Traditional building materials are regularly improved, acquiring new performance characteristics and increasing the quality of existing technical parameters. At the same time, it is also observed tendency to replace classical approaches in construction with innovative solutions. These include the successful entry into the building materials market of composite reinforcement.
Although disputes about the extent to which the use of this material as replacement of steel bars are still relevant, a number of its advantages are indisputable and have long been appreciated by experts. In particular, composite reinforcement for the foundation, reviews of engineers about which emphasize its strength and ease of use, is becoming more popular and expanding its scope.
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 the case with classical reinforcement.
However, similar performance characteristics are fully consistent with composite fibers 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 names of such reinforcement - fiberglass, glass-reinforced or basalt-plastic.
However, the use of synthetic fibers alone is not enough to ensure high strength and reliability of the same foundation structures. An essential step in the fabrication process is undergoing treatment with thermoset or thermoplastic polymer additives. Thanks to them, the structure of future rods is rejected.
Further, as in the case of steel reinforcement, composite analogues endowed with ribs and a special coating of sand, which increases the binding and adhesive qualities in contact with concrete pouring under the foundation.
Advantages of composite reinforcement
The advantages of composite materials are due using synthetic raw materials. Thus, ample opportunities are provided for introducing the necessary physical and technical qualities of the material, and the influence of negative factors is excluded or at least minimized.
One way or another, most of the advantages are focused on reinforcing the foundation with composite reinforcement in order to create strong and reliable foundations for buildings and structures. So, among the advantages of synthetic rods, the following stand out:
Disadvantages of composite reinforcement
Despite all the advantages of composite reinforcement, disputes about the advisability of its use also indicate the presence of disadvantages. In particular, the following disadvantages are noted:
Applications
Synthetic reinforcement has found application in various fields industrial and civil construction. With its help, residential buildings are erected, factory complexes are being built, 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 do not do without synthetic material and where it is impossible to use steel rods. For example, in frosty conditions it is necessary to add special additives in the form of hardening accelerators and antifreeze additives to masonry mortars. Such introductions have a negative effect on metal rods, but they are harmless for composite reinforcement.
Modern road construction technologies also provide for the possibility of using synthetic reinforcement. It is used in the construction of pavements, embankments, to strengthen other road elements exposed to chemically harmful reagents. As a rule, the use of a composite in this area involves one goal - the creation of a strong bond with a strengthening property. For this purpose, the rods are introduced into road slopes, bridge structures and various canvases that experience increased traffic loads.
When fiberglass reinforcement was first developed (57 years ago), its cost was much higher compared to steel bars, so the composite material was not widely used. Today the situation has changed, the cost of reinforcing material has decreased, and its advantages have been appreciated by construction companies involved 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 bays. 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
Plastic reinforcement is a physical body, which consists of the following elements:
- The main trunk, made of parallel fibers, interconnected with a 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 shaft of plastic reinforcement. Such winding can be sand-sprayed or bi-directional winding.
If we talk about the use of fiberglass reinforcement in construction, then today composite materials are widely used for:
- reinforcement of various reinforced concrete structures;
- repair of reinforced concrete and brick surfaces;
- installation of buildings made of lightweight concrete;
- layered laying of walls (flexible connection technology);
- reinforcement of tiled, columnar and strip foundations;
- strengthening concrete screeds;
- water disposal;
- creation of roadbeds and fences;
- 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 mass production.
Manufacturing technology
Composite reinforcement can be manufactured using one of three technologies:
- Winding. In this case, winding is performed on specialized equipment. The winder moves along the rotating mandrel. After several approaches, an integral cylindrical surface is created, which is sent to the heat treatment furnace.
- Stretching. First, the fiberglass is unwound from the 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 concrete mortar. At the next stage, the fiberglass reinforcement is sent to the furnace, where the resin hardens. Once the rods are fully polymerized, they pass through the broaching mechanism.
- Manual production. This is the most expensive process for making plastic rebar, so it is only used for small-scale production. In this case, a special matrix is first prepared, on which a gel coat (protective decorative layer) is applied. After that, the fiberglass is cut, impregnated in resin and hardeners and placed in a mold. Next, the product is heat treated and cut.
The first method of manufacturing plastic fittings is considered the cheapest, so products that have been wound are used most often.
In the manufacture of rods of this type, various types of fibers are used.
Varieties of composite reinforcement
Fiberglass reinforcement is of various types, the most famous of them are:
- ASP is a fiberglass reinforcement, which is manufactured by the classical method of winding fiberglass. The diameter of the fibers 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 - carbon fiber reinforcement, which uses both fiberglass and thermoplastic. The diameter of the fibers used is up to 20 microns.
