What is composite reinforcement

Pros and cons of composite fiberglass reinforcement

Fiberglass reinforcement, which appeared on the construction market relatively recently, has both advantages and disadvantages, which the consumer must be aware of. Despite the assurances of manufacturers that this product is a complete replacement for metal fittings, its use cannot be considered justified in all situations.

Frame of a monolithic slab made of composite reinforcement

What is fiberglass reinforcement

The so-called composite reinforcement is a fiberglass rod around which a carbon fiber thread is wound, which serves not only to strengthen the structure of such a product, but also to ensure its reliable adhesion to the concrete mortar. This type of fittings has both pros and cons, and its use should be approached very carefully.

Plastic clamps serve as elements for fixing carbon fiber reinforcement bars to each other. Conveniently, connecting the elements of such fittings does not require the use of welding, which is undoubtedly a big plus.

Fastening fiberglass reinforcement using clamps and clamps

When assessing the feasibility of using fiberglass reinforcement, it is necessary to consider all the pros and cons of its use in individual situations. This approach will ensure the high efficiency of this material as a means of strengthening building structures for various purposes.

If you do not take into account the characteristics of fiberglass reinforcement and do not compare them with the parameters of similar products made of metal, you can cause serious damage to the future building structure or finishing elements. That is why, before you start choosing elements for reinforcing concrete structures, you should understand in which cases the use of certain products is more appropriate.

Physical and mechanical properties of composite reinforcement of various types

Main advantages

Among the advantages of carbon fiber reinforcement, it is worth highlighting the following.

• An important advantage of fiberglass reinforcement is its low specific weight, which makes it possible to use it for reinforcing light structures made of cellular concrete and some other building materials. This allows you to significantly reduce the weight of structures that are reinforced with its help. Meanwhile, the weight of a conventional concrete structure when using fiberglass reinforcement will decrease slightly, since the building material itself has an impressive mass.
• Low thermal conductivity is also an advantage of fiberglass reinforcement. When using such reinforcement in concrete structures, no cold bridges are formed (which cannot be said about metal reinforcing elements), which significantly improves their thermal insulation parameters.
• The high flexibility of fiberglass reinforcement allows it to be shipped to the customer in coils, rather than cut into individual rods. Thanks to the compact form of packaging, it is much easier to transport such reinforcement, for which you can use the trunk of any passenger car, and this seriously reduces the cost of delivering the material to the construction site. The use of reinforcing elements, which are shipped not as cut rods, but in coils, also makes it possible to reduce material costs by reducing the number of overlaps. This has a positive effect on both the strength characteristics of the future concrete structure and its cost, which is especially important when performing construction work.
• The advantage of fiberglass reinforcement, such as its durability inside a concrete structure, is considered quite controversial. Metal fittings, being in an isolated state, are also not subject to the negative influence of external factors, which ensures the durability of its use.
• Carbon fiber reinforcement is a dielectric material, which is an advantage of products made from this material. Electrically conductive metal fittings are more susceptible to corrosion, which negatively affects its durability.
• Compared to metal reinforcing elements, fiberglass products are not exposed to chemically active environments. This advantage of fiberglass reinforcement is especially important in cases of construction of buildings in winter, when various salt solutions are added to the concrete, accelerating the hardening process.
• Being a dielectric, carbon fiber reinforcement does not create radio interference inside the building, unlike metal rods. This advantage is important when there are many reinforcing elements in a concrete structure. Otherwise, the use of composite reinforcement will not be a disadvantage, but it will not be so relevant.

The main advantages of composite reinforcement

Fiberglass reinforcement also has disadvantages, which potential consumers should also be aware of.

Main disadvantages

The disadvantages of fiberglass reinforcement are associated with its following characteristics.

• The disadvantages of fiberglass reinforcement include, in particular, the fact that it cannot withstand high temperatures. At the same time, it is difficult to imagine a situation where a reinforcement cage located inside concrete can be heated to a temperature of 200 degrees.
• The rather high cost is a drawback, given the fact that for the reinforcement of concrete structures it is possible to use fiberglass reinforcement of a smaller diameter in comparison with metal products.
• Carbon fiber reinforcement does not bend well. This drawback limits its use in creating reinforcing frames for concrete structures. Meanwhile, bent sections of the reinforcement frame can be made from steel elements, and then they can be extended using fiberglass rods.
• Reinforcement made of fiberglass does not withstand fracture loads well, which is very critical for concrete structures. Accordingly, their reinforcing frame must successfully withstand such loads, which reinforcement made of composite materials cannot boast of.
• Unlike metal reinforcement frames, fiberglass products have less rigidity. Because of this drawback, they do not tolerate vibration loads that occur when pouring them using a car mixer. When using this technique, the reinforcement frame is subjected to significant mechanical loads, which can cause its breakage and disruption of the spatial position of its elements, therefore quite high demands are placed on the rigidity of such concrete structures.

Reinforcement rupture due to insufficient binder in the rod structure

Considering the advantages and disadvantages of fiberglass reinforcement, it is difficult to say how much better or worse it is made of metal. In any case, the choice of this material should be approached very reasonably, using it to solve the problems for which it is really intended.

Areas of application of fiberglass reinforcement

Reinforcement made of composite materials, the installation rules of which are easy to learn from the corresponding videos, is used in both capital and private construction. Since capital construction is carried out by qualified specialists who are well acquainted with the nuances and disadvantages of using certain building materials, we will dwell on the features of using such material in the construction of private low-rise buildings.

Areas of use of composite reinforcement

• Reinforcement made from composite materials is successfully used to strengthen the following types of foundation structures: strip, whose height is greater than the freezing depth of the soil, and slab. The use of carbon fiber reinforcement to strengthen foundations is advisable only in cases where the structure is being built on good soil, where the concrete foundations will not be subject to fracture loads that fiberglass elements simply cannot withstand.
• Using fiberglass reinforcement, they strengthen walls whose masonry is made of brick, gas silicate and other blocks. It should be noted that, as a connecting element of walls, composite reinforcement is very popular among private developers, who use it not only to strengthen the masonry of load-bearing structures, but also to ensure their connection with facing partitions.
• This material is also actively used to bind elements of multilayer panels. The structure of the latter includes a layer of insulation and concrete elements, which are connected to each other using fiberglass reinforcement.
• Due to the fact that the type of reinforcement in question does not have such a disadvantage as susceptibility to corrosion, it is often used to strengthen various hydraulic structures (for example, dams and swimming pools).
• In cases where it is necessary to effectively increase the rigidity of laminated timber beams, they are also strengthened with fiberglass reinforcement.
• This material is also used in road construction: it is used to strengthen the asphalt layer, which is subjected to increased loads during its operation.

Summarizing all of the above, it should be noted that fiberglass reinforcement can be used quite effectively, if we take into account its disadvantages and associated limitations, which are specified by the manufacturer.

Can fiberglass reinforcement replace metal counterparts?

