Everything about the reinforcement of aerated concrete blocks: reinforced areas and materials used. Reinforcement of aerated concrete Reinforcement of masonry walls made of aerated concrete blocks

A series of articles dedicated to... We discussed:

- - in the article there is a dispute between manufacturers of aerated concrete blocks and designers of buildings made from this building material: is it generally necessary to reinforce the masonry of walls made from these blocks?;
  - in the article the choice of mesh material for each specific case of masonry;
  - The article contains complete information about this building material.

So, having read the above articles, you have decided on the need to reinforce walls from aerated concrete blocks (in certain cases, walls from this material are not reinforced). And you know that all types of structural reinforcement of masonry walls of buildings made of aerated blocks do not increase its load-bearing capacity, but only lead to a significant reduction in the risk of temperature-shrinkage cracks.

Now you need to select the material for reinforcement. Today we will answer the question: what is better in different cases to reinforce aerated concrete blocks - with mesh or reinforcement?

Selecting reinforcement material

Metal reinforcement has great mechanical strength and can withstand greater loads compared to non-metallic reinforcement. The total cross-sectional area of the reinforcing steel rod should be only ≥ 0.02% of the same parameter of the reinforced aerated concrete masonry. Therefore, this material is widely used, but not everywhere.

The fact is that steel has several disadvantages, forcing, at the first opportunity (i.e., when ensuring the necessary mechanical strength of the masonry), to replace it with non-metallic reinforcement. Here is an incomplete list of these annoying “cons”:

- - susceptibility to corrosion. In an aggressive environment, such as mortar or glue, a metal rod or mesh may rust and lose its original strength;
  - the process of reinforcement with steel reinforcement has a high cost (transportation and loading and unloading costs, cost of material and installation with gating and fitting of rods in place, etc.);
  - steel reinforcement creates “cold bridges”, which significantly increase the thermal conductivity of walls made of aerated blocks.

Non-metallic meshes are used to replace metal: propylene, composite and fiberglass. They have less mechanical strength compared to metal structures. But they contain a large number of polymer additives that are not susceptible to corrosion and exposure to an aggressive alkaline environment. In addition, these meshes eliminate the formation of “cold bridges”, which significantly reduces the thermal conductivity of the wall (this is especially true if the wall is external).

Metal fittings

Rods and welded mesh are used as metal reinforcement. Rods must be used when installing the entire contour of vertical reinforcement (lower and upper reinforced belts, vertical braces, etc.).

They are used to strengthen masonry under window and door frames, service hatches, etc. Grooves are made for laying rods. To reduce the corrosion process, the metal rod must be recessed in the mortar (inside the groove) by at least 2 mm on each side.

The most complex, labor-intensive and expensive reinforcement process is the process using welded mesh. If, to increase strength, you use a mesh made from large-diameter reinforcement, this will lead to an increase in the thickness of the seam and, accordingly, a decrease in its strength. This is due to the fact that there will be a large amount of mortar between the rows of blocks. Therefore, meshes with a rod diameter of 3...5 mm are used.

The technical characteristics of the mesh are regulated by the GOST 23279-2012 standard “Welded reinforcement mesh for reinforced concrete structures and products. General technical conditions". In accordance with it, the mesh is made from reinforcing wire of class Vr-1 and V-1 Ø 3...5 mm. Dimensions are shown in the picture.

Non-metallic fittings

This type of reinforcement includes propylene, composite and fiberglass mesh. They are discussed in detail in the article. We will not repeat ourselves, but here we will only note that the most widespread, due to its properties, is a composite mesh consisting of basalt rods.

Composite meshes are produced in accordance with the enterprise standard STO 5952-022-98214589-2013* “Meshes made of basalt fiber brand SBNPs “GRIDEX”. Technical conditions". This document prescribes the following cell sizes, mm: 25 x 25, 25 x 8, 50 x 50, 100 x 100, 150 x 150, 200 x 200. The mesh width must be within the range, mm: 105...5400.

Recommendations for reinforcing aerated concrete using masonry mesh

Many building materials are used to construct buildings. Gas-filled concrete blocks are no exception. They have increased thermal insulation properties and are widely used in the construction industry due to many advantages - lightness, workability, environmental friendliness, frost resistance. However, the material is not strong enough and cracks under stress. Reinforcement of aerated concrete blocks allows you to strengthen the walls of a house made of aerated concrete. Reinforcement is made with masonry mesh or steel reinforcement is used.

