In addition to its direct purpose - gluing paper, wood, leather, etc., PVA glue is used as an improver for putties and mortars.

Concrete and cement-sand mortar, to which polyvinyl acetate dispersion is added, acquires better plasticity, the composition sets faster.

Usage PVA as a plasticizer additive - effective reception to solve various problems. So, thanks to the mixing of cement with PVA glue, the floor screed better fills all the voids, clings more strongly to concrete base, cracks do not form on the surface of the finished screed.

By adding the dispersion to an ordinary cement-sand mortar, you can get a good tile adhesive. As part of the base plaster, PVA prevents the formation of cracks, improves adhesion with brick wall, eliminates sprinkling of the surface. Sometimes an aqueous emulsion of vinyl acetate polymer is also used as a masonry mortar improver.

What PVA glue can be added to cement mortar

It should be noted that for construction purposes only suitable:

Universal PVA glue (PVA-MB)- viscous homogeneous mass white color with a yellowish tint. It is used as an improver of any concrete mixtures on water based, putties and primers. PVA-MB withstands up to 8 freeze-thaw cycles. All-purpose construction adhesive for cement mortar is sold in plastic container up to 10 liters. 1 kg of glue costs about 80 rubles.

PVA dispersion is a polyvinyl acetate homopolymer emulsion with excellent binding properties and excellent adhesion to various building materials. It is produced in two versions: plasticized (afraid of frost) and non-plasticized (frost-resistant).

Attention! PVA clerical glue, intended for gluing paper, is categorically not recommended as a plasticizer, since it consists of 60-80 percent starch. Wood glue is also not suitable for these purposes, because. it contains a large number of carboxymethyl cellulose.

Correctly add PVA glue to the solution - step by step instructions

The proportions of PVA and cement in the solution can be from 5 to 20 percent. How much to add PVA glue to cement mortar? It depends on its purpose and scope.

For a floor screed, 5% -12% of the polymer content will be enough. AT tile adhesive the ratio of PVA and cement is usually made 1:5.

Cooking process plaster mortar with the addition of PVA:

1. Cement brand M400 dry mixed with sand in a ratio of 1:3;
2. Then water is added to the mixture until the desired consistency of the solution is obtained;
3. Next, PVA-MB is introduced into the mass at the rate of 50-70 grams of glue per 10 liters of solution. To quickly mix cement with PVA to a homogeneous structure, the glue is diluted with water to a milky state.

A plaster mortar prepared using a polymer plasticizer lays down better and sticks to the base, sets faster.

Similarly, PVA glue is added to the concrete solution. In this case, it is recommended to use the proportion: 200 grams of glue per 10 liters of solution. The plasticizer improves the mobility of concrete, increases the final strength. In the process of drying, PVA polymerizes, which increases the water resistance of concrete.

Attention! As an admixture for mortar or concrete, only universal construction PVA-MB. Household and office glue is suitable only for working with paper, its use in cement mortars is unacceptable.

Add an aqueous emulsion of vinyl acetate polymer to masonry mortars experts do not recommend, since the polyvinyl acetate dispersion withstands a limited number of freeze-thaw cycles.

Can another glue be used?

PVA is the most affordable plasticizer. There are also more expensive analogues that are intended directly for use as an additive to the solution:

• Latexkol is a latex plasticizer additive for tile adhesives. It is diluted with water in a ratio of 1:1. It makes the mortar more elastic, increases adhesion and strength, increases resistance to moisture, cracking and other deformations. A 3.75-liter Latexkol canister from Litokol costs about 1000-1200 rubles.

• Plasticizer INTER PLAST AT- superplasticizing mixture based on an aqueous solution of modified surfactants. The additive increases the mobility of concrete mixtures, increases the strength of concrete by 21%, reduces cement consumption by up to 15%. 1 liter of plasticizer costs about 150 rubles.

PVA has been used to improve the quality of cement-sand mortar since Soviet times, when it was very difficult to purchase high-quality tile adhesive and ready-made plaster mixes. Today, when the market offers a huge variety of modern and inexpensive dry building mixtures there is no need to resort to alternative technologies.

