Concrete should be used only from factories, which ensures strict compliance with the requirements for the production of a mixture intended for installation under water. The plant should produce a mix with a consistency appropriate for underwater concreting and in the case of high air temperature or long transport time, with correspondingly increased fluidity. However, you should avoid adding water to the mixture in car mixers ("Pears") on construction site. The operation of the mixer is all the less effective, the more liquid it is in the mixture. Therefore, adding water causes the mixture to segregate.
It is sometimes used to bring to the construction site aggregate and cement mixed in the factory, and to add water and possibly liquid additives only before installation, after mixing in a concrete mixer.
The organization of transport of the concrete mix to the place of incorporation should meet the following requirements:
— transport mieszanki powinien trwać krótko,
— mieszankę należy przewozić w mieszarkach samochodowych,
— dostawa mieszanki powinna przebiegać bez przerw i zatrzymywania mieszarek na budowie.
It follows from these requirements, that the mix plant should be located near the underwater concreting site and that good organization of truck mixers transporting concrete is necessary.
Any interruption in the supply of concrete and any deviation from the movement plan of the mixers increases the risk of starting concrete setting before placing it in the trench., which is usually catastrophic for construction.
The requirement to use truck mixers results from the segregation susceptibility of the liquid concrete mix. It cannot be counteracted when the mixture is transported in containers.
Mixers with a capacity of 4-6 m3 should be used. Unloading of the mixer is slow and if a larger batch of the mixture is brought in too much time between its production, and the beginning of concrete setting.

In order to ensure the continuity of concrete supplies, it is necessary to use production plants and truck mixers in very good technical condition.

It is expedient to use radio communication between the construction sites, concrete factory and mixer drivers.

It is best to pour the concrete mix from the truck mixer directly into the filler pipe. When this is not possible, the mixture is fed to the pipe by a pump. Pump transport is also used in the case of a short distance between the concrete plant and the place of its incorporation into the water.

When a pump is used to transport the concrete mix, then it is necessary to precisely dose the components of the mixture and to make it very regularly. When these requirements are not complied with, the mixture is segregated and the transmission pipes are clogged.

Due to the special requirements for underwater concreting, the choice of concreting method should be adapted to the constructed structure and local conditions, in which it will be performed.