Fiberglass reinforcement – how to choose and where to use it. Advantages and disadvantages, technical characteristics and application of fiberglass reinforcement (FRP) Materials for composite reinforcement products
Fiberglass reinforcement is a building material that is made from glass roving, connected using an epoxy compound based on thermoactive resins. The main feature is lightness; the mass per unit volume is only 2 g/mm³. Working with fiberglass reinforcement is more convenient and economically feasible than working with metal reinforcement. Significantly lower costs are required for logistics and directly during reinforcement.
In addition, due to the fact that fiberglass does not react to an aggressive environment, the reinforcement therefore protects concrete from premature destruction, thereby increasing the service life of the object. Fiberglass reinforcement reacts to temperature changes similarly to concrete, which also has a good effect on the strength of the structure.
The strength of fiberglass compared to metal is 2.5 times higher. At the same time, the thermal conductivity index is 100 times lower than the thermal conductivity index of steel. Therefore, a structure that is reinforced with fiberglass does not freeze (does not form “cold bridges”) and a building built using fiberglass will be warmer than a building based on metal reinforcement. This allows you to reduce heating costs, and therefore the material is actively used in the construction of modern energy-efficient buildings.
Another undeniable advantage that may interest builders is the fact that fiberglass is surprisingly durable material, which for 100 years after installation does not require additional repair work. This is what fiberglass reinforcement for foundations is famous for.
Fiberglass reinforcement has found its application in many areas of industry, construction, public utilities:
- in construction it is used in the construction of civil and industrial construction as a basis for foundations, floors, beams, as well as for the construction of earthquake-resistant belts;
- in the construction and repair of roads, reinforcement is used in the construction of embankments, road surface, during the construction of bridges and highway barriers. It is resistant to reagents applied to road surfaces(for example, anti-icing reagents), therefore it can be used both in Moscow and in colder regions.
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Fiberglass reinforcement will be an ideal basis for concrete and brick structures. It is used in the creation of supports for power lines and lighting, in the construction of road, sidewalk and fence slabs, as well as in the installation of sleepers on railway tracks. Reinforcement for floors, where a mesh of reinforcement is used, even together with metal, has become widely used.
Fiberglass is used in such building structures as monolithic foundation and foam concrete. It is also actively used in the creation of structures that must have increased resistance to chemicals, for example:
- during the construction of storage facilities for chemical waste and components;
- when installing sewerage systems, water pipelines, land reclamation systems;
- during the construction of port facilities and during the strengthening of coastlines.
Despite the uniqueness of the product, the price of fiberglass reinforcement in Moscow, which is indicated on our website, is available material and for construction organizations, and for individuals. Its cost is 40-50% lower than the cost of steel reinforcement, which allows you to significantly reduce costs and at the same time improve the quality of constructed objects. In general, composite reinforcement can be called one of the most reliable and efficient building materials of our time.
This reinforcement is made from straight strands of glass or basalt fibers (ASP and ABP, respectively), which are collected into a bundle, impregnated with a thermosetting polymer binder, molded, heated (polymerized) and cooled. The result is a monolithic rod of high strength, which, according to test results, is 3 times higher than the tensile strength of steel, and the weight, in an equal strength ratio, is 9 times less.
Standardly manufactured in the form of rods of any length, at the request of the customer. With a diameter of up to 8 mm inclusive, it can be manufactured in the form of coils (coils) containing 100 meters of reinforcement. Dimensions coils: height – up to 8 cm, diameter – up to 1 meter.
release form
With a diameter of 10 mm and 12 mm, it can be manufactured in the form of coils (coil fittings) having a length of 50 meters. Overall dimensions of the coil: height – up to 5 cm, diameter – up to 1.5 meters.
By agreement with the customer, it is possible to produce rods and coils of any length.
Can be manufactured with a smooth, construction, periodic profile:
- ASP-ABP of periodic profile, used instead of steel reinforcement class A-I II (A-400);
- ASP-ABP with a smooth profile is used instead of steel reinforcement of class A-I (A-240).
Fiberglass reinforcement is becoming more and more popular and its use is becoming more and more relevant every year, because it is a complete replacement for traditional steel rods of different grades. High performance strength, optimal operational properties, small specific gravity and low price are factors that determine the popularity of the use of non-metallic reinforcing elements in all areas of construction.
Composite reinforcement is a material for reinforcing structures. Mainly used for reinforcement concrete structures. It is used in the construction of buildings, roads, reservoirs, laying communications and other purposes.