For any type of wall decoration, be it putty, plaster, painting, and also before wallpapering, you must first prepare the surface. Priming is one of the main steps that must be completed first of all, because with the help of soil you can achieve better adhesion. finishing material with surface. However, the materials presented on the construction market have a rather high cost. But there is an excellent economical solution - a PVA primer. It is not difficult to make it yourself, moreover, such a solution is suitable for both wooden and concrete, brick surfaces.

PVA glue - an aqueous emulsion of polyvinyl acetate. it Chemical substance solid granular substance without pronounced color and odor. The material is used in construction furniture production, carpentry. It is actively used by schoolchildren, students, needlewomen. Polyvinyl acetate glue connects various materials: paper, cardboard, wood, rubber, ceramics.

To obtain a primer, PVA glue is diluted with water. On the surface, such a mixture forms a thin transparent film, which has many of the properties of specialized primers.

A PVA-based primer can be used as an intermediate layer between the surface and finishing coating, contributing to good adhesion of materials and reducing the risk of their peeling from the wall as a result of moisture getting on it. In addition, the use of such a primer will reduce the consumption of putty or paint used.

Advantages and disadvantages

PVA glue primer has its advantages and disadvantages. The undoubted advantages are:

• Increased adhesion. An additional layer is created to securely fix the finish to the surface.
• Decreased moisture absorption. The soil penetrates the structure of the surface, filling its pores and preventing moisture from entering them.
• Creation of a protective layer. Thin polymeric barrier helps fight aggressors environment.
• Consumable Reduction(plaster, paint, glue).

In addition, the primer made of PVA ensures even application of paint, facilitates the process of wallpapering. Of course, all this is sufficiently provided by the purchased primer available in a wide range. But often its high price makes it necessary to look for more profitable solutions. Therefore, the use of PVA instead of a primer is a completely justified option.

Despite all the advantages, this composition still has disadvantages. These should include:

• Inefficiency– insufficient penetration deep into the material.
• Lack of antiseptic properties- the primer coating will not be able to resist the reproduction of microorganisms (mold, fungus).
• Education yellow spots and divorces- deteriorates appearance finishes.
• The material loses its properties during wet rooms - not used to cover walls, ceilings in baths, pools.

Knowing some subtleties, you can turn disadvantages into advantages and improve the properties of an aqueous PVA solution for priming walls. So, for example, you can increase the ability to resist mold by adding a little whiteness to the composition in the proportion: 50 g of a disinfectant per liter of the finished solution. Ate in the soil from PVA add 3% of its volume liquid glass, it is possible to increase the penetration into the processed material, especially into wooden substrates.

In case of limited financial resources, it is better to use a glue primer in utility or non-residential premises. In the living room and bedroom, a combination with expensive wallpaper will not work, because there is a possibility of yellowness, which will significantly change the interior for the worse.

We prepare the primer ourselves

How to make a mixture that has the properties of a primer? You need to take the following components:

• PVA glue - 1 part;
• water - 2 parts;
• cement - the amount is determined by the density.

The preparation technology does not cause difficulties: the glue is diluted with water, mixed, the required amount of cement is added. The finished solution should resemble liquid sour cream and lie well on the surface.

Important! Before you make a PVA primer with your own hands, decide on its quantity. You should not prepare the mixture for future use, since unused surpluses lose their bonding properties over time.

Diluted primer is an excellent economical tool that precedes wall treatment. wallpaper glue, but not enough for a reliable finish. Can the quality of the primer be improved? Repair specialists advise adding crushed chalk and liquid resin to the mixture with PVA glue. Their mass should not exceed 5% of the total volume of the composition.

Important preparation conditions:

• Work on creating a primer should be carried out in a warm room, away from drafts, sources of fire.
• Use a convenient container: a large bucket, a basin, a wide-mouth canister.
• Water is added to the glue gradually, the classic ratio is 2:1.
• Constant stirring of the composition will prevent the formation of a surface water layer. To facilitate labor and obtain the greatest uniformity, you can use a construction mixer.

The primer of the walls with glue is different in that it forms a film on the surface to be treated, without filling small cracks and gaps. But, given the relatively low cost of the components used, it turns out an excellent building material that is quickly made at home.

Finishing goals should be clearly defined. Under the wallpaper, a universal primer is suitable that does not require increased water resistance. Elite finishing decorative plaster requires a more expensive adhesive coating.

