Reinforcement of aerated concrete blocks in construction. Reinforcement of aerated concrete masonry, diagram of the reinforcing frame

Reinforcement of aerated concrete is a necessary construction procedure, which is due to the fact that aerated concrete material Although it is resistant to compressive loads, with this feature it is not capable of stretching. The slightest bending leads to the appearance of cracks on the surface if the load that affects a specific installation location exceeds the strength of the block. Reinforcement of aerated concrete blocks is carried out by two different ways– strengthening masonry rows with reinforcement (mesh) or installation monolithic belt. Two methods increase the deformation resistance of the masonry, but they do not affect the load-bearing capacity of the partitions.

Problem areas that require mandatory wall reinforcement:

Developers often ask the question: is it necessary to reinforce the masonry in every 4 rows of gas blocks. This is determined based on the design features and length of the walls of the future building, the characteristics of the soil at the construction site and the type of foundation. Houses made of aerated concrete located in climatic, seismic and windy areas require reinforced wall reinforcement.

If the ends of the individual reinforcing bars were not tied into one contour, they should be bent at an angle of 90 degrees and deepened into the grooves - this will ensure reliable anchoring in the partition of the house.

Technology

First, the installation method will be described. reinforced concrete structure designed to strengthen the walls of a building against various loads. This armored belt is made from dense blocks 100 and 50 mm thick or wooden formwork is installed. The first technology is simpler and faster to implement.

Execution order

1. A 100 mm block is mounted from the front part of the wall and placed on the adhesive mortar to the main masonry.
2. Blocks 50 mm thick are laid on the inside.
3. Thermal insulation. Panels of extruded polystyrene foam adjusted to the height are glued to the wall with five centimeter gas blocks.
4. Reinforcement is placed inside the formwork at a distance of 5 cm from the partitions. It is recommended to weld vertical reinforced aerated concrete lintels YTONG to the longitudinal reinforcement every 30 cm, the height of which is selected in such a way that the upper part of the frame is located at a distance of five centimeters from the outer contour of the monolithic belt. Horizontal connection rods are welded to the vertical jumpers, on which the upper longitudinal chord of the structure must be fixed.
5. The space between blocks should be filled concrete mortar, the M200 or M300 brand is suitable for this.

Reinforcement with reinforcement between rows does not require special skills. To work, you will need a manual or electric wall chaser. In blocks, 2 strobes are made at a distance of 6 cm from the edge. The depth and width must correspond to the size of the reinforcement used.

After deepening, you should clean it from dust and fill it with an adhesive solution for laying gas blocks, then lay the parts of the reinforcement. Remove excess glue with a spatula. In the corner areas of partitions, rods are used, L-shaped. The fittings are interconnected by welding.

When a mesh is used to reinforce aerated concrete blocks, a building material with 5x5 cm cells made of 3-4 mm thick wire should be used. There is no need to do gating in this case, if installation work Glue is applied to the surface of the gas blocks, the approximate thickness is 2.3 mm. Afterwards, a mesh for reinforcement is laid, the edges of which should be 5 cm away from the end of the block. Next, a second layer of glue is applied.

Reinforcement of aerated concrete during masonry

When carrying out work, you should know how to properly reinforce and through how many rows to lay the rods. Reinforcement of the first row of masonry must be carried out without fail, and if necessary, every fourth (whether it is necessary - this is clarified from individual characteristics the buildings). The process is carried out as follows:

• Strengthening of the structure is carried out with steel bars with a diameter of 8 mm grade A3. Reinforcement of partitions with a thickness of 20 cm, the laying method allows the use of one reinforcement bar exactly in the middle of the row. IN special cases It is permissible to use reinforcement with a diameter of 6 mm.
• For thick walls, use 2 rods laid parallel to each other. To do this, with the help of a wall chaser, two parallel recesses are made. The distance from the internal and external edges of the partition is at least 6 cm. In the corners of the building, the grooves must be rounded.
• The overlap of the reinforcement is done in the middle of the wall, fixing is done with a knitting wire.

It is not necessary to lay reinforcement around the entire perimeter of each wall row. It will be enough to place the metal reinforcement in the most dangerous parts of the partition structure .