Manufacturing Features
Unlike its metal counterpart, it is not made of steel, but has a base made up of tear-resistant carbon, glass or basalt fibers. The latter are covered with a shell made of special plastic. To increase rigidity, an epoxy resin is used to coat the fibers.
In order to improve adhesion to concrete, the rods are wrapped with a thin cord. To make the latter, the same material from which the base is made is used.
The cord forms a helical relief, similar to metal fittings. For polymerization epoxy resin a special drying chamber is used.
After polymerization, the product is slightly stretched using special equipment, after which it is cut into pieces of the required length.
Some manufacturers sprinkle composite rods with sand before polymerization to improve adhesion to concrete.
Areas of use
Unlike metal, composite reinforcement has a less wide range of applications. It is used to improve the connection between finishing facade materials and load-bearing structures. It can also be used to install road slabs. Composite reinforcement is used in the construction of tank formwork.
It can be used in frames constructed to strengthen the foundations of a strip structure, as well as in the process of manufacturing concrete floors. But, for these purposes, such fittings are used less often.
Reinforcement of floor slabs, lintels and other structures that experience tensile loads with composite reinforcement should not be performed. This is due to the higher level of flexibility of composites compared to steel.
Performance characteristics
Composite materials have a significantly lower elastic modulus compared to steel. For the latter it is 200 hPa, while for composites it varies in the range of 60-130 hPa.
Therefore, under the same conditions, steel reinforcement will start working earlier, preventing concrete cracking. The plastic reinforcement will continue to bend until the force reaches a certain value.
In general, reviews of composite reinforcement are positive. But, it must be borne in mind that it is only suitable for certain types of structures. In some cases, its use is unacceptable due to greater flexibility, low heat resistance and other characteristics.
All composite reinforcement is divided into 4 types, depending on the material used:
- ASK – fiberglass;
- ABK – basalt;
- AUK – carbon;
- ACC – combined, fiberglass and basalt fibers.
The cheapest is fiberglass; the price of composite reinforcement per meter is about 10 rubles. But this is the cost of products with the thinnest diameter - 4 mm. The thickest fiberglass reinforcement, with a rod diameter of 20 mm, has a price of around 95-100 rubles. per linear meter.
Moreover, such products are the most common, but have the lowest strength compared to other types. Carbon composite reinforcement (ACR) has maximum strength. But, its cost is the highest.
Advantages and Disadvantages
Pros and cons composite reinforcement come directly from the characteristics of the composite materials themselves. The main advantages include:
- chemical inertness. The material is completely resistant to corrosion and most aggressive environments;
- low thermal conductivity increases the thermal insulation parameters of concrete structures;
- inert to influence magnetic field and does not interfere with the passage of radio waves. Thanks to this, it can be used in the construction of objects where shielding of electromagnetic waves is not allowed;
- the weight of composite reinforcement is 3-4 times lower compared to its metal counterpart. This facilitates the installation and transportation process;
- Composites do not conduct electricity. This eliminates the formation of stray currents and reduces the risk of short circuits if the wiring is damaged.
Main disadvantages:
- small radius bending cannot be performed directly on the construction site. That's why curved products must be pre-ordered from the manufacturer;
- low heat resistance. Excessive heat and fires can cause the concrete structure to fail. Fiberglass is highly heat resistant, however, the polymers used to bind the fibers lose strength at temperatures above +200°C;
- aging. All polymer materials subject to aging.
Fiberglass or steel reinforcement – which is better?
It is believed that polymer composite reinforcement outperforms steel reinforcement due to its more affordable cost. But, if you study the prices of metal warehouses, the situation sometimes turns out to be the opposite. Steel products are often 20-25% cheaper.
This is due to the fact that sellers of plastic products often rely on the so-called “equivalent” diameter. The bottom line is that composite reinforcement is more tensile strength than metal reinforcement.
Therefore, to achieve performance similar to steel, a thinner composite can be used. Therefore, it is believed that the amount of composite for reinforcement will be smaller compared to plastic. This led to the emergence of the opinion that plastic is cheaper. Although if you take products of the same diameter, steel will cost less.
But, in reality, you need to use more plastic, since not only the tensile strength parameter is taken into account, but also other characteristics. Therefore, which material is better depends on the specific case.
In some situations it is more expedient to use composite reinforcement, in others it is impossible to do without steel. Each type of product has its own purpose. Therefore, when choosing, you should proceed from the goals set, the characteristics of the object being built and building codes.
