Fiberglass reinforcement use. Fiberglass composite reinforcement. Comparison of fiberglass and metal reinforcement

Connoisseurs of the construction business attribute the invention of composite reinforcement to the 60s of the last century. During this period, active studies of its properties were begun in the United States and the Soviet Union.

However, despite the fairly advanced age, this material is still not familiar to most developers. This article will help you fill in the knowledge gap about fiberglass reinforcement, its properties, advantages and disadvantages.

Along the way, we note that this material is very controversial. Manufacturers praise him in every way, and practical builders are skeptical. Ordinary citizens look at those and others, not knowing who to believe.

What is composite rebar, how is it produced and where is it used?

In short, the structure of composite reinforcement can be described as “fiber in plastic”. It is based on tear-resistant threads made of carbon, glass or basalt. The stiffness of the composite rod is given by an epoxy resin that wraps around the fibers.

For better adhesion to concrete, a thin cord is wound on the rods. It is made from the same material as the main shaft. The cord creates a helical relief, like a steel one. The epoxy resin hardens in a drying chamber. At the exit from it, the composite reinforcement is slightly pulled and cut. Some manufacturers sprinkle plastic rods with sand before the polymer hardens to improve adhesion to concrete on smooth areas.

The field of application of fiberglass reinforcement cannot be called very wide. It is used as a flexible connection between the facade cladding and the load-bearing wall, and is also laid in road slabs and tank formwork. In the frameworks that reinforce strip foundations and concrete floors, plastic reinforcement is not used so often.

It is not recommended to install composite rods in floor slabs, lintels and other structures working in tension. The reason is the increased flexibility of this material.

Physical properties of composite reinforcement

The elastic modulus of the polymer composite is significantly lower than that of steel (from 60 to 130 versus 200 GPa). This means that where the metal comes into play, preventing the concrete from cracking, the plastic continues to bend. The tensile strength of a fiberglass rod is 2.5 times higher than that of a steel one.

The main strength parameters of composite reinforcement are contained in table No. 4 GOST 31938-2012

Here we see the main classes of composite material: ASK (fiberglass composite), ABC (basalt fiber), AUK (carbon), AAK (aramid composite) and AKK (combined - glass + basalt).

The least durable, but the cheapest are fiberglass reinforcement and basalt composite. The most reliable and at the same time the most expensive material is made on the basis of carbon fiber (AUC).

We will return to the strength properties of the material when we compare it with metal.

In the meantime, let's consider other characteristics of this material:

• The positive qualities of the composite include its chemical inertness. It is not afraid of corrosion and aggressive substances (alkaline environment of concrete, sea water, road chemicals and acids).
• The weight of plastic reinforcement is 3-4 times less than that of steel. This provides savings in transportation.
• The low thermal conductivity of the material improves the energy-saving characteristics of the structure (there are no cold bridges).
• Composite rebar does not conduct electricity. In the structures where it is used, there are no short circuits in the wiring and stray currents.
• Composite plastic is magnetically inert and radiotransparent. This allows it to be used in the construction of structures, where the factor of shielding electromagnetic waves must be excluded.

You can't bend a fiberglass rod at 90 degrees at a construction site

Disadvantages of composite rebar:

• Impossibility of bending with a small radius in construction conditions. The bent rod must be ordered in advance from the manufacturer.
• The inability to weld the frame (minus the relative, because even for steel reinforcement, the best way to join is knitting, not welding).
• Low heat resistance. Under strong heating and fire, the concrete structure reinforced with composite rods is destroyed. Fiberglass is not afraid of high temperatures, but the plastic that binds it loses its strength when heated above +200 C.
• Aging. Common minus of all polymers. Non-metallic fittings are no exception. Its manufacturers overestimate the service life up to 80-100 years.

Knitting with plastic ties or steel wire is the only possible method for assembling the frame

Which reinforcement is better metal or fiberglass?

One of the main arguments in favor of fiberglass when compared with is the lower price. However, looking at the price tags of metal warehouses, you will see that this is not the case. The cost of the metal is on average 20-25% lower than the composite.

The reason for the confusion is that plastic sellers take into account the so-called “equivalent” diameter. The logic here is this: non-metallic reinforcement is tensile stronger than construction steel. Therefore, a polymer bar with a smaller diameter will withstand the same load as a thicker steel bar. Based on this, the conclusion is drawn: less plastic is needed to reinforce the structure than metal. Hence the "lower" price appears.

For a reasoned comparison of a composite with a metal, a regulatory document is required. Such guidance is already available today. This is annex "L" to the order of the Ministry of Construction of Russia No. 493 / pr dated 08.07. Feb 2016

In paragraph L.2.3. incomprehensible for ordinary developers, but very interesting for professionals, there are two reduction factors for all types of composite reinforcement.

For example, consider the most common fiberglass (ASK):

• Under the action of a continuous load, its tensile strength should be multiplied by 0.3. That is, instead of 800 MPa, we get 240 MPa (800x0.3 \u003d 240).
• If the structure works in the open air, then the result obtained must be multiplied by another 0.7 (240 MPa x 0.7 \u003d 168 MPa).

Reduction factor table for composite reinforcement

Table with factors taking into account operating conditions

Now you can correctly compare the strength of plastic and metal reinforcement. Let's take A500 grade construction steel as an example. Its ultimate tensile strength, taking into account the safety factor, is 378 MPa. We obtained only 112 MPa for the fiberglass composite.