Despite the fact that reinforcement made from composite materials is a fairly new material on the construction market, you can already find many recommendations (and even videos) on its use. Considering these recommendations, we can conclude that it is best to use fiberglass reinforcement to strengthen walls built from bricks and building blocks, as well as to connect load-bearing walls with interior partitions.

Reinforcement of walls made of gas silicate blocks with 4 mm composite reinforcement

The advantages of using such reinforcement are that it is not subject to corrosion, and also that it does not create cold bridges, as happens with metal reinforcing rods. The use of such reinforcement to strengthen foundation structures is justified in cases where a building is not too heavy and the construction is carried out on highly stable soil.

In any case, the success of using this new building material has not yet been confirmed by long-term practice, therefore, when using it, any developer acts at his own peril and risk. Experts with extensive experience in construction recommend that for structures that have high requirements for reliability, stability and durability, use reinforcing frames made from traditional metal elements.

Source: http://met-all.org/metalloprokat/sortovoj/stekloplastikovaya-armatura-nedostatki-preimushhestva.html

Composite reinforcement, its features and installation technology

Traditional building materials are regularly improved, acquiring new performance characteristics and increasing the quality of existing technical parameters. At the same time, there is also a tendency to replace classical approaches in construction with innovative solutions . These include the successful entry of composite reinforcement into the building materials market.

Although debates about the extent to which the use of this material as a replacement for steel rods are still relevant, a number of its advantages are indisputable and have long been appreciated by experts. In particular, composite reinforcement for foundations, reviews of which from engineers emphasize their strength and ease of use , are becoming increasingly popular and expanding their scope of application.

What is composite reinforcement?

The main feature of this material is its non-metallic origin . Although the main list of functions of such rods involves providing very important load-bearing tasks, they are not made of steel, as is the case with classical reinforcement.

However, composite fibers made of glass, basalt, carbon and aramid . It is these components, as well as their combinations, that form the basis of composite rods. Actually, this is where the names of such reinforcement come from – fiberglass, glass-reinforced or basalt-plastic.

However, the use of synthetic fibers alone is not enough to ensure high strength and reliability of the same foundation structures. A mandatory step in the manufacturing process of the material is processing using thermosetting or thermoplastic polymer additives .

Thanks to them, the structure of future rods is rejected.

Further, as in the case of steel reinforcement, composite analogues are endowed with ribs and a special sand coating , which increases the binding and adhesive qualities in contact with concrete pours under the foundation.

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Advantages of composite reinforcement

The advantages of composite materials are due to the use of synthetic raw materials . This provides ample opportunities to introduce the necessary physical and technical qualities of the material, and also eliminates or at least minimizes the influence of negative factors.

One way or another, most of the advantages are focused on reinforcing the foundation with composite reinforcement in order to create strong and reliable foundations for buildings and structures. So, among the advantages of synthetic rods the following stand out:

• High tensile strength . Compared to first-class steel reinforcement, the composite analogue has this characteristic 2.5 times higher;
• Manufacturers provide a guarantee of up to 100 years . As a result, the service life of the foundation increases several times;
• Temperature does not affect the properties of the reinforcement . In the corridor from – 70 to +100 ºC, the rods do not lose their technical characteristics. Moreover, at negative temperatures, the strength of composites increases by 35%;
• Based on the nature of the material used in the manufacture, it can be stated that fiberglass and other synthetic reinforcement are completely protected from corrosion processes , as well as negative acidic and alkaline effects, which is often detrimental to metal reinforcement;
• Such fittings are completely antistatic and are not electrical conductors . Accordingly, when using the material you do not have to worry about creating radio interference. And on the other hand, electromagnetic fields do not affect composite rods and their properties in any way;
• Builders do not pay attention to the thermal conductivity of metal, since the “cold bridges” formed from it can only be tolerated. However, composite reinforcement for the foundation, reviews from engineers about which note minimal thermal conductivity, eliminates heat loss , thus increasing the energy-saving function of the house;
• In addition to performance qualities, it is worth noting the ease of handling of such fittings. First of all, this is facilitated by the modest mass. For a visual example: a 100-meter rod can weigh about 10 kg . A similar steel rod will weigh about 8-9 times more;
• It would seem that, given the obvious advantages, the cost of such a material should be several times higher than metal reinforcement. But even in this indicator, composite reinforcement outperforms steel - its price is on average 30% cheaper ;
• Manufacturers produce fiberglass rods of any length and with different rib parameters .

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Disadvantages of reinforcement made of composites

Despite all the advantages of composite reinforcement, disputes about the advisability of its use also indicate the presence of disadvantages. In particular, the following disadvantages are noted:

• Although composite reinforcement is heat resistant, experts note its low combustion threshold . According to fire hazard criteria, such fittings are included in the group of self-extinguishing materials. In addition, if the ambient temperature exceeds 200 ºC, the material loses its strength properties;
• The elasticity coefficient of composite reinforcement gives rise to controversial opinions. If composite fiberglass reinforcement is used for the foundation, then the low modulus of elasticity is a plus, but if it is used for floors, difficulties may arise in the form of the need for additional calculations of the reliability of the structure. There is another side to this property. If the formation of curved reinforcement is required, then this technological solution will have to be calculated in advance and the rod will have to be deformed in the factory, since it will be impossible to perform this operation on the construction site;
• Unlike metal reinforcement, composite bars cannot be joined by welding . This somewhat limits the functionality of the material, but, given the common method of viscous joining, this drawback is not so significant.

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Areas of application

Synthetic reinforcement has found application in various areas of industrial and civil construction . With its help, residential buildings are erected, factory complexes are constructed, used in the installation of technological structures, etc.

The use of composite reinforcement in foundations for low-rise buildings and cottages . In addition, composite rods perform well in concrete structures. This can be wall masonry with flexible ties , as well as the construction of brick and reinforced concrete structures.

Modern builders cannot do without synthetic material even where the use of steel rods is impossible. For example, in frosty conditions , it is necessary to add special additives in the form of hardening accelerators and antifreeze additives to masonry mortars. Such additions have a negative effect on metal rods, but they are harmless for composite reinforcement.

Modern road construction technologies also provide for the possibility of using synthetic reinforcement.

It is used in the construction of coatings, embankments, and to strengthen other road elements exposed to chemically harmful reagents. As a rule, the use of a composite in this area assumes one goal - the creation of a strong bond with strengthening properties.

For this purpose, rods are introduced into road slopes, bridge structures and various road surfaces that experience increased traffic loads.

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Installation technology of composite reinforcement

In low-rise construction, composite rods with a diameter of 8 mm are usually used. If we compare strength indicators, such rods will correspond to 12 mm steel reinforcement.

As a result, composite reinforcement strip foundation from which is made with pouring a concrete mixture allows you to qualitatively prepare the foundation of the house at minimal cost . But for this it is necessary to carry out installation in compliance with the rules for laying the foundation and using the optimal reinforcement scheme:

First, formwork is formed . If you plan to use it in the future for other buildings, then it is advisable to provide protection for it in the form of a glassine coating; Using a building level, it is necessary to mark the area inside the formwork , within which the concrete mass will be poured.

