Proportions of broken glass in concrete. Glass concrete manufacturing technology and applications

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An alternative to concrete is glass concrete, which has greater strength, frost resistance and thermal conductivity. There are six types of glass concrete on the market, and they will be discussed in this article.

Each house is a unique structure with its own characteristics. Even if a standard project is used, factors such as the characteristics of the soil, the depth of its freezing, soil and air humidity, the prevailing wind and wind strength have to be taken into account during construction. To take into account means to make appropriate adjustments to the project.

For example, the increased seismic hazard of the region will require an increase in the total footage and diameter of the reinforcement, a decrease in its knitting step; with increased soil moisture, it is necessary to increase the layer of concrete around the reinforcement - in order to slow down its corrosion, etc. Sometimes such issues can be solved by replacing the calculated material with another one with more convenient and advantageous characteristics in this situation, or reduce the cost of construction due to equal-strength replacement of materials for cheaper ones.

In the cases described above, for example, an alternative to increasing the cost of the foundation by increasing the amount of material can be the use of glass concrete.

However, glass concrete is a very large group of building materials with different properties, so it is worth understanding the classification and properties of different types of glass concrete, their strengths and weaknesses, before settling on a particular type.

A common property for all glass concrete is concrete, in which glass in various forms is added as an integral part. The function of this additive determines the properties of the resulting material.

Glass concrete classification:

1. Glass-reinforced concrete (composite concrete);
2. Concrete with the addition of liquid glass;
3. Glass-filled concrete with fiber (glass fiber reinforced concrete);
4. Fiberglass concrete (translucent with optical fiber);
5. Glass-filled concrete with cullet;
6. Glass concrete with glass as a binder.

Glass concrete properties

Glass reinforced concrete (composite concrete)

In fact, this is an analogue of reinforced concrete, the technological difference is only in the replacement of a metal reinforcing bar with a fiberglass (composite) one. However, this type of concrete, precisely because of the replacement of reinforcement, differs in a number of properties.

It is necessary to take into account what exactly causes the need to reinforce concrete: this is its low tensile strength, bending, compression. This shortcoming eliminates reinforcement.

Now, the expensive (in every sense) metal reinforcing bar is being replaced by less expensive composite materials based on plastic, glass or basalt fiber. Fiberglass reinforcement is most in demand, although it is slightly inferior in strength to basalt, but it is much cheaper.

• Low weight of reinforcement: fiberglass reinforcement is 5 times lighter than steel reinforcement of the same diameter, and with equal strength diameter - almost 10 times.
• Fiberglass and basalt rebar are produced in the form of a bundle, rolled up into coils of 100 m each (coil weight from 7 to 10 kg), the diameter of the coil is about a meter, which allows it to be transported in the trunk of a car, that is, it is very convenient to transport and waste-free cutting, in contrast from a metal bar - heavier and requiring long-length freight transport.
• Fiberglass and basalt reinforcement is 2.5-3 times stronger in tension than steel of the same diameter, which allows replacing steel reinforcement with fiberglass with a smaller diameter without loss of strength (this is called equal-strength replacement).
• Fiberglass and basalt fittings have 100 times less thermal conductivity than metal and therefore are not cold bridges (thermal conductivity of glass fittings is 0.48 W/m2, thermal conductivity of metal fittings is 56 W/m2).

Glass-composite reinforcement is not subject to corrosion and is resistant to aggressive environments (although it is desirable to avoid strongly alkaline environments). This means that it does not change its diameter, even if it is in a humid environment. And metal reinforcement, as you know, with poor waterproofing of concrete, can corrode until it is completely destroyed. At the same time, corroded metal reinforcement due to oxides increases in volume (almost 10 times) and is itself capable of breaking a concrete block.

As a result, it is possible to safely reduce the thickness of the protective layer of concrete blocks reinforced with fiberglass. After all, the large thickness of the protective layer was due to the need to protect the steel reinforcement from moisture impregnating the top layer of concrete, and thereby prevent possible corrosion. Reducing the thickness of the protective layer, together with the low weight of the reinforcement itself, leads to a significant reduction in the weight of the structure without reducing its strength.

And this is, firstly, a reduction in the price of a glass concrete structure; secondly, reducing the weight of the entire building; thirdly, reducing the load on the foundation - and additional savings on the size of the foundation.

Glass-reinforced concrete is stronger, warmer and cheaper.

Concrete with the addition of liquid glass

Liquid silicate sodium (rarely potassium) glass is added to concrete in order to increase resistance to moisture and high temperatures and has antiseptic properties, therefore it is recommended to use it when pouring foundations on swampy soils and in hydraulic structures (wells, waterfalls, pools), and to increase heat resistance - when installing fireplaces, boilers and sauna stoves. In fact, here the glass acts as a binder.

There are 2 ways to use liquid glass to improve the properties of concrete:

1. Glass, diluted with water to the desired proportion, closes the dry mixture. For 10 liters of finished waterproof concrete, 1 liter of liquid glass is introduced. The water used to dilute liquid glass is not taken into account and does not affect the volume of water required for concrete mixing, since it is completely spent on the chemical reactions of glass and concrete to form compounds that prevent the top layer of concrete from getting wet.