Our small study clearly illustrates a table of real, and not theoretical, equal-strength replacement of steel reinforcement with composite. It can be used when choosing and buying.

Having looked through this table, it is easy to see that plastic for an equivalent replacement of metal requires not less, but more metal. Only the most expensive carbon fiber material (AUC) outperforms steel of equal diameter.

Range and price of composite reinforcement

The most demanded at the construction site is fiberglass composite reinforcement. We have summarized its assortment and average prices in one table.

You can get information from the table below about how much plastic reinforcement of different diameters weighs.

They sell material in coils of 200, 100 and 50 meters and in the form of rods of any length.

Taking into account the price factor (a composite of equal strength with steel will cost more), we cannot recommend composite reinforcement for widespread use in private construction.

For the reinforcement of beams, floor slabs, load-bearing beams, columns and stiffening diaphragms, experts strongly advise not to install it. As a constructive, such fittings can be used. It can be used to reinforce slab foundations.

Slab foundation with a frame made of fiberglass reinforcement

To strengthen the pile grillages and strip foundations, it is better to buy steel rods.

When fiberglass reinforcement was first developed (57 years ago), its cost was much higher compared to steel rods, so the composite material did not find widespread use. Today the situation has changed, the cost of the reinforcing material has decreased, and its advantages have been appreciated by construction companies engaged in the construction of facilities in regions with a cold climate.

Now fiberglass reinforcement is produced both in the form of threaded rods and in coils. The cross-section of the rods is from 4 to 32 mm. Let us consider in more detail the areas in which reinforcement of this type is most often used.

Features and scope

A plastic armature is a physical body, which consists of the following elements:

• The main trunk is made of parallel fibers connected by polymer resin. This element provides the strength characteristics of the reinforcement.
• An outer layer of fibrous material that is wound in a spiral around the main barrel of the plastic reinforcement. Such winding can be sand spraying or bidirectional winding.

Speaking about the use of fiberglass reinforcement in construction, today composite materials are widely used for:

• reinforcement of various reinforced concrete structures;
• repair of reinforced concrete and brick surfaces;
• installation of lightweight concrete buildings;
• layered wall masonry (flexible connection technology);
• reinforcement of slab, columnar and strip foundations;
• strengthening of concrete screeds;
• wastewater disposal;
• creation of road surfaces and fences;
• the design of seismically resistant reinforcing belts.

In addition, fiberglass reinforcement is used in many other industries, and its characteristics meet all building requirements and standards, so products of this type are suitable for both private construction and for streaming production.

Manufacturing technology

Composite reinforcement can be manufactured using one of three technologies:

1. Winding. In this case, winding is carried out on specialized equipment. The winder moves along the rotating mandrel. After several approaches, an integral cylindrical surface is created, which is sent to the furnace for heat treatment.
2. Broaching. First, the fiberglass is unwound from spools and impregnated with resin. After that, the material passes through the dies and excess scrap is removed from it. At the same time, the plastic reinforcement bars are given a cylindrical shape. After that, the winder manually applies a spiral rope to the workpiece, which is used to increase the adhesion of the material and the concrete solution. In the next step, the fiberglass reinforcement is sent to an oven where the resin is solidified. Once the rods are fully polymerized, they pass through the broaching mechanism.
3. Manual production. This is the most expensive process for making plastic fittings, therefore it is used only for small batch production. In this case, first, a special matrix is \u200b\u200bprepared, on which a gelcoat (protective decorative layer) is applied. After that, the fiberglass is cut out, soaked in resin and hardeners and fit into the mold. Next, the product is heat treated and cut.

The first method of making plastic reinforcement is considered the cheapest, therefore, products that have passed the winding are used most often.

In the manufacture of rods of this type, various types of fibers are used.

Varieties of composite reinforcement

Fiberglass fittings are of various types, the most famous of them are:

• ASP is a fiberglass reinforcement, which is made by the classical method of winding fiberglass. The fiber diameter of the product is from 13 to 16 microns.
• ABP - basalt-plastic reinforcement. In this case, the main stem of the product is made of basalt fibers with a diameter of 10 to 16 microns.
• AUP is a carbon fiber reinforcement that uses both fiberglass and thermoplastic. The diameter of the fibers used is up to 20 microns.

Most often in construction, ASP and ABP are used. Carbon fiber reinforcement has a reduced mechanical strength, so it is used very rarely. In addition, on sale you can find ASPET products (a mixture of fiberglass and thermoplastics), AKK (combined fittings) and many other varieties.

In addition, fiberglass fittings are sold:

• piece rods;
• mesh;
• frameworks;
• ready-made structures.

In addition, products are classified based on the type of structures for which they are used:

• fittings for ZhKB;
• assembly room;
• working;
• distribution.

It is also worth paying attention to the properties and characteristics of composite reinforcement.

Technical properties, advantages and disadvantages of plastic fittings

When choosing plastic reinforcement for strengthening the foundation, it is worth considering the following characteristics of products, which in most cases are much better than their metal counterparts:

• The maximum operating temperature is from 60 degrees.
• Tensile strength - not less than 800 MPa (for ASP reinforcement) and not less than 1400 MPa (for AUK type products). For metal, this indicator barely reaches 370 MPa.
• Elongation - 2.2%.
• Since this material belongs to the first group in terms of chemical resistance, fiberglass reinforcement can be used in an aggressive or alkaline environment.
• The density is 1.9 kg / m 3, so the ASP weighs 4 times less than the steel frame.
• Easy to transport.
• Low thermal conductivity.
• Long operational life (over 80 years).
• Corrosion resistant.