Aerated concrete blocks: material properties

When thinking about the question of whether it is advisable to reinforce gas-filled concrete, it is necessary to study the properties of the material, as well as become familiar with the characteristics of the composite. A detailed analysis will allow you to make the right decision. The technology used to produce aerated concrete determines the properties of the building material. It has a cellular structure due to air pores evenly distributed throughout the mass. This feature improves thermal insulation characteristics.

Houses made of aerated concrete do not require additional thermal insulation protection, and a favorable temperature is maintained indoors with minimal heating costs. This is just one of the advantages.

Aerated concrete is a popular building material characterized by minimal cost and excellent performance characteristics.

Aerated concrete blocks have many other advantages, which are appreciated by professionals and private developers:

excellent sound insulation. Thanks to the cellular structure, noise cannot penetrate from the street into the room through the masonry;
frost resistance. When freezing as a result of a sharp drop in temperature followed by thawing, moisture cannot destroy aerated concrete;
ecological frequency. As a result of the use of environmentally friendly materials, there is no negative impact on human health;
ease of processing. Using a conventional tool, it is easy to process an aerated concrete wall into the required shape;
ease. Due to the light weight of the blocks, aerated concrete walls do not create a significant load on the foundation of the building;
durability. The material does not rot, since conditions for mold growth are not created in the depths of the array and outside.

The main disadvantage of gas-filled composites is low strength. There is a proven solution to strengthen problem areas. It is necessary to reinforce aerated concrete with mesh or steel reinforcement. Reinforced material is able to withstand significant loads, maintaining integrity during long-term use.

Is it necessary to strengthen aerated concrete walls?

There is no need to doubt whether it is worth reinforcing a cellular composite.

In order for a building to be reliable and durable, it is necessary to provide reinforcement for its walls.

Reinforcement of aerated concrete masonry is a mandatory measure, since negative factors reduce the strength characteristics of the material:

the upper tier of load-bearing walls takes the load from the rafters, which are secured with the help of special actors. At the fixation points, loads act that violate the integrity of the array if the aerated block is not reinforced;
load-bearing roof beams located at an angle create serious thrust loads. They act horizontally, trying to cause the top level of the walls to move. The reinforcement frame concreted along the contour smooths out the forces;
walls made of porous material deform unevenly. This is due to the presence of openings for window frames and doors. Uneven settlement can be prevented by reinforcement concreted in a groove along the upper contour of the opening.

The characteristics of the material dictate the feasibility of its additional reinforcement, which provides:

masonry stability;
compensation of loads from rafters;
prevention of deformations;
reducing the likelihood of cracks forming;
proportional distribution of efforts;
integrity of load-bearing walls;
maintaining the geometry of openings;
durability of aerated concrete in seismic zones;

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 not capable of tensile and bending.

strength of the material during deformation;
stability of a building erected on an inclined site.

After a thorough analysis of these factors, doubts completely disappear as to whether it is necessary to strengthen the walls of a building built from cellular concrete.

In which areas is reinforcement of aerated concrete blocks required?

Aerated concrete blocks, which include many air cavities, have insufficient strength and require additional reinforcement at various levels.

The following problem areas need strengthening:

the lower tier of masonry at the foundation level. It perceives forces from the mass of the building and the reaction of the soil. To ensure the strength of the supporting surface, aerated concrete is reinforced with a mesh;
aerated concrete masonry blocks. At intervals of four levels, reinforcement is installed in pre-made grooves or the blocks are strengthened with masonry mesh, followed by cementation;
upper level of main walls. It is affected by the weight of the floor panels and the weight of the truss structure. The concreted reinforcement frame does not allow cracks to develop and evens out the existing loads;
openings for installing doors and windows. These areas weaken the masonry. They are strengthened with reinforcing bars placed in special grooves and filled with cement mortar.

Having figured out how to reinforce cellular blocks, you can strengthen problem areas on your own.