The addition of undiluted glass (or even its solution in the required dilution) to an already prepared mixture worsens the properties of concrete, leading to cracking and increased brittleness.

1. Application of liquid glass in the form of a primer (waterproofing) on ​​the surface of the finished concrete block. However, it is better to apply another layer of cement mixture containing liquid glass after such a primer. In this way, ordinary concrete products can also be protected from moisture (the main thing is to apply a primer and plaster layer no later than a day after pouring, or chip and pre-wet the surface, otherwise the adhesion of the layers will be weak).

The addition of liquid glass increases the curing rate of the finished concrete mixture (it hardens in 4-5 minutes), and the faster, the more concentrated the glass solution was. Therefore, such concrete is prepared in small portions, and the glass must be diluted with water.

Glass-filled concrete with fiber (glass fiber reinforced concrete)

Concrete reinforced with alkali-resistant fiberglass (fiber) is called glass fiber reinforced concrete. This is a universal building material that allows the production of both monolithic blocks and sheet material (glass-cement sheet, in fact, a technological analogue of slate), now sold under the brand name "Japanese wall panels".

The properties and qualities of the material can change under the influence of additives or a change in the amount of additives: acrylic polymers, quick-setting cement, dyes, etc. Glass fiber reinforced concrete is a water-resistant, lightweight and very durable material with valuable decorative properties.

The material consists of fine-grained concrete-matrix filled with sand (no more than 50%) and pieces of glass fiber (fiber). In terms of compressive strength, such concrete is twice as strong as usual, in terms of bending and tensile strength, on average, 4-5 times (up to 20 times), impact strength is 15 times higher.

Improved chemical resistance and frost resistance. However, filling concrete with fiber is a rather complicated process, since the fiber must be distributed evenly. Introduce it into the dry mixture. Filling with fiber increases the rigidity of the mixture, it is less plastic, compacts worse, and requires mandatory vibrocompaction in a large layer. Sheet materials are produced by spraying and spraying.

Fiberglass concrete (Litrakon)

It is made on the basis of concrete-matrix and specially oriented long glass (including optical) fibers.

Optical fibers penetrate the block through and through, the reinforcing fibers are randomly located between them. As a result of grinding, the ends of the optical fibers are freed from cement laitance and can conduct light with virtually no loss.

The level of transparency and color reproduction of the material depends on the number and location of optical fibers. At the same time, the thickness of the block can, if necessary, be increased to ten meters - as much as the optical fiber allows, and it can, of course, be of any length.

The material is still very expensive, about $ 1,000 per square meter, but developments are underway to reduce its cost. Has glass fittings. The material can be imitated at home if there is an optical fiber and patience, but not as a building material, but rather as a decorative one.

Glass-filled concrete with cullet

This type of concrete saves on filling materials, replacing sand and gravel with cullet and closed glass containers (tubes, ampoules, balls). Moreover, crushed stone can be replaced by glass by 20–100%, without loss of strength and with a significant reduction in the weight of the finished block.

Glass concrete with glass as a binder

As a rule, this type of concrete is for industrial production: it is manufactured at enterprises and used in them, because it has high acid resistance and relatively low alkali resistance.

Glass is sorted, crushed and ground, and then sifted through screens, divided into fractions. Particles larger than 5 mm are used as coarse aggregate, less than 5 mm instead of sand, and finely ground powder as a binder.

However, if it is possible to finely grind glass, this concrete can be made independently.

Glass powder, when mixed with water, does not show binding properties in itself, a catalyst is needed. In an alkaline environment (soda ash), cullet dissolves, forming silicic acids, which soon begin to turn into a gel. This gel binds aggregate fractions and after curing (at normal or elevated temperature, it depends on the properties of glass and filler), a durable and strong silicate conglomerate is obtained - acid-resistant glass concrete.

It is possible to manufacture concrete in a concrete mixer only on a silicate binder. First, dry components are mixed for 4-5 minutes (sand, crushed stone, ground filler and hardener (sodium silicate fluoride), then liquid glass with a modifying additive is poured into a rotating concrete mixer. The mixture is mixed for 3-5 minutes, until homogeneous. The viability of the mixture on this binder will be only 40-45 min.

Such concrete is not inferior in its construction properties to materials made from traditional binders, while surpassing them in biostability, thermal conductivity, and acid resistance. This is important if the soils on which the foundation is laid are acidic.

Glass concrete is widely used and, due to its properties, is in great demand for the production of finishing panels, gratings, fences, walls, partitions, ceilings, decor, complex architectural or transparent roofs, pipes, noise barriers, cornices, tiles, cladding and many other products. Having mastered the technology of making glass concrete with your own hands, you can significantly save on construction and create a unique design for your home.