Most often, ASP and ABP are used in construction. Carbon fiber reinforcement has a reduced mechanical strength, so it is used very rarely. In addition, ASPET products (a mixture of fiberglass and thermoplastics), ACC (combined fittings) and many other varieties can be found on sale.
In addition, fiberglass reinforcement is sold:
- piece rods;
- grid;
- frames;
- finished designs.
In addition, products are classified based on the type of structures for which they are used:
- fittings for ZhKB;
- mounting;
- 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 fittings to strengthen the foundation, it is worth considering the following product characteristics, 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 products of the AUK type). For metal, this figure barely reaches 370 MPa.
- Relative 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.
- Density - 1.9 kg / m 3, so the ASP weighs 4 times less than the steel frame.
- Ease of transportation.
- Low thermal conductivity.
- Long service life (more than 80 years).
- Corrosion resistance.
In addition, when using fiberglass reinforcement, you do not have to be afraid that it will jam the cellular signal 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 about how to cut fiberglass reinforcement, since it lends itself well to processing with an ordinary grinder.
The most obvious disadvantage of composite reinforcement is its instability. If you want to prepare it separately from the formwork, it can “skew”, so it is better to install the armo-belt directly into the formwork.
If we talk about the cost, then basalt-plastic reinforcement will cost about 6 rubles per linear meter, and fiberglass - from 9 rubles. If we compare it with steel bars, costing from 21 rubles per meter, it becomes obvious that today fiberglass rods not only do not “hit the pocketbook”, but also cost almost two times cheaper than metal ones.
However, do 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 manufacture, the rods did not undergo the necessary heat treatment, or the temperature regime was observed incorrectly. Such products must be rejected at the factory.
- If you notice that the rods are greenish in color, 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.
Color is the main indicator of the quality of the rebar, so make sure that the shade of the rods does not differ.
It is also necessary to choose the right clamps for the fiberglass armored belt. Plastic holders are best suited for this purpose:
- Horizontal (for concrete slabs and ceilings) allow you to create a layer with a height of 25-50 mm.
- Vertical (for wall surfaces) - layer thickness 15-45 cm.
Which appeared on the construction market relatively recently, has both advantages and disadvantages, which the consumer must be aware of. Despite the assurances of manufacturers that these products are a full-fledged replacement for metal fittings, their use can not be considered justified in all situations.
What is fiberglass reinforcement
The so-called composite reinforcement is a fiberglass rod around which a carbon fiber thread is wound, which serves not only to reinforce the structure of such a product, but also to ensure its reliable adhesion to the concrete solution. This type of reinforcement has both pros and cons, and its use should be approached very carefully.
Plastic clamps serve as elements for fixing carbon-fiber reinforcing bars to each other. It is convenient that the use of welding is not required to connect the elements of such fittings, which is undoubtedly a big plus.
Assessing the feasibility of using fiberglass reinforcement, it is necessary to consider all the pros and cons of its use in individual situations. This approach will ensure the high efficiency of this material as a means of strengthening building structures for various purposes.
If you do not take into account the characteristics of fiberglass reinforcement and do not compare them with the parameters of similar products made of metal, you can cause serious damage to the future building structure or finishing elements. That is why, before proceeding with the selection of elements for reinforcing concrete structures, it is necessary to understand in which cases the use of certain products is more appropriate.
Main advantages
Among the advantages that distinguish carbon fiber reinforcement, it is worth highlighting the following.
- An important advantage of fiberglass reinforcement is its low specific gravity, which makes it possible to use it for reinforcing lightweight structures made of cellular concrete and some other building materials. This allows you to significantly reduce the weight of structures that are reinforced with it. Meanwhile, the weight of a conventional concrete structure when using fiberglass reinforcement will decrease slightly, since the building material itself has an impressive mass.
- Low thermal conductivity is also one of the advantages of fiberglass reinforcement. When using such reinforcement in concrete structures, cold bridges are not formed (which cannot be said about reinforcing metal elements), which significantly improves their thermal insulation parameters.
- The high flexibility of fiberglass reinforcement allows it to be shipped to the customer in coils, rather than cut into individual bars. Thanks to the compact form of packaging, it is much easier to transport such fittings, for which you can use the trunk of any car, and this greatly reduces the cost of delivering the material to the construction site. The use of reinforcing elements, which are shipped not in cut bars, but in coils, also makes it possible to reduce material costs by reducing the number of overlaps. This positively affects both the strength characteristics of the future concrete structure and its cost, which is especially important when performing construction work.
- Such an advantage of fiberglass reinforcement as its durability inside a concrete structure is considered quite controversial. Reinforcement made of metal, being in an isolated state, is also not exposed to the negative influence of external factors, which ensures the durability of its use.
- CFRP reinforcement is a dielectric material, which is an advantage of products made from this material. Electrically conductive metal reinforcement is more susceptible to corrosion, which negatively affects its durability.