It is important to take into account here that the reinforcing mesh must be laid in the base of the foundation so that its edges are 50 mm from the boundaries of the formwork. To fulfill this condition, bricks can be laid at the bottom of the foundation; Next, the direct laying of composite reinforcement .

It has already been mentioned that electric welding as a way to bundle rods will not help in the case of fiberglass. You can, of course, use knitting, but the most reliable reinforcement of the foundation with composites is done without connections; At the next stage, crossbars are laid, that is, horizontal reinforcing lintels .

Another technological knitting is performed here, for which nylon clamps should be used - in essence, this is a plastic tie. In this way, the rods are tied and a mesh is formed; The final stage involves pouring concrete . For composite reinforcement, it is advisable to use concrete grade 400.

To eliminate air bubbles , the resulting concrete base should be compacted with construction vibrators. In the future, maintenance of the foundation can be carried out according to general rules, as with reinforcement with steel rods.

Source: http://dachaorg.ru/kompozitnaya-armatura-ee-osobennosti-i-tehnologiya-montazha.php

System for activating and increasing the effectiveness of the innovation process - Knowledge Base / Publications

Composite reinforcement is a construction reinforcement based on non-metallic fibers bound with a composite composition. For the manufacture of reinforcement, glass fiber, basalt fiber, carbon fiber, etc. are usually used. These fibers can be used either alone or in combination.

In practice, two types of composite reinforcement are most widespread: based on glass fiber alone and based on basalt fiber alone. This is where the names “fiberglass reinforcement” and “basalt-plastic reinforcement” come from. Of these two types, the second is slightly superior to the first in some of its properties, but at the same time it is much more expensive.

For this reason, fiberglass reinforcement has become most widespread in the world. The physical body of composite reinforcement conventionally consists of two parts:

• The main trunk, which sets the main strength characteristics of the reinforcement, which is usually a bundle of parallel fibers bound with a composite binder based on epoxy and polyester resins;
• The outer layer, responsible for the adhesion properties to concrete, is usually a unidirectional winding of fibers in a spiral (reminiscent of periodic steel reinforcement). This layer also has variations common among various manufacturers, such as bidirectional fiber winding or sand spraying. In fact, the model of the physical body of the reinforcement can have a huge number of variations, the number of which is limited only by the manufacturer’s imagination and economic considerations. For example, there are developments of reinforcement in which the main trunk is a braided braid of basalt fiber and carbon fiber, fastened with a composite, and the outer layer is a bidirectional winding of basalt fibers, which are not just twisted, but woven into a braid, like the main trunk of the reinforcement. This design has a much greater relative elongation than composite reinforcement, the body of which is a bundle of parallel fibers.

When did composite reinforcement appear?

Now it is difficult to establish in which country composite reinforcement was invented. Research on the creation and study of the properties of high-strength non-metallic reinforcement and methods of its use began in both the USSR and the USA in the 60s of the last century. Since the 70s, a fairly large number of civil and industrial facilities have been built using various composite reinforcement in the USSR, Germany, USA, Canada, Great Britain and Japan.

Today, such fittings are most widespread abroad, since they notice and implement advanced technologies much faster there than in Russia. For example, the first mass production of composite reinforcement began in the USA already in 1974.

The largest number of major global manufacturers of composite reinforcement are also located in the United States.

Unfortunately, in the USSR, research and development of composite reinforcement was curtailed, and today in Russia there are not many manufacturers of composite reinforcement located in different regions.

What regulatory documents on composite reinforcement exist?

Due to the lack of attention to composite reinforcement in our country, today in Russia there is no GOST that describes non-metallic composite reinforcement. There is only a draft of such a GOST, the approval of which is expected at the end of 2012. However, non-metallic composite reinforcement is already approved for use in SNiP 52-01-2003 (back in 2003). In this document, in section 5.

3 we read: “For reinforced concrete structures, the following types of reinforcement should be used, established by the relevant standards: non-metallic composite reinforcement.” And in the same section below: “Non-metallic reinforcement (including fiber) is also subject to requirements for alkali resistance and adhesion to concrete.”

That is, in essence, SNiP recognizes only the fact of the existence of composite reinforcement and the possibility of its use in reinforced concrete structures.

At the moment, the absence of the corresponding GOST is compensated by TU (technical conditions), which are developed by each of the manufacturers of such fittings and registered in the prescribed manner. Now all Russian manufacturers are in an equal position from the point of view of regulatory and technical documentation. All manufacturers have:

• Own specifications with the declared characteristics of the manufactured fittings;
• Test report confirming the characteristics specified in the specifications;
• Certificate of conformity, which confirms the compliance of the characteristics specified in the specifications with the actual values;
• Sanitary and hygienic certificate (which, in principle, is of little interest to builders).

Reinforcement manufacturers also have recommendations from NIIZHB, but these are just recommendations. There are also documents such as organizational standards (STO), but they are developed by them independently, and are approved and put into effect by order of the head of the organization itself, which in itself explains the low value of this document from the point of view of regulatory documentation.

What are the advantages of non-metallic reinforcement?

1. Composite reinforcement does not corrode and is resistant to aggressive environments. Belongs to materials of the first group of chemical resistance, including the alkaline environment of concrete. Builders know that a layer of corrosion, growing on traditional steel reinforcement, can eventually increase its diameter by 8 times, which leads to the appearance of cracks and even rupture of the concrete structure.
2. Composite reinforcement has approximately 2.5-3 times greater tensile strength than steel reinforcement with the same diameter. For this reason, the concept of “equal-strength replacement” was introduced, in which steel reinforcement is replaced with composite reinforcement with a smaller diameter, but with the same tensile strength.
3. Composite reinforcement is 5 times lighter than steel with equal diameter and 11 times lighter with equal strength diameter. This allows you to save on transportation and reduces the weight of the final concrete structure.
4. Composite reinforcement is much cheaper than steel when replaced with equal strength.
5. Such reinforcement has a coefficient of thermal expansion that is almost identical to the coefficient of thermal expansion of concrete.
6. Composite reinforcement has low thermal conductivity and is not a cold bridge. For example, a fiberglass composite has a thermal conductivity of 0.48 W/m•K, while metal has an average thermal conductivity of 56 W/m•K.

   Thus, fiberglass is 100 times less thermally conductive than metal.

7. Being a dielectric, composite reinforcement (with the exception of carbon fiber) is radio transparent and magnetically inert.
8. Does not lose strength when exposed to low temperatures. Operating temperature range from -70 °C to +100 °C.

