M50 compressive strength. Cement masonry mortar grade M50. Wall materials plant

Expanded clay concrete (expanded clay) blocks are a fairly popular building material, which in Lately became widely used not only in the design of commercial buildings, but also in the construction of cottages and private houses. The great popularity of this material is explained by its high performance and technical characteristics.

The most popular brands of expanded clay concrete are: M50, M75, M100, M150, M200, M300.

Technology for the production of expanded clay concrete blocks

Despite the fact that each enterprise engaged in the production of expanded clay blocks can use different proportions of raw materials, as well as additionally add plasticizers, with the help of which the original mixture becomes more plastic, the technology for their production is practically no different.

At the first stage, the initial mixture is prepared, which includes expanded clay, cement, water and fillers. These substances in certain proportions are poured into a concrete mixer and mixed thoroughly for 2-3 minutes. Cement here plays the role of a binder. The ratio of proportions depends on what output characteristics the concrete block should have. For example, if cement predominates in the composition, then the material will have increased strength and density, but have little thermal insulation. Conversely, a high concentration of expanded clay will increase the insulating characteristics of expanded clay concrete, but will reduce its strength.

At the second stage, molding is carried out using a vibrating machine. To do this, a stainless steel plate is placed in a special recess of the required dimensions, onto which the prepared mixture is poured. After this, vibration is used to compact it.

The last stage is drying the compacted mixture. Concrete blocks, being in special plates, are dried for 2 days, after which the plates are removed and drying continues for outdoors about 8 more days. The result is construction material, which has the following advantages:

• high frost resistance (more than 25 cycles);
• low moisture absorption (less than 20%);
• excellent heat and sound insulation;
• complete environmental friendliness;
• high strength;
• light weight;
• durability;
• good value for money and quality of finished product.

Return to contents

Brands of expanded clay concrete

The grade of this material directly depends on its density. The greater the density, the correspondingly greater the grade. Expanded clay blocks have a slightly lower density than most other building materials, but this does not affect their mechanical strength.

Thanks to internal structure Expanded clay granules significantly increase its resistance to mechanical loads.

The most popular brands of expanded clay concrete are:

• M50 - used in the construction of partitions and load-bearing walls;
• M75 - used for construction load-bearing elements both in private and industrial construction;
• M100 - for pouring screeds;
• M150, M200 - used for the production of expanded clay concrete blocks;
• M300 - used in the construction of bridges and road surfaces.

The dependence of the brand of expanded clay concrete on strength is shown in the table (Fig. 1).

Return to contents

Dimensions and characteristics of blocks

The sizes of the blocks depend on the customer’s needs and structural purpose, so they can be completely different. According to GOST 6133-99, standard concrete blocks from expanded clay for load-bearing structures have dimensions of 400x200x190 mm, and for the construction of partitions - 390x90x190 mm.

The main characteristics of expanded clay concrete blocks are:

1. Strength. Depending on the scope of application of the blocks, it can be in the range from 5 to 500 kg/cm 2.
2. Volume weight. This value also depends on the scope of use of the material and can be 350-1800 kg/cm 3.
3. Thermal conductivity. It is 0.15-0.35 W/(m*K). The thermal conductivity of expanded clay concrete increases with increasing amount of cement in its composition. According to this property, concrete blocks are at the level of wood. The use of hollow blocks in construction reduces the thermal conductivity of the structure and makes the building warmer.
4. Frost resistance. Increases with decreasing porosity. The minimum value is 15 cycles and the maximum is up to 500 cycles.
5. Shrinkage. It is at the level of heavy concrete and is about 0.4 mm/m.
6. Vapor permeability. It is 0.3-0.9 mg/(m*h*Pa). This characteristic increases with increasing hollowness and porosity of the material.
7. Moisture absorption. Contains no more than 10% by weight. Moisture absorption can be reduced by adding various plasticizers to the initial mixture.

Concrete blocks can have not only different sizes, but also different designs. The entire range of expanded clay blocks is conditionally divided into 2 groups:

• expanded clay wall blocks;
• partition expanded clay blocks.

The table shows the main types of expanded clay concrete blocks and their characteristics.