On the video: primer deep penetration from PVA.

Correct application technique

Knowing the theoretical techniques of how to dilute PVA for a primer, it is necessary to achieve the correct consistency. To begin with, it is worth trying to apply the mixture on small area wall for wallpaper. The liquid mass is applied to the surface with a paint roller or a wide brush, leaving a white mark.

After drying, the formed film should not be noticeable. This emphasizes the correctness of the chosen proportions. A little water should be added if the reverse occurs.

Priming works are carried out in several stages:

1. First of all, the corners and hard-to-reach places. Next, with a short pile roller, the primer is applied to the main areas.

2. The roller must be dipped in the resulting solution and slightly squeezed on the ribbed part of the container. A convenient device is a special bath with an inclined ribbed surface. By rolling a roller over it, it is possible to squeeze out excess liquid. As a result, wet spots and smudges do not form.

3. For best result you can apply another coat of primer. This ensures reliable adhesion of fine dust particles, makes it possible to further evenly apply the putty (it will peel off less).

4. It is necessary to wait for the complete drying of the surface. The wall should take on a whitish color.

The resulting two-layer polymer coating reliably protects the surface, increases adhesion, allows you to proceed to the application of decorative finishes.

Save on repairs

If not PVA, then what?

Ordinary wallpaper paste can also be used as a primer. It has distinctive features:

• does not form yellowness;
• has better absorbency;
• does not form a film;
• inexpensive;
• easy and quick to apply.

You can make a primer and save money at the same time in another way - this is the use of concentrates. The instructions for them indicate how to breed such a composition. Sometimes it can be increased by 10 times.

Before painting acrylic paints the use of an independent primer is impractical. It is enough to mix the coating composition with water in a ratio of 1:1. The primer will be the paint itself. It should be applied evenly with a roller. Savings are achieved by reducing the applied layers.

Brush, roller or spray gun?

The choice of tools also plays an important role. Applying a primer with a spray gun is a quick job from the technical side, but in terms of aesthetics, this is not an acceptable option, as there are many hard-to-clean marks and smudges.

Using a brush is unprofitable from an economic point of view - it increases the consumption of material. Used to work in corners. For large areas, it is better to use a roller with a short or medium pile. But on walls that have irregularities in the form of protrusions and dimples, you can’t do without a brush.

The PVA primer does not have the properties that special formulations for repair. Despite this, it is an indispensable tool for preparatory work, allows you to significantly save material resources. Proper preparation, compliance technological process turns a homemade composition into a high-quality primer material.

Cement is perhaps the most demanded material in the construction market. Without it, it is impossible to prepare plaster for walls and ceilings, concrete floor screed, mortar for ceramic tiles. For whatever purpose the mixture is used, the ingredients in it are the same: cement, sand, water. The differences are only in their percentage and additives. For example, crushed stone is added to concrete, pigments are added to the composition for tiles, glass, shavings for decoration are added to plaster. A component that can be present in any solution is PVA (polyvinyl acetate).

Ready-made tile adhesive is good where the walls are absolutely even, and cement mortar is suitable for all types of surfaces. The basis is cement and sand, the ratio is 1 to 3. Other components improve the properties of the mixture.

Most often, PVA is added to the cement mortar. The main arguments in his favor:

1. In correct proportion this additive transforms an ordinary mortar into a universal adhesive and at the same time into a sealant with good waterproof properties.

2. The mixture becomes more plastic.

3. Increases adhesion to the substrate and the strength of the finish.

The tiles in the bathroom will last at least 15 years (and in the kitchen - all 20), if you take fresh cement, quarry sand (in a ratio of 1: 4) and PVA glue (1/20 part of total volume). The quality can be improved if PVA is added to the cement, having previously been mixed with water (in the ratio: 2 hours of glue to one part of water).

An important point: it is PVA that is poured into water, and not vice versa. The resulting mixture is carefully stirred. As a result, after drying, the glue is practically not noticeable, since when mixed with water, it becomes transparent.

Surface plastering

By adding glue to the plaster, you can achieve more high-quality plastering walls or ceiling due to the slow absorption of moisture. The cement mortar will not dry as quickly, allowing finishers to finish the surfaces more thoroughly.