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However, the expansion of the extraction of the main types of concrete aggregates cannot always be realized. Deposits of non-metallic materials such as building stone, sand and gravel mixtures and building sands cannot always be used, since they are built up, located in floodplain terraces of rivers or in other protected areas. At the same time, household and industrial cullet, which is not currently marketed, but has high strength characteristics and availability, is practically not used as a concrete filler. In our country, about 35-40 million tons of municipal solid waste is generated annually, while only 3-4% of MSW is recycled. The amount of cullet for different territories is 6-17 wt. %. The annual volume of cullet that ends up in solid domestic waste landfills is 2-6 million tons. Compared to the annual need for aggregates, this value is small, but it is necessary to take into account the environmental effect not only from the disposal of the MSW component, but also the possibility of reducing the extraction of natural resources when replacing on raw materials of anthropogenic origin. In addition, the use of waste is 2-3 times cheaper than natural raw materials, fuel consumption when using certain types of waste is reduced by 10-40%, and specific capital investments by 30-50%.

However, the problem of the interaction of soda-lime silicate glass with cement stone creates serious problems when using cullet as an effective filler in cement composite materials. The same can be said about many glass-containing materials - mineral and glass fibrous materials (wool), fiberglass, foam glass, which could be used as effective aggregates in cement compositions.

As a result of the alkali-silicate reaction, a gel is formed, which swells in the presence of moisture, leading to the formation of cracks and the destruction of concrete. This reaction can also occur in ordinary concrete if the naturally occurring filler contains reactive (usually amorphous) silica. On the one hand, the glass filler promotes the alkali-silicate reaction in concrete due to the fact that glass contains Na + on the surface, which can create a certain concentration of NaOH in the cement composition even in the absence of alkali in the original cement, and on the other hand, it is glass that contains compounds on the surface silicon oxide in amorphous form. Known studies of soda-lime glass as a cement paste filler. In this case, cullet of various composition and dispersion was added to the cement composition, and the expansion and strength of the resulting concrete were mainly investigated. So research was carried out at Columbia University (USA) by Professor S. Meyer. It was found that the addition of glass to the composition in most cases leads to the process of alkali-silicate interaction and a decrease in strength. Also studies of the effect of temperature and glass composition on the process were carried out. Highly dispersed glass powders have been found to result in no sample expansion. The authors make an assumption about the high rate of the alkali-silicate reaction in this case, which leads to the completion of the process in 24-28 hours, as a result of which the expansion and destruction of the samples cannot be recorded in the future. It can be assumed that as possible ways to suppress the process of alkali-silicate interaction in glass-cement compositions, the authors propose the use of glass of a certain granulometric composition, the addition of fine glass, and the modification of the composition by adding lithium or zirconium compounds.

Rice. one. The dependence of the strength of concrete compositions on the size of the glass filler in different periods of time with and without additional alkali in the composition: 1 - at the age of 13 weeks without alkali; 2 - at the age of 1 week without alkali; 3 - at the age of 13 weeks

In this paper, various options for suppressing the alkali-silicate interaction were considered when using glass cullet and its processing product, foam glass, as fillers.

The experiments were carried out in accordance with ASTM C 1293-01 at elevated temperature. To do this, standard samples of concrete 250 mm long were kept at a temperature of 60°C for three months. Samples were periodically removed from the oven to control expansion. After the sample was cooled to room temperature, its length was measured using an optical dilatometer. The strength control of the samples was carried out on an IP 6010-100-1 compression test machine. For the manufacture of samples, standard cement M400 produced by the Pashiysky cement plant was used. Cullet was obtained by crushing in a hammer mill followed by grinding in a vibrocentrifugal mill VCM_5000. Used granulated foam glass produced by CJSC "Penosital" (Perm).

To assess the intensity and depth of the alkali-silicate reaction, a number of experiments were carried out on the interaction of cement material with glass of various fractions, both in the absence of additional free alkali in cement and in its presence. The main parameter characterizing the course of the reaction is the expansion of samples of concrete composites. An indirect confirmation and consequence of this reaction was a decrease in the strength characteristics of the obtained concretes. As reference samples, in which the reaction should not proceed, concretes with a crystalline filler - quartz sand were taken.

It was revealed that a significant expansion of the samples, characteristic of the alkali-silicate interaction, is observed only in concretes with large maximum of the studied fractions, more than 1.25 mm, and the effect is enhanced with the additional introduction of alkali into the composition of concretes. The dependence of compressive strength on the holding time of concretes made it possible to reveal an abnormally high strength value for samples of alkali-free concretes when using fillers of both the minimum and maximum investigated fractions. Moreover, the strength of the resulting concretes significantly exceeds the strength of concretes without glass filler. This feature suggests a significant effect of the size of the filler fraction on the strength of the resulting concrete. The corresponding dependences of concrete strength on the filler fraction in the initial and final periods of cement stone formation are shown in Fig. one.

On all curves, a pronounced minimum can be traced, corresponding to the filler fraction 0.1-0.3 mm. The nature of the dependences of strength on the dispersion of the filler remains unchanged - with a steep increase in the area of ​​decreasing the size of the filler and a smooth increase in the area of ​​increasing the size of the filler particles when using alkali-free compositions and a slight increase and stabilization of strength in the area of ​​increasing the size of the filler particles when using alkaline compositions. Over time, the nature of the curves does not change, but they shift upward - to higher strength characteristics as the cement stone hardens.