The brand and class of concrete determine its strength characteristics and are the main indicator of quality when choosing a ready-made solution or proportions for mixing it yourself. The remaining criteria - frost resistance, water resistance and mobility are considered secondary. These values ​​​​are regulated, in project documentation The required strength class must be indicated; it is different for each design. But in private construction, sometimes it becomes necessary to select mortar parameters without the help of professionals; it is important to understand general principle current classification.

The relationship between brand, class and other characteristics of concrete

This table additionally indicates such important indicators as:

1. Frost resistance: indicated by the letter “F” and characterizes the number of cycles of freezing and thawing of concrete. It has important when choosing a brand for pouring a foundation in flooded areas or under conditions of constant soil freezing. The higher this indicator, the better.

2. Water resistance (from W2 to W20) - reflects the bond strength of the concrete structure and resistance to moisture penetration inside. The higher this characteristic, the fewer microcracks in the material and the lower the risk of destruction of building structures during freezing.

3. Workability or mobility grade of concrete (indicated by the letter “P” and indexed from 1 to 5). A temporary indicator reflecting the ability of a solution to uniformly fill and distribute the proposed form under the influence of its own weight (without additional vibration). Compositions with high mobility (P4) are used when filling hard-to-reach areas; in standard cases it is convenient to work with P2 and P3.

There is a clear connection between the quality of the binder, the selected proportions and grade of concrete and, as a result, its strength. Other characteristics can be controlled and changed by introducing antifreeze additives or using hydrophobic cement, but only taking into account permissible limits and the inevitable increase in price. Standard ratios are shown in the table:

In addition to using the specified proportions to obtain concrete with the required strength grade, attention is paid to the quality and preparation of the components. The introduction of unsifted sand with impurities, stale cement or dirty crushed stone worsens the structure of the material and negatively affects the process of strength gain. Despite the increase in the mobility of concrete when diluted with water, it is strictly not recommended to violate the proportion indicated for it. The same applies to ready-to-purchase solutions.

Area of ​​use

The scope of application of various brands is determined by the operating conditions and the loads experienced; in particular, one of the following options is selected:

1. M75 – “lean” solution for filling drainage layers.

2. M100 – used in road construction(curbs) and when preparing the base of a building for pouring the main structures. Not suitable for concreting critical and loaded areas.

3. M150 – lung brand concrete for auxiliary purposes. The scope of application includes screeding floors, constructing garden and pedestrian paths, curbs, foundations for light buildings, and pouring monolithic slabs.

4. M200 – a strengthened concrete grade, optimally suitable for retaining walls, floor screeds, foundation structures, blind areas, garden areas and paths.

5. M250 - a heavy variety, in demand in private construction. Used when pouring foundations, flights of stairs, bases for fences and outbuildings, tiled floors with low load. It is allowed to use M250 concrete in industry, but exclusively for low-rise buildings.

6. M300 – for pouring foundations of any complexity, including slabs, flights of stairs and landings.

7. M350 – initial grade for foundations multi-storey buildings. This concrete is characterized by high strength and water resistance and is suitable both for the construction of hollow-core slabs and beams, and for concreting monolithic structures. It is from this that bowls of public swimming pools, airfield roads, columns, supports, grillages and other loaded concrete products are poured.

8. M400 – super-heavy quick-setting grade. Due to the high cost, it is practically not used in individual construction, exceptions are private houses with basements in areas with risks of flooding groundwater. The main scope of application is hydraulic structures, bank vaults and other reinforced concrete facilities with increased requirements for concrete strength and building safety.

9. M450 – another professional brand with high speed grasping. Selected for regulated objects: dams and dams, bridges, metro tunnels.

10. M500 – a grade of concrete with a high cement content, exclusively for hydraulic structures and specialized products.

There is a clear relationship between the quality, performance indicators and cost of solutions; in private construction, the use of concrete above M400 is not economically feasible. The main operating range includes M100-M450 and V7.5-V35, respectively. Checking the manufacturer's specifications concrete mixture(recommended stage when constructing critical facilities) is impossible at home. To conduct a laboratory examination, a 15x15 cm cube is poured, the final results will be known only in a month (28 days are allotted for hardening and achieving the design strength).

In addition to choosing the right brand to get reliable building structure It is important to organize appropriate hardening conditions: concrete needs care for at least 15-20 days after pouring. The surface is protected from direct rays, moistened and covered with plastic films.

You should remember the main rule of cement hydration - at sub-zero temperatures this process stops, which leads to a decrease in the final strength and frost resistance. In case of sudden cold weather or the need to carry out work in winter time the concrete is covered with a film or heated.