In addition, when using fiberglass reinforcement, you do not have to be afraid that it will jam the signal of cellular communication or radiotelephone, since this material is a dielectric.

Also, fiberglass is resistant to low temperatures, but at extremely high rates, the material begins to melt. However, in this case, you will have to heat the surface to at least 200 degrees.

Interesting! Builders never have a question of how to cut fiberglass reinforcement, since it lends itself well to processing with a conventional grinder.

The most obvious disadvantage of composite reinforcement is its instability. If you want to prepare it separately from the formwork, it can be "skewed", therefore it is better to install the armored belt directly into the formwork.

If we talk about cost, basalt-plastic reinforcement will cost about 6 rubles per running meter, and fiberglass - from 9 rubles. If we compare it with steel rods, costing from 21 rubles per meter, it becomes obvious that today fiberglass rods not only do not "hit the pocket", but are almost twice as cheap as metal ones.

However, you should not rejoice ahead of time, because there are many unscrupulous manufacturers on the market who offer customers low-quality products.

What to look for when buying fiberglass reinforcement

To distinguish a low-quality product, pay attention to the following nuances:

• Composite reinforcement must be manufactured in accordance with the technological process. If the product has an uneven color with sharp transitions, then such rods are not suitable for construction.
• If the rods are brown, then this indicates that at the final stage of manufacturing, the rods did not undergo the necessary heat treatment, or the temperature regime was not observed correctly. Such products must be rejected in production.
• If you notice that the rods are greenish, then such products are also not worth buying, they will have a very low modulus of elasticity for fracture. This is due to the too low processing temperature of the fiberglass.

The color is the main indicator of the quality of the reinforcement, so make sure that the shade of the bars does not differ.

It is also necessary to choose the correct clamps for the fiberglass armopoyas. Plastic holders are best suited for this purpose:

• Horizontal (for concrete slabs and floors) allow you to create a layer 25-50 mm high.
• Vertical (for wall surfaces) - layer thickness 15-45 cm.

Fiberglass reinforcement for foundation

A few years ago, classic steel reinforcement was used in the construction of foundations. But already now modern reinforcing materials are slowly replacing steel, and fiberglass is especially popular.

It is a composite material that is durable and flexible, resistant to tearing, because it consists of many monofilament fibers connected in a single bundle.

But at the moment, fiberglass reinforcement has not yet passed the test of time and various influences, therefore it is difficult to judge the quality of such products and the correct choice of diameter.

Also, there are still no optimal calculations for the choice of the optimal reinforcing fiber, moreover, there are still complex technologies for connecting fibers to each other.

But the advantages of such composite materials already exist:

• This is the only material that is practically not susceptible to all types of corrosion;
• It can be used in all existing types of foundations;
• Affordability, because fiber is slightly cheaper than steel reinforcement;
• Low weight and small core diameter.

But fiberglass reinforcement also has disadvantages:

• Through relative flexibility, the armature cannot take on the tensile force. It will lie on concrete, therefore, it is necessary to install reinforcement on concrete, which is already subject to the maximum possible boundary tension;
• Fiberglass is limited in use, it must be used in an already tense state;
• It should not be used in mass construction, fiberglass will only be used by beginners who decided to experiment.

Fiberglass reinforcement for the foundation: features

With a core diameter of 10 mm, the fiber weighs 10 times less and is easier to transport. Fiber is produced and transported in bays, therefore, funds on transportation costs are significantly saved;

Complete absence of cold bridges and low thermal conductivity;

Dielectric conductivity, electromagnetic permeability, it is a complete dielectric (does not create a secondary electromagnetic field and does not serve as an obstacle to radio waves);

High tensile strength, and it is about 3 orders of magnitude of steel reinforcement;

This is a monolithic structure that can be stacked in layers as many as you like. It is cut with ordinary assembly scissors;

No cracks appear in concrete through different indicators of the temperature gradient;

When buying a fiber, a private trader gets an excellent flexible reinforcing material, connected with an ordinary blowtorch or plastic ties.

How to reinforce foundations with fiberglass

Knitting of fiberglass reinforcement with plastic ties

Considering that the reinforcement of foundations is used more in low-rise construction, then rods are also used with a diameter of up to 8 mm (this is a cross-section of steel rods of 12 mm). Glass fiber reinforcement technology consists of several stages:

1. Calculation of the required amount and diameter of the fiber;
2. Formwork preparation, installation at the construction site;
3. For multiple use of the formwork, it is recommended to cover it with glassine, which protects the structure from moisture and concrete;
4. Installation of level marks, horizontal markers, according to the level of which the concrete solution will be poured;
5. Preparation of a cushion with bricks, sand or sand-gravel mixture, on which the reinforcing mesh will be laid. The mesh must be installed at a distance of up to 50 mm from the outer edges of the formwork;
6. Now you need to start laying the reinforcement with fiberglass. If the calculation showed the use of several layers of the mesh, then you need to lay the first layer on bricks, the next on vertical guides, and so on to the very top;
7. It is better to connect all connecting elements in strip foundations and pile grillages flexibly with the help of plastic ties; soldering is not practiced here. And in monolithic foundations, you can also use soldering with a blowtorch;
8. Installation and fixation of vertical rods, longitudinal and transverse fibers from the horizontal mesh itself;
9. Pouring the base with concrete.