In addition, polyvinyl acetate:

1. Plays the role of a plasticizer. Read more about plasticizers for cement mortar.

2. Increases the strength properties of the plaster.

3. The quality of adhesion to the treated surface improves.

But, if you plan to plaster the walls in a room with high humidity, the addition of glue is not recommended even in a small proportion. It is not used in facade decoration.

Specialists who use cement-based plaster with the addition of PVA for wall decoration note high qualities:

• cement in places where chips are sealed in the blind area is more durable;
• the plaster lays down in an even layer and is securely fastened to the surface.

To prepare the plaster, glue is added to the cement-based solution in a ratio of 150 ml per 10 liters of the composition. Although just one spoon of high-quality polyvinyl acetate can not only improve the structure of the mixture, but also change its appearance.

Screed mortar

Concrete easily yields to compressive deformation, bending can lead to the destruction of the structure. Water-soluble polymers help to improve the plastic properties of concrete during screeding. Masters consider latex to be the best of them, but it is in great short supply. Therefore, the more affordable PVA glue is used as an additive. At the same time, the proportions are not very strictly observed - as a rule, from 5 to 20% in relation to the mass of the solution.

As a result, strength properties, according to experts, improve one and a half times. At least 3 times the strength of adhesion of concrete to the base. Increases wear resistance by 50%. When buying polyvinyl acetate for the preparation of a mixture for screed, you should be careful. Exist different types glue of this brand, in particular:

• PVA glue for paper based on starch;
• glue for wood with a high content of CMC.

These types are unsuitable for the manufacture of concrete. Polyvinyl acetate containing at least 50% polymer is required.

Optimal for concrete pavement sex is considered the composition in the following proportion:

• portland cement - 100 kg;
• PVA - 20 kg;
• sand - 200 kg;
• crushed stone - 250-300 kg;
• additive in the form of alkali-resistant pigments - at least 5 kg (maximum - 10);
• water to ensure the mobility of the mixture.

The introduction of glue into concrete allows not only to make high-quality new screed but also to repair the old one. It's believed that fresh concrete practically does not fall on the old one. But if you introduce special additives, including PVA, the problem is easily solved. Composition (in parts of the total amount):

• cement - 1;
• sand (preferably fine) - 3;
• PVA - 1/2;
• epoxy resin - 4/100;
• hardener (polyethylene polyamine) - 4/100;
• water.

Water is added until the consistency of the mixture begins to resemble batter.

They learned to mix PVA glue with cement mortar for a long time. In this case, PVA glue is used to improve the quality of the solution. The material to which it is added becomes more plastic and quick-setting than a standard solution mixed with water.

Therefore, if in the premises where the solution is used there is no constant source high humidity, and the ambient temperature does not drop below 7 degrees Celsius, builders recommend that PVA glue be added to cement-sand mortars. This significantly improves adhesion and greatly facilitates the process of working with the material.

PVA glue and its properties

This substance is a homogeneous mass of white color without a strong odor. PVA is based on polyvinyl acetate emulsion and water.

Depending on the purpose, three types are distinguished: stationery, furniture and construction PVA glue, each of which has its own additives and thickeners. Construction adhesive is packaged for sale in special plastic buckets and barrels with a capacity of 1, 2, 5, 10 and 30 kilograms.

At the same time, the guaranteed shelf life of building PVA is 6 months at an ambient temperature of 5 to 20 degrees Celsius. PVA glue is non-toxic and completely environmentally friendly.

Features of the application and proportions of the solution with the addition of PVA

You should know that PVA tends to break down and lose its properties under the influence ultraviolet rays. At the same time, when it is added to the cement mortar, after it reacts with cement, it changes its properties and is no longer "afraid" of ultraviolet radiation.

Typically, a material with a similar additive is used to equip self-leveling floors and screeds in closed, dry rooms. In rooms where the regulatory appearance of free moisture is possible (saunas, bathrooms, toilets, etc.), it is not recommended to use PVA in mortars or concretes.

The standard proportion of adding PVA to the masonry or "pouring" cement-sand mortar is from 5 to 10% of the volume, provided that the mortar is prepared on water.

