Strength characteristics of concrete are the main parameters of the choice of this construction material intended for filling of the base of the house, extension or other building. Directly they influence bearing capacity of foundation of the building. As to choose concrete for the base?
1. Professional builders recommend to use several types of concrete which are in range from M100 (durability in the amount of 7.5 MPas) and to M700 (the same indicator in 50 MPas). And it is necessary to be guided, proceeding from several parameters – the size of load of the basis of design which defines bearing capacity of construction material; the moisture resistance degree depending on depth of underground waters in relation to the base; other construction features and its bases. And the last are defined by directly architect supervising the project and familiar with all features of construction.
2. So M100 and M150 brands ordinary apply to laying of the bases of tape type on the soil which is characterized by weak flowability and also in case of filling of the bases on average or small depth. Normally it is frame or wooden buildings. In turn classes M200 and M250 are applied in case of need fillings of bored piles in the buried bases of tape type or for fixing of soles under further mounting of columns on soils of puchinisty type.
3. Stronger quality classes – M300 and M400 – are applied in need of construction with participation of monolithic grillage or floating plates. Their bearing capacity is much more, than at the previous classes. Ordinary such construction materials use at construction of the multy-storey buildings made brick, reinforced concrete and blocks of cement.
4. Above-mentioned classes belong to "easy" type, and M500, M600 and M700 brands are considered as stronger and expensive. At construction of the country house or cottage even to 3-4 floors there will be quite enough M300 and M400, and three others – for industrial and high-rise buildings. In private works they will not be necessary at all. Builders also do not recommend to be overzealous in the choice of class of concrete which can be calculated most precisely, otherwise the construction estimate will be strongly overloaded, and the customer will incur unreasonable expenditure.
5. Calculation of total load on the base of the building has to be conducted, proceeding from the cumulative mass of all its constructional elements. Therefore for exact definition of future loading it is necessary to carry out calculation of density of the used materials on all spent volume to building weight. And it is the best of all not to do it independently, and to ask for the help the architect.