Reconstruction with the restoration of the waterproofing of old houses is even more difficult than new construction. In a building, in this case, it may be necessary, for example, to drain and clean the basement, and then remove dirt, peeling plaster, wetting parts of the screed.
Using regular concrete for this repair might not be a good solution. After all, several hours pass before the setting of cement mixtures of a standard composition. During this time, the solution will easily wash away the water. Therefore, in the reconstruction of old buildings and structures, concrete mixtures of a special variety are often used - fast-hardening. Cement of this type in construction is in great demand. The article presents the main characteristics of this material.
Composition
Many companies produce such building material. If desired, today you can buy mixtures of this variety from a variety of manufacturers. The specific proportional composition of fast-hardening cements is a trade secret of the companies producing them. On the packageit is usually not indicated as a percentage of such materials.
But in any case, the basis of such mixtures, as well as conventional ones, is cement. As additives that give the finished solution the ability to quickly set, manufacturers can use the following components:
- Quicklime.
- Potassium carbonate.
- Hydrochloric acid.
- S alts of various kinds.
Depending on the type of additive, the hardening time of such solutions may vary within certain limits. Of course, in the production of building materials of this type, various components can be additionally used to increase their plasticity, waterproofing properties, and chemical resistance.
Cooking Methods
Now there are two main varieties of such building materials on the market. Most often, fast-hardening dry mixes are used in the repair and construction of buildings. In the composition of such a material, components that provide quick setting are added already at the production stage.
Also, fast-hardening cement-based mortars can be prepared directly on the construction site. In this case, the dry material itself comes with a canister or bottle of liquid that contains fast setting additives. When preparing the solution, it is added to the mixture instead of water.
Scope of application
Most often fast setting cement mixturesused in the reconstruction of buildings and structures. In such houses, they can be used, for example, for waterproofing, puttying, sealing:
- Seams.
- Cracks.
- Gaps.
- Holes.
Very often, with the use of such materials, plinths and foundations of old buildings are repaired.
In new construction, such materials are used for quick fastening of anchors to concrete, any other metal structures, all kinds of details. In some cases, such solutions are also used when laying furnaces. Also, the material of this variety can be used for the manufacture of molded interior decorations, when installing columns.
Brands and Manufacturers
In Russia, concrete mixes of this variety are produced by the following companies:
- MAPEI. Concrete from this manufacturer is supplied to the market under the Mapefill brand. This company was founded in the 30s of the last century in Italy. It is currently Europe's largest producer of building mixes, including fast setting mixes.
- KT Throne. This domestic manufacturer has been operating in Russia for over 20 years. In addition to fast setting cements, it supplies waterproofing compounds and sealants to the market.
- "BIRSS". It is also a domestic manufacturer supplying the market with the highest quality building mixtures. Fast hardening cement from this company is differentexcellent quality and relatively inexpensive. The company also produces mixtures for self-leveling floors, plaster, putty and others.
There are only two brands of such mixtures on the modern domestic market: M400 and M500. Fast-hardening cement M500 differs from M400 only in that after hardening it is able to withstand a large load. Such mixtures are usually used in the repair of foundations, fastening critical metal structures to concrete bases.
Basic Features
The main difference between quick-setting cement mortars and ordinary ones is precisely the ability to turn into stone in a short period of time. Depending on the manufacturer and the additives used, such mixtures can harden within 1 to 5 minutes. Most often on the market today you can find materials that harden in about 3 minutes.
Nowadays, fast-hardening mixtures are produced that can self-compact. The advantage of using such solutions is that they can penetrate microcracks during setting and expand in volume.
All brands of fast-hardening cement produced today are distinguished by waterproofing properties. Materials of this variety are capable of solidifying even in the presence of a fairly strong backwater. Under such conditions, they are not washed out and create an airtight plug, which can subsequently last a very long time. In most cases, such solutions are able to set well and quickly even under water orin the cold.
How to use it correctly
The method of preparing a quick-setting material is practically no different from the method of mixing conventional cement mixtures. However, it is important to understand that it is impossible to prepare a lot of such a solution at once. Mixing is supposed to be such a dose that can be used within 1-5 minutes.
It is not recommended to dilute a fast-setting composition that has already begun to harden. If this is done, the performance of the finished material will drop sharply. When preparing such solutions, the following rules are usually supposed to be observed:
- Water or a special liquid should be introduced into the composition gradually, in small portions until a pasty mass is obtained.
- Total solution preparation time should not exceed the manufacturer's instructions.
- The surface to be patched should be prepared and cleaned in advance.
- The prepared solution is supposed to be used immediately.
Special Instructions
Kneading waterproof fast-hardening cement is usually done using a construction mixer. It is believed that it is impossible to perform this procedure, despite the need for a quick preparation of a plastic mixture, at too high speeds. This may lead to deterioration of the properties of the finished solution.
In the presence of water backwater, the corrected area is first rubbed with a dry quick-setting mixture. Thena second layer is applied over the resulting patch from a solution prepared using a liquid or water.
Helpful advice
Quick-hardening cement, like any other, in the process of setting and curing, it is supposed to be periodically watered. In this case, it is desirable to carry out such a procedure for at least three days. This recommendation should not be ignored. Otherwise, the patch may develop surface cracks in the future, which will reduce its performance.
