Glass fiber reinforced concrete: universal and unique. Glass fiber reinforced concrete - characteristics, advantages and disadvantages of the material, composition: Portland cement, aluminous cement, high-strength gypsum Product sales and business profitability

The paper presents the results of studies of the physical and mechanical properties of glass fiber reinforced concrete depending on the degree of dispersed reinforcement and binder consumption. Data on the ultimate bending and compressive strength of glass fiber reinforced concrete were obtained, and the dependence of long-term concrete deformations (creep and shrinkage) on the degree of reinforcement was established. It has been shown that the introduction of glass fiber significantly increases the flexural strength, while the compressive strength decreases slightly. It has been determined that dispersed reinforcement leads to a reduction in creep and shrinkage strain by almost 2 times. In general, the data obtained make it possible to evaluate the influence of the method of laying glass fiber reinforced concrete (gunning of moving “fat” compositions and packing of rigid “lean” compositions) on the properties of the material.

fiberglass

glass fiber reinforced concrete

shrinkage deformation

creep deformation

1. Volkov I.V. Problems of using fiber-reinforced concrete in domestic construction // Construction materials. – 2004. – No. 6. – P. 12–13.

2. Gabidullin M.G., Bagmanov R.T., Shangaraev A.Ya. Study of the influence of glass fiber characteristics on the physical and mechanical properties of glass fiber reinforced concrete // Izvestia KGASU. – 2010. – No. 1(13). – pp. 268–273.

3. Gazin E.M. Study of strength, crack resistance and deformability of bendable three-layer elements with enclosing layers of glass fiber reinforced concrete: abstract of thesis. dis. ...cand. tech. Sci. (05.23.01). – M.: NIIZhB, 1998. – P. 22.

4. Pukharenko Yu.V. Scientific and practical principles of formation of the structure and properties of fiber-reinforced concrete: dis. ...cand. tech., sciences. – 2005. – P. 3.

To date, extensive experience has been accumulated in the use of dispersed reinforced concrete. The properties of steel fiber concrete, concrete reinforced with basalt and asbestos fiber have been well studied. Distinctive features of fiber-reinforced concrete are high anisotropy and discreteness, which makes it possible to distinguish them in independent group construction materials. The use of glass fiber as dispersed reinforcement is one of the promising directions for producing high-quality structural materials. Despite the research carried out in this area, at present the use of glass fiber reinforced concrete in domestic construction is still limited. This is not least due to insufficient knowledge of the properties of glass fiber reinforced concrete, as well as the lack of a regulatory framework. The most important factor The lack of demand for fiber-reinforced concrete in construction is its relatively higher initial price compared to conventional concrete or reinforced concrete.

The technology of its application requires study and consideration when developing glass fiber reinforced concrete compositions. Dispersed reinforcement can be carried out using two methods. The first, traditional one, involves the introduction of fiberglass into the mortar mixture at the stage of its preparation. Modern method Pneumatic spraying is used in the second method, when glass fiber is introduced into the mortar mixture at the time of its placement in the mold. Laying technology is directly related to special requirements for the rheological characteristics of the mixture, which cannot be achieved without significant modification of the compositions, which is expressed primarily in an increase in binder consumption. This, in turn, can cause an increase in creep and shrinkage strains. To assess the operational reliability of glass fiber reinforced concrete, a study of long-term deformations of the material was required.

Experimental part

The immediate objective of this work was to study the physical and mechanical properties of glass fiber reinforced concrete depending on the degree of reinforcement (in order to minimize glass fiber consumption) and the method of laying the concrete mixture.

The following components were used in the study: Portland cement CEM I 42.5 N from the Slantsev cement plant “TSESLA”, quartz-feldspathic sand of fraction 0-2.5 mm (Mkr = 2.68), as well as alkali-resistant fiberglass.

Today there are enough reinforcing components on the market large selection. Alkali-resistant glass fiber is produced by companies such as Nippon Electric Glass Co. Ltd (NEG) (Japan), Technologies International Ltd (Bristol, England), L’Industrielle De Prefabrication (Priest, France), OWENS CORNING (EU). Fiberglass is supplied both in the form of reels (roving) and in the form of chopped fiber, treated with special substances (sealing agents) that allow the fiber to be easily distributed in concrete.

