Is it possible to use broken glass for filling? Glass containers in construction

What is glass concrete?


Traditionally, concrete is used as the main building material. We are used to this, and not always by design new project, we study modern developments. Concrete is familiar and accessible. But there are situations in which it is worth paying attention to new products in the construction industry. These rightfully include glass concrete (glass-filled composite), the distinctive feature of which is increased tensile strength. This makes concrete structures much stronger. But to figure out which glass concrete option you should choose, check out distinctive features each type.

Varieties

Depending on the form in which the composition is modified by glass, glass concrete can be of the following types:

  • glass reinforced concrete;
  • composition with the addition liquid glass;

Glass concrete is a very flexible, elastic and high-strength material, which, while remaining concrete, is nevertheless unusually light

  • glass concrete with fiber;
  • translucent array with optical fiber;
  • composition with broken glass;
  • a solution where glass is used as a binding element.

Advantages

Due to the use of special fillers, glass concrete is superior to traditional concrete. Main advantages:

  • Reduced weight, since the main fillers - cement, fiberglass, sand - are mixed in equal proportions.
  • Increased strength, since the glass-filled composite is characterized by increased resistance to deformation, and the impact resistance parameters are fifteen times higher than the characteristics of concrete mortar.
  • Expanded scope of use and wide range of products made from concrete with glass filler.
  • A significant number of possible additives that have a diverse effect on the characteristics.

Glass reinforced composition

Concrete, fiberglass reinforced, in fact, similar to reinforced concrete. It uses instead of metal. Based on this difference, the advantages are clearly visible:

  • increased thermal insulation;

An alternative to concrete is glass concrete, which has greater strength, frost resistance and thermal conductivity.

  • light weight. The use of composite concrete significantly reduces the load on the foundation;
  • at negative temperatures does not freeze, which makes construction work easier in winter;
  • affordable price.

Concrete with liquid glass

When conducting construction in regions with low groundwater, it is recommended to use a composition with the addition of liquid glass for pouring foundations. The antiseptic properties of silicate glass make it possible to use it in the construction of wells, swimming pools and other artificial reservoirs. High heat resistance makes it possible to use it in the construction of stoves and fireplaces.

Liquid glass is used in two versions:

  • The most efficient method is to dilute the glass with water and mix the ready-made solution with concrete. If undiluted glass is introduced, it causes cracks to appear on the top layer.
  • In the second option, glass is used as a primer. It is applied to the finished block. If you apply another one on top thin layer cement with glass, the product will be reliably protected from moisture.

When preparing such a concrete mixture, keep in mind that it hardens quite quickly. Prepare the solution in small portions in order to have time to use it without waste.

A property common to all glass concrete is concrete, in which both component added glass in different types

Composite with fiber

Fiber is alkali-resistant fiber. An additive to concrete increases strength characteristics and provides decorative properties.

Depending on the type and amount of additives, the properties of glass fiber reinforced concrete change, but remain unchanged:

  • moisture resistance;
  • increased impact strength;
  • frost resistance;
  • light weight;
  • resistance to chemical reagents.

Concrete composition with optical fibers (litracon)

The main ingredients and fillers of the array are optical fibers made of glass of increased length. When forming the composition, the fibers chaotically reinforce the block, and after cleaning the ends, they allow light to pass through unhindered. The ability of an array to transmit light depends on the concentration of fibers and the degree of color rendering of the material.

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The material is different increased price, but work is underway to reduce it. The use of litracon in private settings is limited to the decorative functions of the composite, and not to its use as a building material.

Liquid sodium silicate (less commonly potassium) glass is added to concrete to increase resistance to moisture and high temperatures and has antiseptic properties.

Concrete filled with broken glass

Glass concrete of this type provides the opportunity to achieve savings on the use of glass fillers. Traditionally used crushed stone and sand in glass-filled composites are replaced by broken glass. Glass production waste in the form of containers, balls, tubes, and ampoules is used as filler.

The strength characteristics of the finished material do not differ from concrete in which crushed stone is used. At the same time, the mass finished product is significantly reduced, and traditional crushed stone can be completely replaced with glass filler.

