Composite fiberglass reinforcement. Fiberglass rebar: characteristics and application of composite glass rebar Diameter of plastic rebar

Fiberglass reinforcement, which appeared on the domestic market relatively recently, has become a worthy alternative to traditional metal bars. Glass fittings, as this material is also called, has many unique characteristics that distinguish it favorably from other products of this purpose. Meanwhile, the choice should be approached very carefully.

What is fiberglass reinforcement

Fiberglass reinforcement, if you understand its design features, is a non-metallic rod, on the surface of which a fiberglass winding is applied. The diameter of the spiral profile of reinforcement made of composite materials can vary in the range of 4–18 mm. If the diameter of a bar of such reinforcement does not exceed 10 mm, then it is released to the customer in coils, if it exceeds, then in bars, the length of which can reach up to 12 meters.

For the manufacture of composite reinforcement, various types of reinforcing fillers can be used, depending on this, it is divided into several categories:

  • ASK - products made on the basis of fiberglass;
  • AUK - carbon composite reinforcing products;
  • AKK - fittings made of combined composite materials.

In the domestic market, fiberglass reinforcement is most widely used.

Structure features

Fiberglass rebar is not just a bar of composite material. It consists of two main parts.

  • The inner core consists of parallel fiberglass fibers interconnected with a polymer resin. Some manufacturers produce rebar, the fibers of the inner barrel of which are not parallel to each other, but curled into a pigtail. It should be noted that it is the internal fiberglass rebar that forms its strength characteristics.
  • The outer layer of a reinforcing bar made of fiberglass can be made in the form of a bidirectional winding of fibers of a composite material or in the form of a spraying of a fine abrasive powder.

The design of fiberglass reinforcing bars, which largely determines their technical and strength characteristics, depends on the imagination of manufacturers and the technologies used to manufacture this material.

Basic properties

Fiberglass reinforcement, according to the results of numerous studies conducted by competent organizations, has a number of characteristics that distinguish it favorably from other materials of a similar purpose.

  • Fiberglass reinforcing bars have a small mass, which is 9 times less than the weight of similar metal products.
  • Fiberglass reinforcement, unlike metal products, is very resistant to corrosion, perfectly resists the effects of acidic, alkaline and salty environments. If we compare the corrosion resistance of such reinforcement with similar properties of steel products, then it is 10 times higher.
  • The ability to conduct heat in fiberglass reinforcement is much lower than that of metal products, which minimizes the risk of cold bridges during its use.
  • Due to the fact that fiberglass reinforcement is transported much easier, and its service life is much longer than that of metal, its use is more profitable financially.
  • Fiberglass reinforcement is a dielectric material that does not conduct electric current, has absolute transparency for electromagnetic waves.
  • It is much easier to use such material to create reinforcing structures than metal rods, for this there is no need to use welding equipment and technical devices for cutting metal.

Due to its indisputable advantages, fiberglass reinforcement, having appeared relatively recently on the domestic market, has already gained high popularity among both large construction organizations and private developers. Meanwhile, such fittings also have a number of disadvantages, the most significant of which include:

  • sufficiently low modulus of elasticity;
  • not too high thermal stability.

The low modulus of elasticity of fiberglass reinforcement is a plus in the manufacture of frames to strengthen the foundation, but a big minus if it is used to reinforce floor slabs. If it is necessary to apply in such cases, it is to this valve that it is first necessary to carry out careful calculations.

The low thermal stability of fiberglass reinforcement is a more serious disadvantage that limits its use. Despite the fact that such reinforcement belongs to the category of self-extinguishing materials and is not capable of serving as a source of fire propagation when used in concrete structures, it loses its strength characteristics at high temperatures. For this reason, such reinforcement can only be used to strengthen those structures that are not exposed to high temperatures during operation.

Another significant disadvantage of reinforcement made of fiberglass should be attributed to the fact that over time it loses its strength characteristics. This process is greatly accelerated if it is exposed to alkaline environments. Meanwhile, such a drawback can be avoided if fiberglass reinforcement made with the addition of rare earth metals is used.