In this work, alkali-resistant fiber from Saint-Gobain Vetrotex, brand Cem-FIL Anti-Crak HD (ARC14 HD), was used as dispersed reinforcement. The characteristics of the fiber are given in table. 1.

The small diameter and optimal length allow the glass fiber to be distributed fairly evenly in the cement-sand mortar, as shown in the photograph of the microstructure of concrete taken using a Vega 3 electron microscope (Fig. 1).

Fine-grained concrete mixtures were prepared based on ensuring a constant water-cement ratio through the use of a polycarboxylate type plasticizing additive.

Table 1

Characteristics of alkali-resistant glass fiber

Two series of samples were prepared, differing in the ratio of binder and filler: “lean” and “fat”. Each series included compositions with varying degrees of fiber reinforcement: 0; 1.5 and 2.5% by weight of the mixture.

The aggregate, cement and fiberglass were mixed in a laboratory mixer until a homogeneous mixture was obtained, then mixed with the required amount of water and mixed until a homogeneous mass was formed. Next, beam samples measuring 4x4x16 cm were made, which were kept in a normal-humidity curing chamber until testing. Testing of samples was carried out at the age of 7 and 28 days.

The studied compositions and their properties are presented in Table. 2.

Rice. 1. Fiberglass in a cement-sand matrix

From the data obtained it follows that the introduction of fiber in an amount of 1.5% increases the tensile strength in bending at the age of 7 days relative to the control composition by 56%, regardless of the ratio of binder and filler (compositions No. 2 and 5, respectively). At the age of 28 days, the flexural strength increases compared to the unreinforced composition by 38% for the “fat” composition and by 48% for the “lean” composition. IN graphical form The strength characteristics of the compositions are presented in Fig. 2.

It should be noted that the maximum increase in bending strength (almost 2 times) is achieved with the introduction of 2.5% glass fiber.

The introduction of glass fiber into cement-sand compositions (Fig. 3) leads to a slight decrease in the compressive strength, which can be explained by decompaction of the concrete structure due to insufficient dense packing of the cement-sand matrix. It should be noted that for the “lean” composition there is a greater decrease in compressive strength compared to the control sample at the age of 28 days than for the “fat” composition. This is probably due to to a greater extent decompaction of the structure under conditions of lower binder consumption.

Table 2

Composition and properties of concrete mixture and concrete

Rice. 2. Bending strength of glass fiber reinforced concrete at the age of 7 and 28 days

Rice. 3. Compressive strength of glass fiber reinforced concrete at the age of 7 and 28 days

Rice. 4. Shrinkage deformation depending on the degree of reinforcement of the compositions at different ratios of binder: aggregate (H:W)

Of no less interest for study are the intrinsic deformations of glass fiber reinforced concrete. Tests to determine shrinkage were carried out using the Terem-4 measuring complex for 28 days under normal humidity hardening conditions. The test results are presented graphically in Fig. 4.

Analysis of the graphs shows that, regardless of cement consumption, compositions without fiber have the maximum shrinkage at the age of 28 days (up to 2 mm/m). Increasing the degree of reinforcement to 1.5% slightly reduces shrinkage in “fat” compositions (“FG”). And only an increase in the fiber content to 2.5% reduces the shrinkage of “ZhS” (up to 1.05 mm/m). In compositions with minimal binder consumption, the tendency for shrinkage to decrease depending on the amount of fiber is more obvious. At the same time, the maximum reduction in shrinkage deformations is also achieved with the introduction of 2.5% glass fiber.

Under conditions of increased binder consumption, the increase in residual deformation over time under constant load can be quite significant. Therefore, the next stage of the work was to test the creep deformations of glass fiber reinforced concrete in accordance with GOST 24544-81.

The creep of concrete depends on more factors than shrinkage. Moreover, most factors affect creep deformation in a similar way to their effect on shrinkage. The main factors determining shrinkage include the following: consumption and type of Portland cement; water-cement ratio; type and size of aggregate; degree of concrete compaction; degree of cement hydration at the time of load application; temperature and humidity environment and concrete.

In this work, the creep of “fat” and “lean” compositions was studied depending on the degree of reinforcement. Prism samples 70×70×280 mm in size were made from glass fiber-reinforced concrete with different W:W ratios, reinforced with glass fiber, which were subjected to creep tests at the age of 28 days. Spring presses were used as a device for testing long-term deformations.

The test results are presented graphically in Fig. 5.