Areas of application of composite reinforcement

Composite reinforcement is used:

• in foundations below the zero ground level (today, fiberglass reinforcement is the best reinforcing material for constructing strip foundations and pouring foundation slabs);
• as flexible connections;
• for the manufacture of lighting poles, power line supports, insulating power line traverses;
• for road construction: when strengthening the roadway, bridges, fences;
• for strengthening such products as: road and paving slabs, fence slabs, curb stones, posts and supports, railway sleepers;
• in structures operating under conditions of accelerated corrosion of steel reinforcement and concrete (berths, dry docks, strengthening the embankment by concreting), as well as in structures exposed to general corrosion and dynamic loads during operation.

Disadvantages of composite reinforcement

It must be remembered that composite reinforcement also has significant disadvantages. Most Russian manufacturers do not advertise these disadvantages, although a qualified builder can notice them on their own. The main disadvantages of any composite reinforcement are the following:

• The modulus of elasticity of composite reinforcement is almost 4 times lower than that of steel, even with the same diameter (in other words, it bends easily). For this reason, it can be used in foundations, road slabs, etc., but application in floors requires additional calculations;
• when heated to a temperature of 600 °C, the compound that binds the reinforcement fibers softens so much that the reinforcement completely loses its elasticity. To increase the resistance of a structure to fire in the event of a fire, it is necessary to take additional measures for thermal protection of structures that use composite reinforcement;
• Composite reinforcement, unlike steel, cannot be welded using electric welding. The solution to the problem is to install steel tubes at the ends of the reinforcing bars (in the factory), to which electric welding can already be applied;
• It is impossible to bend such reinforcement directly on the construction site. The solution to the problem is to manufacture reinforcing bars of the required shape in production according to the customer’s drawings. There is confidence that the adoption in the near future of a separate GOST for non-metallic composite reinforcement will raise interest in composite reinforcement to a new level.

Comparison of the characteristics of metallic and non-metallic reinforcement

here alientechnologies.ru/production/armatura/armatura-properties.php

Source: https://www.startbase.ru/knowledge/articles/110/

Composite reinforcement: types, advantages, scope, reinforcement with composite reinforcement

The development of composite reinforcement was carried out back in the last century, but it became expedient to produce and use it only recently.

This was facilitated by the availability of raw materials and the introduction of new technologies into the manufacturing process. Often such products are called fiberglass or basalt plastic.

Basically, different definitions are given due to the difference in combinations of raw materials used. But this does not affect the quality and durability of the products. It differs from its steel counterparts in appearance.

Composition and features

The material is a structural rod similar to steel rebar, but made from the following components:

- glass;

- basalt;

— carbon;

- aramid;

- polymer additives.

Glass products are light in color with a yellowish tint. Black basalt and carbon rods. The periodic section, as in metal products, ensures the strength of the reinforced concrete structure. Some manufacturers include colored pigments in their composition. This fact does not affect the properties and characteristics in any way.

Types of composite reinforcement

The classification of types of composite reinforcement directly depends on the main component in the composition.

• ABP (basalt product) is produced using basalt fibers and resins of organic origin, which act as a binding element. A distinctive quality of the species is its resistance to aggressive substances and environments (alkalies, salts, gases).

• FRP (fiberglass product) is obtained by mixing fiberglass and thermosetting resins. The advantage of this type is considered to be high strength with low weight.

• AUP (carbon fiber product) is based on hydrocarbons. It has high strength, but due to its high cost, this type is not in wide demand.

• ACC (combined product) is made on the basis of basalt and fiberglass. It has high wear resistance and a wide range of applications.

Advantages of composite reinforcement

Composite reinforcement has rapidly gained popularity in the construction market. This is due to its technical performance and durability. Among the advantageous qualities:

- does not corrode;

— moisture resistance;

— long operational period;

— strength indicators exceeding metal analogues;

— low thermal conductivity, eliminating the formation of cold bridges in the concrete structure;

Source: https://nastroike.com/stroitelnye-materialy/939-kompozitnaya-armatura-vidy-plyusy-oblast-primeneniya-armirovanie-kompozitnoj-armaturoj

Composite reinforcement: pros and cons, application, characteristics, binding

The modern world is changing rapidly, and this also applies to the construction sector - new technologies and materials. Today, the use of composite reinforcement in construction is not widespread, and the main reason for this is the lack of information and real, independent reviews from builders. After all, it is much more common and reliable to use good old metal fittings, the characteristics of which are well known and confirmed by time.

But reinforcement made of composite materials has been used in Western countries since the 70s, and has received quite a high rating. Although even there she was unable to squeeze out steel.

In our country, many people still ask: what is fiberglass reinforcement? And they receive a lot of information - both fantastically laudatory (as a rule, coming from the manufacturers of plastic reinforcement themselves) and very negative (manufacturers of steel reinforcement do not need competitors either). We will try to calmly and impartially analyze the advantages and disadvantages of composite reinforcement.

How are composite reinforcement produced?

Let's start with the fact that the term “composite reinforcement” combines all types of non-metallic reinforcement made on the basis of different types of fibers, which are used as the reinforcing base of the rod. The fibers from which the reinforcement is produced can be the following:

• 1. basalt fiber;
• 2. glass fiber;
• 3. aramid fiber.
• 4. carbon fiber.

Thus, the types of composite reinforcement, depending on the applicable fibers, are as follows:

• 1. Basalt-plastic reinforcement, usually black (ABP);

• 2. Fiberglass reinforcement, light yellow in color, however, thanks to coloring additives, the color range is wide (ASP);

• 4. Carbon fiber reinforcement;

• 5. Combined reinforcement (based on fibers of different types).

Any composite reinforcement is produced on the same equipment, the technology is also no different. The only difference is the type of fiber. Currently, there are several production methods:

1. A bundle of fibers, having previously formed a rod - the main reinforcement rod, is impregnated with epoxy resin and pulled out. Then the bundle of fibers is pulled through the shafts, while at the same time a bundle made of the same fibers using resins is wound onto it.

The strand in this process performs two tasks - it tightly presses the fibers of the rod, and serves as reinforcement ribs, which will improve the adhesion of reinforcement and concrete in the future. After this, the reinforcement goes through the oven drying stage, and now the reinforcement is ready.

This method is the oldest; it is used by almost all Russian manufacturers of plastic fittings.

1. Fiber feeding system (fiberglass, carbon fiber, basalt fiber)

2.Polymer bath (polyester, epoxy resins)

3. Preforming device

4. Die

5.Heating/cooling zones of the die

6.Pulling machine

7.Cutting machine

2. The second method differs from the first only in that the rope is wound onto the rod with very strong force; it is literally pressed into the main rod, as a result of which the ribs are formed from the fibers of the rod itself. Such fittings are more durable than those produced by the first method, since there is no risk of ribs falling off. However, it is almost impossible to find similar Russian-made fittings, since most people use the first method.

3. The third method is also similar to the first, however, the tightening rope here does not form ribs, but only tightens the fibers of the rod until polymerization in the oven. To adhere to concrete, a layer of abrasive – quartz sand – is applied to the reinforcement.

This type of reinforcement has the poorest adhesion to concrete, and on top of that, the shortest service life.