Photo of composite reinforcement
Reinforced concrete structures are traditionally reinforced with a metal rod, but it is becoming more and more popular alternative option– fiberglass reinforcement. It replaces steel due to its high performance and technical characteristics. Growing popularity plastic fittings This is also explained by the low price compared to metal analogues.
Description
The production and characteristics of the so-called composite reinforcement for concrete monoliths and structures are regulated by GOST 31938-2012 developed according to ISO 10406-1:2008. A high-strength carbon thread is wound onto a base made of specially prepared fiberglass. It improves adhesion to concrete due to its spiral profile.
The main element of composite fiberglass reinforcement is the barrel, made of strong fibers located parallel to each other, united by a polymer resin sintered at high temperatures. The barrel is covered with a fibrous structure applied by spraying or winding in two directions.
According to SNiP 52-01-2003, the use of modern fiberglass reinforcement is possible as a full replacement for metal reinforcement. Each manufacturer indicates technical specifications for its products, which can be used in walls, ceilings, basements and other concrete structures. It is mandatory to provide quality certificates based on examinations and test reports in laboratories.
Species
Fiberglass reinforcement is classified according to the types of materials used in production. These are non-metallic raw materials of mineral or artificial origin. The industry offers the following types:
- Glass composite (FRP) is a heat-treated mixture of longitudinally located fiberglass and polymer resins.
- Basalt reinforcement or basalt composite (BCP) is made from basalt fibers interconnected by organic resins.
- Carbon fiber reinforcement or carbon composite (AUK) reinforcement has increased strength and is made from hydrocarbon compounds. It is more expensive than composite.
- Aramidocomposite (AAC) is the basis polyamide fibers like nylon threads.
- Combined composite (ACC) - based on a fiberglass rod, onto which basalt plastic is tightly wound. This type is not basalt-plastic reinforcement, which is what it is confused with, since it has a fiberglass rod.
Indicator | TSA | BPO | AUK | AAK |
---|---|---|---|---|
Tensile strength, MPa | 800-1000 | 800-1200 | 1400-2000 | 1400 |
Tensile modulus of elasticity, GPa | 45-50 | 50-60 | 130-150 | 70 |
Ultimate compressive strength, MPa | 300 | 300 | 300 | 300 |
Ultimate strength at transverse cut, MPa | 150 | 150 | 350 | 190 |
Manufacturers offer large selection fiberglass reinforcement in thickness. This makes it possible to make both a thin mesh of 4 mm and a strong reinforcing frame with a diameter of 32 mm for load-bearing structures. It is supplied in the form of cut rods or coils up to 100 m long.
This material is available in two types of profiles:
- Conditionally smooth. Made from a main rod coated with a layer of fine quartz sand, which improves adhesion to the concrete mixture;
- Periodic. It is made of a rod onto which a fiberglass strand is tightly wound, resulting in anchor ribs appearing on the rod that securely hold it in the thickness of the concrete.
Advantages and Disadvantages
Fiberglass rebar is a new building material that is gaining popularity and has characteristics that allow it to be used for load-bearing structures. Its advantages include:
- Corrosion resistance. Fiberglass can be used in aggressive environments. According to this indicator this material 10 times superior to metal.
- Low thermal conductivity of 0.35 W/m∙⁰С, which makes it possible to increase the thermal insulation of a concrete monolith and eliminates the risk of cold bridges. For comparison, the thermal conductivity of steel is 46 W/m∙⁰С.
- High resistivity allows it to be used in the construction of bridges, railway structures, power lines and other structures where there is a risk of penetration electric shock under high voltage.
- Low specific gravity, which allows reducing the pressure of structures on the surface of the soil and foundation. Average density this material has 1.9 kg/m³, while steel has four times more – 7.9 kg/m³.
- The cost of reinforcement with fiberglass is almost 2 times lower than with metal rods.
- Application in a wide temperature range. It does not lose its properties at temperatures from -60 to +90⁰С.
- Unlike metal, fiberglass has a coefficient similar to concrete thermal expansion, therefore, a monolith with such reinforcement does not crack during temperature changes.
- No reinforcing mesh is required for installation. welding machine, it is enough to connect it with plastic harnesses and clamps.
Like any material, polymer reinforcement based on fiberglass has disadvantages that are taken into account during operation:
- Insufficient resistance of fiberglass to high temperatures, the resins used to bind fibers ignite at a temperature of 200⁰C. For private houses or utility rooms this is not a problem, but in industrial facility where the concrete monolith must be fireproof, the use of this reinforcement is unacceptable.