If M400 / M500 cement, sand and PVA glue are mixed in proportions of 1: 5 (for M400 cement) or 6 (for M500 cement): 1/25 part, without adding water, a very powerful adhesive composition is obtained, which is great for fixing tiles especially on vertical surfaces.

PVA glue is part of the most popular stucco recipe. The proportions of the cement-sand mortar with the addition of PVA are as follows: M400 cement - 1 part, sifted sand - 3 parts.

Cement and sand are mixed dry. Next, water is added to the mixture, the solution is brought to the desired consistency, after which PVA glue is introduced into it - from 50 to 70 grams per 10 liters of solution. The material prepared using this technology lays better on the surface, better “sticks” to the base and sets faster.

Quite a long time ago, PVA began to be used as a useful additive to cement mortar. The main goal is to improve the quality of the cement-sand mortar. This sticky substance allows you to get more ductile concrete, which instantly seizes on the surface.

PVA and its properties

PVA is a white adhesive emulsion based on polyvinyl acetate polymer with a sour cream consistency. The glue is practically odorless, non-toxic, environmentally friendly, can be stored long time without loss of properties. There is a stationery, furniture and building type.

The adhesive composition is not moisture resistant. It dissolves easily in water in liquid form. However, during the curing process, polyvinyl acetate polymerizes, loses color and becomes resistant to water. After gluing, the surface acquires a tensile strength of up to 1300 g/cm², which indicates high strength cured polymer.

Polyvinyl acetate withstands low temperatures while maintaining properties even at -20°C. The polymer can go through up to three cycles of freezing and thawing. Polyvinyl acetate itself is not resistant to UV rays, but in a concrete mixture it acquires this property, so it can be used for the construction of structures, screeds for outdoor use.

Application features

• increases plasticity;
• reduces hardness finished product by increasing the bending strength;
• increases adhesion concrete mortar to the surface.

This is achieved by observing clear proportions of mixing concrete and PVA. In this case, the amount of water should not exceed 5%. Not every type adhesive composition can be used. Stationery PVA contains a lot of starch, and wood glue contains unnecessary chemical fillers that degrade properties. cement mixture.

Depending on the purpose of the prepared mixture, the proportions of cement to polyvinyl acetate are determined. For example, for screed and masonry you need different properties solution.

An important criterion for choosing the type of adhesive for cement is the final humidity in which it will be operated. finished construction. Despite polymerization, when solidifying and acquiring moisture resistance, it is better not to add glue to concrete mixtures for finishing bathtubs, showers, and pools.

As a reinsurance, the adhesive-cement composition is best used for arranging the territory where the operating temperature will be above 7 ° C.

Terms of use

Basically, the adhesive additive works as a plasticizer. To work with a screed mortar, you need to add glue in an amount of 5% -10% or 0.5 liters of PVA for 2-3 buckets of cement. If laying tiles is planned, then polyvinyl acetate is better to take 20% or more.

Adhesive should be mixed after it has been diluted with water. This will allow you to get a more homogeneous mass in the end. However, if you need a composition with high adhesion and plasticity, it is better to mix cement with glue without first dissolving in water.

Conclusion

The distinctive properties of PVA allow it to be used as an additive to concrete mixtures for various purposes. In this case, the resulting surfaces will be endowed with increased strength and durability.

Glue facilitates the laying of mortars, therefore it is enriched with building masses for carpentry, finishing with plaster and primer.

kladembeton.ru

Cement mortar and PVA glue

• PVA glue and its properties
• Features and application of cement mortar with the addition of PVA glue

It has been customary to mix cement mortar and PVA glue in the construction industry for a long time. With this, they tried to improve the quality of the cement-sand mortar. Application began almost from the moment PVA glue appeared in free sale. The concrete to which it was added acquired a higher plasticity and set much faster than a conventional aqueous solution.

Components of cement mortar.

Today's trade building materials offers a considerable number of varieties of dry mixes, in which glue is added in already balanced quantities. However, their cost is quite high. Meanwhile, if PVA glue is correctly added to an ordinary cement mortar, in some cases the result can be no worse. Financial expenses same on expendable materials will be significantly reduced.

PVA glue and its properties

This substance is a white mass without a distinct odor, having the consistency of medium-fat sour cream. It is based on a polyvinyl acetate emulsion, which is one of the varieties of polymers.

