The foundation is the support and foundation of any structure, its base and foundation. It accounts for the load from all floors of the house, and therefore it is especially important to pay attention to the quality of concrete for the foundation and the choice of materials from which it is poured. The service life of buildings depends on its reliability and strength. Therefore, the main requirement for developers is not to save on building materials, choose high-quality components for pouring the foundation and concentrate on the brand of cement .
Types of foundation
The types of structures used for the foundation depend on the characteristics of the ground of the construction site, the type of structure, the wall material, and the climate. There are 2 main types of foundation: columnar and ribbon.
The peculiarity of a ribbon foundation is determined by its appearance: it is a continuous ribbon of reinforced concrete. Although the name aspic is more suitable for it, since the solution is mixed in a concrete mixer to a homogeneous mass, and then it is poured into the formwork. Its required depth depends on the level of freezing of the soil + another 20 cm. Additives such as Buta stone, gravel, and brick exclude the ingress of ground water. Due to the large amount of cement mortar, the cost of the composition is quite high. However, the foundation turns out to be strong and durable, able to withstand a lot of weight, and therefore it is used for the construction of heavy buildings, multi-storey buildings and cottages.
For the construction of structures that have a small mass and have small dimensions, a columnar foundation is used. This option has sets of pile posts located in the corners of the building and in places experiencing increased load. Pillars of the base are made of concrete, Butane, pipes. Such a foundation is suitable for the construction of small structures no higher than one floor (houses, baths, outbuildings).
How correctly and in what proportions to prepare a solution for the foundation?
When self-preparing concrete for the foundation with your own hands, you need to study the characteristics of the elements that make up its composition. Portland cement is the basis of a binding solution, the presence of various fillers and additives give it certain properties and qualities, adding water to the mixture guarantees the necessary viscosity and ductility. The cement ratio and the content of parts of the mortar affect the final performance of the finished structure.
Important! If buckets are used to measure the proportion of the foundation, the brand of cement must be taken into account. If it changes, then the ratio of cement, sand and crushed stone will also be different.
For large-volume construction work, it is necessary to use a concrete mixer, in which cement, sand, crushed stone and clean water are immersed in the right proportions, which, when mixed, form a mixture of the desired consistency. The proportions of concrete for the foundation are 1: 3: 5.
Why do I need to know the brand of concrete?
To determine the brand of concrete, it is necessary to calculate the load that the foundation of future houses will experience, because depending on this, the proportions of cement and sand for the foundation are calculated. From the selected grades, the ratio of sand and the ratio of crushed stone is determined.
When building a house independently, developers often ask what proportions of cement for the foundation must be observed in order for the building to become stable and be able to withstand the negative effects of the external environment.
M200 concrete is a universal material of medium strength, suitable for the construction of low-rise buildings with light floors. For the mortar, 500 cement is used (sometimes the M400 brand is used). The required number of elements must be mixed in a ratio of 1: 3: 4.5:0.7 (cement, sand, crushed stone, water).
The use of heavy concrete M300 is justified for the construction of high structures, the foundation of which should be much stronger.
The ratio of the proportions of cement 500 with other elements is 1: 2.5: 3.5: 0.7.as you can see, in this case, the proportions of sand and crushed stone have decreased, which indicates an increase in the proportion of cement and water, which make the mortar plastic, and the foundation is much more wear-resistant.
Thus, as the concrete grade increases, the volume of the most expensive cement component increases. Therefore, the question of careful calculation of the mass of the structure and the bearing capacity of the foundation should be made even before choosing and buying cement of a specific brand and dry mixes.
Another way to reduce construction costs is to buy ready-made concrete mortar from the factory. To make a good foundation, you need to add only fresh and high-quality components and observe the storage conditions for building materials.
Basic requirements for components:
- the cement should not be “older” than 2 months before the mortar is prepared;
- the sand must not contain any foreign matter or particles. If it is dirty, keep in mind that it needs to be sifted and rinsed;
- the fraction of crushed stone and gravel should be no more than 8 cm, the use of limestone is not allowed;
- only clean tap water is used.
Thus, taking into account all the features and nuances, as well as if it is impossible to comply with all the above conditions, it is better to buy ready-made mortar for the foundation at the factory. The buyer always has the opportunity to study the documentation, because in the construction industry there is a careful selection of components for mixing concrete, and compliance with quality standards and expiration dates is set with special attention.
As a rule, manufacturers offer a choice of several grades of concrete, each of which has different technical and operational characteristics. And, in order not to make a mistake with the choice, the buyer, in addition to the strength grade, needs to pay attention to such indicators as:
- frost resistance (F50-150 values are allowed in civil construction);
- moisture resistance (W2-W4 is the norm for foundations);
- mobility (P3 or P4 allowed).
Using concrete mixers, the manufacturer has the opportunity to deliver fresh and ready-to-use product from the factory directly to the construction site. The buyer should expect that the solution has a limited shelf life and must be used immediately after transportation. Therefore, if you buy a ready-made mortar for pouring the foundation, carefully plan the time of construction work and coordinate the terms with the delivery service.