- Almost 4 times lower elastic modulus compared to steel.
- When preparing the mesh, it is almost impossible to bend the composite at the desired angle; due to its low fracture strength, such elements must be ordered at the factory.
- One of the disadvantages of fiberglass composite reinforcement is that it does not allow for rigid reinforcement, and its strength decreases slightly over time, but decreases.
Characteristics
Composite reinforcement is assessed according to technical parameters. This material has a relatively low density. Therefore the weight linear meter fiberglass reinforcement, depending on the diameter - from 20 to 420 g.
The plastic reinforcement has a constant winding pitch of 15 mm. This is the optimal value so that minimum cost material, provide high level adhesion with concrete mortar.
Technical characteristics of fiberglass reinforcement are summarized in the table:
Density (kg/m³) | 1.9 |
1200 | |
Modulus of elasticity (MPa) | 55 000 |
Elongation (%) | 2.3 |
Stress-strain relationship | Straight line with elastic-linear dependence until destruction |
Linear expansion (mm/m) | 9-11 |
Resistance to corrosive environments | High, does not rust |
Thermal conductivity (W/m⁰С) | 0.35 |
Electrical conductivity | Dielectric |
Diameter (mm) | 4-32 |
Length | Arbitrary length according to customer's request |
Features of production and installation
Any type of fiberglass reinforcement is made from raw fibers bound with polymer resins, to which a hardener and hardening accelerator are added. All components are determined by manufacturers depending on the technologies used, the type and purpose of the elements that will be reinforced with manufactured fiberglass reinforcement.
The material is produced on special production lines. First, the fiberglass is impregnated with resin, hardener and reaction accelerator. After this, it is passed through a die, where the excess resin is squeezed out. Here the fiberglass is compacted and takes on a shape - conventionally smooth or with anchor ribs and a technologically specified diameter.
At the next stage, the composite fiberglass reinforcement is knitted - additional winding in the form of a rope is wound onto it to increase adhesion. After this, it is sent to the oven, where the polymer resins and hardener are set. The resulting products are placed into coils or cut into rods of the required length.
The rods are fastened with plastic clamps or clamps. The edge of the reinforcing mesh should retreat from the formwork by 50 mm, which will create a protective layer of concrete. This is done with improvised means or plastic clamps. If the rod protrudes beyond the formwork, it must be cut with a hacksaw or a grinder with a diamond or abrasive wheel.
Bend fiberglass reinforcement on the site without special equipment impossible. After the force stops acting on the rod, it returns to its original shape. If you soften it with temperature and still bend it, it will lose its design characteristics. The only way out is to order pre-curved fiberglass elements from the factory, in which case they will fully meet the technical and operational requirements.
Conclusion
Composite reinforcement may well replace traditional metal construction. She is superior steel reinforcement in many ways. It is used in the construction of walls, foundations and other structural elements from blocks and bricks, it is increasingly used to reinforce solid concrete monoliths.
The use of fiberglass composite reinforcement significantly reduces the weight of structural elements, which allows additional savings on the foundation. Restrictions on the use of this material include the requirements fire safety on separate industrial enterprises, in other cases it is a better alternative to metal.
Thanks to reinforcement it acquires increased strength and durability. Previously, exclusively metal rods tied together into a frame were used as reinforcement, but now plastic or composite reinforcement frames have appeared on sale. These products are made from basalt, carbon or glass fibers with the addition of polymer resins. Plastic fittings, the pros and cons of which will be discussed below, are produced in accordance with the requirements of the international standard, which are worth studying in more detail.
Forms of release of plastic fittings
Standard 31938-2012, regulating technical requirements, related to polymer reinforcing products, defines elements of this type as solid rods round section. The rods consist of a base, a filler and a binding component.
Composite reinforcement is produced in the form of rods with a cross-section from 4 to 32 mm. Such products are sold either cut or in bundles or coils up to 100 m long.
There are two types of plastic profile:
- Periodic - corrugated rods produced by the spiral winding method.
- Conditionally smooth. In this case, fiberglass rods are sprinkled with quartz sand, due to which finished goods have better adhesive properties.
Important! its parameters must necessarily comply with GOST 30247.0-94 for fire resistance and GOST 30403-2012 for fire safety.
To determine whether it is worth using composite materials instead of metal ones, consider the pros and cons of fiberglass reinforcement.
