Reinforced concrete structures are used on a construction site so widely that without them it is impossible to imagine modern construction. This group of products is highly popular among specialists for a number of advantages that will be discussed in this article. In addition, we will examine what is reinforced concrete and what technologies are used in its production to improve performance properties and characteristics.
The main features of the material
First of all, you should understand the difference between concrete and reinforced concrete. The main difference is the presence in the structure of the metal frame, which gives the properties of a completely new level.
And if concrete perfectly maintains huge weight, but weakly resists bending loads, then the reinforced version is able to withstand even the highest loads without any damage to the structure and integrity of the products.
Advantages of reinforced concrete structures
The popularity of reinforced concrete products (abbreviated as concrete) is due to a number of factors:
- The price of this option is much lower than any other material with similar properties of strength and durability.. Even considering the significant costs of transportation, loading and unloading and installation, the cost will be quite democratic. Particularly noticeable savings in large buildings, which uses a large number of elements and structures.
- The speed of construction using prefabricated reinforced concrete structures allows you to build huge buildings in record time. The main thing is that the work should be carried out by qualified installers, this guarantees the quality and safety of the structures being erected, since any mistake can lead to the occurrence of cracks, or even to the destruction of the structures.
- Assembled structures after sealing seams do not require special protective measures.. Products have the highest durability, which over the years only increases. At the same time, concrete products are resistant to weathering and can be used in almost all climatic zones, they tolerate both heat and negative temperatures.
- As is well known, concrete has high fire resistance properties, due to which additional fire protection is not required, since the material perfectly resists even open fire and is able to withstand its impact for a long period of time.. Concrete goods are recommended for use in all buildings and structures where fire safety is especially important.
- The metal frame, which is responsible for the resistance of products to deformation, retains its properties for many years, as it is reliably protected by a layer of concrete and is not subject to the corrosive effects of corrosion. That is why it is especially important that all the elements be complete, without cracks and chips, opening the metal frame.
Note! Due to the properties of the two main components: concrete and metal, the structures cope equally well with both static and dynamic loads. This significantly increases the stability of buildings, which is an important factor in areas with unfavorable seismic conditions.
How is the production process
To better understand the issue, consider why the combination of reinforcing steel frame and concrete is so durable:
|Compatibility||The physicomechanical properties of materials are very close, which excludes structural damage due to different deformation indicators.|
|Reliability||After hardening, the concrete with the reinforcing elements creates a very strong adhesion, which prevents them from shifting during installation and operation.|
|Durability||Heavy grades of concrete used in the production, perfectly resist adverse weathering and reliably protect the fittings from moisture|
|Stability||Due to similar linear expansion coefficients, even heating structures to a temperature of 100 degrees does not cause additional stress and shear of the reinforcement belt relative to concrete|
Note! The strength of reinforced concrete products is indicated by the fact that with the addition of a metal frame of rigidity, the strength of structures for bending increases 15-20 times.
The strength and stability of products even under high loads is provided by the features of the technological process:
- The use of the highest quality cement grade is not lower than M400. It is the quality of the binder component that largely determines its strength characteristics; therefore, mixtures without additives are used.
- Use as a filler crushed stone with a fraction of not more than 10 mm. This allows you to seal each product as accurately as possible, without air bubbles in the structure. In addition, such a composition penetrates well even into the densest reinforcing bars.
- After pouring the solution into the mold and its compaction, the structure is sent to the steam chamber, in which treatment is carried out within 8-12 hours (depending on the size). This allows you to achieve high strength characteristics after 12 hours, while with normal drying the process would take at least 4 weeks.
Remember! Special recipes solutions allow you to give extra strength to finished products. It also creates the effect of additional stress, when in the process of drying the concrete is under pressure in a form that does not allow it to swell, after drying the finished product is able to withstand enormous loads.
All large companies (such as PKF Reinforced Concrete in Moscow) have their own secrets of giving additional strength to products that are not disclosed. Nevertheless, the essence of reinforced concrete remains unchanged: it is designed to create prefabricated structures with enhanced characteristics of reliability and durability.
Prestress technology - what is it?
For products that are subject to significant strain loads during operation, a special technology is provided. Its essence lies in imparting additional stress to the product, due to which the reinforcement, like a spring, additionally compresses the concrete, which increases the resistance to bending effects by several times.
The production process is as follows:
- In a special form, reinforcing bars are pre-tensioned and secured in such a position with special equipment. Tension can be made either mechanically (when powerful hydraulic jacks are used), or thermomechanically (when the metal is heated by electric current).
- After tensioning the metal elements, the mold is filled with concrete and then vibrated. The main thing at this stage is the qualitative filling of the forms and the removal of air bubbles from the material structure.
- This is followed by heat treatment, after which the product is removed from the mold, as a result of which the reinforcing bars are compressed, forming tension in the adjacent concrete structure.
Types of concrete products
If you need to know all the basic standards that reinforced concrete must meet - SNiP52-01-2003 "Concrete and reinforced concrete structures" will help you learn all the necessary information. Each of the products must have a margin of safety in order to ensure the maximum level of safety - bets on reliability without knowing the characteristics are unacceptable here, since any mistake is fraught with danger to people's life and health.
The most common and popular reinforced concrete products are the following options:
- Floor slabs, they are used in both multi-storey and single-storey buildings and perform a variety of functions: floor, ceiling, flooring, and so on. According to the design features, there are three main options: full-bodied, hollow and ribbed. In addition, each of the options has many modifications, so in each case the choice is made individually.
- Foundation blocks - a very demanded group of products, with which you can very quickly build a strip, slab or columnar foundation. Products of this group have a wide range of sizes and can weigh from 30 to 400 kilograms. Accordingly, the appointment of products is changing, again, when choosing one or another option, it is best to consult with qualified specialists.
- Well rings are widely used both for industrial purposes, and for arranging personal wells with their own hands. Products in accordance with the purpose of the destination may have a different diameter, wall thickness and height. Some options are completed with covers, but they need to be purchased additionally, this factor should also not be overlooked.
- Road plates are used for airfields and sections of routes with particularly high loads. Characteristics and dimensions of products are determined individually in each particular case. In this case, it is worth remembering the basic rule: it is better to order concrete products with excessive strength than insufficient ones, since this directly affects the durability of the finished structures.
- Piles are designed to create reliable supports in large buildings. They can be of various sizes and configurations. In addition, they distinguish both solid and composite structures. It all depends on how long the elements should be.
Features of acceptance of products
It is very important for delivery to make the correct reception of reinforced concrete. It depends on how reliable the erected structure will be. The reception process consists in a visual inspection, minor defects of reinforced concrete in the form of surface cracks and chips do not affect, they can be sealed with cement mortar.
If the cracks are large, or chipped open the metal frame, then the products should be replaced, as they are unsuitable for construction. The same applies to geometry - any of its violations are unacceptable. In principle, this is a brief instructions for acceptance.
It is important to remember one thing, all building structures must comply with GOST standards - reinforced concrete bears significant loads, and any deviations are unacceptable. The video in this article will reveal some questions in more detail.