Concrete is an artificial construction material obtained during the formation and further solidification of rationally selected and compacted mixture.It consists of cement or other binders, as well as small and large aggregates with the addition of water.In some cases, where the need of special density concrete, for example, asphalt concrete technology, no water is added, and the use of special additives.
Its main advantages are environmentally friendly, as well as the presence of huge raw material base.It is possible to apply it in different operating conditions.It can be called a versatile material that is used extensively in all fields and sectors of construction.It is chemically and heat resistant, sound-absorbing and conducting nuclear radiation.
mixing sand, cement, water and gravel allows to obtain the desired density of the concrete.The ratio will depend on the moisture content of sand and gravel, cement brand and factions.In some cases, it will affect the amount and composition of additives, water repellents, plasticizers, and so forth. For example, to obtain a density of concrete M200, used cement grade 400.
One important characteristic of this material is water-cement ratio.There is a direct relationship water / cement.That is, the lower the ratio the stronger the concrete.A material having a density of 200, has a considerable mass (which is its only "net").It reaches 2400 kg / m3.This is great for the concrete load-bearing structures, columns, headers, etc.With too small amount of water and high density of concrete has a low ductility.It is used for the basis of equipment, blind area around the house and so on.
There is one mistake that often make when mixing the solution.The handicraft production often added an excessive amount of water, which reduces the density of the concrete and increases mobility.This in turn greatly reduces its strength.
For concrete has its own classification, which is done on purpose, types of fillers and binders, curing conditions and structure.By appointment, you can select normal (for civil and industrial buildings) and special (road construction, thermal insulation, hydro and decorating work) concrete.
By type of binder it is gypsum, lime, cement, shlakoshchelochnyh (asphalt, or polimernbeton of reservoir).Forms its aggregates are also different: porous, dense and specific, and its content - skinny, fat and commodity.Also on the concrete structure can be dense, porous, cellular and large pore.Terms hardening distinguish the following: natural, heat and humidity treatment at atmospheric pressure or autoclave.
main indicator in the characterization of concrete - is its compressive strength.It defines a class of concrete.For example, the density of concrete B25.This means that 95% of this class will withstand a pressure of 25 MPa.That is, the letter "B" and the numbers indicate the pressure that can withstand the concrete in megapascals.Counting indicator of strength is required to take into account regulatory factors compressive strength.It is suitable for the density of concrete B25.Age of concrete on the basis of his class will be determined by the compressive strength and axial tension, which is appointed at the design stage.Are taken into account the possible ways of construction and design loads on the structure and the conditions of concrete hardening.
density of concrete in 25 is ideal for floor slabs, solid foundations, bowls pools.This most commonly used material for this purpose.Additionally, builders and the material used for other structures for critical applications.The density of concrete in 25 ensures excellent quality of the finished structures, provided, of course, that the product purchased is fully consistent with the published specifications.