Composition with a binder - glass

Scope of application of this material- industry. Produced industrially, it is resistant to aggressive acids and has a negative reaction to aggressive alkalis. Stages industrial production provide:

  • Sorting of glass mass.
  • Particle crushing.
  • Glass crushing.
  • Division into factions.

The coarse filler is elements larger than 5 millimeters, and the rest, smaller ones, can be used instead of sand. If you have a thin glass fraction, you can prepare such a filling yourself.

Glass concrete is widely used and, due to its properties, is in great demand for the production of finishing panels, gratings, fences, walls, partitions

Astringent properties are provided by the introduction of a catalyst, since glass powder when mixed with water does not provide astringent characteristics. The manufacturing technology involves dissolving cullet with alkali - soda ash. During the reaction, the resulting silicon acids are gradually transformed into a gel, which holds the filler together and hardens. The result is a durable conglomerate with acid-resistant properties and increased strength.

Currently, one of the alternatives to plain concrete is glass concrete. This building material differs from ordinary concrete in its 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, and its properties will be at the highest level.

A little 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 expensive process. The solution to placing glass in concrete was proposed by the Ellen MacArthur Foundation after 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 greatest negative environmental impact - due to the cement used to make it.

To reduce its carbon footprint, the concrete industry has begun using two main cement substitutes: coal ash, which is produced by burning coal, and slag, a byproduct of steel production. These substitutes have reduced carbon emissions by 25 to 40% per ton of concrete, increased strength and reduced costs.

But these replacements are not ideal solution: they contain heavy metals- mercury, which makes them potentially toxic. Producers and users remain dependent on fossil fuels:"As more and more more companies are trying to reduce their carbon footprint and use renewable energy, using by-products fossil fuels in their factories are increasingly seen as counterintuitive and counterintuitive,” writes Ellen MacArthur Foundation Ph.D.

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. Although glass is 100% recyclable, the study says more American cities are abandoning their recycling programs - mainly for financial reasons: sorting glass is difficult and expensive.

General description and classification

Each building is a unique structure with features unique to it. Even if during construction it is applied standard project, it is necessary to take into account some factors, for example, the characteristics of the soil, the depth of its freezing, the humidity of the soil and air, the available wind and its strength. When taking these nuances into account, some adjustments will have to be made to the construction project.

So, if there is an increased seismic hazard in the area of ​​the building, then it is necessary to increase the total footage and diameter of the reinforcement, and also reduce the distance of its tying. If the soil moisture at the site of the future building is too high, you will have to increase the layer of concrete near the reinforcement, slowing down corrosion. In some cases, such problems are solved by replacing the calculation material with another that has more convenient and advantageous characteristics. You can make construction cheaper by equally replacing building materials with cheaper ones.

For example, alternative option An expensive foundation due to an increase in quantity can 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 various types. You will also have to become familiar with the strengths and weaknesses of concrete before making a choice. specific type.

Each type of glass concrete has its own properties and characteristics. Depending on this, it is worth starting from 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 rod is replaced with fiberglass. Thanks to the replacement of reinforcement, composite concrete has a number of distinctive properties.

Currently, expensive metal reinforcing rods have been replaced by more budget-friendly ones. composite materials made from plastic, basalt fiber or glass. In construction, the greatest demand is fiberglass reinforcement, which, although inferior to basalt in strength, is much cheaper. Main characteristics:

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

Glass composite material is not subject to various types of corrosion and is very resistant to aggressive environments, although experts recommend avoiding highly alkaline environments.

This means that the reinforcement does not change in diameter, even if the surrounding environment is humid. If the concrete is poorly waterproofed, metal material can completely collapse. Corroded metal reinforcement begins to increase in volume almost 10 times, which can cause the concrete to burst.

This makes it possible to safely reduce protective layer concrete blocks, reinforced with fiberglass. The large thickness of the protective layer is determined by the function of protecting steel reinforcement from high humidity, which impregnates the top concrete layer, thereby preventing all possible corrosion.

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

With the addition of liquid glass

Liquid sodium silicate glass is added to glass concrete blocks to increase resistance to high humidity and high temperatures. In addition, the material is distinguished 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;
  • swimming pools;
  • wells and more.