The fact is that epoxy resin is destroyed quite quickly in the alkaline environment of concrete, and polyester resins, which are not afraid of alkali, are extremely rarely used by manufacturers in Russia.

4. Finally, reinforcement made using the pultrusion method. In this case, the fibers are formed into a rod, impregnated with polymer resins, and pulled through dies with different cross-sections, arranged in descending order.

This method allows the formation of a periodic relief (ribs) with high precision, so that they can be used as a thread (for example, as a tie screw for formwork, with a fiberglass or steel nut).

The fittings produced in this way are distinguished by high quality, durability and high price. In addition, such fittings are almost never produced in Russia.

If you search, you can find a completely unusual material on sale - composite reinforcement with an internal cavity. Despite its exotic nature, tube reinforcement deserves attention - after all, thanks to the cavity, the diameter increases, and with the same number of fibers, reinforcement with a cavity has a larger area of ​​​​contact with concrete, and therefore better adhesion.

Composite reinforcement pros and cons

Like any building material, composite reinforcement has its advantages and disadvantages. Advantages of composite reinforcement:

1. Weight – non-metallic fittings are almost like feathers compared to metal ones. The weight of composite reinforcement is 10-12 times less than steel reinforcement of equal strength. For example, 1 meter of 10 mm plastic reinforcement weighs 100 grams, and steel reinforcement of the same diameter weighs 617 grams. And the fact that plastic rolls into coils allows you to load several coils (the length of a coil is usually 100-200 meters) of reinforcement into the trunk of a car.

2. Composite reinforcement has an impressive tensile strength - 2.5-3 times more than steel (of course, this means with the same diameter). Thus, composite reinforcement with a diameter of 12 mm replaces steel reinforcement with a diameter of 14-16 mm. Hence the term “equal strength replacement” is used by builders and manufacturers.

3. The cost of composite reinforcement today is lower than that of metal, although a few years ago it was the other way around. Moreover, the price of steel reinforcement is growing steadily, while composite reinforcement remains almost the same.

4. Another plus is that composite reinforcement is sold in coils of 100-200 meters, which can significantly reduce the number of scraps when reinforcing structures.

But not everything is so rosy; there are also disadvantages of composite reinforcement:

1. Experts call the main disadvantage of composite reinforcement the low modulus of elasticity, 4 times lower than that of steel – and this is with the same diameter. Of course, this is not a critical drawback; the main thing is to make additional calculations, and it is better if specialists do this. Or our calculator.

2. Composite reinforcement can only be bent in production; it cannot be bent at an angle at a construction site. True, few elements in the form of rods at an angle are usually required, and they can be replaced with steel reinforcement.

3. Fiberglass reinforcement cannot withstand high temperatures - at 100 degrees it ceases to be elastic and breaks easily.

4. Welding when using composite reinforcement is unacceptable, although some experts consider this an advantage. Indeed, when reinforced with either steel or plastic reinforcement, both are mainly tied with wire or plastic ties.

Knitting composite reinforcement

There is an erroneous statement that tying composite reinforcement can only be done with plastic ties (clamps). Of course this is not true. Moreover, we recommend knitting with regular baked steel knitting wire. The process of tying composite reinforcement is no different from tying metal reinforcement. And the goal is the same - to fix the frame until the concrete gains strength, then it doesn’t matter at all what and how the fiberglass reinforcement was knitted.

By the way, it is necessary to say a few words about cutting composite reinforcement. Not everyone knows that it is possible to chop, bite or resaw fiberglass reinforcement, but it is not at all necessary. The best option to cut the composite is with a grinder.

The fact is that biting or chopping creates microcracks, which, although not visible to the naked eye, go deep into the core.

Water and alkali get into the cracks, and during freezing and defrosting, the cracks will expand, gradually destroying the reinforcement.

Important! When cutting composite reinforcement, you should take the necessary safety measures - protect your eyes and respiratory organs, since fine dust from basalt or glass fibers is extremely harmful.

Where is fiberglass reinforcement used?

The use of composite reinforcement in construction is quite widespread, although not very widespread in Russia. It is mainly used in the construction of foundations in private housing construction, in the construction of roads, and in the production of slabs. It is often used to create flexible connections between brickwork, to improve the characteristics of walls, etc.

If you have experience using composite reinforcement, please share in the comments!

Source: http://firststroy.ru/kompozitnaya-armatura-plyusy-i-minusy-primenenie-harakteristiki-vyazka.html

Composite reinforcement, can it be used in construction?

however, its tensile strength is limited; in order to overcome such tensile limitations, use fiberglass reinforcement in construction. Steel reinforcement is still an effective material for concrete reinforcement; its main disadvantage is that it is very sensitive to oxidation and the effects of chlorides.

An example of such oxidation is a road, which is sprinkled with salt in winter to melt the snow, or sea areas, where part of the concrete in the area of ​​variable water is especially deteriorated. All these factors lead to the destruction of steel reinforcement.

Naturally, if you protect steel reinforcement with additional coatings, it will serve without visible corrosion processes for many years, however, it is not always possible to provide such protection. So sometimes workers can prepare concrete in violation of technology, which contains a large number of aggressive agents that can destroy the reinforcement and the concrete will begin to crack.

Since fiberglass reinforcement has reinforced fibers, the problem of corrosion can be solved. Composite reinforcement is resistant to the effects of chloride ions, so the tensile strength of composite reinforcement is high, several times greater than that of steel reinforcement.

Purchasing composite reinforcement is not a problem now, especially since many builders and designers give it their preference, as they have realized that fiberglass reinforcement is the future in construction. This can be seen in the ever-growing demand for non-metallic reinforcement. Fiberglass reinforcement is superior to steel in many respects, because this material has more advantages than disadvantages, this is obvious.

Non-metallic reinforcement was allowed in construction back in 2003. A document such as SNiP 52-01-2003 confirms this.

In addition to such a basic requirement as tensile strength, additional requirements are prescribed for composite reinforcement that must meet the following standards: ductility, endurance, corrosion resistance, cold resistance, resistance at temperatures above 50 degrees, elongation at break, alkali resistance and adhesion to concrete. Technical conditions are taken into account at the initial stages of designing concrete structures, and various environmental influences on the object are taken into account.

So, composite reinforcement can be used in construction, but when designing buildings, one should rely on the characteristics of non-metallic reinforcement, obtained only experimentally in special laboratories; the results of the study must be recorded in a special conclusion.

What documents must a valve manufacturer have?

All producers are in an equal position	therefore each of them
must	be:
•	THAT,	With	detailed	characteristic	fittings;
•	The sanitary and hygienic certificate, however, is	interested	builders in
less	degrees;

•A protocol in which all test results are recorded, which

confirms all characteristics of the valves stated in the technical specifications;

• Certificate of conformity, it confirms that the characteristics specified in the specifications correspond to the actual indicators;

• There is SNiP 52-01-2003, which recognizes the possibility of using non-metallic reinforcement in construction.

