A mixture based on sand, cement and water is universal, used in construction. Wall masonry, foundation and screeding, rough plastering, concreting and other operations - this material is used everywhere. There are certain building standards in which proportions are set to get a high-quality cement-sand mixture. Consumption per 1 m2 of it is determined by the type of work performed. The quantitative component of sand directly depends on the brand of cement used.
Types and brands of cement
The composition of any cement includes limestone and clay in a ratio of 3: 1. These components are fired and clinker is obtained - basic raw materials (granules). Next, an admixture of gypsum is introduced and everything is ground. Larger grinding is characterized by slow setting and lower strength, but it has a longer shelf life. And vice versa.
Adding additional elements to this mass, various grades of cement are produced. Their importance is that they are designed for various construction operations and climatic conditions:
- Portland cement (PC). Brand with moisture resistance and frost resistance. Suitable for the creation of any kind of cement mortar, as well as for the manufacture of concrete.
- Slag Portland Cement (SHPC). It has increased water resistance and heat resistance. Suitable for masonry and plastering, as well as for concreting underwater and underground objects. It has a long setting time and hardening.
- Hydrophobic cement. It has increased moisture resistance and resistance to low temperatures. The dry mix is well preserved even in a humid environment.
- PC plus fillers. Designed for the manufacture of low grade concrete.
- Portland cement of fast hardening (BPC). It is characterized by a short setting time. Ideal for reinforced concrete structures and monolithic structures in the winter. Shelf life is limited.
- White cement. Suitable for interior use at positive temperatures. It is a component of paint mixes.
- Colored cement. Quick setting material. It is used to create mixtures (grout for joints of tiles) and paints.
- High strength alumina cement.
- The cement is expanding. Waterproof grade for sealing joints in concrete structures.
Material marking characterizes two features: the degree of resistance to mechanical stress and the amount of impurities, expressed as a percentage. So, for example, the designation M 300 shows that a concrete block made of cement of this brand is able to withstand a pressure of 300 kg / cm.
Depending on which brand the cement-sand mixture is prepared from, the consumption per 1 m2 (proportion) will be different. After all, you need a different amount of water to knead the solution in each case.
The proportion of sand and cement
As mentioned earlier, in order to properly make the mixture, you need to look at the marking of cement. Since cement acts as a binder, and sand as a filler, the first will be one part, and the last several.
For example, the marking M 400 allows a proportion of 1: 4, M 500 - 1: 5. That is, the number "5", "4" or "3" after M shows how many parts of sand can be applied to one part of cement. It is not forbidden to put a smaller amount of filler with a high grade, but not less than 3 to 1, otherwise the solution will tear when solidified.
How much solution is needed
How to calculate the consumption of cement-sand mixture per 1 m2? It all depends on the amount of work performed. Indeed, in addition to the area, it is necessary to take into account the thickness of the mortar layer if the foundation, reinforcing belt or any reinforced concrete structure is poured.
In this case, the experimental method of calculation will help. In the finished formwork, an area equal to a square meter is measured and limited by its partition - this is a measured volume. Next, a large amount of cement-sand mixture is prepared. Consumption per 1 m2 is obtained by weighing the mass of the mixture and subtracting from it the residue that was not included in the manufacture of concrete and pouring this space.
The method has an error, but is convenient for small private construction. In industrial buildings, everything is regulated by consumption rates.
Bricklaying: production rates
For masonry work, a cement-sand mixture is also determined, the consumption per 1 m2. The calculation depends on the type of wall - the carriers are removed using high-quality cement, partitions - with a lower breakdown.
It was experimentally established that per cubic meter of masonry there is an average of 0.3 m3 of mortar plus up to 5% for losses. The area of one square of the real wall is calculated. The volume of the solution is divided by the number of rows of bricks. The result is a mixture consumption per row.
The amount of mortar in the screed
The preparation of the solution for this operation is specified by standards. When fulfilling the rules by which a cement-sand mixture is created, the consumption per 1 m2 of screed does not exceed the norms and is calculated as follows:
- For cement grade M 500 and mortar M 150 - 410 kg of cement / 360 kg of sand, and for M 200 - 330 kg of cement / 280 kg of sand.
- For brand M 400 and mortar M 150 - 490 kg of cement / 450 kg of sand, and for M 200 - 400 kg of cement / 350 kg of sand.
All this for one cube of mass. Having determined the thickness of the screed, the consumption per square is calculated. The prescribed proportions allow you to get a high quality surface without peeling, crumbling and chips.
Wall alignment: mortar flow
Before calculating the consumption of cement-sand mixture per 1 m2 of plaster, determine the thickness of the working layer. If it is, for example, within 1 cm, then up to 9 kg of the granular mixture will go per square surface. In this case, it is necessary to take into account the deviation of the surface deviation under the plaster. It is determined by measuring by plumb at three points along the length of the plane. Summing up and choosing the average indicator, the real thickness of the layer of mortar for plaster is calculated.
The optimal proportion of cement, sand and water in the mixture is 4/16/2, respectively. From this ratio it is easy to derive the mass of each component for a specific amount of work.
How to reduce consumption
The addition of additional components saves the cement-sand mixture. Consumption per 1 m2 will be less under certain conditions:
- Lime mortar is introduced. This is permissible when organizing plaster and gives plasticity to the mass.
- A standby is made when pouring the foundation and some reinforced concrete structures that do not carry heavy loads.
- Expanded clay is added, resulting in a warmer screed.
- Used high-quality cement for the manufacture of concrete, then you can increase the percentage of filler in the form of crushed stone or gravel.
Although the cement-sand mixture is universal, the consumption per 1 m2 of it largely depends on the professionalism of the builder.