The vertical reinforcement of the walls is a connection between the foundation of the building and the interfloor or roofing monolithic armored belt located above it. This technology differs in that all loads are absorbed not by the wall masonry, but by the reinforcement frame. The walls serve as thermal insulation.

Door and window openings

When reinforcing jumpers, U-shaped blocks are used, which also need to be reinforced by at least 90 cm on both sides of the opening. First it is made wooden structure in the openings on which the U-shaped block will rest. Such blocks are installed with the thick side outward. It is also recommended to insulate the grooves with a 3-5 cm polystyrene foam board to close side walls outer surface of the blocks. Afterwards the reinforced structure is laid and filled with concrete. When the concrete has completely hardened, the structure is dismantled.

To prevent the process of laying the wall from slowing down, U-shaped blocks should be laid together with ordinary ones. Afterwards, the grooves are filled with reinforcement and concreted. It is recommended not to forget about the insulation.

Reinforcement under window openings requires laying reinforcement in the last row of blocks in front of the window being constructed. To do this, you will need to mark the planned length on the surface of the masonry, and the reinforcement bars should be half a meter longer than the window.

To obtain a reliable load-bearing wall from aerated blocks, you should pay attention Special attention choosing her correct design. It is necessary, for example, to take into account that aerated concrete has high compressive strength, but does not work well in bending and tension. At the same time, the masonry is subject to temperature fluctuations, wind loads, and foundation movements. These impacts can cause cracks in the walls. Reinforcement during the construction phase will help prevent the occurrence of such defects. This action has nothing to do with increasing the bearing capacity of the wall, but is aimed only at reducing its deformations.

To prevent the appearance of cracks in walls made of aerated concrete blocks, the following methods have become widespread:

• strengthening masonry and partitions with rods or mesh;
• installation of armored belts.

Use local rather than continuous reinforcement in places most susceptible to deformation:

• the first row of masonry above the base;
• window and doorways, lintels and areas of their support;
• every fourth row of masonry, if the length of the wall is less than 6 meters;
• gables and other parts of the building subject to strong wind loads.

Review of reinforcement materials

• Steel rods.
• Basalt mesh.
• Steel mesh.
• Fiberglass reinforcement.

1. Rods.

The peculiarity of aerated concrete masonry is that there are restrictions on the thickness of the wall seam (no more than 3 mm). At the same time, the recommended diameter of class AIII steel reinforcement is 6-8 mm. Therefore, the rods are laid in longitudinal grooves and filled with masonry glue. Cross connections are not used, the rods are rounded in the corners, and electric arc welding is needed to connect them at the junction points.

The disadvantages of using steel reinforcement for wall reinforcement are corrosion, high thermal conductivity and weight. There is an opinion that possible way to solve these problems is to use fiberglass reinforcement.

Compared to steel, it has a number of advantages.

• Higher corrosion resistance.
• Lower thermal conductivity.
• Higher tensile strength.
• Less weight.
• Resistance to aggressive environments.
• Radiotransparency of fittings.

A comparative analysis of these materials shows that non-metallic reinforcement also has disadvantages:

• it cannot be welded;
• mechanical processing produces dust that is harmful to the respiratory system;
• very low fire resistance;
• the elastic modulus is 3.5 times lower than that of steel. This extremely important difference must be taken into account when reinforcing walls. In other words, the cross-section of the fiberglass reinforcement must be increased by the same amount (according to crack opening). In the West it is indeed widely used, but with pre-tensioning. The proposals among some developers to alternate steel and composite reinforcement within one element, as follows from the large differences in their elasticity, are unacceptable.

These negative properties significantly limit the use of fiberglass rods for strengthening load-bearing walls and making armored belts on aerated concrete.

Some manufacturers do not require it to be used when laying a wall, citing the high strength of the blocks. At the same time, designers indicate the requirements for the mandatory use of reinforcing mesh, arguing that only it can withstand tensile loads.

In fact, everything is determined by the method of laying and the characteristics of the aerated concrete block. For example, if it has dimensions 625x400x250, grade D500, strength class B3.5, then a mesh is not required. But if the same wall is made of two elements 200 mm wide, then reinforcement is necessary every three rows. To make armored belts, fabric is not needed.