Every manufacturer should have this list. The following recommendations for the use of non-metallic reinforcement

puts forward	institute	NIIZHB:
Apply	composite	fittings	Can:
—	For	reinforcement	relaxed	concrete	designs
-cement	solutions
- foundations	structures,	which	work	on	elastic	basis
-clothes	roads
- structures,	which	are exposed	influence	aggressive environments
-soils	mountain	breeds	at	gasket	tunnels
-embankments	on	weak	basis
-various	species	concrete
—	For	improvements	thermotechnical	indicators	walls,	application

fiberglass reinforcement in the outer layer of three-layer wall panels. Design of structures: Non-metallic reinforcement can be used either as individual rods or in a mesh; the rods must be fastened to each other with polymer clamps or clamps.

Requirements for structural calculations should be based on the following documents:

•	JV	52-102-2004
•	SNiP	52-01-3003	"Concrete	And	reinforced concrete	designs.";

• Recommendations from NIIZHB for the calculation of structures with fiberglass reinforcement

Fiberglass reinforcement and 11 of its advantages

Fiberglass reinforcement is manufactured in two versions:

•Smooth profile fittings.

•Periodic profile fittings.

In order for the reinforcement to have the necessary adhesion to the concrete, a glass thread is wound onto it in a spiral with force, thus creating the desired ribbed surface.

Fiberglass reinforcement is unique in its performance properties; in many respects it is superior to steel reinforcement. This fact allows it to be used in the construction of various objects that are constantly exposed to aggressive environments. So it is used in the construction of infrastructure, roads, coastal structures, bridges.

So, thanks to the efforts and fruitful cooperation of the scientific and industrial sectors, fiberglass reinforcement appeared. What are its main advantages:

1. The first and very important point is that fiberglass reinforcement is many times stronger than steel, so its tensile strength is 2 times higher than that of steel reinforcement, with the same diameter. Accordingly, when using composite reinforcement, its calculated area will be many times smaller than if using steel reinforcement.

2. Lightness. It weighs only 1.9 times more than water and is 5 times lighter than steel. If we compare equal-strength types of reinforcement, the weight of composite reinforcement will be 9 times less than the weight of steel reinforcement. This fact greatly facilitates the loading and unloading of such fittings and saves money on its transportation and installation.

3.More economical. The use of such fittings allows you to save on construction work. Savings also include funds spent on purchasing fittings of smaller diameter.

4.Does not rot or corrode. Fiberglass reinforcement does not corrode and does not destroy concrete. Also mechanical properties

Such fittings remain unchanged in aggressive environments, such as alkalis, salt and acid.

5.Does not lose its properties at low temperatures. It can be used at temperatures from -70 to +100 degrees Celsius. At the same time, it retains its technical characteristics.

6.Does not conduct heat. Its thermal conductivity is 100 times less than that of conventional fittings. It practically does not allow heat to pass through. Accordingly, fiberglass reinforcement significantly reduces heating costs.

7.The coefficient of thermal expansion is equal to that of concrete. This fact eliminates the possibility of cracks in concrete and reinforcement breaks in

as a result of systematic temperature changes.

8. Fiberglass reinforcement is radio-transparent, dielectric and magnetoenergetic. It does not accumulate static energy and does not conduct current. Easily transmits radio waves. The strength of such reinforcement does not change even under the influence of electromagnetic waves.

9. Durable. If you use fiberglass reinforcement in the construction of a structure, its service life increases by 2-3 times; this is very important from the economic side, especially with constant exposure to aggressive environments. Thanks to this fact, the need for expensive repairs disappears.

10. It is environmentally friendly, as it does not emit harmful substances that could harm human health.

11.Any length. The fittings can be made to any length as requested by the customer and required by the project.

Fiberglass reinforcement - new technologies forward!

Some types of fiberglass reinforcement are specially coated with a layer of sand. They do this so that adhesion to concrete is much better. This has been confirmed by numerous studies. In addition to its main function, sand additionally protects fiberglass reinforcement from the effects of concrete, which contains a lot of salts and alkali.

The main areas of application of fiberglass reinforcement are:

•foundations of various structures;

•airfield and road surfaces;

•strengthening the road surface;

•slabs for bridge;

• floor reinforcement;

• strengthening the line of coastal structures;

• reinforcement of swimming pools of various capacities.

Thanks to its unique properties, fiberglass reinforcement allows solving very serious problems such as “concrete shooting” and electrochemical corrosion. Fiberglass fittings are environmentally friendly, safe for health and will last for decades.

Savings on reinforcement are possible if you use fiberglass reinforcement instead of steel. This is possible in the construction of those structures where composite reinforcement works in tension and where the tensile load is several times greater compared to metal. In this case, you can replace the steel reinforcement with fiberglass reinforcement with a smaller diameter.

If you compare prices for steel and fiberglass reinforcement, then you should be guided by the fact that the price in both cases is per ton of material, and fiberglass reinforcement is several times lighter than metal, also take into account the table of equal strength replacement.

There are some other indicators that should be taken into account when calculating cost savings. These are: weight, the ability to supply any length, cutting, warehousing, transportation, loading and unloading. If you add up all this, the savings are exponential.

When choosing a manufacturer of fiberglass fittings, look at what kind of company it is and how long it has been working on the market, since now there are many garage factories that shout about the high quality of their products, but in fact they produce complete defects. Since the production of fiberglass reinforcement requires special conditions and professionals who will control the technological process.

The use of composite reinforcement in permanent formwork

The principle by which permanent formwork is used is very simple. The structure that will be the future foundation is laid out on the markings.

The space inside the structure made of polystyrene cubes is reinforced with composite reinforcement, due to the fact that this reinforcement, like polystyrene, is absolutely inert, does not corrode and is very light; it is easily attached to the inside of the future foundation.

After the composite reinforcement is installed, the space is filled with concrete solution. There is no need to dismantle the formwork; it can provide thermal insulation for concrete and protect it from cracks.

Permanent formwork provides new opportunities in construction; with its help and with the help of composite reinforcement, it is possible to fill foundations of various shapes.

Source: https://studfile.net/preview/3719676/page:4/

Composite (plastic) reinforcement: types, characteristics, pros and cons, area of ​​application in construction

Relatively recently, metal reinforcement was not just the most common - it was the only material of its kind. It is not surprising that all concrete reinforcement was carried out with its help. But today the market is saturated with numerous analogues, most of which are superior to metal rods in a number of parameters. One of them is composite reinforcement, also known as plastic. Let's take a closer look at what it is.

What is composite reinforcement?

Outwardly, it is similar to classic metal rods, but the main material in its manufacture is fibers made of carbon, basalt, glass or aramid. They are held together with special thermoplastic or thermosetting polymers, giving them high strength and durability.

https://www.youtube.com/watch?v=ODNPoO5-axA

Non-metallic reinforcement can have special ribs on the surface, which improves the quality of adhesion to concrete during reinforcement. In some cases, the surface is simply sprinkled thickly with sand. By adhering to the polymer that has not yet hardened, it also improves adhesion, but due to the ease of manufacture, the cost of the material is much lower.