How and from what fiberglass reinforcement is made

Many fiberglass reinforcement is familiar not only from photos on the Internet, but also in practice in construction, but few people know how it is produced. The technological process for the production of fiberglass reinforcing bars, which is very interesting to watch on video, is easy to automate and can be implemented on the basis of both large and small manufacturing enterprises.

For the manufacture of such a building material, first of all, it is necessary to prepare raw materials, which are used as aluminoborosilicate glass. In order to give the initial raw material the required degree of ductility, it is melted in special furnaces and threads are drawn from the resulting mass, the thickness of which is 10–20 microns. The thickness of the resulting threads is so small that if you shoot them in a photo or video, then you can’t see them without enlarging the resulting image. An oil-containing composition is applied to the glass fibers using a special device. Then beams are formed from them, which are called glass roving. It is these bundles, assembled from many thin threads, that are the basis of fiberglass reinforcement and largely form its technical and strength characteristics.

After the fiberglass filaments are prepared, they are fed to the production line, where they are turned into reinforcing bars of various diameters and lengths. The further technological process, which can be found on numerous videos on the Internet, is as follows.

  • Through special equipment (creel) the threads are fed to the tensioning device, which simultaneously performs two tasks: it equalizes the stress in the glass threads, arranges them in a certain sequence and forms the future reinforcing bar.
  • Bundles of threads, on the surface of which an oil-containing composition was previously applied, are blown over with hot air, which is necessary not only for drying them, but also for slight heating.
  • Heated to the required temperature, the bundles of threads are lowered into special baths, where they are impregnated with a binder, also heated to a certain temperature.
  • Then the bundles of threads are passed through the mechanism, with the help of which the final formation of the reinforcing bar of the required diameter is performed.
  • If the reinforcement is made not with a smooth, but with a relief profile, then immediately after leaving the sizing mechanism, bundles of glass fibers are wound onto the main rod.
  • To speed up the process of polymerization of binder resins, the finished reinforcing bar is fed into a tunnel furnace, before entering which a layer of fine sand is applied to the bars produced without winding.
  • After exiting the furnace, when the fiberglass reinforcement is almost ready, the rods are cooled with running water and fed for cutting or to the mechanism for winding them into bays.

Thus, the technological process of manufacturing fiberglass reinforcement is not so complicated, which can be judged even from a photo or video of its individual stages. Meanwhile, such a process requires the use of special equipment and strict adherence to all modes.

In the video below, you can more clearly see the production process of composite glass fittings using the example of the TLKA-2 production line.

Parameters - weight, diameter, winding pitch

Reinforcement, for the manufacture of which fiberglass is used, is characterized by a number of parameters that determine the scope of its application. The most significant are:

  • weight of one linear meter of reinforcing bar;
  • for products with a relief profile - the step of winding fiberglass bundles on their surface;
  • rebar diameter.

To date, reinforcement with a relief profile is produced mainly with a winding pitch of 15 mm.

The outer diameter of the reinforcing bar is characterized by a number that is assigned to the product in accordance with the Specifications for the production of such products. In accordance with TU, fiberglass reinforcing bars are now produced under the following numbers: 4; 5; 5.5; 6; 7; 8; 10; 12; 14; 16; 18. The weight of a running meter of fiberglass reinforcing bars on the modern market varies between 0.02–0.42 kg.

Types of fiberglass reinforcement and its scope

Reinforcement, for the production of which fiberglass is used, has many varieties that differ not only in diameter and profile shape (smooth and corrugated), but also in the area of ​​\u200b\u200buse. So, experts distinguish fiberglass reinforcement:

  • working;
  • mounting;
  • distribution;
  • specially designed for reinforcing concrete structures.

Depending on the tasks to be solved, such reinforcement can be used in the form of:

  • piece bars;
  • reinforcing mesh elements;
  • reinforcing cages of various designs and dimensions.

Despite the fact that reinforcement made of fiberglass has recently appeared on the domestic market, enterprises, construction companies and individuals are already quite actively using it to solve various problems. Thus, the use of fiberglass reinforcement in construction is gaining popularity. With its help, foundations and other structures made of concrete are reinforced (drainage wells, walls, etc.), it is used to strengthen masonry made of bricks and block materials. The technical characteristics of fiberglass reinforcement make it possible to successfully use it in road construction: for reinforcing the roadway, strengthening embankments and weak foundations, and creating monolithic concrete foundations.