Calculation of fiberglass reinforcement for various foundations

The correct calculation of the type, diameter and amount of fiberglass is the key to a solid and reliable base, taking into account an innovative and completely new material in terms of technical characteristics.

At the same time, the calculation will indicate how much of what material is needed, because the absence of a surplus of production plays an important role here.

To calculate the reinforcement for a slab foundation, you must first determine the number and length of rods, based on the parameters of the base and the pitch of the frame mesh.

It is also necessary to take into account in the calculation that all slab bases have at least two reinforcement belts, interconnected by vertical rods along the entire length of the mesh, as well as in the corners of the load-bearing cells.

The same principle is used to calculate the reinforcement for strip and prefabricated foundations.

But the reinforcement of the columnar foundation is significantly different in technology. First of all, the calculation takes into account the diameter and the number of vertical rods installed directly into the wells. It is also taken into account that such rods must be sufficiently rigidly connected to each other, because the vertical displacement is stronger than the horizontal one.

Thus, when calculating the amount and diameter of the reinforcing fiber, it is taken into account that the ribbed fibers are installed in the posts, and the smooth ones in the grillage and for strapping.

Where is fiberglass reinforcement found now?

Given the clear advantages of fiberglass as a reinforcing material, it is actively used in:

1. Civil, industrial and housing construction;
2. For concrete, brick, block masonry of all types and sizes;
3. When construction is carried out in the winter time. After all, then you have to use special mineral and organic additives that can destroy the steel reinforcing frame;
4. When installing a concrete base for highways and in the construction of dams on the banks of mountain rivers.

But now many developers are still with some fear of fiberglass, because this material has not yet established itself as a worthy substitute for heavy, bulky and difficult to install steel rods.

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Fiberglass rebar weight table

Comparison of fiberglass and metal reinforcement

Fiberglass reinforcement products are called trending products. Developed over 40 years ago, it is actively promoted as an alternative to rolled steel.

According to the manufacturers, fiberglass is successfully replacing traditional metal rods. Let's carry out a comparative analysis of the two types.

Brief characteristics of metal products

In accordance with GOST 10884-94, reinforcing steel products are metal bars of circular cross-section, the surface of which is of two types - smooth or corrugated (periodic). It is used as a frame in reinforced concrete structures: foundations, monolithic and multilayer walls, floor slabs, pillars, roadways, and so on.

According to their physical and mechanical properties, the following types of fittings are produced:

1. A1 or A240 - assembly products. Metal rods have a smooth profile, they are used to form the transverse frames of the frame, as well as for the basis of light structures such as greenhouses, shields, gazebos. Available in a diameter of 4-40 mm.

2. А2-А6 - work products, which are marked according to the steel yield index: А300, А400, А500, А600, А800 and А1000.

The surface is corrugated, crescent, annular or mixed type. These are load-bearing elements of the frame, located in the longitudinal horizontal axis. Metal fittings are available in a diameter of 4-80 mm. Fields of application: small and high-rise construction, the construction of large-sized buildings for industrial and public purposes, the production of reinforced concrete products, the formation of a roadbed and much more. Often used in restoration and renovation work.

The advantages of rolled metal are its high strength, resistance to temperature extremes, including extreme ones, and relative unpretentiousness.

In addition, steel reinforcement is durable and safe, and belongs to non-combustible materials. Among the shortcomings, we note the fear of water, a decent weight and the need to form a protective layer of concrete, which protects against contact with the external environment.

Metal products have standard marking indicating the class of products, diameter.

In addition, additional engraving is included:

• C - intended for connection by welding.
• K - corrosion-resistant rolled products.
• T - thermally or thermomechanically hardened steel with a high yield index from A600 and above.

Metal fittings are classified by experts as long or oversized products. It is sold with rods up to 11.7 m long, packed in packs weighing up to 3 tons, or rods of 6-12 m each are rolled into small bays.

The price is calculated based on the ton / ruble ratio. Installation in a single frame mesh is carried out by welding or knitting cold-drawn wire with a diameter of 3-4 mm.

Features of composite products

Fiberglass reinforcement was developed as an alternative to metal.

Represents rods of non-metallic products, which include:

• Staple glass and aramid fiber of inorganic type.
• Binder thermosetting resins of non-curing or curing type (epoxy, epoxy-diana, vinyl ester and others).
• Various additives that improve product ductility and strength.

Customers can buy reinforcement products in two varieties:

1. With a surface of a periodic profile.

A thin bundle of twisted fiberglass is wound on the rod in a spiral. Then a layer of polymer resin is applied, which provides additional protection.

According to the manufacturers, this "option" increases the area of \u200b\u200bcontact between the reinforcement and concrete and enhances the mutual adhesion of materials.

2. With a conditionally smooth profile.

During the production process, sand is applied to the surface, the task of which is to enhance the adhesion properties.

Fiberglass reinforcement has the following advantages:

• Chemical, corrosion and water resistance.
• Light weight.
• Dielectric properties and radio transparency.
• Ease of transportation.

Comparison on these parameters is partially in favor of glass composite.

The products are chemically resistant, but they work only in a limited temperature range, and have low fire resistance. The metal is resistant to any temperature, but corrodes when exposed to water. However, manufacturers offer rods marked "K", covered with a thin film of oxides or zinc layer, due to which corrosion of the frame is prevented.

Fiberglass reinforcement contains epoxy and similar polymer resins that emit formaldehyde, phenol, toluene, benzene and other toxic substances.

Of course, under a layer of concrete, this is almost invisible, but when used in open frames (for example, in greenhouses), the risk from low-quality products is too great. Metal in this respect is completely safe.

