Concrete, Dry Mixtures

Concrete is a non-natural stone building material that acquires as a result of solidification of a special mixture, which includes a small gluing material, water and aggregate (large or small). If necessary, all of the above can add special additives that make better performance. But the composition of the concrete mix should ensure cold resistance, watertightness, strength and other necessary features. In general, this is the main building material, which is used in all construction sectors. In fact, such material is very well known, because it makes it possible to obtain material with different combinations of features, for the highest ease, simplicity and accessibility, for excellent technical and financial properties (small production costs, mechanization and automation of its preparation, etc.) and much Other. The most important features of concrete are density, strength and fire resistance. But there are also disadvantages, which, in fact, have every stone - this is low tensile strength, but this defect is eliminated in the manufacture of reinforced concrete - the armature takes care of everything. Depending on the density, concrete is divided: - especially heavy (density of more than 2500 kg / m3) - are used for protective systems, are made on especially heavy fillers (ore, cast-iron scrap, etc.); - heavy (density 2200 - 2500 kg / m3) - produced on sand, gravel or gravel from heavy rocks; - light weight (density 1800 - 2200 kg / m3); - light (density 500 - 1800 kg / m3). Density is the ratio of the mass of concrete to its volume (kg / m3). The higher the density, the stronger the material. The density is directly influenced by the presence of pores that appear during its manufacture: by evaporating unnecessary water that has not interacted with cement, with very poor mixing of the concrete mix or with a small amount of cement. Strength is considered to be the most important indicator of concrete, for the strength index of concrete, the compressive strength is taken. Strength increases due to the contact of cement with water, which naturally passes in warm and humid conditions. After laying for 15 - 28 days, concrete needs maintenance. In the warm season, the water in the concrete should be preserved by the method of periodic watering and shelter from the sun's rays. Retention of moisture in concrete is an extremely important factor, it is realized by watering (concrete without plasticizer) - at an air temperature of over 20 C - after three hours, including at night and kept under a layer of raw sawdust, burlap and sand for 7 days. And if the material with the addition of plasticizer, keep at least 14 days. To create a variety of types of grounds, the question arises: what brand of concrete will be more appropriate for the established tasks, which depend, first of all, on the type of monolithic construction, even on the conditions for further use. Features that affect the choice of the type and brand of concrete for the foundation of the house, not so much. Here are the main ones: the load on the concrete system and the cumulative weight of the building; Relief of the site; The variant is located under the ground and the basement of the structure: piles, tape, the existence of the basement. All of these listed points directly affect the selection of the brand of concrete. Projected overloads on the construction is a very important indicator, which should be taken into account when selecting a concrete solution. The properties of the earth are also a significant factor. If the land is sandy or rocky, convenient for installing a strip foundation, then it's time to take the brand of concrete M200 - M250. Clay soils are much more capricious to the choice of concrete for the foundation. Remember, normally selected concrete grades will ensure the durability of the structure.

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