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

Glass-filled material with fiber

Thereby universal 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 changes in the amount of dyes, acrylic polymers and other additives. Glass-filled concrete with fiber is a strong, lightweight and water-resistant material that has a number of valuable decorative qualities.

GRC consists of a fine-grained concrete matrix that is filled with sand, as well as lengths of glass fibers called fibers.

Litracon, or glass-optic concrete

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

Currently the material is expensive. In one square meter fiber optic concrete will cost about $1,000. But experts continue to work to reduce costs. The building material has glass reinforcements. You can imitate it yourself at home if you find optical fiber and be patient, but in this case it will not be a construction material, but, most likely, a decorative one.

With broken glass

Thanks to this type of concrete, you can significantly save on filling materials by replacing sand and crushed stone with broken glass and closed glass containers:

  • ampoules;
  • balls;
  • tubes.

Crushed stone can be replaced with glass 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 a screen and is separated into fractions. Glass particles, the size of which is more than 5 mm, are used for the manufacture of glass concrete as a coarse aggregate, and smaller grains act as a binding powder. If you have the opportunity to finely grind glass at home, you can make concrete yourself.

For decorative purposes

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

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

Manufacturers do not use “dirty” glass containers or glass with stickers. Recycled glass is sorted by color, but it can also be mixed together. In any case, it melts and crushes, rather than being extinguished by water (which breaks the glass badly). The material is then sorted by size and the edges are blunted.

Glass concrete can be purchased at 20 various colors, the most expensive is red. For one bag you will have to pay 150 dollars.

Currently, glass concrete is widely used, and thanks 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 unique design in my house.

Properties of glass fiber reinforced concrete.

Glass fiber reinforced concrete (GFRC) is a type of fiber reinforced concrete and is made from cement-sand mortar and reinforcing pieces of glass fiber (fibers), evenly distributed throughout the volume of the concrete product or its individual parts. SFRC is used in thin-walled elements and structures of buildings and structures, for which it is essential to: reduce its own weight, increase crack resistance, ensure water resistance of concrete and its durability (including in aggressive environments), increase impact strength and abrasion resistance, as well as increase architectural expressiveness and environmental cleanliness. SFRC is recommended for the manufacture of structures in which the following can be most effectively used: technical advantages compared to concrete and reinforced concrete:

  • Increased crack resistance, impact strength, wear resistance, frost resistance and weather resistance;
  • Possibility of using more effective design solutions than with conventional reinforcement, for example, the use of thin-walled structures, structures without rod reinforcement, etc.;
  • Possibility of reducing or completely eliminating the consumption of steel reinforcement;
  • Reduced labor and energy costs for reinforcement work, increasing the degree of mechanization and automation in the production of fiber-reinforced concrete structures, for example, prefabricated thin-walled shells, folds, ribbed covering slabs, monolithic and prefabricated floors for industrial and public buildings, permanent formwork structures, etc.
SFRC elements with fiber reinforcement are recommended for use in structures operating:
  1. To bend;
  2. For compression at eccentricities of application of longitudinal force, for example, in elements of spatial floors;
  3. Mainly for impact loads, abrasion and weathering.

Properties of SFB at vintage age.

Density according to GOST 12730.1-78 1700-1900 kg/m3
Impact strength (Charpy) 110-250 J/m2
Compressive strength according to GOST 10180-90 490-840 kg/cm2
Tensile strength in bending according to GOST 10180-90 210-320 kg/cm2
Elastic modulus according to GOST 10180-90 (1.0-2.5) 104 MPa
Axial tensile strength according to GOST 10180-90: conditional elastic limit / tensile strength 28-70 kg/cm2 / 70-112 kg/cm2
Elongation at failure (600-1200) 10-5 or 0.6-1.2%
Shear resistance: between layers / across layers 35-54 kg/cm2 / 70-102 kg/cm2
Thermal expansion coefficient (8-12) 10-6 ºС-1
Thermal conductivity according to GOST 7076-90 0.52-0.75 W/cm2 ºС
Water absorption by weight according to GOST 12730.3-78 11-16%
Water resistance according to GOST 12730.5-78 W6-W12
Frost resistance according to GOST 10060.0-95 F150-F300
Combustibility according to GOST 12.1.044-89 Fireproof material, fire spread rate 0
Fire resistance according to GOST 30247.1-94 Higher than the fire resistance of concrete (better retains strength properties in a fire of 1000..1100 ºС)

Raw materials for glass fiber reinforced concrete.