Based on the analysis of the obtained dependencies, we can conclude that the amount of glass fiber has a noticeable effect on the long-term shrinkage of both compositions. Thus, the introduction of only 1.5% of reinforcing fibers sharply reduces the creep of the material. It was natural to assume that a further increase in the amount of glass fiber would lead to an even greater reduction in creep deformations. Experimentally obtained data show that concrete with 2.5% glass fiber in the composition has the least creep; the creep of such compositions decreased by 95-100% compared to the control ones. It should be noted that deformations in the presence of glass fiber in compositions with a ratio of W:G = 1:1.6 stabilize at the age of 150 days, while “fat compositions” (W:G = 1:1) continue to experience creep deformations even after 180 days. days.

Rice. 5. Relative creep deformations depending on the degree of reinforcement of the compositions at different ratios of binder: filler (H:W)

Conclusion

Thus, regardless of the ratio of binder: filler, the introduction of fiber in amounts of 1.5 and 2.5% makes it possible to increase the tensile strength in bending by 1.5 and 2 times, respectively.

Dispersion-reinforced “fat” compositions (H:W = 1:1) are characterized by greater compressive strength, but also higher shrinkage deformations than “lean” compositions. To minimize shrinkage in “fat” areas, fiber consumption should be at least 2.5%.

Compositions with a ratio of V:G = 1:1.6 (“TC”) exhibit a significant reduction in compressive strength when fiber consumption exceeds 2.5%. Shrinkage deformations are 42% less than those of the control composition.

It has been experimentally proven that the introduction of glass fiber into concrete has a positive effect on the dynamics of reducing long-term deformations of the material (the creep deformation of reinforced compositions is reduced by 2 times compared to the control composition).

Reviewers:

Pukharenko Yu.V., Doctor of Technical Sciences, Professor, Head of the Department of Technology of Building Materials and Metrology, St. Petersburg State University of Architecture and Civil Engineering, St. Petersburg;

Kharitonov A.M., Doctor of Technical Sciences, Associate Professor, Professor of the Department of Technology of Building Materials and Metrology, St. Petersburg State University of Architecture and Civil Engineering, St. Petersburg.

Bibliographic link

Construction technologies are actively developing, offering materials with improved qualities. Quite simple, but already quite in demand in private construction, is one of these new products - based on glass fiber. The material is obtained by combining ordinary concrete and cut glass monofilament. This article will talk about this in more detail, and you will also learn how to create glass fiber reinforced concrete with your own hands.

General information

Conventional concrete, which is made from sand and gravel, has low tensile and compressive strength. The reason for this is the compactness of the filler grains, and the bursting of concrete occurs precisely along their boundaries ().

Scientists have come to the conclusion that glass fibers of small cross-section, but of quite long length, if they are randomly arranged in the mass of the block and mixed homogeneously, help increase the strength characteristics tens of times. Ordinary reinforced concrete can also be strengthened through the use of iron reinforcement, which absorbs tensile stresses.

But, this solution has “side” effects:

• the self-weight of the reinforcement is high, so the concrete becomes heavier;
• the dimensions of reinforced blocks are increasing, since it is necessary to protect the reinforcement from moisture and corrosion.

Speaking about fiberglass, the dispersed reinforcement of the block, the following properties can be noted:

• greater value of the total cross-section in comparison with steel reinforcement bars;
• its weight is less than that of steel;
• higher values ​​of compressive/tensile strength than steel;
• resistance to corrosion, which allows you to make a block of exactly the dimensions required by the results of a real load calculation, without increasing it to protect the reinforcement.

These qualities contribute to the production of a lighter and more compact glass fiber concrete block, which will have strength characteristics similar to reinforced concrete and a lower cost in comparison with it.

Some material properties:

1. The surface of the blocks is polished, which, in combination with such indicators as the thickness of the concrete layer, the nature of the arrangement of the fibers and the properties of the fiber itself, can give it original effects and even translucency of the material.
2. The material tolerates staining well, which is done both in bulk and on the surface of finished blocks. To do this, dye is introduced directly into the concrete mixture or colored fiber is added.

Advantages and Disadvantages

TO negative points include:

• low resistance to alkali, which is why alkali-resistant glass fiber is used for foundations;
• Due to the fact that hardening occurs faster than conventional concrete, laying must be carried out at a faster pace.

