Concrete is the main building material that is used universally in private and industrial construction. Reliable and durable material is made from a mixture of sand and cement (quite often gravel or crushed stone is also added to it). Depending on the technology of solution preparation and the ratio of its components, the physicochemical properties of concrete will also change . Most often, for its kneading, the M300 DSP is used.
Classification
All cement-sand mixtures differ in their properties. Based on this, they can be used for various construction needs. Today, the following brands of DSPs are distinguished:
- M100 - plaster mixes, which additionally contain lime.
- M150 - the lowest strength "thin" compounds that are used only for masonry work, plastering and restoration of the fundamental foundations of ancient buildings.
- M200 is the optimal composition, if we talk about its price and quality. Such solutions are used in the construction of walls and in the manufacture of cellular concrete.
- M300 is the most durable composition, which is designed for a wide variety of types of work. Very often it is used for concreting.
Application area
Dry mix is used for a wide variety of types of construction work. Most often, M300 DSPs are used in the construction of facilities for which no serious operational requirements are imposed. Thus, the solution can be used both for internal and external work. Most often, dry screeds are made from it. In this case, the cost of the concrete base will be lower, and by its properties the slab will meet all the requirements. Also, mixtures are used when filling cracks in concrete, leveling various surfaces, etc.
DSP M300: characteristics
Cement-sand mixtures of this brand have the following properties:
- Frost resistance. This parameter indicates how many times the hardened concrete structure can be thawed and frozen without a pronounced decrease in strength and other characteristics. DSP M300 withstands up to 50 cycles, respectively, it can be used in the construction of unheated rooms (for example, garages).
- Compressive strength. This parameter determines how strong the finished concrete structure will be when pressure is applied to it. The cement-sand mixture M300 is able to withstand loads of up to 30 MPa or 9.81 kg / cm 2 .
- Temperature condition. There are specific recommendations regarding the conditions under which concrete mortar can be laid. If we are talking about the M300 DSP, then it is recommended to implement it at a temperature of +5 to +25 degrees. If the air temperature is lower, then you will have to take care of additional heating of the solution.
- Adhesion. In simple terms, this parameter indicates how well the mixture will adhere to the base. For a solution of brand M300, this value is 4 kg / cm 2 . This means that the solution will adhere well to almost any surface.
Grain sand for the mixture
When preparing a dry screed or other concrete structure, an indicator such as the fraction of sand is taken into account. Depending on the granule size of this material, a DSP can be used for various purposes:
- Less than 2 mm - fine sand. Such raw materials are used in the preparation of mixtures for filling cracks, seams and chips in concrete substrates.
- From 2 to 2.2 mm - medium fraction sand. This material is applicable for arranging screeds, laying paving slabs, borders and much more.
- More than 2.2 mm - coarse sand. Such raw materials are suitable for the construction of more serious structures (foundations and other foundations).
Consumption
DSP M300 is considered a fairly economical composition. However, it all depends on the thickness of the concrete being laid. If the height of the base is 1 mm, then for 1 m 2 you will need about 1.7 kg of the finished dry mixture. With a thicker concrete layer (about 2 mm), the consumption will increase to 3.5 kg. If the thickness of the screed is 10 mm, then you need to purchase at least 22 kg of dry composition.
Let's look at an example. Let's say you need to fill in a screed with an area of 20 m 2 . In this case, about 460 kg of the M300 DSP will be required, the price of which will be 3,000 rubles. Of course, you can save significantly if you make the mixture yourself on the construction site. However, it is much more convenient and easier to work with ready-made dry solutions.
Cooking
In the manufacture of the solution, the proportions of the components used must be taken into account.
Also, you need to take into account the type of construction under construction:
- For screed, you will need 1 part of Portland cement brand not lower than M400 and 3 parts of sand. To make the base more durable, it is recommended to add fiber or reinforcement to the mixture.
- To prepare the mortar for plastering, the proportion will be 3: 2 (sand, cement). It should be borne in mind that such a solution must be developed as quickly as possible. Otherwise, it dries quickly.
Some novice builders believe that for self-preparation of the solution it is enough to mix all the components with water. In fact, first of all, it is necessary to combine sand with cement and mix them thoroughly until a homogeneous dry mass is obtained. Only then can water be added to the solution. At the next stage, it is better to use a concrete mixer and mix everything thoroughly again.
If the solution is made in the wrong sequence, then the finished building will have low strength characteristics and will quickly collapse. Therefore, it is better to make batches on specialized equipment.