Reinforcement of the masonry is carried out with one central belt if the thickness of the walls does not exceed 20 cm

Reinforcement of aerated concrete masonry - preparing tools and materials

To carry out reinforcement activities, you will need the following tools:

a saw that allows you to adjust the size of the blocks;
wall chaser, which allows you to form grooves;
grinder with a metal circle for cutting reinforcement;
special equipment that allows bending rods;
hook for crocheting wire, speeding up the assembly of the frame;
tape measure and building level to control the correctness of the work.

It is also necessary to prepare the building materials used for reinforcement:

steel wire mesh. A masonry mesh with square cells with a side of 5–7 cm is used. It is laid on an aerated concrete surface and covered with cement mortar;
reinforcing bars with a diameter of 0.8–1.4 cm. They are able to withstand significant compressive and tensile loads. The rods are placed in grooves and cemented;
cement mortar. It is prepared according to a standard recipe using cement M350 and higher. When pouring the mixture, it is important to completely cover the fittings with the solution, avoiding contact with air;
knitting wire. Heat-treated wire is used, which becomes more pliable after annealing. It will be needed to fix the reinforcement frame elements using a crochet hook.

After preparing the materials and tools necessary to complete the work, you can begin work.

The armored belt should occupy the entire area of the building and be located in the areas of the basement and interfloor ceilings

Reinforcement of aerated concrete masonry - work technology

The maximum effort is absorbed by the lower tier. It is important to strengthen it correctly. The technology for performing the work is quite simple:

Use a wall chaser to form a groove in the horizontal surface of the gas blocks.
Clean the resulting cavity from dust and construction debris.
Mark the reinforcement according to the drawing, cut the blanks with a grinder.
Place the rods in the grooves and connect them together with binding wire.
Cement the cavities with liquid cement and plan the base.

Some developers doubt which method is best to connect the reinforcement. Should I use electric welding or tying wire? Professional builders recommend knitting with wire, since welding weakens the metal structure and, under load, the integrity of the reinforcement may be damaged.

Reinforcement of aerated concrete with reinforcement - strengthening the upper chord of the walls

The upper tier of main walls requires special attention. It absorbs the loads from the roof structure. When using heavy slate or clay tiles, the forces on the surface of the aerated concrete increase significantly and can cause serious deformation. Reinforcing the upper tier of the masonry will help avoid damage.

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

It will allow:

reduce the influence of locally acting loads;
distribute forces proportionally around the perimeter.

In addition, after pouring the reinforcement with mortar, a flat surface is formed for installing the roof structure.

There are various options for reinforcing the upper level of walls:

using collapsible or stationary formwork. Wood, plywood or polystyrene boards can be used to make formwork;
using ready-made U-shaped aerated concrete blocks. The use of standard products with a groove significantly reduces the duration of work.

Let's consider the algorithm of actions for strengthening aerated concrete using collapsible formwork:

Cut boards for assembling panel elements.
Assemble the formwork.
Prepare reinforcing bars of the required sizes.
Assemble the reinforcement grid by tying the rods with wire.
Place the frame in the formwork and fill it with concrete solution.
Compact the concrete and cover its surface with plastic film.
Regularly moisten the array until it reaches its final hardness.
Dismantle the formwork panels after the concrete has dried.

It’s easy to do all the work yourself after studying the technology.

Installation of armored belt on aerated concrete wall

Learning to reinforce walls from gas-filled blocks

Reinforcement with masonry mesh is a simple operation:

Lay the purchased mesh on the aerated concrete surface.
Spread a layer of solution evenly over the mesh.
Lay aerated concrete blocks.

By laying metal mesh at intervals of four rows, you can significantly increase the strength of aerated concrete walls. It is important to completely cover the mesh with solution to prevent corrosion.

Reinforcement of aerated concrete walls in the area of openings

Stresses are created in the reception area, which cause cracks to appear. To avoid defects, the upper section of the opening should be reinforced with reinforcement.

Horizontal reinforcement provides:

Preparing grooves in the upper part of the opening.
Laying steel reinforcement in the cavity.
Filling the rods with cement mortar.

To speed up the work, it is advisable to use standard U-shaped aerated concrete elements.

Let's sum it up

Reinforcement of aerated concrete blocks is a necessary operation to strengthen the structure and increase the durability of the building. It is important to comply with technological requirements and use high-quality building materials. Doing the work yourself will reduce costs.