The masonry mesh made of steel wire with 50x50 mm cells recommended for reinforcement has a diameter of 3-4 mm. Its use entails an increase in the thickness of the masonry joint above the norm (with a corresponding deterioration in the thermal properties of the wall). Reason: since grooves are not performed and it is laid on the first layer of glue 2-3 mm (with a distance of 50 mm from the ends of the block), then a second one of the same thickness is applied and then the gas block is mounted.

In order to eliminate “cold bridges” due to an increase in the thickness of the masonry seam, a mesh can be used made from basalt-plastic rods fastened at the contact points with clamps, wire, and glue to form cells of a given geometry. In this case, it is necessary to take into account the disadvantages of composite materials mentioned above.

Reinforcement technology

Required tools:

• Hacksaws or grinder.
• Brushes or hair dryer.
• Container for mixing glue, construction mixer.
• Measuring tools (tape measure, squares).
• Putty knife.
• Electric arc welding machine.

How to properly reinforce aerated concrete masonry:

1. In blocks over 200 mm wide, two grooves of 25 mm each are marked at a distance of 60 mm from the outer edges of the wall. If the thickness does not exceed 200 mm, for example, for a partition, then one groove in its middle is enough.
2. Cut grooves in the body of the block with a depth of 20-25 mm along the wall - in a straight line, in the corners - with a rounding.
3. Reinforcing bars are cut to specified sizes. For corners, they are bent in an L-shape, while providing the necessary overlap at the junction points.
4. The grooves are thoroughly cleaned of dust using brushes or a hairdryer, moistened and filled with glue.
5. The reinforcement is welded and placed in the grooves, and it is important to fill it completely with glue so that it does not come into contact with aerated concrete to avoid corrosion of the steel.
6. After hardening the walls, the irregularities on their surface are carefully cleaned and polished before laying the next row.

Under the lintel supports, 900 mm of reinforcement must be provided on each side of the opening. As for partitions, in addition, at the points of their connection with the wall, T-shaped anchors or metal brackets made of of stainless steel with a diameter of 4 mm. They are laid in the horizontal joints of the block masonry every two rows. Not load-bearing walls partitions can be reinforced with rods or mesh made of composite materials.

Installation of a monolithic armored belt:

• By using permanent formwork from U-shaped blocks and wooden panels.
• Production of armored belts using additional aerated concrete blocks with a thickness of 100 and 50 mm.

Installation procedure:

1. On the outside of the wall, an additional 100 mm wide extension block is installed flush and glued to it around the perimeter.
2. WITH inside walls for forming the formwork of the belt, an additional block of 50 mm is similarly glued along the contour.
3. Extruded polystyrene foam 5 cm thick is glued to the 50 mm block for thermal insulation of the armored belt.
4. A reinforcement frame of the belt is mounted inside such aerated concrete formwork: the longitudinal upper and lower rods are welded together with transverse rods at intervals of 300 mm. Their diameter must be at least 6 mm. It is important to ensure that the reinforcement does not come into contact with the walls of the formwork and does not exceed its height.
5. Heavy concrete grade M200-M300 is poured into the resulting armored belt formwork, compacted and leveled along the upper plane of the additional block.

The construction of a reinforced belt using U-shaped elements is carried out in the same way as for ordinary blocks. If the thickness of the wall allows, then use it as formwork. ready block this form. When making an armored belt, it is installed with a wide shelf outward. The reinforced frame is placed inside a U-shaped gas block belt and filled with concrete.

If the width of the permanent formwork of the additional U-shaped element is less than the thickness of the masonry, it is installed on the outside of the wall of the belt. Fasten along the inner contour wooden boards. The reinforcement is mounted in both resulting trays of the reinforced belt.

Price

The price depends on the size and type of material. A comparison with the same diameters shows that a metal mesh is 30% cheaper than a composite one. Prices for steel and fiberglass reinforcement are similar in many respects. At the same time, sellers, advertising their goods, offer an “equal-strength” replacement of metal with a composite. Thus, fiberglass with a diameter of 6 mm is recommended instead of steel 8 mm. The maximum strength of this product is higher, but the modulus of elasticity is 3.5-4 times lower than that of metal. That is, to work under the same tensile loads, the diameters of fiberglass must be larger (several times) than those of steel.