PVA glue is able to withstand low temperatures and is non-toxic and environmentally friendly.

By appointment, it differs in stationery, furniture and construction, each of which has in its composition the appropriate thickeners and other additives. The latter is packaged for sale in plastic buckets and barrels with a capacity of 1, 2, 5, 10 and 30 kg and can be stored at a temperature of +5 to + 20°C for six months.

It is worth remembering that this substance in itself is not waterproof, it is easily diluted with water and is afraid high humidity. Nevertheless, after the complete completion of the solidification cycle, it polymerizes, it becomes transparent and cannot be dissolved in water. The glued surface withstands a tensile strength of about 1300 g per 1 cm².

At the same time, this adhesive is able to withstand low temperatures. It retains its properties in frost down to -20 ° C enough for a long time and can freeze and thaw up to 3 times. At the same time, PVA does not have a toxic effect and is completely environmentally safe.

Back to index

First of all, it is worth remembering that this glue is gradually destroyed and loses its properties under the influence of ultraviolet radiation. However, adding it to masonry mortar or concrete leads to the fact that after it reacts with cement, its properties change, and it is no longer afraid of exposure to ultraviolet radiation.

Table of proportions of the ingredients of the cement composition.

That is why concrete with such an additive can be used for pouring screeds both indoors and outdoors in places where Sun rays. At the same time, in rooms like baths or saunas, where an increased level of humidity is provided, it is still not recommended to put it.

The usual proportion when adding PVA glue to a cement-sand mortar is from 5 to 10%, provided that it is diluted with water. Adding it to concrete significantly increases adhesion and creates an additional margin of safety.

If the cement is mixed with it without the addition of water, a sufficiently powerful adhesive will be obtained, which is very well suited for fixing ceramic tiles, especially on a vertical surface. The idea of ​​adding this component to the solution for plastering works. It becomes much more plastic because of this, it fits better on the main surface and sets faster.

The addition of PVA glue to concrete or other cement mortar in any case has a positive effect on the consumer properties of the latter. This is especially noticeable when compared with conventional cement-sand mortar water based. Adhesion, plasticity and curing speed clearly increase.

If there is no constant source of dampness, and the ambient temperature is not lower than + 7 ° C, then adding PVA is definitely worth it, this greatly facilitates the process of working with cement mortar.

tolkobeton.ru

Proportions for the introduction of PVA glue into the cement mixture

One way to improve the properties of cement mixtures is to add polyvinyl acetate, a water-soluble adhesive emulsion. This practice is often used in the preparation of plasters, leveling and bonding mortars and even concretes. The proportions and sequence of input depend on the intended purpose of the compositions; in most cases, PVA is pre-diluted with water. Application limitations include the operation of treated surfaces in conditions of high humidity.

The effect of adding glue to cement mortar

The material is a kind of polymers and is used as a plasticizer. PVA does not have a distinct smell, it dissolves in water (only until the end of the hardening process of the CPS or concrete), there are no toxic substances. The standard proportion varies from 5 to 10%, the introduction into the cement-sand composition allows:

• increase its plasticity.
• Increase its bending strength after curing. Experiments show that the surface treated with PVA can withstand a tensile strength of 1300 g/cm2.
• To improve the quality of adhesion of mixtures based on cement. The adhesion value in this case depends on the ratios used, if you want to obtain a reliable adhesive for tiles, its share reaches 20% of the total volume.
• Simplify work processes.

Application limitations include operation under conditions of exposure to hot and humid steam, this is due to the acceleration of the hydrolysis of polyvinyl acetate and alkaline media and its conversion into alcohol even in bound form. For this reason, glue is not introduced into solutions for bathrooms, saunas, swimming pools and for facing areas subject to frequent moisture loads. A clear improvement in elasticity and adhesion is recognized, the disadvantages include the lack of control over the set of strength (the process of hydration of the cement stone is combined with the drying of the polymer dispersion and is generally more complicated).

AT cement composition add PVA of a certain brand - namely for construction purposes. Stationery or wallpaper contain excess starch, wood adhesives - extraneous additives and impurities that are poorly combined with Portland cement. The properties necessary for improving building mortars are possessed by an aqueous dispersion containing at least 50% polymers. It is sold in packaged plastic containers from 1 to 30 kg and has a limited shelf life of 6 months.

