts are used just for a distance of 20 m and if the distance is large, the working part of the belt should be trough shaped. While the concrete is unloaded from the conveyor or while it is transferred from one part of the conveyor to another, guide boards should be used to avoid segregation of concrete. Boards shall be arranged properly so as to prevent segregation (Figure). Free falling of concrete from the roller of the conveyor is also not allowed.

For getting continuous supply of concrete this technique is used. This method is most appropriate under summer conditions for concreting structures at a distance of 250 to 500 m from the place of mixing and also in those cases where it is hard for Lorries and other kinds of transport to reach the structure.

Figure: Methods of Discharging Concrete from Belt