The construction industry, despite the crises that follow one after another, is one of the most actively developing industries. The share of private housing construction also tends to grow. This is largely due to the fact that modern materials and technology allows you to build houses quickly enough. Wherein stove heating is becoming a thing of the past, it has been replaced by individual heating systems that automatically maintain the temperature in the house.

But there is always a need to save on construction. Therefore, many developers prefer to use lighter materials for the construction of their homes than before. This allows you to significantly reduce the cost of building the foundation of a house, which often "eats up" up to 25% of the total estimated cost of construction.

One of these materials are gas blocks, which are produced using cement, sand, water, lime, gypsum and aluminum powder. Often materials such as ash and slag are also used for their manufacture.

Gas block - what is it

The gas block is a light building stone of artificial origin.

According to the production method, gas blocks are divided into 2 types:

• Autoclaved aerated concrete - cured by exposure to high pressure and saturated steam. At the same time, the structure of the material changes, giving the material strength.
• Aerated concrete of natural hardening. It also has a cellular structure, but its properties are inferior to the autoclaved counterpart. This material is more susceptible to shrinkage and cracking, so it is used mainly for structures with light loads.

The use of lightweight blocks gives the developer the following advantages:

• Reducing the cost of construction up to 40%.
• Durability of construction correct operation is up to 100 years.
• Thanks to the substances used to produce the blocks, the blocks are highly resistant to low temperatures, moisture and fire, while being lightweight and environmentally friendly.
• Aerated concrete is easy to process - it is easy to plan, saw and drill. If necessary, a nail or staple can be easily driven into the partition.

But the tendency to deformation is weak side material, therefore, when constructing walls, the masonry must be reinforced.

The following types of reinforcement are used to reinforce aerated concrete structures:

• Hot-rolled corrugated reinforcement of class A3 with a diameter of 8 mm - used for inter-row reinforcement of walls. It fits into specially prepared grooves cut into the blocks, and thus does not increase the thickness of the masonry joints. This is important, since it is the thin seams that allow maximum use thermal insulation properties aerated concrete.
• Masonry mesh made of wire with a thickness of at least 3 mm does not require grooves, as it is small in thickness. This method reduces the labor intensity of work and the speed of wall construction.
• A galvanized steel strip with a cross-section of 8*1.5 mm also does not require grooves.
• Fiberglass reinforcement, which, like steel, is laid in prepared strobes.

The use of composite reinforcement has a number of advantages:

• low weight, allowing you not to unnecessarily load the masonry;
• low coefficient of thermal conductivity, ensuring the absence of cold bridges between the rows;
• absolute corrosion resistance even in the presence of moisture;
• excellent resistance to tensile loads, which aerated concrete weakly resists;
• service life up to 100 years;
• low (compared to steel reinforcement) cost.

The disadvantages of fiberglass are:

• the impossibility of bending rods under construction site conditions;
• the impossibility of welding the bars together, requiring the use of special sleeves to connect the elements into a single frame.

There are three main types of reinforcement for aerated concrete masonry:

• Horizontal reinforcement of the first type, aimed at preventing the formation of cracks in partitions and openings made of aerated concrete. This type is mainly used for small block buildings.
• Reinforcement of the second type is used to protect masonry from cracks, which will subsequently be often subjected to wind influences, temperature fluctuations or other loads that exceed the allowable ones.
• Vertical reinforcement of the masonry (connecting the upper strapping of the building to the foundation) is used when the building can be subjected to severe horizontal loads - when located on a slope, with possible exposure to hurricanes, in places with a high probability of avalanches. In Russia, this type of reinforcement has not yet found widespread use.

Ideally, the reinforcement scheme is specified in project documentation on house. But if the house is being built without a project, then the reinforcement is laid in the most loaded masonry places, where there is a high risk of tensile loads.

The busiest places:

• the first row of blocks laid directly on the foundation;
• rows of masonry located under window and door openings;
• jumper support zones;
• reinforced concrete belt along the top of the masonry;
• every 4th row of walls, especially long or blank ones.