Proportions of input and features of the preparation of building mixtures

There are two ways to combine a solution of cement and glue: in the first, the additive is diluted with water (the emulsion is poured into a container with liquid and thoroughly mixed until it is completely transparent), in the second, it is administered undiluted. Violating the standard W/C ratios is not recommended in any case. The addition of undiluted PVA is required when mixing connecting compounds, well-mixed - when preparing concrete or in order to improve plasticity. The proportions of the DSP components are selected based on the intended purpose:

1. The proportion of a standard additive in a diluted state to increase ductility and flexural strength is 5-10%. In recalculation, this means 0.5 liters of PVA for 2-3 buckets (or 1 bag) of binder.

2. In the manufacture of a cement mortar for pouring the main floor screed, it is recommended to mix 100 kg of Portland cement, 200 - sand, up to 300 - fine gravel, 5 - alkali-resistant pigment and 20 - PVA directly. Water is added until the desired mobility is achieved, the standard W / C ratio varies from 0.45 to 0.55, it is not recommended to exceed it.

3. When preparing a cement mixture for laying tiles, the proportion of glue reaches 20% of the total mass. In this case, it is combined with dry cement and sand mixed in a ratio of 1: 5 (strength grade of the binder is not lower than M400) without adding water. The resulting composition is characterized by high adhesion and is suitable for fastening products on vertical walls. Some experts advise using liquid solution cement, PVA glue and water for the preparation of complex surfaces (on smooth concrete slabs, for example, it replaces notches).

4. If you need to repair old concrete screeds it is recommended to mix cement, sand and polyvinyl acetate emulsion in proportions of 1:3:0.5, respectively, and add 4% of the total binder to them epoxy resin and hardener. Water is introduced until the desired consistency is reached - batter. The resulting composition has good quality adhesion and holds even on old and dried concrete.

5. When mixing plasters, standard proportions of Portland cement and sand are used - 1:3. For 10 liters of finished (already mixed with water) mixture, 50-70 g of PVA building glue is added.

stroitel-lab.ru

Cement with PVA - how much to add to the solution?

The method in which PVA is added to the cement mortar has been known since Soviet times. It improves not only technical, but also performance characteristics.

Properties of PVA glue

This solution is obtained:

• more homogeneous;
• plastic;
• increases the adhesion force between the particles of the solution;
• improves strength;
• increased wear resistance;
• prevents the formation of cracks, etc.

PVA glue is a polymer and consists of a polyvinyl acetate emulsion. It dissolves perfectly in water, but after drying it is resistant to moisture. It is non-toxic, safe for health and at the same time can retain its properties at very high and low temperatures.

Application features

Before determining the proportions of adding PVA to cement, it should be noted which type of this adhesive is not suitable for construction purposes. This is, first of all, PVA, intended for paper and cardboard products. It contains too much starch and other fillers. Also, do not take PVA for wood, as it also contains various unnecessary additives.

Second important point is the purpose of the solution. Because the proportions of cement with PVA will be different. For screed, some properties are needed, and for laying ceramic tiles, others. And the last nuance, what humidity will be in the room. Despite the fact that after the glue hardens, it polymerizes and is not afraid of moisture, however, it is still not recommended to use it in wet rooms (bath, shower, pool).

Another feature is temperature regime. Although the adhesive withstands high and low temperatures, but in order not to risk the end result of reliability and durability, it is better that the temperature is higher than +7 ° C.

Terms of use

The addition of PVA is used as a plasticizer, but in addition it improves the properties of the cement-sand mortar. The proportions of PVA in relation to cement range from 5% to 20%. It all depends on the specific application of this solution. If this is a screed, then 5% -10% of the glue content is quite enough, and if it is for tiles, then it is better not to spare PVA and add 20%.

To make it clearer, for 2-3 buckets of cement mortar for a screed, you need somewhere around 0.5 liters of PVA. Add PVA already diluted with water so that it mixes more evenly with the whole mixture.

If the glue is mixed with cement, without first dissolving in water, then a composition will be obtained that will have excellent adhesion and plasticity properties.