- Compared to metal reinforcing elements, fiberglass products are not exposed to chemically active environments. This advantage of fiberglass reinforcement is especially important in cases of construction of buildings in winter, when various salt solutions are added to the concrete, which accelerate the solidification process.
- Being a dielectric, carbon fiber fittings do not create radio interference inside the building, unlike metal bars. This advantage is important when there are many reinforcing elements in the concrete structure. Otherwise, the use of composite reinforcement will not become a minus, but it will not be so relevant.
Fiberglass reinforcement also has disadvantages, which potential consumers should also be aware of.
Main disadvantages
The disadvantages of fiberglass reinforcement are associated with its following characteristics.
- The disadvantages of fiberglass reinforcement include, in particular, the fact that it does not withstand exposure to high temperatures. At the same time, it is difficult to imagine a situation where a reinforcing cage inside concrete can be heated to a temperature of 200 degrees.
- A rather high cost is a conditional disadvantage, given the fact that fiberglass reinforcement of a smaller diameter can be used to reinforce concrete structures in comparison with metal products.
- CFRP reinforcement does not bend well. This disadvantage limits its use in the creation of reinforcing frames for concrete structures. Meanwhile, it is possible to make bent sections of the reinforcing cage from steel elements, and then build them up using fiberglass rods.
- Reinforcement made of fiberglass does not withstand fracture loads well, which is very critical for concrete structures. Accordingly, their reinforcing frame must successfully withstand such loads, which reinforcement made of composite materials cannot boast of.
- Unlike a metal reinforcing cage, fiberglass products have less rigidity. Because of this drawback, they do not tolerate vibration loads that occur when they are poured using a car mixer. When using this technique, the reinforcing cage is subjected to significant mechanical loads, which can cause its breakage and violation of the spatial position of its elements, therefore, rather high requirements are imposed on the rigidity of such concrete structures.
Considering the advantages and disadvantages of fiberglass reinforcement, it is difficult to say how much better or worse it is made of metal. In any case, the choice of this material should be approached very reasonably, using it to solve the problems for which it is really intended.
Fields of application of fiberglass reinforcement
Reinforcement made of composite materials, the laying rules of which are easy to learn from the corresponding videos, are used in both capital and private construction. Since capital construction is carried out by qualified specialists who are well acquainted with the nuances and disadvantages of using certain building materials, we will dwell on the features of using such material in the construction of private low-rise buildings.
- Reinforcement made of composite materials is successfully used to strengthen the foundation structures of the following types: tape, the height of which is greater than the depth of soil freezing, and slab. The use of carbon fiber reinforcement for strengthening foundations is advisable only in cases where the building is being built on good soil, where concrete foundations will not be subjected to fracture loads that fiberglass elements may simply not withstand.
- With the help of fiberglass reinforcement, walls are strengthened, the laying of which is made of brick, gas silicate and other blocks. It should be noted that as a connecting element of walls, composite reinforcement is very popular among private developers, who use it not only to strengthen the masonry of load-bearing structures, but also to ensure their connection with facing partitions.
- This material is also actively used for bonding elements of multilayer panels. The structure of the latter includes a layer of insulation and concrete elements, which are interconnected using fiberglass reinforcement.
- Due to the fact that the reinforcement of the type in question is free from such a disadvantage as susceptibility to corrosion, it is often used to strengthen various hydraulic structures (for example, dams and basins).
- In cases where it is necessary to effectively increase the rigidity of glued wooden beams, they are also reinforced with fiberglass reinforcement.
- This material is also used in road construction: it is used to strengthen the layer of asphalt pavement, which is subjected to increased loads during its operation.
Summarizing all of the above, it should be noted that the use of fiberglass reinforcement can be quite effective, given its shortcomings and associated limitations, which are specified by the manufacturer.
Can fiberglass reinforcement replace metal analogues
Despite the fact that reinforcement made from composite materials is a fairly new material in the construction market, you can already find many recommendations (and even videos) on its use. Considering these recommendations, we can conclude that it is best to use fiberglass reinforcement to strengthen walls erected from bricks and building blocks, as well as to connect load-bearing walls with interior partitions.
In this article, we will analyze and describe in detail 15 ways how and where fiberglass composite reinforcement is most often used.
1. Foundation plates
The technology of reinforcing foundation slabs in low-rise construction no higher than three floors using fiberglass composite reinforcement occurs by replacing metal reinforcement with fiberglass according to the table of equal strength replacement.
Proper replacement with fiberglass reinforcement is guaranteed to lead to significant cost savings, because. fiberglass reinforcement is cheaper than metal. The principle of reinforcing foundation slabs with fiberglass reinforcement does not differ from reinforcement with metal reinforcement, but leads to significant savings in installation time.