The starting materials for the production of SFRC are: cement, sand, water, alkali-resistant glass fiber and chemical additives. To obtain any special properties of SFRC, polymers, pigments and other chemical additives can also be used together with these basic materials.

Cement: For the production of SFRC, Portland cement of a grade not lower than M400 is used. The choice of a specific type of Portland cement - regular (without additives), quick-hardening, colored - is dictated by the purpose of the SFRC product. The cement used must comply with generally accepted building regulations. In Russia, Portland cement must comply with GOST 31108-2003 (this standard is identical to the EN 197-1:2000 standard developed by the European Committee for Standardization). Portland cement according to GOST 10178-85 is also used in the production of SFRC, since GOST 31108-2003 does not cancel GOST 10178-85, which can be used in all cases where it is technically and economically feasible.

Sand: The choice of filler (sand) is very important for the production of high-quality SFRC. The sand must be pre-sifted and washed. The ingress of individual particles larger than 3 mm is not allowed (when operating equipment for the production of SFRC, work without a sieve is not allowed). For manual pneumatic spraying of SFRC, the particle size modulus should not exceed 2.5 mm (measurements are carried out in accordance with GOST 8735-88). Sand must meet the requirements of GOST 8736-93 for grain composition, the presence of impurities and contaminants (measurements are carried out in accordance with GOST 8735-88). Quartz sands are most widely used in the production of SFRC. Quartz sand must meet the requirements of GOST 22551-77. Included quartz sand the fraction less than 150 microns should not exceed 10% (measurements are carried out in accordance with GOST 8735-88). Dried sand makes it easier to control the preparation of the mixture (this refers to the water-cement ratio) and is usually already purchased dry and then stored in a dry state either in bags or in bins.

Fiberglass: For fiber reinforcement of SFRC structures, fiber is used in the form of pieces of glass fiber with a length from 10 mm to 37 mm (the length of the fiber is taken depending on the size and reinforcement of the structures in accordance with VSN 56-97), made by cutting roving from alkali-resistant glass fiber - this is glass fiber with oxide additives zirconium ZrO 2 . The following glass fibers can be used, such as those from Fiber Technologies International Ltd. (Bristol, England), L’Industrielle De Prefabrication (Priest, France), Cem-Fil (Chicago, USA), NEG (Nippon Electric Glass, Tokyo, Japan), ARC-15 or ARC-30 (China) and others. Glass roving must comply with GOST 17139-2003. Glass roving should not be moistened during storage and during work. Before use, a coil of wet glass roving must be dried at a temperature of 50-60°C for 0.5-1.5 hours to a moisture content of no more than 1%.

Water: For the production of SFB, water is used in accordance with GOST 23732-79. In conditions of extreme temperatures, heating, or, conversely, cooling of water may be necessary.

Chemical additives: are widely used in the manufacture of SFRC to influence manufacturing process and improving a number of final properties of products. A plasticizer should be used to maintain the fluidity of the mixture as the water-cement ratio decreases. Using additives, you can also speed up, slow down or reduce water separation, regulate the water resistance of the material, and reduce the delamination of the mixture. The selection of the most suitable additive also depends on some local factors, in particular the cement and sand used, as well as climatic conditions. Chemical additives must satisfy GOST 24211-2003. Chemical additives are classified into groups:

  1. Superplasticizers are highly effective thinners for concrete and mortar mixtures, which make it possible to increase their mobility several times without causing a decrease in the strength of concrete or mortar. With the introduction of superplasticizers, the water content in the cement-sand mixture is significantly reduced;
  2. Air-entraining additives – increase the frost resistance of SFRC and durability, increase mobility, salt resistance;
  3. Antifreeze additives – ensure the preservation of the liquid phase in cement-sand mixtures necessary for hardening of the cement paste;
  4. Setting accelerators - are introduced at temperatures below +10ºС, to reduce the heat treatment regime, accelerate the setting and hardening of SFRC;
  5. Set retarders - are introduced to increase the thickening time in dry and hot climates;
  6. Hydrophobizers – impart hydrophobic properties to SFB, making the water-repellent effect more pronounced.