Reinforcement of aerated concrete is a mandatory stage of construction when using this material, thanks to which it is possible to neutralize the impact of block deficiencies on the strength and reliability of the building. demonstrate excellent performance characteristics, are inexpensive, do not require additional thermal insulation, are convenient and easy to use, and allow you to speed up the process of building construction.

But the material has one drawback - the gas block is poorly resistant to bending deformations and is fragile, therefore, without additional reinforcement, the walls will soon become covered with cracks and require additional finishing and repairs. Reinforcing aerated concrete blocks with reinforcement will help to avoid shrinkage cracks and increase bending strength.

Aerated concrete: pros and cons of the material

The material is used quite widely today. And before abandoning it due to the reluctance to reinforce a house made of aerated concrete and spend money on additional work, it is worth considering the positive aspects of using blocks in construction.

Main advantages:

Light weight, allowing you to save on the foundation and significantly simplify the process of transportation and construction of the building
Low heat transfer coefficient - heating the house will be much more economical
High strength - the ability to build multi-story buildings without constructing a complex, expensive foundation
Possibility of eliminating the cement mixture - a special adhesive composition minimizes the negative effect of cold bridges, reducing heat loss from 25% to 7-10%
Durability - according to laboratory tests, blocks can last at least 100 years with full preservation of the original appearance and operational properties
Sufficient level of air and vapor permeability - corresponds to the indicators of wooden structures and guarantees natural air circulation in the room, which creates an optimal microclimate and normalizes humidity levels
Resistance to changes in humidity and temperature, open fire, microorganisms (fungus, mold)
Ease and simplicity of installation and processing - even a beginner can lay walls from neat, even blocks
Large dimensions and high precision - walls can be erected with minimal deviations, saving money on external finishing, avoiding gaps in the masonry thanks to the use of blocks with grooves, spending less time on forcing walls
Safety – the material is environmentally friendly, not afraid of fire, resistant to damage by rodents and insects
Frost resistance - blocks can withstand frost down to -50C, survive about 50 freeze/thaw cycles

Disadvantages of aerated concrete:

The need to make the wall of sufficient thickness (about 65 centimeters) subject to the presence of cold bridges, thermal resistance, the obligation to strengthen the canvas and lintels of window and door openings
High hygroscopicity - in the total mass the volume of moisture reaches 35%, which destroys the material, reduces the thermal insulation properties, but can be solved by treating with water-repellent impregnations (carried out at least once every 2 years)
Increased cost of interior finishing due to the need to use reinforcing mesh and certain types of plaster
Poor tensile and bending performance - under high compression and other loads, the material quickly collapses, but this problem is solved by strengthening with metal rods or mesh

How to increase the resistance of an aerated concrete structure to bending

To avoid the appearance of cracks on partitions and walls due to soil subsidence or external influences, aerated concrete is reinforced with reinforcement. The question of why and whether this should be done should not arise at all, because metal rods will take on tensile loads and protect the structure from cracks and destruction.

The type of reinforcement and location for it must be selected at the design stage. Metal rods and meshes are laid around the perimeter of the walls in the most dangerous structural elements. Before starting work, it is imperative to study how to properly reinforce, what materials are best to use and where it is necessary, and in which cases it is unnecessary.

Where the presence of a reinforcing element is required:

The first row of aerated concrete blocks laid on the foundation creates monolithic reinforced concrete belts
In walls whose length exceeds 6 meters, where it is important to compensate for the wind load, make a horizontal laying in every subsequent fourth row
Window and door openings - reinforced with reinforcing bars with a diameter of 8-12 millimeters in the longitudinal grooves of the upper floor blocks, under the lintels, at the bottom of the window openings in width with an overlap of 90 centimeters on both sides of it

Places where rafters and ceilings adjoin wall structures - you will need an armored belt with the laying of rods in U-shaped blocks
Potential high load locations
Areas subject to roof loads are reinforced with metal rods with a diameter of 10-14 millimeters, creating a single reinforcing system
Staircase elements often require strengthening and necessarily ceilings

The designer decides whether reinforcement is needed in every fourth row, taking into account the following factors: design features, length of walls, wind pattern and strength, seismic zone, soil features, type of foundation, strength of the aerated concrete block. Experts still advise not to save money and reinforce the walls in order to definitely avoid the destruction of the building.