Knitting of fiberglass reinforcement is carried out with a knitting wire, cutting of fiberglass reinforcement is carried out.
2. Strip foundations
Reinforcement of the strip foundation with the use of fiberglass reinforcement occurs by replacing metal reinforcement with fiberglass according to the table of equal strength replacement.
Table of equal replacement of metal reinforcement with composite fiberglass reinforcement
Proper equal-strength replacement of metal reinforcement with fiberglass will allow you to get economic benefit up to 45%(savings in 2 times).
When replacing metal reinforcement with fiberglass, there is no need to increase the number of reinforcement layers and the number of whips in one layer.
If it is necessary to lengthen the whip of fiberglass reinforcement, the connection occurs in an overlap. The length of the overlap is from 20 to 50 cm.
Knitting of fiberglass reinforcement is also carried out with a knitting wire, carried out by a "grinder".
3. Reinforcement of industrial concrete floors
Reinforcement of industrial concrete floors with the use of fiberglass composite reinforcement occurs by replacing metal reinforcement with fiberglass according to the table of equal strength replacement.
Proper replacement with fiberglass reinforcement when reinforcing industrial concrete floors also leads to significant cost savings, because. fiberglass reinforcement is cheaper than metal.
The principle of reinforcement with fiberglass reinforcement does not differ from reinforcement with metal reinforcement, but leads to significant savings in installation time.
When replacing metal reinforcement with fiberglass, there is no need to reduce the reinforcement step.
If it is necessary to lengthen the whip of fiberglass reinforcement, the connection occurs in an overlap. The length of the overlap is from 20 to 50 cm.
Knitting of fiberglass reinforcement is carried out with a knitting wire, carried out by a grinding machine - "grinder".
4. Blind areas around buildings
A blind area is a strip with a width of 0.6 m to 1.2 m, which adjoins the foundation or basement of a building with a slope.
The slope of the blind area must be at least 1% (1 cm per 1 m) and not more than 10% (10 cm per 1 m).
The blind area around the building is recommended to be built using fiberglass reinforcement, since the main task of the blind area is to drain surface rain and melt water from the walls and foundation of the house. The blind area with the use of fiberglass reinforcement will last several times longer, since fiberglass reinforcement has high anti-corrosion properties, which prevents the occurrence of cracks in concrete.
5. Armopoyas (seismic belt) between floors of brick or block buildings
The use of fiberglass composite reinforcement when reinforcing the armored belt (seismic belt) between the floors of brick or block buildings due to high strength characteristics increases the spatial rigidity of the building and protects the foundation and walls from cracks caused by uneven settlement and frost heaving of the soil.
6. Binder for brickwork
To increase the strength of the brickwork and maintain the same thickness of the seams, it is necessary to use rods made of fiberglass reinforcement with diameters F4 and F6, instead of a metal mesh.
The thickness of the diameter of the reinforcement depends on the thickness of the seam in the brickwork.
Also, the use of fiberglass rods in masonry will significantly reduce heat loss, since fiberglass reinforcement does not conduct heat well, several times worse than metal.
7. Binder for masonry walls made of blocks / bricks, for monolithic walls
To increase the strength of masonry walls made of blocks / bricks, for monolithic walls and to control the thickness of the joints, it is recommended to use fiberglass rods with diameters F4, F6 and F8 instead of a metal mesh. The thickness of the diameter of the reinforcement depends on the thickness of the seam during laying.
Replacing the metal masonry mesh with fiberglass rods will reduce the cost of reinforcing material by more than 5 times.
Also, the use of fiberglass rods will significantly reduce heat loss, since fiberglass reinforcement does not conduct heat well, several times worse than metal.
8. Combination with metal in floor slabs
The floor slab is reinforced in two layers. The load on the floor slab goes from the top down and is distributed over the entire coverage area. Accordingly, the main working reinforcement is located in the lower layer and experiences large tensile loads. The top layer mainly receives compressive loads.
In this case, fiberglass reinforcement is used in combination with metal. The top layer must be made of metal, the bottom layer must be made of metal.
In the mesh itself, fiberglass composite reinforcement should have a solid appearance without gaps. If the ceiling is reinforced with F10 fiberglass reinforcement, then an overlap of 400 mm must be performed. All reinforcement joints should be staggered.
A flexible connection is used to connect the inner wall through the insulation (and the air layer) with the cladding wall into a single whole in a three-layer wall system.
Composite flexible connections manufactured by OZKM LLC are rods made of fiberglass with a length of 200 to 600 mm with a periodic relief surface or rods with a circular cross section (depending on the design solution). Due to this, OZKM flexible bonds have high adhesion with concrete and additional protection against the aggressive effects of the alkaline environment of concrete.