Individuals who are independently engaged in construction in their backyard or in the country, also managed to appreciate the merits of this material. The experience of using fiberglass reinforcement in dachas and gardens of private houses as arcs for the construction of greenhouses is interesting. On the Internet you can find many photos of such neat and reliable structures that are not subject to corrosion, are easy to install and just as easy to dismantle.

The big advantage of using such material (especially for individuals) is the ease of its transportation. Fiberglass rebar wound into a compact coil can be taken away even by a car, which cannot be said about metal products.

Which is better - fiberglass or steel?

To answer the question of which reinforcement is better to use - steel or fiberglass - one should compare the main parameters of these materials.

  • If reinforcing bars made of steel have both elasticity and plasticity, then fiberglass products have only elasticity.
  • In terms of tensile strength, fiberglass products are significantly superior to metal products: 1300 and 390 MPa, respectively.
  • Fiberglass is also more preferable in terms of thermal conductivity: 0.35 W / m * C0 - against 46 for steel.
  • The density of reinforcing bars made of steel is 7850 kg/m3, fiberglass - 1900 kg/m3.
  • Fiberglass products, in contrast to steel reinforcing bars, have exceptional corrosion resistance.
  • Fiberglass is a dielectric material, so products made from it do not conduct electric current, they are completely transparent to electromagnetic waves, which is especially important in the construction of structures for a specific purpose (laboratories, research centers, etc.).

Meanwhile, fiberglass products do not work well in bending, which limits their use for reinforcing floor slabs and other heavily loaded concrete structures. The economic feasibility of using reinforcing bars made of composite materials also lies in the fact that they can be purchased in exactly the amount that you need, which makes their use practically waste-free.

Let's summarize all of the above. Even taking into account all the unique characteristics of composite reinforcement, it should be used very deliberately and only in those areas where this material performs best. It is undesirable to use such reinforcement to strengthen concrete structures, which during operation will experience very serious loads that can cause its destruction. In all other cases, the use of fiberglass reinforcement and other composite materials has proven to be effective.

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 these products are a full-fledged replacement for metal fittings, their use can not be considered justified in all situations.

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 reinforce the structure of such a product, but also to ensure its reliable adhesion to the concrete solution. This type of reinforcement has both pros and cons, and its use should be approached very carefully.

Plastic clamps serve as elements for fixing carbon-fiber reinforcing bars to each other. It is convenient that the use of welding is not required to connect the elements of such fittings, which is undoubtedly a big plus.

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 proceeding with the selection of elements for reinforcing concrete structures, it is necessary to understand in which cases the use of certain products is more appropriate.

Main advantages

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

  • An important advantage of fiberglass reinforcement is its low specific gravity, which makes it possible to use it for reinforcing lightweight structures made of cellular concrete and some other building materials. This allows you to significantly reduce the weight of structures that are reinforced with it. 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 one of the advantages of fiberglass reinforcement. When such reinforcement is used in concrete structures, cold bridges are not 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 bars. Thanks to the compact form of packaging, it is much easier to transport such fittings, for which you can use the trunk of any car, and this greatly reduces the cost of delivering the material to the construction site. The use of reinforcing elements, which are shipped not in cut bars, but in coils, also makes it possible to reduce material costs by reducing the number of overlaps. This positively affects both the strength characteristics of the future concrete structure and its cost, which is especially important when performing construction work.
  • Such an advantage of fiberglass reinforcement as its durability inside a concrete structure is considered quite controversial. Reinforcement made of metal, being in an isolated state, is also not exposed to the negative influence of external factors, which ensures the durability of its use.
  • CFRP reinforcement is a dielectric material, which is an advantage of products made from this material. Electrically conductive metal reinforcement is 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, which accelerate the solidification process.
  • Being a dielectric, carbon fiber fittings do not create radio interference inside the building, unlike metal bars. This advantage is important when there are many reinforcing elements in the concrete structure. Otherwise, the use of composite reinforcement will not become a minus, but it will not be so relevant.