When starting construction, it is necessary to study the classification, properties, and labeling of the materials used. It is likely that to perform some work you will not have to overpay money to purchase or prepare high-quality concrete mixtures, but you will be able to use M50 concrete, marked according to the usual classification or B3.5 - according to the international one. This material belongs to the heavy category, but has low strength and is used in the construction of non-critical structures.

Mix it yourself or buy ready-made concrete B3.5

Buy it at finished form undesirable, and most factories producing ready-mixed concrete refuse to supply low-grade concrete M 50 for the following reasons:

• during the movement of a self-propelled concrete mixer, the mixture may stratify as a result of prolonged mixing;
• there is a threat of thickening of the composition, as a result - an increase in water consumption, a decrease in the already low strength.

The composition of concrete grade M50 includes regular components, the proportions of which are volumetric dimension Depending on the brand of cement, they are:

This category of concrete is considered thin and unassuming, but nevertheless there are requirements for materials for its preparation. The sand must be washed, clean, and free of clay and silt particles. Crushed stone can be used in different ways, including those consisting of a mixture of small and medium fractions, gravel, stone, or both together.

In addition, the concrete manufacturing technology 50 must fully comply existing standards and requirements. Otherwise, the indicators of strength, water resistance and frost resistance will decrease even more.

The usual method for preparing concrete mixture is:

• into a pre-prepared container (trough, bunker) we pour a measured amount of dry components - sand, crushed stone, cement;
• mix thoroughly with a mixer or shovel;
• Continuing to stir, gradually add clean water;
• Continue kneading until the composition reaches the desired plasticity; this requires no more than 5-7 minutes.

To avoid excessive consumption of materials, it is better to prepare grade 50 concrete in small portions, using them completely.

Technical characteristics of concrete m50

To improve the quality of the final product, plasticizers are included in the working composition, antifreeze additives and other useful components. The fact is that for heavy concrete class B3.5 M50, although strength is the main characteristic, it does not play a decisive role.

Often, to give the material additional properties, some amount of sand and cement is replaced with other materials. For example, the use of dry fly ash reduces specific gravity concrete 3.5, increasing its thermal insulation qualities.

According to GOST 26633-2012 “Heavy and fine-grained concrete. Specifications» the finished product must have:

• strength in MPa – 3.5, in kgf/cm 2 – 50;
• water impermeability – W2;
• frost resistance – F50-F100.

As you can see, class B3.5 concrete is characterized by extremely low moisture and frost resistance. To improve these characteristics, hardening accelerators are used. Besides, modern science claims that the use of special nanoadditives in very small quantities helps to change the properties of low-grade concrete. In particular, it acquires the ability to absorb radio radiation in a wide frequency range.

Where is M50 concrete used?

Due to low technical characteristics the use of concrete grade M50 is limited to such areas construction production, where high strength of the material is not needed. It is used:

• to create a preparatory layer for slab, column and strip foundations, or first-level devices of such bases;
• for the purpose of filling the subfloor;
• curbs, curbs and preparation for them are made from M50 B3.5 concrete;
• when strengthening the soil during the construction of concrete platforms for various purposes;
• when installing a radio-absorbing or radio-isolating barrier.

The main advantages of this product are its low cost, unpretentiousness in the selection of raw materials. These are the main reasons to use it without any restrictions in any preparatory work and construction of temporary buildings.

Buy M50 solution for everyone in Moscow and populated areas The Moscow region is offered by the StroySoyuz group of companies. Understanding that the material is in demand at almost every stage of construction, we carry out its uninterrupted production and supply.

Working without intermediaries, we are ready to offer an affordable price for M50 cement mortar. We have our own laboratory at our disposal, so high quality Our products are backed by research.

Where can I buy M50 masonry mortar at a competitive price?

Concrete mortar is used as a binder when performing:

• bricklaying;
• laying other types of stones.

It belongs to the group of complex solutions, but is less durable. The material is rarely used in other types of construction, since products made from it have low compressive strength.

The StroySoyuz group of companies sells favorable price cement-sand mortar M50. Placing an order with us means getting a material with the necessary strength and mobility, which is resistant to climatic factors, versatile and practical. Place your order by phone or online from our website.

Prices for cement mortar M50