Flexible links apply:
- for brickwork (Ф 6 mm),
- for insulation of monolithic buildings (Ф 6 mm),
- for blocks (Ф 4 mm),
- for panel housing construction (Ф 6 mm).
10. Strip foundations for fences
Strip foundations are provided for the following types of fences: a fence with brick pillars, a metal forged fence and a fence made of timber or corrugated board with load-bearing metal posts.
Reinforcing the foundation for a fence using fiberglass reinforcement is very beneficial. Due to the high strength characteristics of fiberglass reinforcement and low loads, when reinforcing the foundation for a fence, composite reinforcement with diameters F4 and F6 is most often used.
Reinforcement technology is no different from the technology when using metal reinforcement, but much cheaper and faster in time. Longitudinal rods of fiberglass reinforcement are laid on the bottom of the dug trench on supports 4-7 cm high. The end rods of fiberglass should recede from the walls of the trench by 6-8 cm
Transverse reinforcement and vertical posts are usually knitted in increments of 400 mm.
The upper row of longitudinal reinforcement is attached to the racks so that it is 5-7 cm lower than the upper level of the trench. Then, the transverse fiberglass reinforcement of the upper row is laid.
11. Reinforcement of the pool bowl (bottom and walls)
12. Road construction
Fiberglass reinforcement receives positive feedback from builders due to its versatility, as it can be used to enhance the strength of the roadway, supports, bridges.
13. Pedestrian concrete paths
To stiffen the concrete path, it is necessary to reinforce the base, although many people neglect this.
When reinforcing the footpath with fiberglass reinforcement, the thickness of the concrete base can be made smaller, which leads to significant savings in concrete costs.
Also, the use of fiberglass reinforcement for reinforcing walkways protects concrete from disintegration into fragments.
14. Concrete platforms for driving and parking.
Before the start of reinforcement from above, under a concrete pad, a layer of crushed stone of 5 cm is poured onto a sand cushion and compacted. Reinforcement of fiberglass reinforcement reinforces the concrete structure, therefore, when arranging a site for a car parking lot, you cannot do without it.
The concreting of the area for the passage and parking of the car is carried out using fiberglass reinforcement, which is cut into bars of the required length. It is recommended to use fiberglass fittings with diameter Ф6.
The reinforcement frame is made directly at the installation site and will not take much time. Fiberglass rods are placed crosswise and tied with wire at the docking points.
15. Reinforcement of monolithic concretes containing antifreeze additives.
Fiberglass reinforcement, unlike metal, is resistant to alkaline environment. Antifreeze additives consist of alkali and salts that cause corrosion of the metal.
The use of fiberglass reinforcement when reinforcing monolithic concretes containing antifreeze additives increases the service life of the concrete base by several times and prevents the occurrence of cracks and protects concrete from disintegration into fragments.
Fiberglass reinforcement for the foundation
A few years ago, classical steel reinforcement was used in the construction of foundations. But now modern reinforcing materials are slowly replacing steel, and fiberglass is especially popular.
This is a composite material that is durable and flexible, resistant to tearing, because it consists of many monofilament fibers connected into a single bundle.
But at the moment, fiberglass reinforcement has not yet passed the test of time and various influences, so it is difficult to judge the quality of such products and the correct choice of diameter.
Also, there are no optimal calculations for choosing the optimal reinforcing fiber, and there are still complex technologies for connecting fibers to each other.
But the advantages of such composite materials are already there:
- This is the only material that is practically not subject to all types of corrosion;
- It can be used in all existing types of foundations;
- Availability, because fiber costs a little less than steel reinforcement;
- Low weight and small diameter cores.
But fiberglass reinforcement also has disadvantages:
- Due to the relative flexibility, the reinforcement cannot take on the tensile force. It will lie on concrete, so it is necessary to install reinforcement on concretes that are already subject to the maximum possible boundary tension;
- Fiberglass is limited in use, it must be used in an already tensioned state;
- It should not be used in mass construction, fiberglass will only be used by beginners who decide 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. The fiber is produced and transported in coils, therefore, funds for transportation costs are significantly saved;
How to reinforce foundations with fiberglass
Binding of fiberglass reinforcement with plastic ties
Given that the reinforcement of foundations is used more in low-rise construction, then bars are used with a diameter of up to 8 mm (this is a section of steel rods of 12 mm). Fiberglass reinforcement technology consists of several stages:
- Calculation of the required amount and diameter of the fiber;
- Formwork preparation, installation at the construction site;
- For multiple use of the formwork, it is recommended to cover it with glassine, which protects the structure from moisture and concrete;
- Installation of level marks, horizontal milestones, at the level of which the concrete solution will be poured;
- Preparation of a pillow from bricks, sand or sand-gravel mixture, on which the reinforcing mesh will be laid out. The mesh must be installed at a distance of up to 50 mm from the extreme edges of the formwork;
- Now you need to start laying reinforcement with fiberglass. If the calculation showed the use of several layers of the grid, then you need to lay the first layer on bricks, the next on vertical guides, and so on to the very top;
- It is better to connect all connecting elements in strip foundations and pile grillages to each other flexibly using plastic ties; soldering is not practiced here. And in monolithic foundations, you can also use soldering with a blowtorch;
- Installation and fixation of vertical rods, longitudinal and transverse fibers from the horizontal mesh itself;
- Pouring the base with concrete.