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 does not withstand exposure to high temperatures. At the same time, it is difficult to imagine a situation where a reinforcing cage inside concrete can be heated to a temperature of 200 degrees.
  • A rather high cost is a conditional disadvantage, given the fact that fiberglass reinforcement of a smaller diameter can be used to reinforce concrete structures in comparison with metal products.
  • CFRP reinforcement does not bend well. This disadvantage limits its use in the creation of reinforcing frames for concrete structures. Meanwhile, it is possible to make bent sections of the reinforcing cage from steel elements, and then build them up using fiberglass rods.
  • Reinforcement made of fiberglass does not withstand fracture loads, 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 a metal reinforcing cage, fiberglass products have less rigidity. Because of this drawback, they do not tolerate vibration loads that occur when they are poured using a car mixer. When using this technique, the reinforcing cage is subjected to significant mechanical loads, which can cause its breakage and violation of the spatial position of its elements, therefore, rather high requirements are imposed on the rigidity of such concrete structures.

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.

Fields of application of fiberglass reinforcement

Reinforcement made of composite materials, the laying rules of which are easy to learn from the corresponding videos, are 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.

  • Reinforcement made of composite materials is successfully used to strengthen the foundation structures of the following types: tape, the height of which is greater than the depth of soil freezing, 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 concrete foundations will not be subjected to fracture loads that fiberglass elements may simply not withstand.
  • With the help of fiberglass reinforcement, walls are strengthened, the laying of which 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 for bonding elements of multilayer panels. The structure of the latter includes a layer of insulation and concrete elements, which are interconnected using fiberglass reinforcement.
  • Due to the fact that the reinforcement of this type is free from such a disadvantage as susceptibility to corrosion, it is often used to strengthen various hydraulic structures (for example, dams and basins).
  • In cases where it is necessary to effectively increase the rigidity of glued wooden beams, they are also reinforced with fiberglass reinforcement.
  • This material is also used in road construction: it is used to strengthen the layer of asphalt pavement, which is subjected to increased loads during its operation.

Summarizing all of the above, it should be noted that the use of fiberglass reinforcement can be quite effective, given its shortcomings and the limitations associated with them, which are specified by the manufacturer.

Can fiberglass reinforcement replace metal analogues

Despite the fact that reinforcement made from composite materials is a fairly new material in 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 erected from bricks and building blocks, as well as to connect load-bearing walls with interior partitions.

Despite the fact that there are still disputes about replacing composite reinforcement with steel, the majority chooses composite. And for good reason, because it has undeniable advantages. Ease of installation and transportation, corrosion resistance and low thermal conductivity save almost 60% of the cost when replacing metal reinforcement with a composite one. Reinforcement composite reinforcement produced in accordance with the normative and technical documentation.


Production of composite reinforcement "Armplast"

The Armplast plant independently produces non-metallic composite polymer reinforcement. We create it in several versions and several types - fiberglass, basalt-plastic and glass-basalt.

Fiberglass reinforcement is made from glass roving and consists of a fiberglass rod with a basalt reinforcing thread as a periodic profile.

Composite and basalt rebar are made from basalt roving. Composite fiberglass reinforcement, in turn, is divided into classic fiberglass reinforcement with a periodic profile, fiberglass reinforcement with a sand coating and with a sandy coating and a periodic profile. In these types of composite reinforcement, sand dressing and a periodic profile are used for greater adhesion to concrete. Diameters above 12 mm are produced in rods, the length agreed with the customer, and diameters less than 12 mm are produced in coils.

Non-metallic composite reinforcement is a reinforcing agent in the form of fiberglass rods with a ribbed surface. In the profile, such reinforcement has a spiral shape, and its diameter can be from 4 to 18 millimeters. The length of this building material can reach 12 meters.

Appearance of polymer rods.

Fiberglass reinforcement before mass introduction to the market has passed many serious tests. As a result, such studies have established that this building material has a number of advantages, such as:

  • Low weight, which is 9 times lower than the mass of classical metal fittings;
  • High resistance to corrosion and acids;
  • Excellent performance in terms of energy efficiency;
  • Economy in delivery;
  • Inertness to electromagnetic and radio impact;
  • Fiberglass reinforcement refers to dielectrics.

Of course, in addition to the advantages, this building material has certain disadvantages. Such shortcomings cannot be classified as critical, but it is important to take them into account when erecting certain types of buildings.