To obtain a reliable load-bearing wall made of aerated blocks, special attention should be paid to choosing its 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 load-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.

Local rather than continuous reinforcement is used in areas most susceptible to deformation:

the first row of masonry above the base;
window and door openings, 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 joint (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 braces are not used; the rods are rounded at the corners, and electric arc welding is needed to connect them at the mating points.

The disadvantages of using steel reinforcement for wall reinforcement are corrosion, high thermal conductivity and weight. It is believed that a 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 the use of it when laying walls, citing the high strength of the blocks. At the same time, designers specify the requirements for the mandatory use of reinforcing mesh, arguing that only it will 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:

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.
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.
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.
The grooves are thoroughly cleaned of dust using brushes or a hairdryer, moistened and filled with glue.
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.
After strengthening the walls, uneven surfaces are carefully cleaned and sanded 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, additionally, T-shaped anchors or metal brackets made of stainless steel with a diameter of 4 mm are used at the points of their connection with the wall. They are laid in the horizontal joints of the block masonry every two rows. Non-load-bearing partition walls can be reinforced with rods or mesh made of composite materials.

Installation of a monolithic armored belt:

Using permanent formwork made of 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:

On the outside of the wall, an additional 100 mm wide extension block is installed flush and glued to it around the perimeter.
On the inside of the wall, to form the formwork of the belt, an additional 50 mm block is similarly glued along the contour.
Extruded polystyrene foam 5 cm thick is glued to the 50 mm block for thermal insulation of the armored belt.
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.
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 a ready-made block of this shape is used as formwork. 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. Wooden panels are attached along the inner contour. 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 metal mesh is 30% cheaper than composite mesh. Prices for steel and fiberglass reinforcement are similar in many respects. At the same time, sellers, when advertising their products, 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 elastic modulus 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.

Name	Dimensions, mm	Price, rubles per 1 meter
Steel reinforcement AIII	Ø6	9
	Ø8	18
	Ø10	29
	Ø12	37
		51
Fiberglass reinforcement	Ø6	14
	Ø8	18
	Ø10	26
	Ø12	36
	Ø14	46
Fiberglass mesh	50x50-2	75
Fiberglass mesh	50x50-3	145
Metal welded mesh	50x50-3	112
Metal welded mesh	50x50-4	170

Articles

The construction of houses from aerated concrete is one of the most used construction technologies. This popularity is associated with the high technical and operational characteristics of the material, combined with a fairly attractive cost. When carrying out masonry work, it is mandatory to reinforce the walls from gas silicate blocks. This procedure ensures the strength of the entire structure and the ability to withstand the effects of negative environmental factors. Let us consider in detail the entire process of strengthening the structure during its construction.

Why you need to reinforce

The need to reinforce masonry from gas silicate blocks is associated with the characteristics of the building material itself. In addition to its low price, aerated concrete has a number of advantages that facilitate construction and increase the comfort of further operation. These include the ideal geometry and size of the blocks, high vapor permeability, excellent thermal insulation characteristics, relatively low weight and much more.

At the same time, aerated concrete is not without its drawbacks. Having good compressive strength, the blocks are vulnerable to strong tensile loads. As a result, uneven shrinkage of the foundation, local sedimentation of the soil, and constant exposure to strong winds can lead to deformation of the structure, which, in turn, will lead to the appearance of thin cracks in the material. This will not affect the strength of the structure, but will reduce the level of thermal insulation and worsen the appearance of the building.

In addition, the already mentioned vapor permeability is a consequence of the high hygroscopicity of aerated concrete. As a result of exposure to high humidity, the material may swell. Sharp temperature changes also contribute to the contraction and expansion of the block array.

To eliminate the influence of all negative impact factors, multi-level reinforcement of gas silicate blocks is carried out.

Places of reinforcement

Modern technology for strengthening constructed structures provides for 5 main locations for reinforcing elements:

Reinforcement materials

Most often, metal reinforcement is used to reinforce gas silicate masonry, the size of which depends on the location of application. When reinforcing walls, rods with a diameter of 6-8 mm are used; to create an armored belt on gas silicate blocks according to the floor level, it is recommended to use products with a diameter of 10-12 mm.