Therefore, the use of coarse cullet - preferably 1.2 mm or more - is possible as a filler in concrete, and the strength of these composites exceeds the strength of ordinary concrete on sand aggregate. However, when using such aggregates, there are at least two problems associated with the possibility of alkali-silicate interaction. Firstly, the presence of free alkali in cement or other concrete components inevitably leads to the occurrence of alkali-silicate interaction and a decrease in the strength characteristics of concrete. Secondly, in the process of large-tonnage production, it is difficult to prevent spontaneous crushing and abrasion of a large fraction, which will also inevitably lead to a decrease in the quality of the resulting concrete. When the filler particle size is less than 50 microns, an abnormal increase in strength occurs, which significantly exceeds the strength of compositions on a standard quartz sand filler. Such an increase in strength can be explained by the ability of dispersed glass to enter into the processes of formation of new phases during the formation of cement stone due to the high specific surface area of ​​glass powders. This feature of highly dispersed glass can be used both to suppress the process of alkali-silicate interaction in those concrete compositions when the reaction takes place, and to create binders based on dispersed glass.

The problem of large fractions of cullet with a high content of alkali, as a filler in concrete, can be partially solved with additional suppression of the reaction of alkali-silicate interaction. For this, two easily implemented technological ways are outlined.

Rice. 2. Concrete with aggregate of foam glass gravel at various degrees of filling: a) ratio (mass.) foam glass / (cement + sand) 0.265; b) ratio (wt.) gravel/cement 1.6

Glass concrete is a very flexible, resilient and high-strength material, which, while remaining concrete, is nevertheless unusually light, since it lacks both coarse aggregate and metal reinforcement. In a previous publication, we talked about what types of glass concrete are known today, i.e. on the classification of glass concrete. Today's publication is devoted to the analysis of the characteristics and properties of various types of glass concrete.

composite concrete

In other words, composite concrete is glass-reinforced concrete. In fact, this is an analogue of reinforced concrete, the technological difference is only in the replacement of a metal reinforcing bar with a fiberglass (composite) one. However, this type of concrete, precisely because of the replacement of reinforcement, differs in a number of properties:

Low weight of reinforcement, because fiberglass reinforcement is 5 times lighter than steel reinforcement of equal diameter;

Fiberglass and basalt rebar are produced in the form of a bundle, rolled into coils of 100 m each (coil weight from 7 to 10 kg), the diameter of the coil is about a meter, which allows it to be transported in the trunk of a passenger car. Thus, fiberglass reinforcement is convenient to transport, unlike a metal bar, which is very heavy and requires long trucks;

Fiberglass and basalt reinforcement is 2.5-3 times stronger in tension than steel of the same diameter. This allows you to replace steel reinforcement with fiberglass with a smaller diameter without loss of strength. This is called equal strength replacement;

Fiberglass and basalt fittings have 100 times less thermal conductivity than metal and therefore are not a cold bridge (thermal conductivity of glass fittings is 0.48 W/sq.m, and thermal conductivity of traditional fittings is 56 W/sq.m);

Glass-composite reinforcement is not subject to corrosion and is resistant to aggressive environments (although it is desirable to avoid strongly alkaline environments). This means that it does not change its diameter, even if it is in a humid environment. And metal reinforcement, as you know, with poor waterproofing of concrete, can corrode until it is completely destroyed. At the same time, corroded metal reinforcement due to oxides increases in volume (almost 10 times) and is itself capable of breaking a concrete block.

As a result, it is possible to safely reduce the thickness of the concrete cover of glass-reinforced blocks. After all, the large thickness of the protective layer was due to the need to protect the steel reinforcement from moisture impregnating the top layer of concrete, and thereby prevent possible corrosion. Reducing the thickness of the protective layer, together with the low weight of the reinforcement itself, leads to a significant reduction in the weight of the structure without reducing its strength. And this gives a significant reduction in the price of a glass concrete structure and a reduction in the weight of the entire building, reducing the load on the foundation. In addition, glass-reinforced concrete is stronger, warmer and cheaper.

Concrete with the addition of liquid glass

Liquid silicate sodium (rarely potassium) glass is added to concrete in order to increase resistance to moisture and high temperatures and has antiseptic properties, therefore it is recommended to use it when pouring foundations on swampy soils and in hydraulic structures (wells, waterfalls, pools), and to increase heat resistance - when installing fireplaces, boilers and sauna stoves. In fact, here, glass acts as a binder.

There are 2 ways to use liquid glass to improve the properties of concrete:

1. Glass, diluted with water to the desired proportion, closes the dry mixture. For 10 liters of finished waterproof concrete, 1 liter of liquid glass is introduced. The water used to dilute liquid glass is not taken into account and does not affect the volume of water required for concrete mixing, since it is completely spent on the chemical reactions of glass and concrete to form compounds that prevent the top layer of concrete from getting wet.

The addition of undiluted glass (or even its solution in the required dilution) to an already prepared mixture worsens the properties of concrete, leading to cracking and increased brittleness.

2. Application of liquid glass in the form of a primer (waterproofing) on ​​the surface of the finished concrete block. However, it is better to apply another layer of cement mixture containing liquid glass after such a primer. In this way, ordinary concrete products can also be protected from moisture (the main thing is to apply a primer and plaster layer no later than a day after pouring, or chip and pre-wet the surface, otherwise the adhesion of the layers will be weak).