Advantages of composite reinforcement
The advantages of fiberglass products compared to metal counterparts include:
- Light weight. For reinforcement with plastic rods, rods of a smaller cross-section are used, due to which total weight design is reduced by almost half. For example, a fiberglass rod with a diameter of 8 mm will weigh only 0.07 kg/l m, while a metal rod with the same cross-section weighs 0.395 kg/l m. Thanks to the lower weight, plastic products can be transported even on passenger car, while metal fittings will require a heavy-duty machine.
- Corrosion resistance. Fiberglass products do not oxidize and are not affected by moisture.
- Dielectric indicators. Composite rods are radiotransparent dielectrics that are inert to electricity and radio waves. That is why plastic fittings are considered the most good material for the construction of medical centers, laboratories and other specialized structures.
- Chemical resistance. Aggressive components, such as: concrete laitance, bitumen, sea water, solvent or salt compounds, have an impact over time negative impact on metal profiles. In turn, composite materials remain inert to such “neighborhood”.
- Temperature range. Composites can be used in conditions from -60 to +120 degrees.
- High thermal conductivity. The thermal conductivity index of fiberglass is 47 W/m*K, and that of metal is 0.5 W/m*K.
- Increased strength indicators. The tensile strength of the composite material is significantly higher than that of metal product. With the same diameter, plastic reinforcement can withstand 3-4 times more longitudinal loads.
- Long service life. Manufacturers of composite materials claim that such reinforcement will last more than 150 years. It is not yet possible to verify this, but the record recorded service life of a plastic reinforced frame was 40 years.
- Installation speed. Fiberglass rods are quickly cut with an ordinary grinder and tied using plastic clamps.
In addition, due to increased elasticity, plastic products are produced in almost any length.
However, we will not rush to conclusions regarding which fittings are better. To be fair, it is also worth considering the negative aspects of fiberglass rods for reinforcing monolithic concrete buildings.
Disadvantages of composite reinforcement
Among the disadvantages of composite materials used when laying reinforcement, the following are highlighted:
- Low bending elasticity. Due to the fact that plastic elements have a low elastic modulus, which can lead to deformation of the concrete structure. Elements that bend well are difficult to use. For comparison, the modulus of elasticity of a composite is 55,000 MPa, while for plastic this figure reaches 200,000 MPa.
- Small range of sizes. Today, when choosing steel reinforcement, consumers are offered a greater variety of products of different sections.
- Lack of SNiPs. Although fiberglass products are standardized according to GOST, another regulatory framework For building elements this type does not exist. Based on this, the process of designing objects becomes more complicated, since making calculations is still quite problematic.
- Inability to use in some regions. Plastic products It is not recommended for use in the construction of facilities in areas where temperatures are too low in winter.
- Instability. complicated by the poor stability of plastic rods. The structure begins to wobble, so you have to resort to “tricks” to fix the frame before pouring the concrete mixture.
- Quite a high cost of the material. Fiberglass will cost 2 times more than its steel counterparts.
Speaking about plastic fittings, its pros and cons, many consider the disadvantages of these products to be such things as: the inability to use welding equipment and low resistance to heat. However, in reality, welding is practically not used when assembling a reinforced frame. The theory about the instability of the material to high temperatures is equally absurd. Fiberglass completely loses its properties when heated above 600 degrees, but not every concrete is able to withstand such temperatures.
Based on the above, it becomes obvious that when reinforcing concrete structures, in order to determine which reinforcement is more suitable - metal or fiberglass, you need to clarify for what purpose you need a reinforced frame. On the one hand, the latest composite materials clearly benefit, but from a cost point of view, it may be more profitable to purchase steel products.
Non-metallic composite reinforcement is a reinforcing agent in the form of fiberglass rods with a ribbed surface. In profile, such reinforcement has a spiral shape, and its diameter can range from 4 to 18 millimeters. The length of this building material can reach 12 meters.
Appearance of polymer rods.
Fiberglass reinforcement has undergone many serious tests before its mass introduction into the market. 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 weight of classical metal reinforcement;
- High resistance to corrosion and acids;
- Excellent performance in terms of energy efficiency;
- Cost-effective delivery;
- Inertness to electromagnetic and radio influences;
- Fiberglass reinforcement is classified as dielectric.
Of course, in addition to the advantages, this building material has certain disadvantages. Such shortcomings cannot be considered critical, but they are important to take into account when constructing certain types of buildings.
Disadvantages of composite reinforcement:
- Low elasticity;
- Low heat resistance parameters.