Let's consider another parameter - service life. The experience of working with metal fittings is enormous, all the disadvantages and ways to overcome them are known.

When used correctly, rolled steel lasts at least 30 years. Fiberglass, according to manufacturers, serves no less, but reviews from builders claim the opposite. There is no exact data yet. Thus, composite reinforcement is seriously inferior to steel.

ASP, diameter in mm

Cost, rub / running meter

Which reinforcement is better, metal or fiberglass?

The construction industry is in high demand and relevant today.

A wide variety of structures are being built, both in the residential and industrial sectors. Modern materials, new technologies and time-tested solutions are used. At the same time, the issue of choosing fittings is quite acute. Which option should you give preference to in a given situation?

Where is fiberglass reinforcement best suited, and where is metal? There are many questions, but, unfortunately, not enough answers. It's time to deal with all aspects of this problem in more detail.

Fiberglass products - scope

• Construction of power lines;
• Arrangement and reconstruction of road surfaces, enclosing supports and bridges;
• Construction of a sewerage, drainage and other similar purpose;
• Construction of chemical industry facilities;
• Construction of facilities requiring the absence of electromagnetic radiation;
• Arrangement of fixed formwork and belts of buildings with increased seismic resistance.

Metal fittings - the relevance of use

But in some situations, metal fittings are still relevant:

• Formation of reinforced concrete structures - with all its advantages, composite reinforcement in concrete reinforcement can play only an auxiliary, but not the main role.

  A flexible steel product is indispensable in the construction of structures for civil and industrial construction, a rigid one is used in the manufacture of heavy concrete and monolithic foundations;

• In those structures where increased lateral compression and the work of corrugations of the reinforcement along the shear are assumed;
• Due to their anisotropic properties, steel products are perfectly combined with concrete, which is not the case with fiberglass.

Disadvantages of fiberglass reinforcement

Studying the disadvantages of fiberglass products, it is worth highlighting the following:

• Weak indicators of heat resistance - fiberglass itself has high heat resistance, but the plastic component of the binder type at temperatures above 200 degrees loses its parameters.

  If the temperature reaches 600 degrees and above, the reinforcement is completely melted. Its use in high-temperature heating conditions and in fire hazardous areas is strictly prohibited;

• Insufficient modulus of elasticity - this parameter provides a fairly simple bending of products.

  Although, when arranging floors, this requires preliminary calculations, which is impossible in the conditions of a construction site.

  That is why the production of elements of the curvilinear formation is carried out exclusively in production;

• Exposure to alkali - alkaline compounds and solutions can significantly affect the operational and technical parameters of the material. The problem can be solved by using a technique for leaching elements from the rare-earth group in concrete.

Disadvantages of metal fittings

• Corrosion predisposition is the main and most noticeable drawback of this material.

  A choice of product variations from special corrosion-resistant compositions is possible, but this will have a significant burden on the construction budget.

  And it certainly won't help to get rid of other problems;

• Excessive weight is also a very significant disadvantage. It not only increases the cost of transporting the material, its loading / unloading, but also storage;
• Fixed length - steel reinforcement often comes in rods of a fixed length, while a fiberglass analogue can be easily purchased in a coil of the required length, which, among other things, also eliminates the waste of materials and the appearance of many scraps;
• Increased thermal conductivity - this factor can lead to the formation of so-called cold bridges in the foundation, which can have a significant impact on the strength indicators of the formed structure.

Price question

Comparing the two reinforcement variations, one cannot ignore the issue of pricing policy.

Yes, at first glance, the cost per meter of a metal-plastic product is higher than that of a similar metal product. But there is one caveat.

Features of fiberglass composite rebar

With the same strength, fiberglass reinforcement has a smaller cross-section than similar steel. Therefore, elements identical in their parameters will have approximately the same cost.

Conclusion

We examined the features of each product, its strengths and weaknesses. There is no unequivocal answer, which is the best fittings - made of metal or fiberglass. It all depends on the characteristics of a particular facility being built and the technical conditions for its use.

Our company offers fiberglass composite rebar with a diameter of 6 mm.

The reinforcement has the form of a periodic profile and is realized in bays from 50 to 200 m. P.

The weight of fiberglass reinforcement is almost 10 times less than that of metal reinforcement, according to the table of conditional replacement of metal reinforcement of class A-III with composite fiberglass reinforcement, without loss of strength. In this example, 6 mm fiberglass reinforcement replaces 8 mm metal reinforcement.

Areas of application of fiberglass reinforcement with a diameter of 6 mm: as a reinforcement mesh for concrete screeds, reinforcement of floors, paths, under cladding, tiles, strip foundations, as flexible ties, to strengthen road and sidewalk tiles, fence slabs, curb stones, posts and supports, railway sleepers.

According to builders, this fiberglass reinforcement has proven itself well in strip foundations, armopoies, shallow slab foundations, in the construction of thermal houses, in the manufacture of underfloor heating and screeds, in the construction of roads, road fences, pools, basements, bridge crossings, in the manufacture of floor slabs and etc.

To increase the life of concrete structures and screeds, we recommend using polypropylene fiber (polypropylene fiber) .When using fiberglass reinforcement and fiber, the service life of concrete structures is significantly increased.

Agricultural workers and farmers use fiberglass reinforcement with a diameter of 6 mm for the manufacture of greenhouses and small greenhouses, as well as use it in the construction of poultry houses, cowsheds, pig farms for foundations and floors.