There are other reinforcement schemes, but this one is used most often.

Reinforcement laying technology

An important step in reinforcement is the installation of a reinforcing belt along the top of the masonry. Sometimes builders replace it brickwork, but this should not be done. The purpose of the reinforced belt is to uniformly distribute the load from the floor and roof structures onto the walls.

The easiest way to install an armored belt is to use additional gas blocks with a thickness of 101 and 50 mm:

• From the outside of the wall along the entire perimeter of the building special glue blocks 100 mm thick are glued.
• Blocks 50 mm thick are placed along the inner contour of the wall. In this way, an improvised formwork is formed for pouring the armored belt.
• A panel of extruded polystyrene foam is glued to the inside of the thinner block as insulation.
• Reinforcement is placed inside the formwork at a distance of 50 mm from the walls using special mushroom stands. The longitudinal rods are connected to each other by vertical rods, the height of which should be 50 mm less than the depth of the formwork. Horizontal connecting rods are welded to them, fixing the upper chord of the frame.
• Then the formwork is filled with M300 concrete.

If the reinforced belt is intended for laying an interfloor floor, then further laying of the upper floors can be continued only after the concrete has gained strength (10-15 days).

Inter-row reinforcement of masonry is not difficult to perform:

• On the upper edge of the laid row of blocks, you need to cut 2 grooves approximately 25 mm wide and deep. To do this, you can use either an electric or a manual wall chaser (aerated concrete is easy to process).
• If the block thickness is no more than 20 cm, the reinforcement is placed in one groove - in the center of the block. If the block is wide, then you need to make two grooves. They should be located at a distance of 60 mm from the outer edges of the block.
• The resulting grooves must be thoroughly cleaned of dust and moistened. After that, they are filled with adhesive for gas blocks to 2/3 of the height.
• The reinforcement, pre-prepared at the installation site, is placed directly into the adhesive layer, which serves additional protection from corrosion. L-shaped rods are laid in the corners of the masonry. The reinforcing bars are connected to each other by welding.
• Excess glue is removed with a spatula.
• Next, the next row of blocks is laid.

• It is necessary to strictly ensure that the edges of the mesh are 50 mm away from the edges of the block.
• A layer of glue 3 mm thick is applied to the surface of the block, and a mesh is placed in it.
• Another layer of glue is applied on top.

Partitions, especially long ones, should also be reinforced. They must be connected with reinforcement to the external walls.

Thus, the reinforcement of walls made of aerated concrete blocks is carried out not with the aim of increasing their load-bearing capacity, but to protect the blocks from tensile loads, as a result of which cracks may form in them. The purpose of concrete reinforced belts is to uniformly distribute loads from interfloor floors or roofs onto the walls.

In order to protect walls and partitions from the appearance of cracks caused by subsidence of the bottom soil or temperature changes, in some cases reinforcement of aerated concrete blocks is used. Metal rods take on tensile loads and protect aerated concrete blocks from cracking. Reinforcement with reinforcement does not increase its load-bearing capacity, but minimizes the consequences of brittle destruction of aerated concrete elements.

Approximate diagram. Reinforcement areas for a specific structure are determined by the designer.

Climatic, seismic and wind conditions directly affect the need for wall reinforcement. More at the design stage, the need to strengthen the walls with reinforcement is clarified, and also indicates the type of reinforcement used and its location.

Laying reinforcement along the entire perimeter of each wall row is not necessary. It will be enough to place metal reinforcement in the most dangerous elements of the wall structure.

Places for mandatory reinforcement of aerated concrete walls:

1. First row of blocks, laid on the foundation;
2. If the wall length exceeds 6 meters, additional horizontal reinforcement is placed in every fourth masonry row to compensate for wind load;
3. Connections of floors and rafters to wall structures. In this case, it is performed), where the reinforcing rods are laid in;
4. Openings in walls: the supporting part under the lintels, as well as the lower part of the window opening over the entire width with the addition of an overlap of 0.9 meters on each side of it;
5. Vertical reinforcement is placed in gas silicate columns;
6. Potential Load Locations exceeding the standard.