The advantages over conventional concrete are the following:

• light weight;
• high tensile, bending and compressive strength;
• higher (5 times) tensile strength value;
• the impact strength is 15 times higher;
• The frost resistance indicator reaches 300 cycles.

In the photo - what types of glass fiber reinforced concrete products are there?

Application

Due to the ability of the material to quickly harden and its high density and mechanical strength, glass fiber reinforced concrete can be used to produce plates whose thickness is less than 10 mm. This makes it possible to form thin-walled, very strong products with a smooth surface ().

Due to the plasticity of the material, the basis of which is a fine-grained concrete matrix, in some cases containing no sand at all, it is possible to create:

• textures of any specified properties and parameters;
• achieve imitation of different materials;
• get quite complex shapes.

Tip: using glass fiber reinforced concrete to decorate facades is an excellent replacement for stucco molding made of plaster, concrete or plaster.

Plates of different thicknesses:

• serve as curtain and ventilated facades;
• can replace tiles, for example, a roof made of glass fiber reinforced concrete will be lighter;
• are used instead of wall and facing materials.

It is also more promising than conventional reinforced concrete when it comes to the construction of floors. Glass fiber reinforced concrete has a low weight, and this leads to a reduction in the load on the foundation and load-bearing walls, increasing the number of storeys of the building under construction due to this.

Compound

Its basis is Portland cement M500-700, white or gray, to which quartz fine sand and alkali-resistant fiber (roving) are added; it is also possible to use aluminous cements.

Improving the aesthetic, molding, technological and operational properties of the material is achieved by introducing additives. Water or liquid glass is used to seal glass fiber reinforced concrete.

The binder has a significant impact on the result. If the base is aluminous cement reinforced with glass fiber, a more intense crystallization of new formations is observed. At the same time, there is a smaller decrease in strength under equal conditions in comparison with composites, where Portland cement is the basis.

Uses of Portland cement

Its hydration is accompanied by the formation of a highly alkaline environment. This is good for steel reinforcement, since it protects it from corrosion, but this environment has a detrimental effect on fiberglass.

The main component of the liquid phase of Portland cement, which is in a state of hardening, is calcium hydroxide. This compound provokes corrosion processes in the glass, causing destruction of the silicon-oxygen frame.

To avoid corrosion of glass reinforcement, only alkali-resistant fiber is added to such glass fiber reinforced concrete. This helps to avoid making a block that is merely impregnated with “liquid glass,” but is completely unreinforced.

Application of aluminous cements

If this material is the basis of concrete, the result is a product that is resistant to aggressive environments, waterproof and has greater density. But the price of such cement is high and it is difficult to buy.

The advantages of the solution are:

• rapid hardening, accompanied by an intensive increase in strength, provides short terms maturation (design strength is achieved in 3 days);
• inertness to fiberglass, which allows maintaining the integrity of the glass fiber due to less chemical exposure;
• increasing the speed of construction several times.

The disadvantages are that these concretes change their strength over time. This should definitely be taken into account when designing.

Advice: due to the fact that when working with aluminas (as opposed to Portland cement), mistakes made become more noticeable, process must be strictly observed.

High strength gypsum

If you plan to produce sprayed and dispersed-reinforced products, and even more so when they are intended for interior or finishing work, use high-strength building gypsum or plasters based on it. The hardening environment of the stone is almost completely neutral.

And if in relation to steel reinforcement the material necessarily causes corrosion, because it is quite hygroscopic, the hydration environment does not affect fiberglass. Distinctive features Such products are characterized by rapid acquisition of strength, fire resistance and low thermal conductivity.

Selection of glass fiber for specific type products are made based on chemical composition and strength.

When choosing roving, take into account:

• chemical resistance;
• adhesion;
• deformability;
• coefficient of linear expansion of monofilament;
• strength.

Mainly used:

• quartz;
• silicate;
• sodium-calcium-silicate;
• aluminoborosilicate;
• zirconium silicate fibers.

Of all of these, only the last type of fiberglass is resistant to alkalis.

Production

Fiberglass concrete is produced in several ways:

1. Pneumatic spray, which is done using a special air gun. Chopped fiberglass is applied to the mold or working surface simultaneously with the cement-sand mortar. Mixing of the mixture components occurs at the outlet of the gun nozzle, while the fiber is introduced into the solution evenly. The result is the laying of a homogeneous layer of glass fiber cement.

