When flooding the base it is always required to put significant amount of forces and time. If it is correct to make everything, the firm reliable support will be guaranteed to construction.
Works on construction of the good qualitative basis have to be performed with strict following of technology. When concrete is prepared, filled in in form and dehydrated, works stop until it does not harden. Time that the base could grab well is very important to wait – water and cement have to react.
What is the time the base hardens
Approximately in week when concrete "grabs", it develops strength about 70%. Upon termination of this term on the flooded base it is possible to begin to carry out construction jobs. In the period of skhvatyvaniye concrete should be moistened a little. Moistening of concrete is carried out with the purpose to support the chemical processes happening in it. As a result of contact with water, minerals of which cement grains are made turn into new formations – potassium hydrosilicates.
Process of transformation will be long, it can be made within several years. But builders not always wait so much.
That works on construction of buildings were carried out nevertheless quicker, the control term of hardening of concrete after which it can be subjected to design load is established. For the concrete made in the conditions of building which will be defended and harden under natural conditions this term is determined equal 28-30 days.
What it is useful to know during the work with concrete
When filling the base from wall it is necessary to leave small distance – about 30-40 centimeters, and to fill up emptiness with sand. So do for prevention of skaplivaniye of water about base walls, otherwise there is risk of inflation of the earth in winter season. Let's sometimes allow also longer term for concrete hardening. For example, at construction of dams and dams, embankments, bridges – such constructions are under construction very slowly therefore it is possible to apply overall load only through long time to the put concrete. When hardening concrete for any construction it is necessary to remember that after control term concrete still continues to gain for a long time durability though now much more slowly. In calculations this time is not considered.
Additional set of durability after time, exceeding established periods of hardening, it is possible to consider kind of guarantee of reliability of designs – concrete or reinforced concrete.
High temperatures are capable to accelerate the chemical reactions happening in concrete. But it must be kept in mind that at very strong warming up concrete dries too quickly, and ceases to harden. It is explained by the fact that the water concluded in concrete will evaporate very intensively, and chemical reactions will not be carried out properly.