Moreover, such shortcomings of the material do not in any way affect its use in the construction of roads and building foundations.
Using this technology in foundation construction (advantages, disadvantages, method of application)
In the process of laying a foundation, composite reinforcement is used in the same way as metal reinforcement. At the first stage, the frame of the future foundation is assembled from this material, which is subsequently tightened with special ties.
The 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 minimal 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 conventional metal rods, while certain funds can be saved during its delivery due to its much lower weight.
There are various methods and construction 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.
At correct selection plastic reinforcement, 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;
- The fittings are of a familiar shape, repeating the structure of the metal one.
Most experts advise giving preference to the second type.
The main area of application of fiberglass reinforcement is the construction of foundations for low-rise buildings. When constructing a foundation, reinforcement of a specific diameter is used in each individual case.
In addition, such material is often used for binding brickwork. In this case, the formation of cold bridges can be avoided, which increases the overall efficiency of the building.
Builders' opinion
Now there is a steady trend towards the popularization of composite reinforcement among builders and large developers. In most cases, you can find positive opinions about this material. Experts note that such rods are virtually waste-free when carrying out construction work. Also an important factor is the ease of their use.
Most experts agree that in certain construction fields such material has significant advantages over metal reinforcing rods. The main advantage of these plastic rods is the ability to use them in almost any length.
Use of composite materials for reinforcement of bridge deck slabs
One of the main factors confirming the high strength and reliability parameters of composite reinforcement is its wide application in construction areas that withstand constant heavy loads (bridges, coastline structures, roads).
This is due to the fact that such material has excellent resistance to seismological activity of the earth. It has been experimentally proven that fiberglass reinforcement does not lose its basic technical specifications even with a magnitude 10 earthquake, which makes it 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 rods is traditional metal reinforcement used in concrete slabs and floors. In general these two building materials very similar to each other. At the same time, in some respects, fiberglass reinforcement demonstrates noticeably 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 elastoplastic material, while composite reinforcement is an ideally elastic building material;
- Indicators of ultimate strength. Metal demonstrates 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. At the same time, steel is a material that rusts relatively quickly;
- 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 reinforcement material
According to today's requirements, composite rods must be characterized by three main physical parameters, namely:
- Mass of elements;
- Winding distance;
- External as well as internal diameter.
For each individual profile number there are corresponding physical indicators. The only constant parameter is the winding distance, equal to 15 millimeters. The current specifications regulate that composite rods differing in profile size have the following digital designations: 4, 5, 5.5, 6, 7, 8, 10, 12, 14, 16 and 18. These digital values correspond to the outer diameter parameters. The mass of reinforcing rods can vary from 0.02 to 0.42 kg/1 running meter.
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 work of a beam using steel reinforcement D12 mm.
Such reinforcing rods A500C, having a diameter of 12 millimeters, have the following characteristics:
- The elastic modulus value is at 200 GPa;
- Standard resistance indicators are 500 MPa, which is not much fewer parameters fluidity of the steel used in the manufacture of these rods.
Based on these data, the estimated 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 sign indicating its compliance with steel reinforcing rods.
Thus, fiberglass reinforcement, 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 with plastic rods is completely similar to calculations with steel rods, the only difference is the use of a correspondence table.
How is composite reinforcement produced?
All composite reinforcement is manufactured in the format of rods with a thickness of 4 to 32 millimeters. Such building materials can be sold both in the form of rods and in coils with a length of more than 100 meters.
There are two main types of plastic reinforcing rods:
- Periodic, which is obtained by using spiral winding;
- Smooth, sprinkled with quartz sand to improve the quality of adhesion.
Connection technique
One of additional benefits composite building materials is the absence of the need for welding work. All rods are formed into a single frame using bonding technology.
Often in construction practice, special binding wire is used, less often plastic ties.
There are the following ways to use tie wire:
- Using a special automatic pistol;
- Using a construction crochet hook;
- 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 tying.
Connection using plastic ties.
Diameter of plastic fittings
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;
- Inner diameter refers specifically to the rod itself;
- The nominal diameter refers to the numerical designation of a specific profile.
All these parameters do not coincide with each other. The nominal diameter is smaller than the external diameter, measured by the protruding ribs. You should pay special attention to these parameters. This will help you avoid purchasing smaller reinforcing rods than necessary.
There are some nuances in determining these sizes of fiberglass reinforcement. The outer diameter of the product is determined in the same way as for steel. As for the internal diameter, it is more difficult to determine due to the non-perfectly round cross-section of the rod.