Disadvantages of composite reinforcement:

  • Low elasticity;
  • Low temperature resistance parameters.

At the same time, such shortcomings of the material do not affect its use in the construction of roads and building foundations.

The use of this technology in the construction of the foundation (advantages, disadvantages, method of application)

In the process of laying the foundation, composite reinforcement is used similarly to metal. At the first stage, the frame of the future foundation is assembled from this material, which is subsequently pulled together with special screeds.

Manufacturers of fiberglass reinforcement themselves do not impose any restrictions on its use for certain types of foundations. In other words, such material can be freely used for the construction of any low-rise buildings.

According to minimum estimates, the service life of such polymer elements is at least 80 years. It should be noted that this building material costs a little more than the usual metal rods, while certain funds can be saved during its delivery, due to the much lower weight.

There are various construction methods and conditions. If the construction site involves the constant presence of metal parts in an aggressive environment for them, it makes sense to use composite reinforcement.

With the right selection of plastic fittings, it will provide the same strength as metal.

Rods before pouring concrete.

Main areas of use

There are two main forms of production of composite reinforcement:

  • Smooth plastic rods, supplemented with a glass spiral to improve the quality of fixation;
  • Fittings of the usual form, repeating the structure of the metal.

Most experts advise giving preference to the second type.

The main scope of fiberglass reinforcement is the construction of foundations for low-rise buildings. When building a foundation, in each individual case, reinforcement of a specific diameter is used.

In addition, such material is often used to bind brickwork. In this way, thermal bridges can be avoided, which increases the overall efficiency of the building.

Opinion of builders

Now there is a steady trend of popularization among builders and large developers of composite reinforcement. In most cases, you can find positive opinions about this material. Experts note that such rods are virtually waste-free during construction work. Another important factor is their ease of use.

Most experts agree that in certain construction areas, such a material has significant advantages over metal reinforcing rods. The main advantage of these plastic rods is the possibility of using almost any length.

Use of Composite Materials to Reinforce Bridge Deck Slabs

One of the main factors confirming the high strength and reliability parameters of composite reinforcement is its widespread use in construction areas that withstand constant severe loads (bridges, coastline structures, roads).

This is due to the fact that such material has excellent parameters of resistance to seismological activity of the earth. It has been experimentally proven that fiberglass rebar does not lose its basic technical characteristics even under a magnitude 10 earthquake, making it the best choice for reinforcing concrete bridge deck slabs.

In addition, it should be noted that plastic, unlike metal, is not subject to corrosion, which is an important factor in the construction of bridges that are constantly in contact with water and a humid environment.

Differences in the characteristics of polymer and metal reinforcing rods

The main competitor for plastic reinforcing bars is the traditional metal reinforcement used in concrete slabs and ceilings. In general, these two building materials are very similar to each other. At the same time, in some respects, fiberglass reinforcement demonstrates significantly more impressive performance than metal reinforcing equipment. In such conditions, it is worth making a small comparison of the technical characteristics of metal and polymer reinforcement:

  • Deformation indicators. Steel rods are an elastic-plastic material, while composite reinforcement is an ideally elastic building material;
  • Indicators of ultimate strength. The metal demonstrates the following parameters 390 MPa, and fiberglass 1300 MPa;
  • The size of the thermal conductivity coefficient. For metal, this parameter is 46 W / mOS, and for composite 0.35 W / mOS;
  • Indicators of structural density. For steel, this parameter is 7850 kg / m3, and for fiberglass 1900 kg / m3;
  • Thermal conductivity parameters. Unlike steel structures, fiberglass does not conduct heat at all;
  • Corrosion resistance. Fiberglass reinforcement does not rust at all. In this case, steel refers to a relatively quickly rusting material;
  • electrical conductivity of the product. Composite reinforcing building material is essentially a dielectric. At the same time, one of the disadvantages of metal fittings is the ability to conduct electrical current.

External differences between metal and composite rods.

Physical parameters of fiberglass reinforcing material

According to today's requirements, composite rods must be characterized by three main physical parameters, namely:

  • Weight of elements;
  • winding distance;
  • External as well as internal diameter.