Developers often have questions and disputes about whether it is necessary to reinforce walls in every fourth row of blocks. The need is determined by the designer based on design features and the length of the walls of the future building, the seismic zone of the area, the strength and wind pattern in the area, the characteristics of the soil in the building area and the type of foundation, as well as the characteristics of the wall material. Here it is determined whether the gas silicate used in construction is strong enough to withstand the resulting loads and not cause microcracks.

If you are saving on the project, then make the calculations yourself. Either reinforce it and sleep well, as it definitely won’t get any worse, but bear the costs of purchasing reinforcement and glue.

If the ends of individual reinforcing bars are not tied into one contour, then they must be bent at a right angle and buried in the grooves to ensure reliable anchoring in the wall of the building.

Execution

First row

Reinforcement of the first row of masonry, as well as every fourth row, if necessary, is carried out as follows.

The structure is reinforced with steel rods with a diameter of 8 mm, grade A III. For a wall 200 mm thick, it is enough to lay one reinforcement bar exactly in the middle of the row.

For thicker walls, use 2 rods. They are laid parallel to each other. To do this, make 2 parallel grooves using a wall chaser. The distance from the inner and outer edges of the wall to the grooves must be at least 6 cm. In the corners of the building, the grooves are rounded along a radius.

Dust is swept out of the finished grooves with a brush, filled with adhesive, reinforcement is laid and excess glue is removed using a spatula.

The reinforcement in the corners should not be interrupted. It is rounded so that it follows the radius of the groove.

Therefore, overlap the reinforcement approximately in the middle of the wall, fixing it with tying wire.

Reinforcement under the window opening

Laying reinforcement in aerated concrete blocks is necessary under window opening. The laying is done in the last row of blocks in front of the window being constructed. To do this, its planned length is measured and marked on the surface of the masonry (the reinforcement bars should be 0.5 meters longer than the length of the window). Next, in the masonry row, at a distance of 60 mm from the outer and inner sides of the wall, aerated concrete is chipped using a manual wall chaser. Namely, 2 grooves are cut, the minimum cross-section of each is 2.5x2.5 cm.

To ensure evenness, the grooves can be nailed to the desired row of blocks wooden board, which will act as a rule when cutting a notch.

From the grooves, using a brush, it is necessary to remove dust and crumbs of aerated concrete formed during the cutting process. Before laying the reinforcing bars and embedding with mortar, the cut-out strobes are moistened with water. This is done for the best bonding of the adhesive solution with reinforced aerated concrete.

At the next stage, the groove is half-height filled with a mortar for thin-seam block masonry, then profiled steel reinforcement with a diameter of at least 6 millimeters is laid. The groove is completely filled with mortar, if necessary, removing all its excess and leveling the seam with a trowel.

The next masonry row can be mounted immediately after strengthening the window sill.

Vertical wall reinforcement

This type is used extremely rarely in the following cases:

1. Reinforcement of a wall that may be subject to strong lateral loads. In this case, it is necessary to carry out horizontal reinforcement.
2. When using low quality aerated concrete with a minimum density index.
3. In places where heavy elements rest on the wall structure ( metal beams and etc.).
4. Corner dressing of the joining of adjacent walls.
5. Strengthening small walls and door and window openings.
6. Construction of a column from aerated concrete blocks.
7. When using large-sized wall panels.

Materials used

Besides classic version(use of reinforcement) other materials can be used to reinforce block masonry:

Galvanized metal mesh

It consists of steel rods welded in a mutually perpendicular position.

Of all the types of mesh used, metal is the most durable. But she has one big minus: special adhesive composition for connecting wall blocks contributes to the development of corrosion, which leads to quite rapid loss all the positive properties of such reinforcement. Also transverse rods act as cold bridges in winter. I do not recommend this type of enhancement.

Basalt mesh

It is made of basalt fiber rods, which are arranged perpendicular to each other. In butt joints, the rods are fixed with wire, clamps or specialized glue. This fastening ensures the correct and even geometric shape of the cells.

Basalt mesh can withstand strong tensile loads - about 50 kN/m. Its weight is several times less than that of metal mesh, which ensures ease of reinforcement work.

Basalt-based meshes are resistant to negative influence corrosion, does not respond to change temperature conditions. They have very low thermal conductivity, which ensures the absence of a cold bridge that occurs when reinforced with steel mesh.