Advantages:

• there is the possibility of separately preparing the solution;
• the fiber is crushed in a gun just before mixing;
• the material is dosed accurately, mixed quickly, and is homogeneous.

There is only one drawback: the high cost of the equipment.

1. Mixing by hand or with a concrete mixer is only suitable for small batches.. It can be made with your own hands, therefore it is widely used in private housing construction.

First, a solution of cement and sand is prepared in a mixer. Having received concrete of the required grade, add pre-chopped roving fiber (10%) and continue mixing for at least another 5 minutes.

The finished mixture must be molded immediately, since its hardening proceeds faster than that in which there is no glass. Additionally, it needs to be compacted by punctures or vibration. In this case, the material should be prepared in small portions.

1. Vibroforming, but to be precise, this is not a separate option for producing a mixture, but a method of additional homogenization. It is used when it is necessary to produce small-sized products and slabs.

It consists of vibrating compaction of concrete placed in molds on a stand. Needed for a more uniform distribution of fiber in the mass.

You can make your own stand for vibration forming. All you need to do is attach the movable tabletop to a mechanism that will create vibration of the required force.

Almost every area of ​​the construction business has prospects. But entrepreneurs more often began to consider implementing ideas related to the production of fundamentally new materials - the market is not overflowing with offers, the technologies are simple, and the raw materials are inexpensive. This includes the production of glass fiber reinforced concrete. Russian manufacturers have already noted these building blocks as reliable, high-quality, beautiful-looking material.

Glass fiber reinforced concrete is a material obtained from glass fiber reinforced concrete. It combines the properties of cement boards and composites. Using different shapes, manufacturers can receive not only building boards, but also beautiful decorative elements. The texture of the final products and their color also vary.

Our business assessment:

Starting investments – from 200,000 rubles.

Market saturation is low.

The difficulty of starting a business is 5/10.

Manufacturing glass fiber reinforced concrete will be a profitable business for a businessman for several reasons:

• High demand for products. The qualitative characteristics of glass fiber reinforced concrete are unique - strength, non-flammability, reliability, seismic resistance, ease of installation, low weight of products. Many consumers have already managed to evaluate the properties of the material - increasingly, preference in finishing is given to this particular composition.
• It is possible to organize an enterprise in several areas - production of blocks and stucco moldings, facade and interior work for surface finishing.
• Little competition. Today, a small number of companies offer facade decor made from glass fiber reinforced concrete. And in some regions there are no such offers at all. This gives aspiring entrepreneurs a great chance of success.
• Low costs for organizing an enterprise. It is possible to start the production of glass fiber reinforced concrete with your own hands, which will allow you to save on the purchase of automatic equipment.
• Simple technology. To understand the matter, you do not need to undergo training and hire a qualified technologist as a consultant.

Be sure to draw up a business plan. On the project pages you will calculate costs and select the optimal consumables.

Technologies for manufacturing glass fiber reinforced concrete

The composition of glass fiber reinforced concrete varies depending on the final purpose of the product. The main components are:

• cement,
• sand,
• water,
• plasticizing additive,
• polymer additive,
• fiberglass,
• pigments.

Not a single successfully operating enterprise will disclose its recipe. If you decide to learn the basics of business on your own, then you will have to act by trial and error.

Each entrepreneur chooses what technology for manufacturing glass fiber reinforced concrete will be, taking into account what exactly he plans to do - produce ready-made building materials or carry out facade works. It’s great if the enterprise implements several production methods at once. But then there will be costs for equipment.

Production technology is:

• Vibroforming of the premix (premixing). Artificial fiber is first added to the cement-sand mixture, after which it is thoroughly mixed and subjected to vibration molding. The material obtained after these manipulations is called SFRC premix. The process uses special forms, removable or permanent formwork made of glass fiber reinforced concrete. This technique is ideal for obtaining small decorative elements.
• Pneumatic spray. This is spraying a solution onto the working surface using a special apparatus operating under high pressure. The mixture is prepared in a special wide-span mixer. From here, the glass fiber reinforced concrete for the façade goes into the spray gun. In this case, the glass roving thread is inserted into the gun itself, which is “cut” into individual long fibers and enters the mixture flow. In this way, it is possible to both process the surface of the building and produce façade panels from glass fiber reinforced concrete.