Each individual profile number has its own physical indicators. The only constant parameter is the winding distance, equal to 15 millimeters. The current TU regulates that composite rods differing in profile size have the following numerical designations: 4, 5, 5.5, 6, 7, 8, 10, 12, 14, 16 and 18. These numerical values ​​correspond to the parameters of the outer diameter. The mass of reinforcing rods can vary from 0.02 to 0.42 kg / 1 p.m.

Calculation procedure for building structures with composite reinforcing materials

The process of calculating structures in which composite reinforcement is used can be demonstrated by the example of calculating the operation of a beam, where steel reinforcement D12 mm is used.

Such reinforcing bars A500C, having a diameter of 12 millimeters, have such characteristics as:

  • The value of the modulus of elasticity at the level of 200 GPa;
  • The normative resistance indicators are 500 MPa, which is slightly less than the yield parameters of the steel used in the manufacture of these rods.

Based on these data, the approximate maximum load on the rod is 4.5 tons. With such a load, the tensile parameters of the reinforcement will reach 2.5 mm / m

In the documentation that comes with fiberglass reinforcement, there is always a plate of its compliance with steel reinforcing rods.

So, fiberglass reinforcement, in order to comply with the parameters of steel A500C with a diameter of 12 mm, must have a diameter of 10 mm.

In other words, the process of calculating buildings from plastic rods is completely similar to calculations with steel ones, the only difference is the use of a correspondence table.

How composite reinforcement is made

All composite reinforcement is produced in the form of rods with a thickness of 4 to 32 millimeters. Such building materials can be sold both in the form of rods and in bays, more than 100 meters long.

There are two main types of plastic reinforcing rods:

  • Periodic, which is obtained by using spiral wrapping;
  • Smooth, sprinkled with quartz sand to improve grip.

Connection technique

One of the additional advantages of composite building materials is the absence of the need for welding. All rods are formed into a single frame using binding technology.

Often in construction practice, a special knitting wire is used, less often plastic ties.

There are the following ways to use the binding wire:

  • Using a special automatic pistol;
  • The use of a construction hook for knitting;
  • The use of a mechanized construction crochet hook.

The last two options are most often used in construction. This is due to their availability, because not everyone can afford to purchase a special automatic gun for a bundle.

Connection with plastic ties.

Plastic reinforcement diameter

Due to certain design features, fiberglass reinforcement has several parameters that characterize its diameter:

  • The size of the outer diameter of the composite rod is determined according to the location of the ribs protruding along the profile;
  • The inner diameter refers specifically to the rod itself;
  • The nominal diameter refers to the numerical designation of a particular profile.

All these parameters do not match. The nominal diameter is smaller than the outer diameter measured by the raised ribs. Pay special attention to these parameters. This will help to avoid buying smaller than necessary reinforcing rods.

There are some nuances in determining these dimensions of fiberglass reinforcement. The outer diameter of the product is determined in the same way as for steel. As for the inner diameter, it is more difficult to determine it because of the not perfectly round section of the rod.

Fiberglass reinforcement is widely used in construction in the west, while its use in the domestic industry is not widespread. However, in recent years, the popularity of this material is growing, the reason for this is the many operational advantages in comparison with traditional rolled metal.

This article presents fiberglass reinforcement (FRP). We will consider the technical characteristics, advantages and disadvantages, standard sizes and application of composite reinforcement.

1 Assortment and GOSTs

Non-metallic composite reinforcement was developed back in the USSR in the 60s, however, mass production of the material was never established due to the then high cost of fiberglass. Nevertheless, composite reinforcement was used in the construction of several large facilities, including power lines in Batumi, Moscow and bridges in Khabarovsk.

To date, there is no GOST standard with technical requirements for this material (the project is under development). The main regulation is SNiP №52-01-2003 "Composite reinforcement", according to which fiberglass products can be used in construction as a replacement for rolled metal. Each of the manufacturers has technical specifications for their products, along with which test reports and certificates of approval are supplied.