An alternative material is galvanized metal mesh. The recommended thickness of steel rods used with this gas silicate reinforcement technology is 3-5 mm, and the side of the cell square is no more than 50 mm. To strengthen the supports of openings, you can use a mesh with a larger cell - up to 70 mm.

In most cases, when constructing walls, gas silicate blocks are reinforced with reinforcement. To lay steel rods, special grooves (grooves) are made across the entire surface of the row to be strengthened, into which the metal rods are laid. The cross-section of the recess must be at least 25 by 25 mm so that the reinforcement does not protrude above the surface and is covered on all sides with an adhesive solution.

When reinforcing walls made of gas silicate in corner areas, it is recommended to make the groove rounded to make it easier to bend the metal reinforcement along the radius. The laying must be planned in such a way as to avoid joints of rods in the corners of the building.

The work is carried out using the following technology:

preliminary marking is made along the entire perimeter of the laid row;
using a wall chaser or an angle grinder, a groove is formed;
use a vacuum cleaner or a regular paint brush to clean the resulting cavity from dust and particles of material;
the surface of the resulting furrow is wetted and filled halfway with a solution or adhesive composition;
reinforcement is being laid;
the remaining space is completely filled with mortar to the level of the surface of the blocks.

Depending on the size of aerated concrete blocks, there are different methods of laying and the diameter of the reinforcement used:

To avoid chipping of the building material, the distance from the groove to the edge of the block must be at least 6 cm.

The second popular way to strengthen the structure being built is to reinforce walls made of gas silicate blocks with mesh. With this option, to lay reinforcement, it is not necessary to cut grooves in the surface of the material. You can apply a layer of solution sufficient to completely immerse the mesh. To reinforce gas silicate blocks using a similar method, galvanized metal is usually used. As an alternative, you can use a mesh made of basalt fibers, which is not inferior in strength characteristics to steel structures, or fiberglass (this material is only suitable for strengthening walls).

One of the modifications of reinforcing gas silicate blocks with mesh is the use of galvanized metal strips with a cross-section of 8 mm by 1.5 mm to strengthen the walls of the building. In this case, laying is also done on a thin layer of mortar; there is no need to prepare channels for laying. It is important to ensure complete coverage of the reinforcing layer with the adhesive solution. This will prevent moisture from entering the metal surface and causing corrosion processes.

The technology for constructing an armored belt using gas silicate in the area of fastening rafters and roofs is somewhat different from strengthening walls and is reminiscent of the method of pouring a foundation. It uses the method of monolithically filling a space with concrete with pre-installed metal structures. The work order is as follows:

by welding or fastening with ordinary wire, a metal frame of the required size is formed from reinforcing rods;
for better adhesion, pieces of wire rod, reinforcement or ordinary construction nails are driven into the top row of blocks;
a wooden box is fixed on both sides of the top row;
the prepared frame is installed in such a way that the distance from the rods to the edge of the formwork is at least 5-6 cm;
concrete is poured.

The armored belt is filled one-time. Pouring in several stages significantly reduces the strength properties of the belt and, accordingly, negatively affects the overall strength of the structure.

Necessary tool

Despite the scale of the work being performed, the list of necessary equipment for carrying out reinforcement work is quite small and includes:

wall chaser (preferably electric, since manual work takes a lot of time) or a grinder with discs for concrete - we equip cavities for laying reinforcement;
a vacuum cleaner, a hair dryer or a regular paint brush – we clean the furrows from dust and debris;
a measuring tool (level, tape measure) and construction string - for carrying out preparatory calculations and markings.

When constructing the upper armored belt, you will additionally need tools for installing the formwork: a screwdriver, a hammer and a screwdriver, as well as a disk for working on metal using the already mentioned grinder for cutting rods of the required length.

Nuances of reinforcement

The construction process of each house is unique in its own way, so it is impossible to foresee all the problems that arise in advance. Here are typical recommendations that will help during construction:

It is not recommended to use fresh or wet gas silicate blocks. They are more easily destroyed and lose their strength characteristics.
The surface of the row must be perfectly flat. Irregularities and protrusions can be easily removed using sandpaper or a grinding machine.
Strengthening external and load-bearing walls is a must.
When reinforcing openings, the reinforcement is inserted at a distance of at least 90 cm in both directions.