Pigments: can be used to color either white or gray cements. In order to obtain uniform color and a permanent surface color, pigments are applied to the front (so-called film) layer, which is then subjected to additional processing, usually by sandblasting or polishing.

Forms for products made of glass fiber reinforced concrete.

Molds can be made from a range of materials that must provide the required turnability, dimensional accuracy and surface finish. The materials for the molds can be steel, plywood, fiberglass, rubber, polyurethane, silicone, and also, in some cases, SFRC itself. Molds can be made from a variety of materials, which must provide the required mold turnover, maintain the accuracy and quality of the surface finish of the products. The most common materials for molds are:

  1. Molds made of polyurethane (PU). One of the most popular forms for the production of SFRC products. Thanks to flexible polyurethane forms, the initial shrinkage of glass fiber reinforced concrete is compensated. Products can be stripped without damaging both the forms themselves and the products themselves. The advantages of flexible molds are their high turnover and durability, the speed of unmolding of SFRC products, as well as improved surface quality of molded products and a lower percentage of defects. Polyurethane molds make it possible to obtain SFRC products with “negative” angles. Polyurethane forms have the ability to maintain specified dimensions and original geometry, withstand all the loads caused by the daily process of molding, stripping of products, as well as movements of the form itself. Polyurethane is produced by mixing the appropriate polyurethane components A and B. Typically, components A and B for polyurethane molds have a simple mixing ratio (1:1). Simple procedure processing of two components (mixing of components is done using a hand mixer). It can be processed at room temperature. Polyurethane molds have a long service life ( big number turnover cycles), high moisture resistance, optimal combination elasticity with strength characteristics with high strength tensile strength, chemical resistance to the alkaline environment of cement-sand mixtures and abrasion resistance, as well as high quality reproduction of the smallest details of the model with minimal shrinkage. To obtain the surface of SFRC products that correspond to the profile of the form, the latter must be lubricated with special compounds. To do this, prepare a release grease. For example, vaseline-stearic, melting stearin and technical petroleum jelly in a water bath, then adding solar oil, stirring and cooling the lubricant, after which it is ready for use. It is also recommended to use for lubrication: stearic-paraffin paste (composition in percentage - % by weight: paraffin - 19, stearic acid - 15, starch - 1, rosin - 65); water-oil emulsion lubricants based on EKS emulsol; water-based lubricants OE-2 or ESO; machine or transformer oil. It is also possible to use other lubricants that ensure the preservation of the high-quality surface of the material; for example, the lubricant that has proven itself excellent in this capacity is spindle oil. The consistency of the lubricant should ensure the possibility of its mechanized application of SFRC to the surface of the molds. All types of lubricants must comply with GOST 26191-84.
  2. Fiberglass. Fiberglass molds are more durable than polyurethane molds and allow you to convey any texture of the product. The disadvantages of fiberglass molds include the impossibility of using them for production decorative items with a texture containing negative corners;
  3. Steel. It is used in cases where repeated reuse of the mold is required in the production of, for the most part, standard SFRC products. For example, massive panels without complex texture (cladding, elements of permanent formwork), simple in-line products;
  4. Tree. This is the most the simplest material for forms. Naturally, the quality of a surface of this shape must be monitored and constantly monitored. The disadvantages of wood forms include the short-lived preservation of their correct geometry during repeated use (heat chamber cycles with high humidity together with drying they can make a wooden form of “story”). Of course, with the help of special processing compounds you can protect the shape - and this also needs to be kept in mind;
  5. Rubber (rubber, silicones). These are universal forms. Similar to polyurethane molds. Distinctive feature Such a form requires the use of a rigid base - a “strap” for fixation. It would be better to say that the rubber molds are used as liners in a rigid base. The rigid base of rubber molds can be wooden harness, fiberglass base, less often - metal base. Molding rubbers can be in the form of fairly elastic sheets or blocks, in paste form, or in liquid form. The range of materials that can be used as a prototype is very diverse: metals, wax, glass, wood, plastics, modeling clay and any other materials. Rubbers are divided into hard and soft. Hard rubbers are good for making flat products. Soft rubbers make it possible to produce very voluminous, complex and filigree products, and to remove them from the mold without damage. However, rubber that is too soft is not able to withstand the pressure of the SFRC mixture, which can lead to deformation of the SFRC product itself. In such cases, to obtain a high-quality product, the rubber mold is secured in a rigid metal casing. The higher the elongation of the material, the easier it is to stretch the rubber mold to remove the SFRC product without damage. For high-quality hard rubbers this value is about 200%, for soft ones - from 300% to 850%.
  6. Other materials for molds. The above list is not exhaustive, and many other materials, including polypropylene, gypsum, and SFRC itself, can be successfully used to make molds.