Technology for the production of glass fiber reinforced concrete using manual pneumatic spraying

Agree with sellers on wholesale supplies of basic raw materials - sand, cement and roving. Modifiers, plasticizers, pigments and chemical additives can be purchased as needed.

Decorative products made from glass fiber reinforced concrete are obtained as follows:

• Development of a layout in accordance with the customer’s wishes.
• Creating a form. It can be made of plastic, wood or plaster.
• Filling the mold with the mixture. The product can be made from glass fiber reinforced concrete or other material.
• Spraying. If glass fiber reinforced concrete was used to fill the form, this stage may be omitted.
• Drying finished product in the steaming chamber.

In order to cooperate with large customers purchasing products in the future in bulk, you will need to undergo inspection of the produced material. Tests for compliance with quality indicators are carried out in accordance with GOST. Collecting all the papers is a hassle. Start early.

Workshop technical equipment

The production of glass fiber reinforced concrete sheet cannot be carried out at outdoors– you will need to rent a workshop. If you have a large garage, use it. Water and electricity need to be supplied to the room.

Are you going to provide internal and external services? finishing works using pneumatic spray technology? There is no need for a separate room - you will come to the site with your own equipment. But all equipment and materials also need to be stored somewhere!

You can buy equipment for the production of glass fiber reinforced concrete using the vibration casting method for at least 500,000 rubles.

The line will include:

• faucets,
• dispensers,
• bunkers for raw materials and working solutions,
• automatic machine for single-strand cutting of glass roving,
• vibrating table

If you buy used units, you can save a lot.

Equipment for glass fiber reinforced concrete produced by pneumatic spraying can be purchased cheaper - up to 300,000 rubles. The productivity of such installations will be low. But small companies who provide services for the production of stucco molding and coating of surfaces with a composition, this will be quite enough.

The following devices will be required:

• mixer,
• dispensers,
• containers for raw materials,
• pumping station,
• air gun.

Sales of products and business profitability

Decorative elements made from glass fiber reinforced concrete are in demand on the market. Offer unique products construction companies, design studios, private clients. Basically, small workshops do work to order. To start cooperation with construction companies, it is necessary to guarantee them stable supplies of large quantities of goods, and this cannot be achieved with small capacities.

The price of glass fiber reinforced concrete will depend on the raw materials used and the type of work. It is quite difficult to determine the exact cost of products. For example, the average price per m 2 of products (stucco, vases, borders) is from 1,500 rubles. Material handling services cost about the same.

To launch a small workshop where construction materials will be produced and services for external and internal repair work will be performed, at least 500,000 rubles will be required. To organize a home business for the production of decorative products from glass fiber reinforced concrete, 200,000 rubles may be enough. Launching a powerful enterprise will cost the entrepreneur much more - up to 2,500,000 rubles.

The price of equipment for glass fiber reinforced concrete and other startup costs can be recouped in 1 year. If you have spent more than a million, and clients are not yet in a hurry to enter into long-term contracts with you, it will take more time - about 2.5-3 years.

Concrete products and structures are used everywhere today. Meanwhile, new times require the introduction of new structural and composite materials in conjunction with new technologies.

In this case, it is often possible to create “new materials from old ones.” For concrete, this is achieved through reinforcement. The filler allows you to obtain a new material that economic indicators and strength characteristics superior to conventional concrete.

Metal, mineral and organic fillers are known - in the form of continuous threads (mesh, fabrics and other similar rolled materials) or in the form of short pieces of fibers - fibers. Fiber reinforcement of concrete gives rise to a new material - fiber-reinforced concrete.

Currently, three types of reinforcing fibrous materials are used:

• Glass fiber;
• Steel fiber;
• Fiber made of synthetic fibers;

Glass fiber reinforced concrete - SFB (glassfiber reinforced concrete - GRC, English).

When pieces of alkali-resistant glass fiber are introduced into fine-grained concrete (concrete matrix), a composite material is obtained - glass fiber reinforced concrete, where the fiber fiber is evenly distributed throughout the volume of the product or its individual parts (zones).

Technical characteristics of glass fiber reinforced concrete:

Note: conversion of kg/cm2 to MPa: g x kg/cm2 = MPa = 10 x kg/cm2.

