What is concrete?

What can be called concrete.

An artificially created stone, consisting of several components. It consists of cement, water, gravel or gravel. The composite material, produced with rationally selected components, is formed and hardened after mixing. The price of concrete depends on cement, and other components included in it. Some of them are not cheap.

Determination of strength.

The strength of concrete is the main of its properties. By analogy with stone, concrete withstands compression much better, the way to determine the strength of concrete structures is their resistance to stress. It depends on the cement used for pouring, increases as a result of chemical processes occurring in the water-cement mixture. To complete all processes and obtain high-quality concrete, the processes must be carried out under the conditions of temperature and sufficient humidity. Chemical processes are completely stopped after the mixture dries or freezes. Previously, concreting took place exclusively in the summer, as freezing led to damage to the pour.

How is the homogeneity of concrete determined?

The main requirement for concrete structures is uniformity. In order to get an idea about the quality of concrete, its uniformity, a control pour is made using the brand of cement used in the performance of the main work. The conditions for temperature and humidity must be fully observed when receiving control samples. After the final formation of concrete, it is possible to analyze its strength, homogeneity. The uniformity of the composition is greatly influenced by the components used in the preparation of the mixture. Quality and brand of cement, crushed stone, gravel. Exact compliance with the proportions of the components in the concrete will undoubtedly affect its quality. It should be understood that when making concrete by hand, each portion will differ in quality, since it is almost impossible to maintain the correct proportion. Therefore, when forming large concrete structures, it is produced in the factory and delivered to the site in special mixes.

Density of concrete.

It is one of the most important components of the quality of concrete products. Density is determined by the ratio of its mass to volume. The more accurate the ratio, the stronger the concrete structure, the greater the load it can withstand. The density is affected by the presence of pores in the hardening mass of concrete. They are formed in case of non-compliance with the technology of its manufacture, poor mixing of the components.

Marking.

You can buy concrete cheaply if its brand is low. The brand is determined by its strength, the more significant it is, the stronger the concrete product. The most commonly used brands in construction include: M50, M 75, M100, and so on.

Its class is determined by the numerical characteristic of one of the properties of concrete with a guarantee of 0.95 percent. In five cases out of a hundred, a class-defined property may not be provided.

Frost resistance of concrete.

When buying concrete, if the price is cheap, any consumer has the right to ask a question about its frost resistance, especially when it is used in the regions of the Far North. The brand is determined based on the number of defrosting and freezing cycles of a control sample of a certain size. The compressive strength should not exceed the deviation from the control samples by more than five percent. Concrete used in pavement must not change mass by more than five percent. There are such brands of frost-resistant concrete: F50 F75 F100 F150 F 200.

waterproof concrete.

There are grades of impermeable concrete, they are defined by the ability to resist the penetration of water into a control sample fifteen centimeters high, at a certain water pressure.

Measuring the draft of a cone and why it is done.

The draft of the cone allows you to measure the plasticity of concrete, the more mobile the concrete, the greater it is. Measurements are made using a truncated cone with a lower hole diameter of twenty centimeters, the upper hole does not exceed ten centimeters with a height of at least thirty centimeters.

A cone mounted on a plane is filled with concrete. Filling takes place in two steps. First, two-thirds are filled, and with the help of a special bayonet, the entire filled volume is pierced to remove excess air. Then the remaining space is filled and excess air is removed from it in the same way.

A completely filled cone is carefully removed from the mass of concrete inside it. The unsupported mass of concrete turns into a kind of hill. It is measured how much the concrete has sunk without a conical frame. We get the value of the mobility of concrete or the draft of the cone.

How concrete is laid in inaccessible places on construction sites.

Old technologies provided for the supply of concrete using a special container in the form of a bucket. This container was supplied by a crane, from which the concrete flowed into the prepared formwork. Concrete was concentrated in one place, its uniform distribution was maintained with the help of internal vibrators. This technology led to significant energy costs. The process was quite labor intensive.

Now there is an easy way to fill the prepared volumes with concrete using a special pump. This method ensures the uniformity of laying, reduces downtime, which necessarily occurs earlier with the need to add formwork. Renting all the necessary equipment with this method of work can be done in companies located in Krasnogorsk, Odintsovo, Istra.

Care method for its best solidification.

Any builder knows what conditions must be observed for the correct solidification of the structure. This is very important in the initial period of fifteen to thirty days from the moment the formwork is filled with concrete. In summer, concrete is sheltered from direct sunlight and constantly spilled with water. Cement to gain the required strength must be constantly wet, in which case the design will be vicious and reliable. A concrete structure can increase its strength throughout its life, but the main point will be the first few weeks of its curing.

The standard curing time is twenty-eight days, this time is universal for builders around the world. To obtain a good concrete product after pouring, it is covered with wet sawdust and watered every three hours for a week or two, depending on the presence of a plasticizer in it.

Controlling the presence of moisture in concrete.

A ratio of twenty-five percent to the mass of cement in the mixture can be considered normal. However, such concrete will be too thick, so there is usually more liquid. It should be borne in mind that excess water forms pores in the finished mixture, thus reducing its strength and ductility. To improve its quality, special additives, plasticizers are used that increase the viscosity and plasticity of the finished concrete.

With good care, its strength only increases over the years. Builders should take into account that when mixing, excess water degrades the quality of the mixture; after pouring, concrete cannot be without constant moisture.

Delivery of concrete to the place of work.

The company serving the facilities under construction in Krasnogorsk, Odintsovo, Istra lease equipment, vehicles, cranes, pumps for laying, delivering, molding concrete into prepared formwork to contractors at a low price. Depending on the ambient temperature, concrete in a dump truck (mixer) can be transported within an hour or two. To increase the time of transportation, it is necessary to use special additives. Builders are well aware that transportation in a mixer does not in the least affect the timing of transportation. It is cheaper to hire a dump truck for transportation, because without special additives, concrete hardens at the same speed in an expensive mixer.

It is necessary to correlate the rental price with expediency. Concrete that has been in a rotating drum for more than three hours will become completely unsuitable for its use in construction.

Using special additives, concrete can be used when pouring structures in any weather conditions. Special modern technologies allow working with concrete even in Siberian frosts.

Concrete is used in the construction of large structures designed to withstand constant heavy loads. Bridge supports, foundations under buildings, load-bearing walls of high-rise buildings. It is widely used in the construction of special structures, military or civil purposes. Modern technologies make it possible to widely use this building material in all climatic zones at any time of the year.