Basalt mesh costs quite a bit, so this solution is the most expensive of those proposed.

Metal mounting perforated tape

This is a galvanized strip of steel with holes made along its entire length.

It is enough to purchase a tape with dimensions of 16x1 mm. Reinforcement of the masonry is carried out without cutting the aerated concrete by fixing it with self-tapping screws. Otherwise the principle is the same as when using reinforcement. To increase strength, it is possible to fasten the strips in pairs using steel wire. Has lower bending strength compared to profiled reinforcement.

Attention!

Online construction stores and punched paper tape with a thickness of 0.5-0.6 mm is common in markets. It is not suitable for reinforcement. Look for 1mm thick punched paper tape in specialty stores or order online in advance. Unfortunately, it is not so easy to buy it on the regular construction market.

I see the advantages of using this material compared to traditional fittings as follows:

• savings on delivery due to the compactness of the tape;
• no need to make grooves (saving on labor and installation adhesive).

Fiberglass reinforcement

The main material of the reinforcement is fiberglass, on which the thread is wound in a spiral to ensure better adhesion to concrete.

Significantly lighter in weight than its metal counterpart. Low thermal conductivity will avoid cold bridges in aerated concrete masonry. Ease of installation is ensured minimum quantity joints, since such reinforcement is sold in packages in coils.

Attention!

Fiberglass reinforcement has a significant disadvantage - it cannot withstand high fracture loads, and this is the main task of reinforcing masonry made of aerated concrete blocks with increased bending stress.

It is impossible to build a rigid frame from this material, so this reinforcement is not recommended in seismically hazardous construction areas. Our verdict is not to use.

The benefits of reinforcing wall structures are obvious. Therefore, it is worth sacrificing small additional monetary costs and time during installation, so that the building being constructed will serve you faithfully for many years.

Useful video

The video shows the reinforcement of the first row clearly and in detail. Namely, chipping blocks, laying reinforcement with bending in the corners, filling with glue.

Aerated concrete is popular construction material, characterized by minimal cost and excellent performance characteristics. Houses with an optimal microclimate are built from aerated concrete and do not require additional thermal insulation. In order for a building to be reliable and durable, it is necessary to provide for its walls, which we will talk about in this article.

You will learn how to reinforce aerated concrete blocks and what materials are best used for this. The places that need to be reinforced and the technology for doing the work yourself will be considered.

1 Why is aerated concrete reinforcement necessary?

The need to reinforce masonry walls is determined by the fact that aerated concrete as a material has high resistance to compressive loads, but at the same time it is practically incapable of tensile and bending, which can cause cracks to appear on the walls if the load at a specific point of the masonry is exceed the deformation strength of the aerated concrete block.

Reinforcement of walls made of aerated concrete (you can read about it separately) involves the implementation of two different methods:

• strengthening masonry rows with reinforcement or mesh;
• installation of a monolithic belt.

Both methods are aimed at increasing the deformation resistance of the masonry, but they do not in any way affect the load-bearing capacity of the walls. Reinforcement with reinforcement is performed in the following areas:

1. The first row of masonry above the foundation (you can read about reinforcement separately).
2. Support points for partitions (windows and doors) and ceilings on the wall.
3. Every 4th row of masonry, if the length of the walls exceeds 6 meters.

When reinforcing partitions, the reinforcement must be laid across the entire width of the opening With 90 cm spades beyond its edges. Reinforcement of the masonry is carried out with one central belt, if the thickness of the walls does not exceed 20 cm, or with two belts spaced on the sides of the block, if the thickness of the walls is more than 20 cm.

The armored belt is a line parallel to the walls of the house made of monolithic concrete, which performs the main function of increasing the strength of walls. The armored belt should occupy the entire area of ​​the building and be located in the areas of the basement and interfloor ceilings. Floor lintels are installed on a monolithic belt, and not on aerated concrete blocks with low point strength.

1.1 What fittings should I use?

When reinforcing walls between rows, reinforcement bars are laid inside grooves specially made on the surface of aerated concrete blocks, so the reinforcement does not increase the thickness of the masonry joints. A proven option is hot-rolled corrugated with a diameter of 8 mm. It is not advisable to use rods with a larger cross-section.

