In the process of building high-rise buildings and small buildings, it is simply impossible to do without the use of concrete solutions. With their help, the foundation, floor screed is arranged and monolithic structures are created. However, the cement, which is part of this mixture, is characterized by significant shrinkage, which creates some difficulties in finishing. In order to eliminate this problem, modern manufacturers have created a tensile cement. Let's look at what the features of this product are, what properties it has.
Determination of composition
Stress cement is a cementitious compound characterized by the highest strength and quick setting. It is made on the basis of dry clinker powder of Portland cement, gypsum and alumina slag.
The mixture diluted with water quickly hardens, gains the necessary strength and begins to expand. A day after pouring, the solution gains strength of more than 300 kg / cm³.
Depending on the proportions of the main components that make up the dry powder, the hardening time and characteristics of the final solution can vary significantly. For this reason, a regulatory document was created, according to which tensile cement is made - GOST 31108-2003. It strictly determines the number of all components, which eliminates the occurrence of misunderstandings in the construction process. According to his recipe, expanding cement can be of 3 varieties:
- SC 10 - non-shrink compositions.
- SC 20 - products with average expansion rates.
- NTs 60 - materials with maximum linear expansion.
The choice of the type of cement is based on the specifics of its scope, but the most commonly used are varieties of the NC 20 group.
The scope of the mixture
Stress cement (SC) is used in the following works:
- during the construction of pools and tanks of treatment facilities;
- for the construction of basements (prone to flooding);
- during the construction of facilities intended for the storage of aggressive chemical compounds;
- during the arrangement of road cloths, runways and floors at industrial enterprises;
- to create hollow and thin-walled structures of increased strength;
- in the manufacture of pressure pipelines;
- in the construction of stadiums, hockey fields, stands and treadmills.
In addition, cementitious compounds are actively used in the repair of reinforced concrete structures. A solution of this type uniformly fills the smallest cracks, making the surface uniform and durable.
The use of tensile cement is also relevant in private construction. It is used for the construction of underground garages, baths and other rooms with a high level of humidity. Often from such a solution pour monolithic stoves and fireplaces.
Specifications
Compared to conventional Portland cement, the tensile composition has improved performance. It gives concrete mortar a number of positive properties that cannot always be achieved even with modern modifying additives.
Specifications The manufacturer of the material indicates the packaging of the dry mix. They are as follows:
- The initial setting of the solution is after 30 minutes.
- Bending strength after 48 hours - 3.8 MPa.
- Bending strength after 4 weeks - 5.9 MPa.
- Self-voltage - 2 MPa.
- The index of frost resistance is F-30.
- The linear voltage of the solution is 0.3% (up to 1.5%).
- The recommended temperature for work is from +5 to + 35 ° C.
- The compressive strength after 48 hours is 14 MPa.
- Compressive strength after 4 weeks - 49 MPa.
Cement can be purchased in paper bags of 25 and 45 kg. Wholesale lots can be shipped by machine (without packaging).
Material advantages
If we consider the advantages and disadvantages of annoying cement, it becomes clear that the positive properties of solutions made on its basis, much more. First of all, this material is appreciated for the lack of shrinkage process, which increases the strength of structures made from it. In addition, the advantages of annoying cement include:
- highest strength;
- setting speed;
- the ability to increase the life of buildings by more than 6 times;
- resistance to the influence of aggressive environments;
- absolute fire safety;
- excellent waterproofing qualities;
- high rates of frost resistance;
- high adhesive ability;
- lack of cracking processes.
The ability to withstand high pressure and water resistance are also significant advantages of such solutions. These qualities make it possible to use concrete made of tensile cement for arranging waterproofing, and no additional materials are needed.
disadvantages
Not one modern material is not without negative characteristics, and expanding concrete is no exception. The disadvantages of annoying cement are not so significant, but it is certainly worth examining them.
The first negative quality developers call the high cost of this material. Of course, if you compare it with ordinary cement mortar, then in this case, the cost of manufacturing concrete will increase by about a third. However, do not forget about the improved characteristics of the finished design, which more than compensates for the additional costs.
The second disadvantage can be attributed to a partial loss of the initial qualities of the composition (under conditions of using structures at temperatures above 35 degrees). This feature of the material is indicated in its technical characteristics, which allows us to foresee possible problems and determine the appropriateness of its use.
Features of the use of tensile cement
Before you start working with this solution, you should study some of the features of this process. To a greater extent, they are associated with high-quality preparation of substrates and repaired surfaces.
If tensile cement is used as a waterproofing, then the base on which the solution will be applied must be strong enough, not have exfoliation, oily stains and paint residues. No less important is the cleanliness of the surface. Small particles of concrete, dust and debris are removed from it.
If a screed is created using a solution, the formwork must first be moistened with water. And if it comes to repairing finished structures, then all sorts of cracks on them must be thoroughly cleaned of debris, washed and degreased.
Material cost
On modern construction sites, tensile cement is presented in a wide variety. Nevertheless, it is sometimes very difficult to acquire it. This is due to the fact that large trading companies prefer to work only with wholesale buyers, and small enterprises very often supply low-quality products.
The volume of the ordered material also affects its total cost. Manufacturers provide good discounts to wholesale buyers, and deliver the goods to the specified location on their own. The cost of a large batch of cement should be checked with the supplier. In retail, a 25-kilogram bag will cost the buyer about 230-290 rubles.
Finally
Stress cement is an innovative material with a number of positive properties. However, non-compliance with the basic rules and technologies for pouring the solution can negate all its unique qualities. It should be remembered that the listed advantages of tensile cement are activated only if the mixture solidifies in a humid environment. When all requirements are met, cement sets quickly and evenly, forming smooth and durable surfaces.