The addition of liquid glass increases the curing rate of the finished concrete mixture (it hardens in 4-5 minutes), and the faster, the more concentrated the glass solution was. Therefore, such concrete is prepared in small portions, and the glass must be diluted with water.

Glass-filled concrete with fiber (glass fiber reinforced concrete)

Concrete reinforced with alkali-resistant fiberglass (fiber) is called glass fiber reinforced concrete. It consists of fine-grained concrete-matrix filled with sand (no more than 50%) and pieces of glass fiber (fiber). In terms of compressive strength, such concrete is twice as strong as usual, in terms of bending and tensile strength, on average, 4-5 times (up to 20 times), impact strength is 15 times higher.

Fiberglass concrete has high chemical resistance and frost resistance. However, filling concrete with fiber is a rather complicated process, since the fiber must be distributed evenly. Introduce it into the dry mixture. Filling with fiber increases the rigidity of the mixture, it is less plastic, compacts worse, and requires mandatory vibrocompaction in a large layer. Sheet materials are produced by spraying and spraying.

Fiberglass concrete

This material is also called Litracon, after the name that this material received from its inventor, the Hungarian architect Aron Losonci.

It is made on the basis of concrete-matrix and specially oriented long glass (including optical) fibers. The level of transparency and color reproduction of the material depends on the number and location of optical fibers. At the same time, the thickness of the block can, if necessary, be increased to ten meters - as much as the optical fiber allows, and it can, of course, be of any length. The material is still very expensive, about $ 1000 per square meter, however, developments are underway to reduce its cost.

Glass-filled concrete with cullet

This type of concrete saves on filling materials, replacing sand and gravel with cullet and closed glass containers (tubes, ampoules, balls). Moreover, crushed stone can be replaced by glass by 20–100%, without loss of strength and with a significant reduction in the weight of the finished block. As a rule, this type of concrete is for industrial production: it is manufactured at enterprises and used in them, because it has high acid resistance and relatively low alkali resistance.

Glass concrete with glass as a binder

Glass is sorted, crushed and ground, and then sifted through screens, divided into fractions. Particles larger than 5 mm are used as coarse aggregate, less than 5 mm instead of sand, and finely ground powder as a binder. However, if it is possible to finely grind glass, this concrete can be made independently.

Glass powder, when mixed with water, by itself, does not show astringent properties, a catalyst is needed. In an alkaline environment (soda ash), cullet dissolves, forming silicic acids, which soon begin to turn into a gel. This gel binds aggregate fractions and after curing (at normal or elevated temperature, it depends on the properties of glass and filler), a durable and strong silicate conglomerate is obtained - acid-resistant glass concrete.

This type of glass concrete can also be made in the Tako2 concrete mixer. It is possible to produce concrete in a concrete mixer only on a silicate binder. First, dry components are mixed for 4-5 minutes (sand, crushed stone, ground filler and hardener (sodium silicate fluoride), then liquid glass with a modifying additive is poured into a rotating concrete mixer. The mixture is mixed for 3-5 minutes, until homogeneous. The viability of the mixture on this binder will be only 40-45 min Such concrete is not inferior in its properties to materials made from traditional binders, while surpassing them in biostability, thermal conductivity, acid resistance.This is important if the soils on which the foundation is laid have an acidic reaction.

Glass concrete is widely used and, due to its properties, is in great demand for the production of finishing panels, gratings, fences, walls, partitions, ceilings, decor, complex architectural or transparent roofs, pipes, noise barriers, cornices, tiles, cladding and many other products.

Currently, one of the alternatives to plain concrete is glass concrete. This building material differs from ordinary concrete in greater strength, frost resistance and thermal conductivity. Today there are 6 types of glass concrete on the market, each of which has its own differences and features. The material can be made independently at home, while its properties will be at the highest level.

A bit of history

On the one hand, there is concrete, which causes pollution, in particular due to the cement used in its composition. On the other hand, there is glass waste that can be completely recycled using a complex and costly process. The solution to encapsulate glass in concrete came from the Ellen MacArthur Foundation following a series of studies published in October 2016.

Concrete is one of the widely used building materials in the world. In the United States, where the study was conducted, 600 million tons of concrete were produced in 2015. However, it is one of the materials with the highest negative environmental impact due to the cement used to make it.

To reduce carbon emissions, the concrete industry has begun using two main cement substitutes: coal ash and slag, a by-product of steel production. These substitutes have reduced carbon emissions by 25 to 40% per tonne of concrete, increased strength and reduced costs.

But these replacements aren't ideal: they contain the heavy metal mercury, which makes them potentially toxic. Producers and users are still dependent on fossil fuels:“As more and more companies try to reduce their carbon footprint and use renewable energy, the use of fossil fuel by-products in their factories is increasingly seen as counter-intuitive and controversial,” writes Ellen MacArthur Foundation PhD.