Calculation of fiberglass reinforcement for various foundations
The correct calculation of the type, diameter and quantity of fiberglass is the key to a solid and reliable foundation, given the 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 excess production plays an important role here.
To calculate reinforcement for a slab foundation, you must first determine the number and length of the rods, based on the parameters of the base and the step 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 bars along the entire length of the mesh, as well as at the corners of the installation of load-bearing cells.
By the same principle, reinforcement is calculated for strip and prefabricated foundations.
But the reinforcement of the columnar foundation differs significantly in technology. First of all, here the calculation takes into account the diameter and number of vertical rods installed directly in the wells. It is also taken into account that such rods must be rigidly connected to each other, because the vertical displacement is stronger than the horizontal one.
Thus, when calculating the number and diameter of the reinforcing fiber, it is taken into account that the ribbed fibers are installed in the poles, and the smooth ones - in the grillage and for strapping.
Where is fiberglass reinforcement found today?
Given the clear advantages of fiberglass as a reinforcing material, it is actively used in:
- Civil, industrial and residential construction;
- For concrete, brick, block masonry of all types and sizes;
- When construction is carried out in the winter. After all, then you have to use special mineral and organic additives that can destroy the steel reinforcing frame;
- When installing a concrete base for main roads and in the construction of dams on the banks of mountain rivers.
But now, many developers are still somewhat apprehensive about 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
Glass composite reinforcing products are called a trend product. Developed over 40 years ago, it is being actively promoted as an alternative to rolled steel.
According to manufacturers, fiberglass is successfully replacing traditional metal rods. Let's make a comparative analysis of the two types.
Brief description of metal products
In accordance with GOST 10884-94, reinforcing steel is a metal rod 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, roadbeds, and so on.
According to the physical and mechanical properties, the following types of fittings are produced:
1. A1 or A240 - mounting products. Metal rods have a smooth profile and are used to form the transverse frames of the frame, as well as for the foundation of light structures, such as greenhouses, shields, gazebos. Available in diameter 4-40 mm.
2. A2-A6 - working products, which are marked according to the steel yield index: A300, A400, A500, A600, A800 and A1000.
The surface is corrugated crescent, annular or mixed type. These are the supporting elements of the frame, located in the longitudinal horizontal axis. Metal fittings are produced in diameter 4-80 mm. Areas of application: low- and multi-storey construction, construction of large-sized industrial and public buildings, production of reinforced concrete products, formation of a roadway, and much more. Often used in restoration and repair 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, it 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 that protects against contact with the external environment.
Metal products have a type marking indicating the class of products, diameter.
In addition, additional engraving is included:
- C - intended for connection by welding.
- K - rolled products resistant to corrosion.
- T - thermally or thermomechanically hardened steel with a high yield index from A600 and above.
Metal fittings are classified by specialists as long or oversized products. It is sold in rods up to 11.7 m long, packed in bundles weighing up to 3 tons, or rods of 6-12 m are folded into small bays.
The price is calculated based on the ratio of tons / rubles. Installation into 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 bars of non-metallic products, which include:
- Staple glass and aramid fiber of inorganic type.
- Bonding thermosetting resins of a non-curing or curing type (epoxy, epoxy-diane, vinyl ester and others).
- Various additives that improve the ductility and strength of products.
Customers can buy reinforcing products of two varieties:
1. With a surface of a periodic profile.
On the rod, a thin strand of twisted fiberglass is wound in a spiral. Then a layer of polymer resin is applied, which gives additional protection.
According to the manufacturers, this “option” increases the area of contact between the reinforcement and concrete and enhances the mutual adhesion of materials.
2. With a conditionally smooth profile.
Sand sprinkling is applied to the surface during the production process, the task of which is to enhance the adhesive qualities.
Fiberglass reinforcement has the following advantages:
- Chemical, corrosion and water resistance.
- Light weight.
- Dielectric properties and radio transparency.
- Ease of transportation.
Comparison of these parameters is partially in favor of the glass composite.