Because this valve is used in close contact with water and aggressive media. The armature does not rust, does not tear the film, it is convenient for assembling and disassembling greenhouses, it can be stored in an open area, or used as supports for bushes of tomatoes, raspberries, currants, etc.

The fiberglass reinforcement is tied with plastic mounting clamps or a knitting wire using a semi-automatic knitting hook.

The minimum tempering rate of fiberglass reinforcement with a diameter of 6 mm, a coil of 50 m.

The weight of a running meter of fiberglass reinforcement with a diameter of 6 mm is 0.05 kg, for comparison (according to the table of conditional replacement) metal reinforcement with a diameter of 8 mm is 0.395 kg.

Composite reinforcement 6 mm can be purchased at the warehouse of St.

Zaporozhye by self-pickup, or order free targeted delivery around the city (by agreement). In Dnepropetrovsk, free delivery is carried out subject to an order of 500 rpm.

Diameters 6,7,8,10 are sold in coils from 50 to 100 meters.

As a result of technological processes, there may also be remnants of fiberglass reinforcement of different lengths, which we also sell.

You can check the details by phone.

Delivery is carried out throughout Ukraine by courier services, targeted delivery by passing transport with additional loading of your order is possible, which significantly saves money on transportation.

Outside working hours and weekends, you can also place an order for the product by clicking on the buy button.

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Reinforcement made of composite materials technical characteristics

fiberglass rebar comparison

Fiberglass rebar comparison with metal

Fiberglass reinforcement

Non-metallic composite rebar for construction works

High-strength non-metallic reinforcement made of composite materials is a new reinforced element for construction work.

Non-metallic reinforcement is produced in the form of a rod with a spiral relief of any construction length from glass fibers impregnated with a chemically resistant polymer.

A reinforcement made of glass fibers is called GRP.

According to the research results, the durability of building structures using reinforcement is at least 100 years.

This durability is due to the high chemical resistance of the fittings to all known aggressive media - high concentrations of gaseous media, chloride salts, deicing agents, sea water, etc.

Comparative characteristics of metal and composite reinforcement.

fiberglass and metal fittings comparison

Replacement of metal reinforcement with non-metallic composite

Calculation and design of concrete products are carried out in accordance with SNiP 52-01-2003 “concrete and reinforced concrete structures.

When designing building structures using reinforcement, one should be guided by the equality of loads applied to the reinforcing elements. The replacement procedure is shown in Table 3.

Metal fittings
A3 (A400S) GOST 5781-82

Non-metallic composite rebar
ASP

Fsech - cross-section of reinforcement, mm2

Rsch is the tensile force of the reinforcement at the design ultimate tensile strength, n.

Non-metallic fittings are 10-20% cheaper than replaceable metal fittings.

Composite reinforcement meshes Meshes of various load characteristics are made from composite reinforcement rods with diameters from 5 to 12 mm (Fig.

Fastening of the mesh rods is carried out with polymer clamps, as well as with the help of anchored metal knitting wire, similar to knitting of nets from metal reinforcement.

Meshes made of fiberglass composite reinforcement with a diameter of 5-12 mm, designed for loads from 50 to 500 kn / m (5-50 tons / m), are shown in Table 4.

Mesh tensile strength, kN / m

AREAS OF USE

• Manufacturing of concrete slabs for the coating of intra-building, bypass temporary automobile roads and other roads with a complete replacement of metal reinforcement with composite reinforcement.
• Reinforcement of asphalt concrete road surfaces.

  Eliminates rutting, prevents destruction of the pavement from the formation of various cracks, provides a guaranteed service life of the road.

• Construction of embankments on weak foundations (swamps, soils of high humidity), roadways, temporary roads. A mesh made of composite reinforcement 8-12 ASP is used.

Mesh 1 at the base of the road in combination with nonwoven fabric 2 and mesh 3 in the middle of the road.

• Strengthening the slopes of embankments, the banks of reservoirs.

Mesh 1 is reinforced on the slope of bored piles 2, reinforced with composite reinforcement.

The structure is filled with a layer of concrete 3.

Industrial and civil construction.

• Use in concrete structures of buildings and structures for various purposes working under systematic exposure to temperatures not higher than + 1000C and not lower than -700C. At the same time, concrete structures can be made of heavy, fine-grained, lightweight, cellular and porous concrete, as well as tensioning concrete.
• Use for the manufacture of flexible ties in the layered masonry of brick buildings.
• Repair of surfaces of damaged reinforced concrete and brick structures.

Characteristics and application of fiberglass reinforcement

The active use of polymeric materials in various production areas leads to the need to endow these materials with the necessary quality characteristics.

Some polymers can be given the required strength by using fiberglass reinforcement.

In addition, fiberglass reinforcement can be successfully used independently, replacing other types of materials, such as steel.

The basis for the use of fiberglass

Fiberglass reinforcement is a compound where non-metallic polymer fibers are bound by a specific composite composition. In this combination, fiberglass not only inherited the main advantages that are inherent in polymers, but also acquired additional properties that are increasingly being used in practice.

For the production of this type of product, fiberglass is used as a basis, as an option - basalt.

In this case, the reinforcement consists of two layers:

1. Internal rod. This element is a kind of bundle of fibers that are tied together using epoxy, possibly polyester resin.
2. Outer shell. The material that surrounds the core is responsible for the strong connection of the reinforcement with the surrounding building material (concrete).