At the same time, solving the problem of glass waste is becoming increasingly problematic. Americans fail to reuse glass after consumption - 11 million tons per year. Only one third is recycled and the rest goes straight to landfills. While glass is 100% recyclable, the study says more US cities are phasing out their recycling programs - mainly for financial reasons: sorting glass is difficult and costly.

General description and classification

Each building is a unique structure with its own characteristics. Even if a typical design is used during construction, some factors must be taken into account, for example, soil characteristics, the depth of its freezing, soil and air moisture, available wind and its strength. Taking into account these nuances, you will have to make some adjustments to the construction project.

So, if there is an increased seismic hazard in the area of ​​\u200b\u200bthe building, then it is necessary to increase the total footage and diameter of the reinforcement, as well as reduce the distance of its knitting. If the soil moisture at the site of the future building is too high, it will be necessary to increase the layer of concrete near the reinforcement, slowing down corrosion. In some cases, such problems are solved by replacing the calculated material with another one that has more convenient and advantageous characteristics. It is possible to make construction cheaper due to the equal replacement of building materials with more budgetary ones.

For example, an alternative option for an expensive foundation by increasing the quantity may be the use of glass concrete. However, it is worth paying attention to the fact that it includes a huge group of building materials that differ in properties, so you need to be able to understand their classification and characteristics of various types. You will also have to familiarize yourself with the strengths and weaknesses of concrete before making a choice in favor of a particular type.

Each type of glass concrete has its own properties and characteristics. Depending on this, it is worth starting when choosing a building material.

Glass reinforced concrete

This type of concrete is called composite concrete, which is an analogue of reinforced concrete. In this case, the metal reinforcing bar is replaced with fiberglass. Due to the replacement of reinforcement, composite concrete has a number of distinctive properties.

At present, the expensive metal reinforcing bar has been replaced by more budgetary composite materials made on the basis of plastic, basalt fiber or glass. In construction, the greatest demand is for fiberglass reinforcement, which, although inferior to basalt in strength, is much cheaper. Main characteristics:

• Light weight.
• Basalt and fiberglass rebars are made in the form of bundles, which are rolled into a 100 mm coil.
• Basalt fiberglass reinforcement has 100 times less thermal conductivity than metal, due to which it is not considered a cold bridge.

The glass composite material is not subject to various corrosions and is very resistant to aggressive environments, although experts recommend avoiding highly alkaline environments.

This means that the rebar does not change in diameter, even if a humid environment prevails around. Metal material with poor waterproofing of concrete can completely collapse. Metal reinforcement that has undergone corrosion begins to increase in volume by almost 10 times, which can break the concrete.

Thanks to this, it is possible to safely reduce the protective layer of concrete blocks. reinforced with fiberglass. The large thickness of the protective layer is due to the function of protecting the steel reinforcement from high humidity, which impregnates the upper concrete layer, thereby preventing all possible corrosion.

When the thickness of the protective layer decreases, together with the small weight of the reinforcement itself, the weight of the entire structure also decreases, without reducing the strength index. This reduces the cost of the material, the weight of the entire structure, as well as the load on the foundation. Thus, glass-reinforced concrete is inexpensive, warmer and stronger.

With the addition of liquid glass

Liquid silicate soda glass is added to glass concrete blocks to increase resistance to high humidity and high temperatures. In addition, the material is characterized by the presence of antiseptic properties, so it is best used for pouring foundations in swampy areas, as well as in the construction of hydraulic structures:

• decorative ponds;
• pools;
• wells and more.

To increase heat resistance, such blocks are used during the arrangement of boilers, stoves and fireplaces. In this case, glass is the connecting element.

Glass fiber reinforced material

Thanks to this versatile material, it is possible to produce monolithic blocks and sheet materials, which are currently purchased on the market under the brand name "Japanese wall panels".

The characteristics and qualities of this building material may change under the influence of certain additional elements or depending on the change in the amount of dyes, acrylic polymers and other additives. Fiberglass reinforced concrete is a strong, lightweight and water resistant material that has a number of valuable decorative qualities.

Glass fiber reinforced concrete includes a fine-grained concrete matrix, which is filled with sand, as well as pieces of glass fibers, which are called fibers.

Litracon, or fiberglass concrete

The main material in the manufacture is a concrete matrix, as well as oriented long glass fibers, including optical ones. They pierce through the block, and the reinforcing fibers are located between them in a chaotic manner. After grinding, the ends of the optical fibers are released from the cement laitance and can pass light through them almost without loss.

At present, the material is expensive. For one square meter of fiberglass concrete, you will have to pay about $ 1,000. But experts continue to work to reduce the cost. The building material has glass fittings. It can be imitated independently at home, if you find an optical fiber and be patient, but in this case it will not act as a construction, but, most likely, decorative.

With glass break

Thanks to this type of concrete, you can save a lot on filling materials. by replacing sand and gravel with cullet and closed glass containers:

• ampoules;
• balls;
• tubes.

Crushed stone can be replaced with glass by 100%, without losing strength, and the weight of the finished block will be much less than conventional glass concrete. Beer bottles inside concrete are suitable for making this material at home.

With binder

Glass concrete with glass as a binder is used for industrial production.