Organization of the production site.

It is preferable to organize the production of SFRC in a workshop rather than in an open area, since the temperature should not be lower than +10 o C. Optimal temperature regime- within the range from +15 o C to +30 o C. The size of the workshop depends on the volume of production of SFRC products; the minimum recommended workshop area should be at least 100 m2.

To organize one SFSC production post, the following is required:

  • electricity with a power of at least 4 kW (excluding power consumption by the compressor), 3 phases, grounding;
  • water;
  • compressed air(1500-2000 l/min, pressure 6-9 bar);
  • Equipment for glass fiber reinforced concrete "ARC® S";.
  • Additional equipment and accessories (lifts, scales, spatulas, rollers for rolling the mixture).

If keeping SFRC products in a humid environment is used, the workshop should provide an area for storing SFRC products for one week. It is important that temperature and humidity levels are controlled in this area. The presence of a thermal-humidity treatment area in SFRC production is desirable, but not mandatory. The thermal-moisture treatment section of newly produced SFRC products will reduce the mold turnover time and also increase the characteristics of SFRC products.

SFRC products have a small thickness, which means significantly less weight compared to similar products made from ordinary concrete (if we consider the same compressive and bending strength values), they are still too heavy to move manually, so it should be possible to use appropriate lifting mechanisms.

Preparation cement-sand mortars for dispersed reinforced SFRC, it is carried out in forced-action paddle mortar mixers, for example, such as SO-46B and others. Containers are used for preparing and storing working solutions of additives.

The ratio of aggregate (sand) to cement is assumed to be equal to unity with the possibility of further adjustment and depends, in the general case, on the type of SFRC product, its dimensions, conditions of use of SFRC products, etc. The calculation of the water-cement ratio and its adjustment are carried out in accordance with VSN 56-97. The water-cement ratio (without the use of plasticizing additives) is usually in the range of 0.40 - 0.45. With the use of plasticizing additives, the water-cement ratio changes to 0.28 - 0.32.

After the initial raw materials are selected, the composition of the mixture is selected taking into account the following recommendations:

  • Water-cement ratio. It should be as low as possible, but at the same time the mixture should remain sufficiently mobile for it to be supplied by a mortar pump and subsequent pneumatic spraying. The water-cement ratio of the cement-sand mortar used for the manufacture of SFRC must correspond to the optimal viscosity (mobility P4-P5), corresponding to the slump of a standard cone according to GOST 5802-86 “Construction Mortars. Test methods". In general, the water-cement ratio has a complex relationship and depends on the active grade of cement, the coefficient of normal density of cement paste, the coefficient of water demand for sand and the calculated coefficient of glass fiber reinforced concrete for compression.
  • The ratio of sand and cement. The 1:1 ratio is the most widely used at present. The ratio is adjusted in accordance with VSN 56-97.
  • Glass fiber content or reinforcement ratio. This is the percentage of the weight of fiberglass to the weight of the entire composite - SFB, that is, taking into account the mass of the fiberglass itself. For manual air spraying, this ratio is usually from 3 to 6%, sometimes higher. The calculation of the reinforcement coefficient is carried out in accordance with VSN 56-97.
Typical mixture composition. The SFRC manufacturer can develop his own mixture composition that meets his special requirements production of SFRC products and consistent with VSN 56-97.

Let's consider the recipe, which is called “classical” as it is the most frequently used. The “classical” recipe is the following composition for one conditional batch, the amount of fiberglass is 5%:

* - dosage depends on the concentration, so for the same amount of cement used it may be different. The dosage is indicated by the supplement manufacturer.