It can be noted that reinforcement made of composite materials, if you call it fiberglass, has a number of competitive advantages:

• small specific gravity;
• chemical resistance when interacting with other materials;
• high dielectric constant;
• high tensile strength, which has a 2-fold superiority in comparison with metal;
• low thermal conductivity;
• wide temperature range of application.

In the manufacture of fiberglass reinforcement, not only the advantages of the material itself are manifested, but a feature of the technological process has a positive effect.

During the manufacturing stage, each core strand receives equal stress compared to the others. This has a positive effect on strength.

The flow of threads during twisting is freed from any possible contamination, which positively affects the high-quality application of binders, optimal consumption of substances and low cost of the product.

In less critical cases of using reinforcement, its surface is covered with sand to give the desired roughness and subsequent relationship with concrete.

However, to give the rods greater chemical resistance, strength and better interaction with concrete, the rods are coated with a venyl ether resin.

Basic properties

Before starting to use fiberglass reinforcement, one should not only know the main competitive advantages, but also assess their impact on the future structure.

The table below shows some values \u200b\u200bof individual parameters, as well as their effect on the design when used:

What is composite material

Composition of composite material

A composite is called a solid heterogeneous material that has been artificially created from several components with different physical and chemical properties.

The mechanical characteristics of the composite material determines the ratio of the properties of the matrix and the reinforcing elements, as well as the strength of their bond, which is ensured with the correct choice of the initial components and the method of their combination.

The most primitive composite materials are straw and clay bricks, which were used by the ancient Egyptians.

Most often, a composite is referred to as materials based on resin or polymer matrices. Phenolic, epoxy, vinyl ester, polyester and polypropylene polymers are used for the manufacture of composite materials.

Reinforcing substances in the manufacture of composites are bulk substances and fibers. The strength of the material depends on the amount of resin - the less, the stronger it is.

Composite fiberglass rebar

Today, in order to achieve the ideal proportions of all components in a composite material, molding technology is constantly being improved.

Composite molding techniques

During the molding process, the matrix of the composite material is combined with its reinforcing substance, as a result of which a particular product can be manufactured.

Thermosetting polymer matrices go through a chemical curing reaction during the molding process. Thermoplastic polymer matrices melt and solidify in a given shape during the molding process.

This process usually takes place at room temperature and normal pressure.

The most common composite today is considered to be cement with metal reinforcement or asphalt concrete.

There is also contact (hand) molding, which has a number of serious disadvantages.

The product formed by this method contains an increased amount of resin, which makes it more fragile. In addition, it is difficult to achieve the ideal proportions of the matrix and the reinforcing substance, as well as to maintain the thickness of the product, while avoiding internal air passages.

The vacuum forming process involves the use of an open tooling into which the composite components are placed, covered with a silicone membrane or polymer film. A vacuum is then applied to the tooling under atmospheric pressure and elevated temperature.

Traditional building materials are regularly improved, acquiring new performance characteristics and increasing the quality of existing technical parameters. In this case, and the trend of replacing classical approaches in construction with innovative solutions... These include the successful entry into the market of composite reinforcement building materials.

Although disputes about how much the use of this material as replacement of steel rods, are still relevant, a number of its advantages are indisputable and have long been appreciated by specialists. In particular, composite reinforcement for the foundation, the reviews of engineers about which emphasize it strength and ease of use, becomes more and more popular and expands the scope of application.

What is composite rebar?

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 done in the case of classic reinforcement.

Nevertheless, similar performance characteristics fully correspond 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, hence the name of such fittings - fiberglass, glass-reinforced or basalt-plastic.

However, the use of synthetic fibers alone is not enough to ensure the high strength and reliability of the same foundation structures. An obligatory step in the process of making the material is processing by means of thermosetting or thermoplastic polymer additives... Thanks to them, the structure of future rods is rejected.

Further, as in the case of steel reinforcement, composite analogs endowed with ribs and a special sand cover, which increases the bonding and adhesive qualities in contact with concrete fillings under the foundation.

Advantages of composite reinforcement

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

One way or another, most of the benefits 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:

Disadvantages of composite reinforcement

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

Applications

Synthetic reinforcement has found applications in various fields industrial and civil construction... With its help, residential buildings are erected, factory complexes are erected, they are 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. It can be wall masonry with flexible ties, as well as the device of brick and reinforced concrete structures.

Modern builders cannot do without synthetic material and where the use of steel rods is impossible. For example, in frosty conditions special additives must be added to mortars for masonry in the form of hardening accelerators and antifreeze additives. Such additions negatively affect metal rods, but they are harmless to composite reinforcement.

Modern road construction technologies also provide for the use of synthetic reinforcement. It is used in the construction of pavements, embankments, 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 a strengthening property. For this purpose, the rods are embedded in road slopes, bridge structures and various webs experiencing increased traffic loads.

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

What is fiberglass reinforcement

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

In the domestic market, fiberglass reinforcement is the most widespread.

Features of the structure

Fiberglass rebar is not just a composite bar. It has two main parts.

• The inner core is made of fiberglass fibers arranged in parallel, interconnected by a polymer resin. Some manufacturers produce reinforcement, the fibers of the inner trunk of which are not parallel to each other, but are curled into a pigtail. It should be noted that it is the inner fiberglass reinforcement bar that forms its strength characteristics.
• The outer layer of the reinforcing bar made of fiberglass can be made in the form of a bi-directional winding from the fibers of a composite material or in the form of spraying a fine-grained abrasive powder.