Products are chemically resistant, but work only in a limited temperature range, are characterized by low fire resistance. The metal is resistant to any temperature, but rusts under the influence of water. However, manufacturers offer rods marked "K", coated with a thin film of oxides or a zinc layer, which prevents corrosion of the frame.
Fiberglass rebar 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 imperceptible, but when used in open frames (for example, in greenhouses), the risk of low-quality products is too great. Metal in this respect is completely safe.
Consider another parameter - the service life. The experience of working with metal fittings has been gained enormously, all the disadvantages and ways to overcome them are known.
With proper use, rolled steel lasts at least 30 years. Fiberglass, according to manufacturers, serves no less, but builders' reviews say the opposite. There are no exact data yet. Thus, composite reinforcement in comparison with steel is seriously losing.
ASP, diameter in mm
Cost, rub/linear meter
Which reinforcement is better, metal or fiberglass?
The construction industry is highly demanded 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 reinforcement is quite acute. Which option is preferred in a given situation?
Where is fiberglass reinforcement optimally suited, and where is metal? There are many questions, and 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 roadbeds, enclosing supports and bridges;
- Erection 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 - relevance of use
But in some situations, metal fittings are still relevant:
- Formation of reinforced concrete structures - with all its advantages, composite reinforcement can only play an auxiliary, but by no means the main role in reinforcing concrete.
A flexible steel product is indispensable in the construction of civil and industrial structures, a rigid one is used in the manufacture of heavy concrete and monolithic foundations;
- In those structures where increased transverse compression is expected and the operation of reinforcement corrugations along the shear;
- Due to their anisotropic data, steel products are perfectly combined with concrete, which cannot be said about fiberglass.
Disadvantages of fiberglass reinforcement
Studying the disadvantages of fiberglass products, it is worth highlighting the following of them:
- Weak heat resistance indicators - fiberglass itself has high heat resistance, but the plastic component of the binder type loses its parameters at temperatures above 200 degrees.
If the temperature reaches 600 degrees and above, the reinforcement is completely melted. Its use in conditions of high-temperature heating 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 a curved 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. To cope with the problem allows the use of 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.
It is possible to choose variations of the product from special corrosion-resistant compositions, 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 bay 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 characteristics of the formed structure.
price issue
When comparing two variations of reinforcement, one cannot ignore the issue of pricing policy.
Yes, at first glance, the cost of a meter of a metal-plastic product is higher than that of a similar one made of metal. But there is one caveat.
Features of fiberglass composite reinforcement
With the same strength, fiberglass reinforcement has a smaller cross section than similar steel. Therefore, elements that are 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 reinforcement is better - made of metal or fiberglass. It all depends on the characteristics of the particular object being built and the technical conditions for its use.
Our company offers composite fiberglass reinforcement with a diameter of 6 mm. The reinforcement has the form of a periodic profile and is sold in coils from 50 to 200 m.
The weight of fiberglass reinforcement is almost 10 times less than that of metal reinforcement, according to the table of conditional replacement of class A-III metal reinforcement with composite fiberglass reinforcement, without loss of strength. In this example, a 6 mm fiberglass rebar replaces an 8 mm metal rebar.
Fields of application of fiberglass reinforcement with a diameter of 6 mm: as a reinforcement mesh for concrete screeds, reinforcing floors, paths, under cladding, tiles, strip foundations, as flexible connections, for reinforcing road and paving slabs, fence slabs, curbstones, posts and supports, railway sleepers.
According to builders, this fiberglass reinforcement has proven itself well in strip foundations, armored belts, shallow slab foundations, in the construction of thermal houses, in the manufacture of underfloor heating and screeds, in the construction of roads, road fenders, 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, and also use it in the construction of poultry houses, cowsheds, pig farms for foundations and floors.
Because this fitting is used in close contact with water and aggressive media. The fittings do not rust, do 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 tomato, raspberry, currant bushes, etc.
The fiberglass reinforcement is connected with plastic mounting clamps or knitting wire using a semi-automatic knitting hook.
The minimum norm for the release of fiberglass reinforcement with a diameter of 6 mm is 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 conditional replacement table), metal reinforcement with a diameter of 8 mm is 0.395 kg.
Composite reinforcement 6 mm can be purchased at the warehouse in St.
Zaporozhye by self-delivery, or order free targeted delivery around the city (by agreement). Across Dnepropetrovsk, free delivery is carried out subject to an order of 500 m.p.
Diameters 6,7,8,10 are sold in coils from 50 to 100 meters.
As a result of technological processes, there may also be leftovers 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.
During non-working hours and weekends, you can also place an order for goods by clicking on the buy button.
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Reinforcement made of composite materials technical characteristics
fiberglass rebar comparison
Fiberglass reinforcement compared with metal
Fiberglass reinforcement
Non-metallic composite reinforcement for construction work
A new reinforced element for construction work is high-strength non-metallic reinforcement made of composite materials.