At the beginning of the process, the glass is sorted and finely crushed, after which it passes through the screen and is divided into fractions. Glass particles with a size of more than 5 mm are used for the manufacture of glass concrete as a coarse aggregate, and smaller grains act as a binder powder. If at home it is possible to finely grind glass, concrete can be made independently.

For decorative purposes

Glass concrete for decorative finishes is used in different ways. Typical surface treatment, sandblasting or diamond polishing can be applied. Glass particles are monolithically mixed with concrete, but more often they are applied to the surface of fresh concrete. This method is used to add uniqueness to the floor in a room.

A logical assumption might be that decorative glass concrete would be made from recycled glass bottles, but this is not the case. Recycled glass has too many contaminants. For this, objects such as windows, glasses and mirrors are used.

Manufacturers do not use "dirty" glass containers and glass with stickers. Recycled glass is sorted by color, but it can also be mixed with each other. In any case, it melts and crushes, and is not quenched by water (which breaks glass badly). The material is then sorted by size and the edges are blunted.

Glass concrete can be bought in 20 different colors, the most expensive being red. For one bag you will have to pay $ 150.

Currently, glass concrete is widely used, and due to its unique characteristics, it is in demand in the manufacture of finishing panels, fences, gratings, partitions, decor and other products. If you master the technique of making glass concrete with your own hands at home, you can save a lot of money and create a unique design in your home.

In the construction industry, concrete mixes are used, which, after hardening, have increased strength. To perform special tasks, various additives are added to concrete that change its characteristics. One of the common components is liquid glass for concrete. It reduces the duration of the concrete mixture hardening, increases the resistance of the monolith to moisture, acids, and elevated temperatures. It is important to properly mix the concrete and glass to ensure that the required material characteristics are achieved. Let's take a closer look at this supplement.

Why add liquid glass to concrete

Getting to know the material

Many have heard that the construction industry uses an additive called liquid glass. However, not everyone has an idea of ​​what it is. The ingredient in question is potassium and sodium silicates dissolved in water, obtained from silica. Almost everyone has encountered an aqueous solution of silicates, using silicate glue for domestic purposes. The material is visually perceived as a viscous liquid with a whitish-yellow hue. Let us dwell on the manufacturing technology, according to which the material is classified by type.

General classification

Modern technology allows you to get the additive in various ways. The component can be produced by high-temperature processing of silicon raw materials together with an aqueous solution of sodium hydroxide. The equipment makes it possible to obtain an ingredient with desired properties by sintering soda with quartz particles. You can also use the method of mixing silicon dioxide with an alkali solution.

Depending on the manufacturing characteristics, two types of ingredients are obtained:

• sodium mixture, characterized by increased adhesion, adhesive properties, resistance to atmospheric factors;
• potassium composition, characterized by accelerated drying, as well as good resistance to elevated temperatures.

The performance characteristics of both types of materials are identical, but the sodium composition has a lower price.

Additive in concrete - sodium liquid glass

Why add liquid glass to concrete

The use of a silicate solution introduced into the concrete mixture at the stage of preparation, as well as the external treatment of the concrete surface, changes the properties of concrete.

After liquid glass is introduced, concrete acquires additional characteristics:

• resistance to moisture penetration. Due to the increased water resistance, the monolith modified with a special additive is in demand for foundations, underground structures;
• high temperature resistance. This allows the use of a modified cement composition for the manufacture of fireplaces and the construction of stoves, the masonry of which is exposed to open fire;
• the ability to freeze in a limited time. With an increased concentration of sodium silicate in the working solution, the concrete mixture hardens at an accelerated rate, which is important for sealing various cavities;
• resistance to acids. The introduction of a silicate solution into the concrete composition increases the resistance to aggressive environments, which is important for the use of concrete in the chemical industry.

To ensure the required characteristics, mixing concrete with liquid glass, the proportions must be strictly observed.

Liquid glass in concrete - pros and cons

Just like all building materials, the additive has its advantages and disadvantages.

What gives liquid glass when added to concrete

Additive Benefits:

• low price of building materials;
• low additive consumption;
• resistance to atmospheric factors;
• durability of the protective film;
• ease of use when injected into concrete and surface application;
• good adhesion to mineral substrates.

In addition, the silicate component has:

• increased hydrophobic properties. As a result of creating a waterproof layer, moisture absorption is difficult;
• high antiseptic properties. The additive prevents the development of bacteria, hinders the growth of microorganisms;
• antistatic properties. The characteristics of the silicate additive prevent the accumulation of static electricity;
• ability to seal cracks on the surface. This ensures that the array is waterproof;
• resistance to open flame, acids, high temperature. The processed material retains its structure and properties.

Along with the advantages, there are weaknesses:

• accelerated crystallization of the modified composition during the implementation of measures for waterproofing foundations;
• the impossibility of using for the treatment of surfaces of buildings made of bricks;
• insufficiently high strength properties of the protective film, which is destroyed by mechanical action.

Among the insulating materials, liquid glass for concrete stands out.

Despite the existing shortcomings, the additive is widely used by professional builders, private developers, and home craftsmen to solve an extended range of problems.

The use of liquid glass in concrete - areas of use

Workers in the construction industry, the repair industry actively use silicate solutions based on sodium and potassium. They increase the performance of the monolith, which allows it to be used for various purposes.

