Numerous varieties of modern building materials in most cases cannot be used without the use of cement. Today, the use of cement (bulk or ready-made) mixtures is in demand when creating coatings, installing structures and capital construction. Excellent physical and technical characteristics and a set of operational properties of the powdered composition are given by the production base (gypsum or clinker), combined with mineral binders and other types of additives. Mixing with water and several parts of sand helps to turn the powder into a high-quality solution, and gravel, crushed stone, lime and certain types of limestone are also added to create concrete.
Characteristics and capabilities of the main types of cement
In fact, cement is a universal building material, since its production is individual (for specific construction tasks). If you use the wrong type of cement, you will end up with a low-quality screed or plaster layer, or a weak foundation that is unable to support the structures being built. It is important not only the brand that the building material has, but also each element that forms the structural content of the powder. Today, the following types of knitting building materials are comprehensively represented::
- Portland cement (plasticized, fast-setting or pozzolanic). Branded powder (from M400 to M700), which finds its application in almost every field. If M400-M500 is suitable for general construction work, then the highest names are considered specialized.
- Powder of alumina (high-alumina) type. It is relevant in emergency engineering, if it is necessary to fill it in winter at low temperatures, and also tolerates the impact of mineralized liquids well. It is not used in hot climates.
- Magnesian. It produces a high-quality type of floor with the same name. A distinctive feature is the small thickness of the applied layer (2-5 cm) and the presence of an original pattern obtained by grinding until the filler texture appears.
- Various shades of white and colored powder. In fact, it is Portland cement, but with unique functional and visual characteristics. Due to its aesthetics, cement is used for decorative purposes (architecture, sculpture, landscape design). Light color is given any tone, using various pigment additives.
- Acidproof. The characteristics that such powders have are necessary for the organization of surfaces in acidic environments. However, their structure loses its strength level under the influence of moisture and alkalis.
- Hydrophobic. It is mainly used to produce cellular concrete, the key advantages of which are frost resistance and minimal moisture absorption.
- Waterproof. The absolute ability to block moisture is in demand when creating waterproofing contours, and this also helps repair reinforced concrete exposed to moisture.
- Slagged. It is used for autoclave production, as well as for the construction of underground and underwater buildings. Cement powders filled with slags are also called slag Portland cement, because it is one of the varieties of the same clinker building material.
Thus, due to the use of a specific type of cement, various engineering and installation processes can be carried out. Let’s consider a possible list of characteristics on the example of one of the most popular building materials – Portland cement.
Portland cement is the most popular structural substance
In fact, Portland cement is produced by grinding the clinker base in accordance with the technical requirements of GOST 10178-85. the same regulation prescribes the conditions for filling the powder with slag residues (ensuring the sulfate resistance of Portland cement). Key requirements for the structure of clinker powder:
- the mass of silicon oxide should not exceed 5%;
- the gypsum component is regulated in accordance with GOST 4013-82;
- it may also contain compounds of phosphorus, boron and fluorine (the amount is prescribed by the specified regulations);
- the mineralized component is selected based on the quality of the final building material in question.
A specific characteristic of a building material can be obtained only when a certain Portland cement is added to its structure. Common features include:
- the maximum density level is 3050-3150 kg / cubic meter (The value of bulk density is more variable).;
- when grinding for sieve No. 008, the passability of powder is from 85%;
- setting time: start-45 minutes, end-12 hours.
Control of strength characteristics is carried out according to the scheme. A sample of 4×4×16 cm is created from proportionally mixed material: for 1 part of cement, 3 parts of the selected sand component are used, and the volume of liquid added is 0.4 to the filled powder. After that, wait 28 days until complete solidification. The strength level of flexural and compressive strength is checked.