Composite reinforcement is produced in the range of diameters 4-20 mm. The profile of the rods can be corrugated or smooth. Depending on the material of manufacture, the following types of non-metallic products are distinguished:

  • ASP - fiberglass reinforcement, made from fiberglass bonded with a layer of synthetic resin;
  • ABP - basalt-plastic products, in which the fiberglass core is replaced by a melt of basalt fibers;
  • ASPET - products made of fiberglass and polymer thermoplastic;
  • AUP - carbon fiber reinforcement.

ASP and ABP are most common in construction, carbon fiber reinforcement is used less frequently due to the lower mechanical strength of the material.

1.1 Applications

Application of s.p. reinforcement in construction is practiced in the construction of residential, public and industrial buildings, as well as low-rise buildings, where ASP is used for:

  • reinforcement of reinforced concrete structures (walls and floor slabs);
  • repair of surfaces of objects made of brick and reinforced concrete;
  • layered masonry walls using the technology of flexible connections;
  • all types (slab, tape, columnar);
  • strengthening of walls and aerated concrete blocks and installation of monolithic armored belts.

The use of s.p. fittings and in the field of road and railway construction, in which ASP is used:

  • when arranging embankments and road surfaces;
  • when strengthening the slopes of roads;
  • during the construction of bridges;
  • while strengthening coastlines.

Composite polymer rebar for reinforcing concrete structures is completely resistant to corrosion and chemically aggressive substances, which greatly expands its scope.

1.2 Benefits of TSA

Composite reinforcement has the following operational advantages:


Disadvantages of s.p. reinforcement - low modulus of elasticity (4 times less than that of steel), which limits the possibility of its use for vertical reinforcement, the tendency to lose strength when heated above 600 degrees. Please note that the composite reinforcement is not subject to bending in the conditions of the construction site- if it is necessary to use bent elements, they must be ordered separately from the manufacturer.

2 Comparison of ASP and metal analogues

We bring to your attention a comparison of the technical characteristics of composite and steel reinforcement.

Reinforcement type metal Fiberglass (ASP)
Production material Steel grade 25G2S or 35 GS Fiberglass bonded with synthetic resin
Weight 7.9 kg/m3 1.9 kg/m3
360 1200
Modulus of elasticity (MPa) 200 000 55 000
Relative extension (%) 24 2.3
Stress-Strain Relationship Curve line with yield pad Straight line with elastic-linear dependence up to failure
Linear expansion (mm/m) 14-15 9-11
Resistant to corrosive environments Low, prone to rust high, does not rust
Thermal conductivity of materials (W/mK) 47 0.46
Electrical conductivity Present Dielectric
Diameters 6-80 mm 4-20 mm
Measured length 6-12 m Custom length according to customer's requirement

Let's consider a comparison of interchangeable diameters of composite and metal products using the example of rods:

  • A3 6 mm - ASP 4 mm;
  • A3 8 mm - ASP 6 mm;
  • A3 10 mm - ASP 8 mm;
  • A3 12 mm - ASP 8 mm;
  • A3 14 mm - ASP 10 mm;
  • A3 16 mm - ASP 12 mm.

2.1 Overview of fiberglass reinforcement (video)


3 Technology for the production of composite products

Fiberglass reinforcement is made from roving (fibers of raw materials), binder material - polymer resin, hardener and hardening accelerator. The specific ratio of materials depends on the temperature and humidity inside the production room.

See also: what is the difference between reinforcement, and what are its parameters?

The production line includes the following equipment:

  1. Heating hopper - in it the fibers are heated to increase adhesion with the resin.
  2. Impregnation bath - roving is impregnated with a mixture of resin and hardeners.
  3. Wrapper - pushes the raw material through the dies, during the passage of which rods of a given diameter are formed.
  4. Sand spreading equipment, where sand grains are evenly distributed over the surface of the rod, and the excess is removed by air flow.
  5. Polymerization furnace, where the design strength of the bars takes place.
  6. The equipment for cooling products is a line 3-5 meters long, located at the outlet of the polymerization furnace.
  7. Broaching equipment, cutting mechanism and installation for winding coils - finished fiberglass reinforcement is cut into sections of the required length or wound into commercial coils 50-100 m long.

There are many standard solutions on the market, including all the necessary equipment. The cost of a new line varies within 3-5 million rubles.

Equipment of average productivity is capable of producing up to 15,000 m of rebar during the working day.