The design of fiberglass reinforcing bars, which largely determines their technical and strength characteristics, depends on the imagination of the manufacturers and the technologies they use for the production of this material.

Basic properties

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

• Reinforcing rods made of fiberglass have a small mass, which is 9 times less than the weight of similar metal products.
• Fiberglass reinforcement, in contrast to 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 significantly lower than that of metal products, which minimizes the risk of cold bridges during 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 in financial terms.
• Fiberglass reinforcement is a dielectric material that does not conduct electric current and is completely transparent to electromagnetic waves.
• It is much easier to use such a 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 both among large construction organizations and private developers. Meanwhile, such an armature has a number of disadvantages, the most significant of which should be attributed to:

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

The low modulus of elasticity of fiberglass reinforcement is an advantage in the manufacture of frames for strengthening the foundation, but a big disadvantage if it is used to reinforce floor slabs. If it is necessary to apply in such cases, it is to this reinforcement that it is first necessary to carry out thorough calculations.

The low thermal stability of fiberglass reinforcement is a more serious drawback limiting 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, at high temperatures it loses its strength characteristics. 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 is that over time it loses its strength characteristics. This process is greatly accelerated if it is exposed to alkaline environments. Meanwhile, this disadvantage can be avoided by using fiberglass reinforcement made with the addition of rare earth metals.

How and from what fiberglass fittings are made

Many fiberglass fittings are familiar not only from photos on the Internet, but also in practice in construction, but few people know how they are made. The technological process for the production of fiberglass reinforcing bars, which is very interesting to watch on video, is easily automated 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. To give the initial raw material the required degree of ductility, it is melted in special furnaces, and from the resulting mass, threads are drawn, the thickness of which is 10–20 microns. The thickness of the threads obtained is so small that if you take them off in a photo or video, you cannot see them without enlarging the resulting image. An oil-containing composition is applied to the glass thread using a special device. Then beams are formed from them, which are called glass roving. It is these bundles, assembled from a multitude of 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 transformed into reinforcing bars of various diameters and lengths. The further technological process, which you can get acquainted with through numerous videos on the Internet, is as follows.

• Through special equipment (creel), the threads are fed to a tensioner, which simultaneously performs two tasks: equalizes the stress in the glass threads, arranges them in a certain sequence and forms the future reinforcing bar.
• The bundles of filaments, 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.
• The bundles of filaments heated to the required temperature are lowered into special baths, where they are impregnated with a binder, also heated to a certain temperature.
• Then the bundles of filaments are passed through a mechanism with which the final formation of the reinforcing bar of the required diameter is carried out.
• If the reinforcement is made not with a smooth, but with a relief profile, then immediately after leaving the calibration mechanism, beams of glass fibers are wound onto the main rod.
• To speed up the process of polymerization of the binder resins, the finished reinforcing bar is fed into a tunnel oven, before entering which a layer of fine sand is applied to the rods made without winding.
• After leaving 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 coils.

Thus, the technological process for the manufacture of fiberglass reinforcement is not so complicated, which can be judged even by 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 get acquainted with the production process of composite glass reinforcement using the example of the operation of the TLCA-2 production line.

Parameters - weight, diameter, winding pitch

The 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 running meter of reinforcing bar;
• for products with a relief profile - the step of winding fiberglass bundles on their surface;
• diameter of the reinforcing bar.

Today, 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 similar products. In accordance with TU, fiberglass reinforcing rods are produced today under the following numbers: 4; five; 5.5; 6; 7; 8; ten; 12; fourteen; sixteen; 18. The weight of a running meter of fiberglass reinforcing rods on the market today varies between 0.02–0.42 kg.

Types of fiberglass reinforcement and its scope

The reinforcement, for the production of which fiberglass is used, has many varieties, differing from each other not only in the diameter and shape of the profile (smooth and corrugated), but also in the area of \u200b\u200buse. So, experts distinguish fiberglass reinforcement:

• working;
• editing room;
• distribution;
• specially designed for reinforcing concrete structures.

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

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

Despite the fact that reinforcement made of fiberglass appeared on the domestic market recently, enterprises, construction companies and individuals are already actively using it to solve various problems. Thus, the use of fiberglass reinforcement in construction is gaining popularity. With its help, foundations and other concrete structures (drainage wells, walls, etc.) are reinforced, 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 roadbed, strengthening embankments and weak foundations, creating monolithic concrete foundations.

Individuals who are independently engaged in construction in their personal plot or in the country also managed to appreciate the advantages of this material. An interesting experience of using fiberglass reinforcement in summer cottages and in the gardens of private houses as arcs for the construction of greenhouses. 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 its ease of transportation. The fiberglass reinforcement coiled into a compact bay can be taken away even in a passenger 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 - the main parameters of these materials should be compared.

• If reinforcing bars made of steel have both elasticity and plasticity, then fiberglass products only have elasticity.
• In terms of ultimate strength, fiberglass products significantly exceed metal ones: 1300 and 390 MPa, respectively.
• Fiberglass is more preferable in terms of the thermal conductivity coefficient: 0.35 W / m * C0 - versus 46 for steel.
• The density of reinforcing bars made of steel is 7850 kg / m3, of fiberglass - 1900 kg / m3.
• Fiberglass products, in contrast to reinforcing bars made of steel, have exceptional corrosion resistance.
• Fiberglass is a dielectric material, therefore, products made from it do not conduct electric current, are distinguished by absolute transparency for 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 enough for 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 carefully and only in those areas where this material manifests itself 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 and other composite materials has proven to be effective.