Applications of the silicate modifier:

• sealing cracks and cavities through which moisture penetrates;
• exterior decoration of the walls of the building to increase their moisture resistance;
• waterproofing masonry basements;
• moisture protection of basements, hydraulic facilities;
• preparation of special compositions for priming concrete surfaces;
• construction of foundations for the installation of heating equipment;
• production at industrial enterprises of special types of concrete;
• construction of foundations for various objects;
• protection of the walls of residential and utility rooms from the development of mold, fungal colonies;
• processing of joints and internal surfaces of well rings.

Liquid glass is sold in plastic cans

According to its characteristics, the component has practically no analogues when performing work related to waterproofing and impregnation. The properties of the silicate material make it possible to provide reliable protection of concrete structures from moisture, elevated temperatures, and aggressive environments.

How much liquid glass to add to concrete - proven recipes

Consider how much silicate component should be poured into the concrete mixture to perform various tasks.

For the preparation of modified cement mortars and concrete, use the following recommendations:

• masonry mixture for the construction of fireplaces, stoves is prepared from Portland cement and fine sand, observing a ratio of one to three. 18–20% of the glass of the total volume of the mixed components should be poured into the sand-cement mixture, after which water should be added. It remains to mix everything thoroughly until smooth, and the finished solution can be used;
• for the preparation of a concrete base with moisture-resistant properties, refractory characteristics and intended for domestic use, the concentration of the additive should not exceed one tenth of the total mass. Such a composition can also be used for waterproofing home pools;
• for waterproofing the joints of well rings and processing the inner surface, a composition is prepared consisting of Portland cement, glass, and sifted sand. It is very important to keep the proportion, adding the ingredients in equal proportions. With the gradual addition of water, it is necessary to achieve a creamy consistency.

Subject to the proportions, the concrete solution acquires the required properties.

Liquid glass as an additive for concrete

Correctly fill liquid glass - the additive in concrete does not tolerate mistakes

There are situations when the introduction of glass does not bring the expected result. This is due to the lack of practical experience, non-observance of proportions.

• it is forbidden to introduce a silicate additive into the prepared concrete solution. You must first mix the ingredients, then dilute the glass with water. Then it is necessary to gradually pour the solution, mixing thoroughly;
• control the percentage of added components, do not exceed the proportions tested in practice. This ensures that the required performance properties of concrete are obtained.

Remember that an increased concentration of silicate filler, as well as a reduced one, negatively affects the properties of concrete.

We introduce liquid glass into concrete - rules of work

To ensure the desired effect from the use of the additive, it is necessary to study the rules for working with a silicate additive, as well as prepare the necessary tools.

Waterproofing with liquid glass

For surface treatment of a concrete mass, you will need:

• a wide roller that allows you to speed up the application of a protective composition;
• a brush for treating small areas and corner areas with a silicate mixture;
• metal brush for preparing the treated surface;
• an airbrush that allows you to apply the material when performing work on an industrial scale;
• a container for mixing ingredients and preparing special mortars;
• protective gloves that protect the skin from contact with the silicate component.

General rules of work provide:

1. Thorough cleaning of the treated surface from contamination of organic and inorganic origin.
2. Sealing deep cracks and leveling the surface using concrete putty.
3. Layer-by-layer application of the material using a wide roller, brush or industrial spray gun.

When applying a coating in two layers, it penetrates deep into the array by 1.5–2 mm. The modifying composition does not contain harmful components, however, the skin should be washed with water if a silicate solution gets on its surface. After completion of work, it is necessary to inspect and clean the tool from the remnants of the silicate mixture.

It is possible to introduce the additive into the concrete solution at the preparation stage. To do this, it is necessary to gradually add liquid glass for concrete to the concrete mixer or container. The instructions for use must be followed to ensure the required characteristics of the concrete.

How to cover a concrete floor with liquid glass

To prepare a modified concrete composition, you will need the following tools:

• a special nozzle for a drill that increases the efficiency of mixing components;
• a container for mixing components using a nozzle or a small-sized concrete mixer;
• personal protective equipment that protects the skin and mucous membranes from the ingress of additives.

The algorithm for preparing the modified concrete composition includes the following operations:

1. Dosing of ingredients in the required ratios.
2. Adding an aqueous solution of a special additive to the concrete mixture.
3. Preparation of concrete mixture according to the recipe.
4. Thorough mixing of the components until a homogeneous consistency.

When pouring liquid glass into concrete on your own, the proportions must be strictly observed. Exceeding the amount provided for by the recipe will cause accelerated drying of the concrete with the appearance of cracks. Adding a reduced volume to liquid glass concrete will not provide the required performance.

Conclusion

To ensure the required performance characteristics of concrete, observe the proportions for concrete when pouring liquid glass. Guided by the recommendations of professionals, following a proven recipe, it is possible to ensure the necessary working properties of the monolith. Due to the cheapness of the silicate additive, the cost of the concrete solution increases very slightly, and the performance characteristics allow the use of modified concrete to solve a wide range of construction tasks. Professional advice will help you avoid mistakes.