Concrete and reinforcing fibers work together because... adhesion takes place over the entire surface of the fiber. Due to such a gigantic area of ​​adhesion between concrete and fiber, qualitatively new properties of the composite material, called glass fiber concrete or glass cement, are formed.

The use of SFRC makes it possible to reduce construction costs, reduce labor costs, and increase the reliability and durability of building structures.

Dispersed reinforcement significantly increases the strength properties of concrete, and also improves the performance characteristics of structures: resistance to dynamic, temperature and humidity influences, wear, abrasion, etc.

According to their purpose, products made from glass fiber reinforced concrete are divided into structural, decorative, waterproofing and special.

The main levers for obtaining the required parameters of SFRC products are:

• percentage of reinforcement (how many kg of glass roving is spent on 1 cubic meter of concrete);
• fiber length (combinations of short-fiber and long-fiber elements are possible);
• manufacturing technologies (“spraying or premixing” or a combination of both).

Glass fiber reinforced concrete has exceptionally high technological properties when forming products of almost any desired shape, any geometry, any relief, any texture.

SFB technology gives architects a powerful tool for realizing any ideas, because... in terms of ductility, the ability to convey surface relief, as well as lightness (products made from SFRC are thin-walled, i.e., light in weight), no other material can compete.

Fiber-reinforced concrete with alkali-resistant glass fiber has high flexural and tensile strength, and is also characterized by high impact strength and elasticity.

Glass fiber reinforced concrete is several times superior to ordinary concrete in terms of such indicators as crack resistance, fracture toughness, frost resistance, water resistance, and fire resistance.

The production of glass fiber reinforced concrete requires the use of special equipment for SFRC. These are stationary complexes STs-45 of the NST company. The task of the STs-45 is to feed the cement mortar under pressure into a special pneumatic spray gun, where the fiberglass is chopped into pieces of the required length, fluffed, mixed with the mortar and sprayed under pressure onto the mold. Today, the line of equipment for SFRC is represented by 2 types of complexes: with gerotor and peristaltic pumps.

Glass concrete structures according to the method of reinforcement are divided into the following types:

• With fiber reinforcement - only fiberglass is used;
• With combined reinforcement - glass fiber is used in combination with steel reinforcement.

The thickness of SFRC products, as a rule, is from 6...10 mm to 20...30 mm, so the cost of materials is minimal. One of the main advantages of products made of glass fiber reinforced concrete on a construction site is that, with increased strength characteristics, they are not heavy, their mass is not large.

Wall cladding panels made of glass fiber reinforced concrete during the reconstruction of old and construction of new buildings allow you to obtain an exclusive and beautiful facade. Decorative concrete gives buildings a cozy and comfortable appearance.

Time has no control over such a façade: even after 50 years it will remain the same: it will not crack or collapse. If, due to external influences, a facade element is mechanically damaged, it can always be replaced with a similar one (it is impossible to distinguish SFRC products obtained today and 10 years later from the same mold).

SFB perfectly withstands temperature changes and feels great at low temperatures. The NST company supplied STs-45 complexes to Chukotka, where they were used in the construction of schools. Protective SFB plaster was applied over the polyurethane foam thermal insulation. For what? Facades where conventional cement mortars are used are subject to destruction within a year, unable to withstand 50-degree frosts.

An important addition to cladding panels can be decorative elements semi-antique during restoration and reconstruction of buildings. Glass fiber reinforced concrete is also indispensable for framing window openings, making porticos, cornices, sun screens, etc.

Fiber cement is an excellent material for various types roofs. They can imitate traditional roofing materials, such as slate, ceramic tiles. But, unlike them, it is not fragile or heavy. To fasten it, ordinary slate nails are used without pre-drilling holes, since glass fiber reinforced concrete is durable and does not crack when fastened.

Glass fiber reinforced concrete panels of various textures

Glass fiber reinforced concrete plays an important role in the design of urban recreation areas from the aesthetic side of construction projects and small architectural forms. It can be used for arranging picturesque decorative ponds, fountains, benches, flower beds, balustrades, kiosks, etc. Small architectural forms made of glass fiber reinforced concrete have a more attractive appearance, because glass fiber reinforced concrete allows you to transfer any shape, relief and surface finish to combine with the surrounding landscape. Plaster coatings when using glass fiber reinforced concrete have high strength, as well as high resistance to cracking and peeling.