In addition, smooth plastic fittings are available for sale. It has a relatively low price, but low grip significantly limits its scope of application. It is not used as the main working fixture - only as an auxiliary one.

When reinforcing large masses of concrete (foundations, thick walls), the rods are not laid on the base, but are assembled into a frame. The main rods that will improve the quality of concrete have ribs. And smooth ones are used specifically for assembling the frame - they bear minimal load.

Therefore, it is possible to use simpler material to reduce construction costs.

Where is it used?

The use of composite reinforcement is rapidly gaining popularity. It is used in the construction of various objects:

• low-rise buildings;
• monolithic construction with light and heavy concrete;
• road surfaces, railway foundations;
• reinforced concrete floor slabs;
• bridges;
• overpasses.

In addition, the high quality of products leads to the fact that plastic reinforcement is often used in the manufacture of concrete products, both with and without prestressing. Power line supports, lighting poles, curbs, fence slabs, railway sleepers - this is not a complete list of reinforced concrete products, in the manufacture of which non-metallic composite reinforcement is used.

Types of fittings

Now we will tell you in more detail what materials non-metallic composite reinforcement is made from. The most common types today are:

• TSA or fiberglass. It is made of fiberglass impregnated with a thermosetting resin, which acts as a binder. The main advantage is low weight and high strength;
• AUP or carbon fiber. The main material in their production is hydrocarbon fibers. Although highly durable, it has certain disadvantages. The main one is the high price. It was because of her that it was not widely used;
• ABP or basalt plastic. Made from basalt fiber and organic resins. It has less strength than fiberglass, but can be used in aggressive environments - salts, gases, alkalis and acids, which makes it a very popular building material;
• ACC or combined. As the name implies, this plastic reinforcement is made from different types of fibers - specifically basalt plastic and fiberglass. It is a compromise between pure species, partially preserving their advantages.

Of course, all the materials considered are fully compliant with GOST 31938-2012, which regulates all the characteristics of the new material. Thanks to this diversity, the use of composite reinforcement is becoming increasingly widespread. For the construction of any object, an option can be selected that is suitable in terms of cost, strength and other characteristics.

Also in some cases you can see rods of different colors. Some sellers claim that color affects strength, chemical resistance and other parameters. In fact, this is nothing more than a publicity stunt.

The coloring pigment does not affect the important technical characteristics of the material in any way - it does not improve or deteriorate it.

The main purpose is to give appearance (again, an advertising move that forces a potential buyer to pay attention to a specific product) and to simplify the visual recognition of rods of different thicknesses.

What diameter composite reinforcement is there?

As is the case with metal, the diameter of composite reinforcement can be different. The most in demand are materials with a diameter of 4 to 32 millimeters - they fully satisfy the requirements of builders both when pouring the foundation for a bathhouse or garage, and when building a multi-story monolithic building.

However, some buyers who are not very well versed in the trade are surprised that when measuring with their own hands, the diameter does not correspond to what was stated in the store. There is nothing surprising here. Firstly, an error of several can always occur - even when measuring one rod at different points.

But this practically does not affect the strength of the material, which is why GOST provides for such differences. Secondly, when studying the characteristics of composite reinforcement, you read about the nominal diameter. There is also external (when taking measurements along protruding ribs) and internal (when measuring along the rod itself).

The nominal value, which is assigned to the material, is the arithmetic mean between external and internal.

Also, during construction, a mesh made of composite reinforcement is often used. Thin fibers and high flexibility greatly simplify the process of leveling ceilings and walls (if the applied layer of plaster has a thickness of 1.5-2.5 centimeters or more), and are also excellent for reinforcing concrete screeds.

Once this has been sorted out, it will be useful to talk about the pros and cons of composite reinforcement, so that each potential buyer can decide whether this material is suitable for him or whether it is better to look for another.

Main advantages

First, let's talk about the advantages of composite reinforcement that allowed it to become such a popular building material:

1. High strength - according to some data, building polymer reinforcement made of fiberglass is 10 times stronger than metal reinforcement of the same diameter.
2. Ecological cleanliness. The material does not harm the environment and does not emit toxic substances even during prolonged use and contact with open fire.
3. Low thermal conductivity coefficient reduces heat loss of the building.
4. Resistance to corrosion - even if during operation the material comes into direct contact with water, gas or an aggressive environment, it can last for many years without reducing its original performance characteristics.

In addition to excellent construction properties, the use of composite reinforcement in construction is justified due to the convenience of workers. It has greater flexibility than metal, but at the same time, as already mentioned, it has high strength. Thanks to these qualities, creating a frame becomes much easier and simpler. To ensure high reliability of corner connections, it is no longer necessary to use special machines to bend the reinforcement.

Also, the positive properties of composite reinforcement can include a coefficient of thermal expansion close to that of concrete. If reinforced concrete is heated or cooled, it does not collapse, since the plastic reinforcement expands and contracts with it.

Does the material have disadvantages?

Each building material has certain disadvantages. Therefore, knowing about the disadvantages of composite reinforcement is no less important than knowing about the advantages. We list the main ones:

1. Low elasticity. Tests show that plastic reinforcement has an elasticity approximately 4 times lower than that of metal reinforcement of the same diameter. Therefore, when reinforcing large volumes of concrete, you need to use 4 times more reinforcement, which is not very cheap.
2. Cutting hazard. If a metal rod can be cut or sawed without unnecessary problems, then when non-metallic reinforcement is sawed, a large number of microscopic particles of fiberglass are released into the air. If they enter the respiratory tract or eyes, they can cause multiple microtraumas.
3. Low ductility. The material is practically devoid of plasticity. Therefore, in order to bend a rod, it is necessary to heat it to the required temperature. It is very important not to exceed 300 degrees Celsius - this will lead to loss of load-bearing properties.

As you can see, plastic fittings have both important advantages and serious disadvantages. Think seriously before finalizing the choice of suitable reinforcement for construction.

Now you know what composite reinforcement is, and also understand its pros and cons. This will make it easy to make the right choice, which you won’t have to regret later. In addition, by understanding the basic properties of the material, you can easily decide in which cases it will be the best choice, and when it is desirable to give preference to other analogues.

Source: https://VseoArmature.ru/vidy/kompozitnaya-armatura

Composite reinforcement - advantages, where it is used

Composite reinforcement is an analogue of metal reinforcement in the building materials market. Modern material with numerous advantages. Composite reinforcement (plastic) - let's look at composite reinforcement - what it is, its advantages and where it is used.

Composite reinforcement - what kind of material is it?

Visually, it is very similar to ordinary metal rods, but the main material in its manufacture is fibers made of carbon, basalt, glass or aramid.
They are held together with special thermoplastic or thermosetting polymers, giving them very high strength and durability.

Non-metallic reinforcement may have special ribs on the surface to increase adhesion to concrete during reinforcement. In some cases, the surface is simply sprinkled thickly with sand. By adhering to the polymer that has not yet hardened, it also improves adhesion, but due to the ease of manufacture, the cost of the material is much lower.

