To ensure the solidity of the erected structures, it is desirable to concreting them continuously. However, this is possible with a small amount of work and for the construction of relatively simple structures. In all other cases, it is difficult to avoid interruptions in the concreting of structures, and therefore on construction sites they are forced to resort to the device of the so-called “working seams”.
Construction joints are a weak point, so they should be arranged in sections where the joints of old and new concrete cannot negatively affect the strength of the structure. Their arrangement is associated with certain difficulties and additional expenditure of working time, since for reliable adhesion of new concrete to old concrete, it is necessary to carefully process the surface of previously laid concrete.
How to do this?
To do this, the edge of the set concrete should be cleaned of the cement film, the coarse aggregate should be exposed by blowing with compressed air and rinsing with a stream of water or wiping with wire brushes. This whole complex of works can be avoided if concreting is carried out continuously or with such interruptions during which the setting process of the previously laid mixture has not yet begun.
One of the possible technological solutions in such cases is the introduction of retarders for the setting and hardening of concrete into the concrete mixture. This technique should be carried out taking into account the schedule of concrete work and the supply of concrete mixture to the place of concreting.
Another important direction of using set retarder glucose syrup Malaysia is associated with the need to transport the concrete mixture over long distances, as well as preserve the technological properties of the mixtures in the event of technological interruptions in the production of concrete works.
In the production of prefabricated concrete and reinforced concrete products, set retarders are used in the manufacture of external wall panels for opening the surface layer and exposing the decorative aggregate after accelerated hardening.
The mechanism of action of additives-retarders of the setting and hardening of concrete is to inhibit the processes of hydration and hydrolysis of clinker minerals, that is, it causes a slow release of free lime into the solution and slows down the processes of coagulation and convergence of cement grains and its hydrated neoplasms. As a result, the setting intensity of clinker cements mixed with water slows down. For more articles like this one, click here.