Manufacturers of aerated blocks also provide the possibility of using. Despite the fact that there is no regulatory documentation for such products in domestic construction, the practice of using fiberglass reinforcement is widespread in the West.

The advantages of composite products include:

• minimum weight that does not place additional stress on the masonry;
• complete resistance to corrosion due to high humidity;
• high deformation resistance to tensile and bending loads;
• low thermal conductivity - when using fiberglass reinforcement, cold bridges do not form between the rows of masonry;
• long service life (up to 100 years) and 2-3 times lower cost than its steel counterpart.

The disadvantages of fiberglass reinforcement include the impossibility of bending it directly on the construction site and the need to use special sleeves to connect the rods to each other - welding is not used for connection.

Also, inter-row reinforcement of walls can be made of wire with a thickness of at least 3 mm or strips of galvanized steel with a cross-section of 8 * 1.5 mm. Reinforcement with mesh and strips does not require gating of gas blocks, since the embedded products have a minimum thickness, which significantly reduces the labor intensity of raising the walls of the house.

1.2 Is vertical reinforcement necessary?

The essence of vertical reinforcement is to connect the foundation of the house with the interfloor or roofing monolithic reinforced belt located above it using reinforcement rods located in grooves filled with heavy concrete.

Such reinforcement can be placed within the first floor of the house or continue throughout the entire height of the building. The main difference of this technology is that in the case of installing a vertical reinforced frame, all loads are absorbed not by the wall masonry, but by the reinforcement frame, while the walls perform an exclusively heat-insulating function.

Vertical reinforcement of masonry must be performed in the following cases:

• at the risk of increased loads to increase the seismic resistance of walls;
• if it is necessary to increase the load-bearing capacity of the masonry (reinforcement allows the use of cheaper low-density gas block for construction);
• if there are large openings in the wall.

For vertical reinforcement, steel rods with a diameter exceeding 14 mm must be used; the use of fiberglass reinforcement is not allowed. The reinforcement is laid inside shaped O-blocks or in grooves with a diameter of 13-15 mm made using a special core drill. The free space between the rod and the walls of the groove is filled with heavy concrete grade M200-M300. The minimum thickness between the rod and the walls is 5 cm.

Under standard conditions, the reinforcement is performed in one rod, but if the house is located in a region with increased seismic activity, the reinforcement can be performed in 4 rods inside each groove. Vertical reinforcement is required embed into the foundation and upper reinforced belt. can be installed at the stage of pouring the foundation or after it has reached its design strength in the drilled holes.

Vertical reinforcement should be placed at a distance of 20 cm from the ends of the walls and no more than 61 cm from the partitions of door and window openings. The maximum step between the belts is 300 cm. It is mandatory to place a vertical belt in the corners and at the junction of the walls of the building.

1.3 Reinforcement of aerated concrete masonry (video)

2 Reinforcement technology

First, let's look at the technology for installing a monolithic armored belt. It can be made using additional blocks 10 and 5 cm thick or by installing wooden formwork. The first option is simpler and faster to implement. The execution technology is as follows:

Further raising of the walls can begin after 1-2 weeks, which are necessary for the concrete to gain strength. If a monolithic floor belt is being installed, then studs are concreted into it for fastening the timber.

Inter-row reinforcement of masonry is extremely simple to implement. Using a special wall chaser (manual or electric), two grooves are made in the block at a distance of 6 cm from the edges. The depth and width of the grooves must correspond to the cross-section of the reinforcement used.

Next, the grooves are cleaned of dust and filled with adhesive for laying aerated concrete, after which reinforcement bars are placed inside the grooves. In the corners of the walls it is necessary to use rods curved in an L-shape. The rods are connected to each other using. Excess glue is removed with a spatula.

If produced, it is necessary to use material with a cell size of 50 * 50 mm from wire 3-4 mm thick. The blocks are not grooved when laying the mesh - it is enough to apply a 2-3 mm thick layer of glue to the surface of the gas block, lay the mesh on it (the edges are 5 cm away from the ends of the block) and spread the second layer of glue.