In addition, smooth plastic fittings are available for sale. Composite reinforcement has a relatively low price, but low adhesion significantly limits its scope of application. It is not used as the main working fixture - only as an auxiliary one.

When reinforcing large masses of concrete (foundations, thick walls), the rods are not laid on the base, but are assembled into a frame. The main rods that will improve the quality of concrete have ribs. And smooth ones are used only for assembling the frame - they bear minimal load.

Therefore, it is possible to use simpler material to reduce construction costs.

Advantages of composite reinforcement

First, let's talk about the advantages of composite reinforcement that allowed it to become such a popular building material:

High strength - according to some data, building polymer reinforcement made of fiberglass is 10 times stronger than metal reinforcement of the same diameter.

Environmentally friendly - the material does not harm the environment and does not emit toxic substances even during prolonged use and contact with open fire.

Low thermal conductivity coefficient - this reduces heat loss from the building.

Resistance to corrosion - even if during operation the material comes into direct contact with water, gas or an aggressive environment.

Composite reinforcement will last for many years without reducing its original performance characteristics.

In addition to excellent construction properties, the use of composite reinforcement in construction is justified due to its convenience for workers. Composite reinforcement has greater flexibility than metal reinforcement, but at the same time, as already mentioned, it has high strength. Thanks to these qualities, creating a frame becomes much easier and simpler. To ensure high reliability of corner connections, there is no need to use special machines to bend the reinforcement.

Also, the advantages of composite reinforcement are its good coefficient of thermal expansion, close to that of concrete. If reinforced concrete is heated or cooled, it does not collapse, since the plastic reinforcement expands and contracts simultaneously with it.

Where is composite reinforcement used?

The use of plastic composite reinforcement is rapidly increasing. Composite reinforcement is used in the construction of various objects:

– low-rise buildings; – monolithic construction with light and heavy concrete; – road surfaces, railway foundations; – reinforced concrete floor slabs; – bridges;

– overpasses.

In addition, the high level of product quality leads to the fact that composite plastic reinforcement is often used in the manufacture of concrete products, both with and without prestressing. Power line supports, lighting poles, curbs, fence slabs, railway sleepers - this is not a complete list of reinforced concrete products where non-metallic reinforcement is used in production.

This description helped you find out what composite reinforcement is, where it is used, and its advantages.
Now knowing this, you can correctly and confidently use it in construction or opt for its analogues.

Source: https://classical4u.ru/stati/o-stroitelnyh-materialah/5662-kompozitnaya-armatura-preimushhestva-gde-primenyaetsya.html

Composite reinforcement: description and types, advantages and disadvantages

The foundation of any building begins with a frame, which is made from reinforcing rods. The traditional material for base reinforcement was special hardened steel, but recently it has been actively replaced by composite reinforcement.

• What is composite reinforcement
• Advantages
• Flaws

In the 60s, the Soviet Union and the United States, which competed in all sectors of the national economy, were actively developing new polymer materials - it was then that composite reinforcement was invented. At first it was not widely used in construction, but recently the situation has changed dramatically.

Many manufacturers of innovative materials have entered the building materials market , vying with each other to talk about its advantages over traditional ones. In turn, manufacturers of familiar materials focus on making them stand the test of time.

As a result, the consumer becomes completely confused and cannot understand who to trust when choosing a product. Let's look at this issue in more detail.

What is composite reinforcement

The main feature of composite reinforcement is the complete absence of metal or steel elements in its composition. It is made from various materials, for example, glass, armid, basalt or carbon fibers. Depending on the composition and components, rods come in several types and have various properties.

The following types of composite reinforcement are most often found on sale:

• Fiberglass (FRP),
• Basalt plastic (BBP),
• Carbon fiber reinforcement.

Regardless of what material the polymer reinforcement is made from, special thermoplastic or thermosetting polymer additives are added to its composition to acquire the necessary load-bearing characteristics. And to increase the adhesion of the frame to the concrete mass, it is endowed with special ribs - like a steel material - or a sand coating is applied to the surface.

Advantages

Composite reinforcement has a number of advantages compared to other similar elements:

1. High specific strength. Composites are 10 times stronger in comparison with their steel counterparts; of course, this is only the case when the conditions of the production technology are fully met.
2. High corrosion resistance. Polymer reinforcement, due to the complete absence of metal components in its composition, is absolutely indifferent to rusting; it also tolerates the negative effects of salts and other destructive substances. All this makes its use justified during construction when materials are exposed to an aggressive external environment, or in winter, when special antifreeze additives and additives, such as a plasticizer, are added to concrete.
3. Low thermal and electrical conductivity. Traditional metal material has a high degree of thermal conductivity and is an electrical conductor, while polymers do not have such properties, due to which they do not create cold bridges in the body of concrete and do not conduct electrical currents, and do not interfere with the transmission of radio waves.
4. Ease of transportation. To transport steel rods, you need to hire (or have your own) freight transport, but to transport polymer reinforcement of small diameters this is not necessary, since it is twisted into coils, like steel wire. Thanks to this, the material can be transported even using a passenger car, which significantly reduces the cost of construction when constructing private houses.
5. Environmental friendliness. Since this type of building materials is not made from chemically harmful substances, there is virtually no harm to the environment during its decomposition or disposal. In addition, this material does not absorb radiation, which is an indisputable advantage in our time.
6. Expansion coefficient identical to concrete. Steel and concrete have different degrees of expansion and contraction with strong temperature fluctuations, this can lead to cracking of the foundation and its accelerated destruction, but in the case of polymers, this problem does not exist, since they expand and contract similarly to concrete, which makes such structures more durable.

Despite all its advantages, this material also has quite a few disadvantages:

1. Insufficient rigidity. This is the other side of the coin of the elasticity of this material, because polymers are approximately 4 times less elastic than steel, which can become a significant disadvantage in the construction of rigid load-bearing structures.
2. Low heat resistance. Composite reinforcement in construction loses its useful qualities with a significant increase in temperature, so ASP becomes ineffective at temperatures above 150 degrees Celsius, and ASP deteriorates after 300 degrees; for comparison, metal can be used at temperatures up to 500 degrees Celsius.
3. Harmful to health. Since composite reinforcement consists of fibers of various polymers, when it is cut at a construction site, a large number of very thin glass needles are formed in the air, which settle on unprotected areas of the skin, eyes and respiratory tract, which can cause great harm to the health of builders.

In construction, although the material is relatively little known, it still has great potential compared to traditional steel.

Of course, there are also disadvantages, and they are significant, but this can also be said about other building materials, so before you run to a hardware store for polymers or to a metal warehouse for steel reinforcement, weigh the pros and cons to choose the material that best suits you in terms of price and quality.

Source: https://tokar.guru/metallicheskie-izdeliya/armatura/kompozitnaya-armatura-preimuschestva-i-nedostatki.html