The weight of the entire solution is = 50+50+16+0.5=116.5 kg, then the content of 5% fiberglass is 6 kg.

To obtain a homogeneous mixture, it is necessary to accurately weigh the starting materials and strictly follow the basic requirements when working with the mixer. Before starting to prepare the mixture, accurately weigh required quantities sand and cement using scales (see section “Additional accessories”). Dosage of water and liquid additive can be done by weight, volume or, preferably, using a special automatic dosing device.

Detailed recommendations for applying glass fiber reinforced concrete, preparation, use, stripping and washing of forms, maintenance and preservation of equipment are indicated in the passport for the complex for glass fiber reinforced concrete "ARC® S" and technological instructions for working with glass fiber reinforced concrete from the equipment documentation set.

The topic of waste disposal is very relevant today, and I want to draw attention to glass containers. Its share in city landfills, as well as in spontaneous landfills in forests, is very significant. This is due to the basic lack of information among the population about the benefits of adding broken glass to concrete solutions. It has been scientifically proven that the addition of broken glass significantly increases the strength of concrete.

So, it took us at least a thousand bottles to concrete the roof of the garage. They picked them up right on the street. If summer residents knew about the benefits of broken glass, the percentage of bottles in trash bins would be significantly reduced.

Adding broken glass creates reliable waterproofing and extends the service life of concrete. But you need to take precautions when breaking bottles. You need to wear safety glasses and beat in a container, for example, in a bucket. It is most convenient to crush glass between two bricks.

Please pay attention to this issue. You just need to inform the population, talk to them, explain the inadmissibility of throwing away, for example, batteries with food waste, etc. It's all about competent organization.

Tatiana Lanskaya

Northern summer resident:I have never heard of a roof being concreted this way, but everything related to the foundation, steps, garden homemade tiles etc. quite fair. Here is some collected life experience so far:

1. "From personal experience I know that any glass container and even broken glass can be used in the manufacture of floors on the ground. To do this, dig a special hole no more than 20 centimeters deep. Then it is covered with any glass. In this case, all the broken glass acts as filler. The floor itself is laid on top of the glass. Do not forget that in this case glass containers can become the most reliable protection from various living creatures, for example from moles. Empty bottles can replace even the highest quality insulation. Earlier during construction country houses Only empty bottles were used. They were laid in continuous layers under the floor. They were also used when laying out a concrete blind area."

2. "The only, somewhat acceptable and in a safe way the use of broken glass in construction, I would say its use in the drainage layer under the foundations. That is, you can pour pre-crushed glass along with sand and crushed stone into a cushion for pouring the foundation. Why is it undesirable to use it as a filler in concrete solutions(instead of crushed stone)? Because glass, unlike crushed stone, is smooth, therefore, its adhesion to cement-sand mixture will be insufficient. Thus, the resulting concrete will be weaker than that made from pure crushed stone."

3. “You can recycle cullet, using it for laying a foundation, using binding materials, in the form of a solution with the addition of 1 part of M400 cement, 2 portions of sand and one part of cullet. The bottles must be carefully broken so that their fragments, such as the neck, do not remain intact ", which may not be filled with solution, so reliable foundation strength will not be achieved. And from whole bottles, having foamed each neck, you can build a fence. So, there is no need to throw away such an economical and environmentally friendly building material."

4. “We also found a lot of glass containers at our dacha. When we were putting up a bathhouse, a neighbor advised us to line the underground under the bathhouse with empty glass bottles, having first dug a hole in the shape of a cone. Along the slopes of this cone, lay the bottles with their necks down, simply drowning them in the ground. What does such a device provide: firstly, water flows down and does not accumulate under the floor, as a result - wooden floor is less susceptible to rotting, and secondly, the glass heats up when we heat the bathhouse, and retains heat for a long time - the floors in the bathhouse become warmer."

5. "Indeed, glass containers are often used in construction if they are available. If you have the desire and sufficient quantity time and probably most importantly patience, then it can be mixed with screenings and poured into concrete. The most important thing is that the glass containers must first be crushed very well. The non-crushed version is not a very good option for use in concrete. For grinding, as an option, you can use a concrete mixer filled with water so that when turning, glass fragments do not fly out of it.”

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