Glass cement is highly resistant to chemicals, including urban pollution and salt solutions. SFRC does not rust, does not rot, does not corrode and does not burn. Therefore, various products can be molded from fiber-reinforced concrete complex configuration, which are used in civil engineering in the construction of highways, bridges, overpasses, tunnels, parapets, noise barriers.

These elements can be quite long and light in weight. In addition, glass fiber reinforced concrete provides more high level protection of steel reinforcement and greater resistance to chloride penetration than concrete of the same thickness.

Elements of cable, drainage and irrigation channels made of glass fiber reinforced concrete can also be used as permanent formwork. In this case, glass fiber reinforced concrete elements are installed in place and then filled with concrete, while the role of glass fiber reinforced concrete is to form an internal channel profile with a smooth surface and eliminate the use of complex temporary formwork.

Fiber cement is an excellent material for the manufacture of elements of channels and water pipelines, because... It can be used to produce long and light segments, while short and heavy elements are cast from ordinary concrete. This is very important, because Reducing the weight of the pipe makes work easier when constructing drainage and irrigation systems on rough terrain.

Glass fiber reinforced concrete can also be used to make large diameter pipes. Reinforced with both chopped roving and mesh made of alkali-resistant fiberglass. The small thickness of the pipe walls and the absence of coupling connections makes it possible to reduce the size of the ditch and the volume of backfill. Pipelines can be laid under roads with heavy traffic load, because... glass fiber reinforced concrete is durable and has high strength properties.

The trends in modern architecture are such that the approaches responsible for the attractiveness and expressiveness of residential and public buildings are constantly being modernized and modified.

The current market is replete with all kinds of building materials, and you can constantly see interesting new products that immediately find their niche with the consumer. To such new building materials in lately can be safely classified as glass fiber reinforced concrete or abbreviated as SFRC.

SFRC is a modern composite composition based on fine-grained concrete; some call it artificial stone, which has unique operational and technical characteristics. What is it about glass fiber reinforced concrete that captivates the modern buyer and why has this building material gained such popularity among buyers?

Firstly, the price of SFRC is very affordable and acceptable for mass construction.

Secondly - high quality this building material is no longer in doubt and has been tested in practice.

And, thirdly, at this stage, glass fiber reinforced concrete has no worthy competitors among similar classified building materials.

Fiberglass concrete and its capabilities

The properties of glass fiber reinforced concrete as a modern building material are very impressive:

The plasticity of SFRC makes it possible to produce all kinds of decorative elements, volumetric and curved structures, large-sized panels and others. complex parts, as required by each individual architectural task;

Texture and color scheme glass fiber reinforced concrete offers almost the entire range of shades, moreover, it has qualities that do not allow the original color to change over time;

It is not subject to the appearance of any significant defects during operation, and the durable structure promises long service for more than one decade, which is confirmed by the test report;

Since glass fiber reinforced concrete (GFRC) is reinforced with glass fiber, it completely lacks such a component as metal, so it is not susceptible to corrosive processes;

Completely waterproof (W20);

Not afraid of fire, does not change its characteristics even in severe fire conditions, which is confirmed by tests;

The low weight of SFRC significantly outperforms all its construction competitors;

Frost-resistant - up to 500 cycles and higher if necessary;

Inert to chemical reagents;

SFB is a completely clean material from an environmental point of view, and it is also transparent to electromagnetic radiation;

It has unique qualities compared to ordinary concrete: impact resistance is 20 times higher, bending strength is 5 times higher, tensile strength is 5 times higher, and compression strength is 4 times higher. Seismically resistant.

GFRC (glass fiber reinforced concrete) has found wide application in the manufacture of decorative elements for building facades: columns, porticoes, capitals, pilasters, stucco decoration, sculptural elements. SFB is also used in landscape design and urban improvement.

Composition of glass fiber reinforced concrete

Already by the name we see that in this building material three components predominate:

1) sand as the main filler;

2) alkaline-resistant fiberglass;

3) high grade white cement. Various additives are also added to SFB to give color, texture, and additional characteristics.

Fiberglass reinforces concrete in such a way that the fiber is evenly distributed throughout the body of the material. As a result, we have a building material that has the properties and characteristics of each individual component. But in general, he is for everyone technical specifications better than ordinary concrete.

Technical characteristics of glass fiber reinforced concrete are given in the table

Physico-mechanical properties of SFRC (glass fiber reinforced concrete)