The most common hydraulic binder is Portland cement. It consists of finely ground cement clinker with gypsum. The last component is added to regulate the setting time of the finished solution.
There are several varieties of Portland cement. To obtain them, the mineralogical composition is regulated, mineral additives are introduced. Each of them has its own properties, which affects the scope of finished products.
There are the following brands of cement into which mineral additives are introduced: 600, 550, 500, 400. The percentage of the added substance is indicated in the marking with the designation D. For example, cement PC 400 D20 means that it is Portland cement grade 400, which contains 20 % additives. Further - in more detail about this brand of material.
Features of cement grade 400
First of all, you need to figure out what the number 400 means. This is an indicator of the pressure of weight in kilograms per 1 cm². In other words, a test sample made of PC 400 D20 cement, cast from M400 cement, was able to withstand the pressure of the specified weight and did notcrumbled, but remained intact. By the way, concrete grades are determined in exactly the same way: they make a prototype and test it in the laboratory using special equipment.
There are several varieties of brand 400 cement. They differ in the volume of plasticizers - their quantity and characteristics affect the properties of the finished mortar and products from it:
- The designation "D0" means that the mixture does not contain any additives. The material has a general construction purpose and is used for the construction of moisture-resistant structures.
- "D5" - the mixture contains 5% plasticizers. It is used to make elements of high density, able to withstand high humidity and corrosion.
- "D20" means that twenty percent of cement is additives. This brand has an important feature - it quickly gains strength in the initial period of solidification.
Why do we need supplements?
Thanks to the introduction of mineral additives, the following characteristics of PC 400 d20 cement are significantly improved:
- Corrosion resistance.
- Water resistant.
- Heat protection indicators.
- High strength.
- Operation of finished products and structures is allowed in any climatic zones.
- Resistant to temperature and fluctuations.
- Resist corrosive wear.
The disadvantages of the use of additives include the deterioration of the frost resistance of the substance. In addition, due tominerals cement mortar hardens longer than without them. But all this is covered by the fact that the use of additives reduces the amount of expensive cement clinker, so that a bag of cement is much cheaper. And this despite the fact that the strength characteristics of Portland cement with additives remain the same as those of the material without additives.
Scope of application
Cement PC 400 D20 is used for the preparation of cement mortars and mixtures of many brands. It is also in demand by enterprises that produce reinforced concrete structures, slabs, beams, wall panels, ceilings and other types of products. The named material is indispensable, starting with laying the foundation and ending with the preparation of the plaster:
- In the construction of low-rise residential buildings.
- On the construction of agricultural structures.
- In industrial construction.
There is one exception where PC 400 D20 cement is not recommended. These are structures that must have high frost resistance.
Purchasing material: what you need to know
The quality of this type of material largely depends on storage conditions. Manufacturers recommend storing mixtures so that moisture does not get into them. For this, a separate dry room should be allocated. It is best if the material is palletized otherwise the bottom bag of cement in each stack may become damp.
Therefore, going to buy material, infirst of all, you need to pay attention to how long ago it was made: the longer the product was lying, the higher the probability of getting a low-quality mixture on hand - in just a month, if stored improperly, cement can lose 50% of its strength.
What is very beneficial for consumers - you can buy bags of cement of 50 kg or 25. This allows you to buy exactly as much material as needed to solve a specific construction task and then not ensure the proper storage of leftovers.