Non-metallic reinforcement is produced in the form of a rod with a spiral relief of any construction length made of glass fibers impregnated with a chemically resistant polymer.
Reinforcement made from glass fibers is called fiberglass ASP.
According to the research results, the durability of building structures using reinforcement is at least 100 years.
Such durability is due to the high chemical resistance of the reinforcement to all known aggressive environments - gaseous media of high concentrations, chloride salts, anti-icing 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 the loads applied to the reinforcing elements. The replacement procedure is shown in table 3.
Metal fittings
A3 (A400C) GOST 5781-82
Non-metallic composite rebar
ASP
Fsec - cross section of reinforcement, mm2
Rrasch - tensile force of the reinforcement at the calculated temporary tensile strength, n.
Non-metallic fittings are 10-20% cheaper than replaceable metal fittings.
Composite reinforcement grids Grids of various load characteristics are made from composite reinforcement bars with diameters from 5 to 12 mm (Fig.
Mesh rods are fastened with polymer fixators, as well as with the help of annealed metal knitting wire, similarly to knitting meshes from metal reinforcement.
Grids 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.
Tensile strength of mesh, kN/m
AREAS OF USE
- Production of concrete slabs for coatings of intra-construction, bypass temporary automobile and other roads with the complete replacement of metal reinforcement with composite reinforcement.
- Reinforcement of asphalt concrete pavements of highways.
Eliminates rutting, prevents the destruction of the coating 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), roadside driveways, temporary roads. A mesh of composite reinforcement 8-12 ASP is used.
Mesh 1 at the base of the road combined with non-woven material 2 and mesh 3 in the middle of the road.
- Strengthening the slopes of embankments, banks of reservoirs.
Grid 1 is fixed 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 operating 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, light, cellular and porous concrete, as well as tension concrete.
- Use for the manufacture of flexible connections in the layered masonry of brick buildings.
- Repair of surfaces of damaged reinforced concrete and brick structures.
Characteristics and application of fiberglass rebar
The active use of polymeric materials in various production areas leads to the need to endow these materials with the necessary quality characteristics.
The necessary strength can be given to some polymers through the use of fiberglass reinforcement.
In addition, fiberglass reinforcement can be successfully used on its own, 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 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 the basis, as an option - basalt.
In this case, the reinforcement consists of two layers:
- Inner rod. This element is a kind of bundle of fibers that are linked together using epoxy, possibly polyester resin.
- Outer shell. The material that surrounds the core is responsible for firmly bonding the reinforcement to the surrounding building material (concrete).
It can be noted that reinforcement made of composite materials, if fiberglass is called that, 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 when compared with metal;
- low thermal conductivity;
- wide temperature range of application.
In the manufacture of reinforcement from fiberglass, not only the advantages of the material itself are manifested, but the peculiarity of the technological process has a positive effect.
At the manufacturing stage, each strand of the core receives equal stress compared to the others. This has a positive effect on strength.
The thread flow during twisting is freed from any possible contamination, which positively affects the 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 venyl ester resin.
Basic properties
Before starting to use fiberglass reinforcement, one should not only know the main competitive advantages, but also evaluate their impact on the future design.
The following table shows some of the values of the individual parameters, as well as their influence on the design when used:
What is a composite material
Composition of the composite material
A composite is a continuous inhomogeneous material that has been artificially created from several components with different physical and chemical properties.
The mechanical characteristics of the composite material are determined by the ratio of the properties of the matrix and the reinforcing elements, as well as the strength of their bond, which is ensured by the correct choice of the initial components and the way they are combined.
The most primitive composite material is straw and clay bricks, which were used by the ancient Egyptians.
Most often, composites are materials based on resin or polymer matrices. For the manufacture of composite materials, phenolic, epoxy, vinyl ester, polyester and polypropylene polymers are used.
Bulk substances and fibers act as reinforcing substances in the manufacture of composites. The strength of the material depends on the amount of resin - the less it is, 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.
Methods for molding composite materials
During the molding process, the matrix of the composite material is combined with its reinforcing substance, as a result of which one or another product can be made.
Thermoset polymer matrices undergo a chemical curing reaction during the molding process. Thermoplastic polymer matrices are melted and solidified in a predetermined shape during the molding process.
This process usually takes place at room temperature and normal pressure.
The most common composite today is metal-reinforced cement or asphalt concrete.
There is also contact (manual) molding, which has a number of serious drawbacks.
The product formed by this method contains an increased amount of resin, which makes it more brittle. In addition, with it 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, in which composite components are placed, covered with a silicone membrane or polymer film. Then a vacuum is applied to the tooling under conditions of atmospheric pressure and elevated temperature.
