Concrete Repair Compounds: Product Characteristics
One of the most popular materials used in construction work is concrete. It is very durable and retains its properties during a long period of operation. But, like any material, it may require correction over time. To eliminate such problems as the appearance of cracks and cracks, special solutions are used. They are called repair mixes for concrete.
If the surface begins to collapse, you can face such unpleasantness as dusting. Its main reasons are a violation of the technology of pouring concrete, heavy loads, low-quality masonry mix and mechanical impact. Loads and significant temperature fluctuations can lead to cracks.The shrinking process can also contribute to the formation of deformations.
Repair mixture helps to eliminate defects, fill the cracks and cracks that appear. Each of the types of this material has its own distinctive features, properties and specificity of application, which must be reviewed before purchasing the material.
Features of concrete mixes
The choice of repair mixtures today is quite extensive and widely represented on the market. They are divided into two types, having a difference in properties.
The first type includes bulk mixtures. They have the ability to penetrate deeper due to its increased fluidity. The use of such mixtures is advisable only on horizontal surfaces.
The second type is dry formulations. Before work, they are mixed with water, getting a viscous mixture, not subject to shrinkage and delamination. Due to its plasticity, it fills the deformed areas and does not flow out of them, and also hardens in a short period of time. The content of the fiber in such compositions is an additional advantage, since it increases the strength of the base.
Dry formulations are frost resistant and high strength, they are also completely non-toxic, which expands the range of their use.
The moisture resistance of the mixture allows it to be used for waterproofing concrete and when working with aerated concrete. Given the wide range of characteristics and properties, these mixtures belong to a higher price category.
The technology of using mixtures
As with any work, before applying the repair mixture it is necessary to clean the surface, removing dust and debris from the deformed areas. This will make it possible to determine the desired volume of material. After this, the crack deepens by about 5 centimeters. The reinforcement cage is thoroughly cleaned, which is subsequently covered with anti-corrosion primer.
Deep cracks will need additional reinforcement. Then the dust is removed, and the treated areas are moistened.
Mix for repair work can be prepared independently.
In order to give it a uniform consistency, it is better to use an electric mixer or a concrete mixer.
Further actions depend on the type of material used.
The treated surface must be smoothed with a steel trowel, masking defects and irregularities.After the mixture grabbed, which will take about half an hour, this action must be repeated.
To prevent cracks in the superimposed material, it should be kept wet for about a day. When exposed to high temperatures, this condition should be extended to three days. For humidification, you can use a spray or a regular hose with water. Next, the treated area must be covered with a waterproof material.
When carrying out the above works, it is necessary to take into account that drafts and sudden temperature changes may prevent thorough and uniform drying of the composition.
The construction market is offered by a number of manufacturers of concrete repair mixes, among which the following companies enjoy particular popularity:
- Ceresit is one of the most popular brands among concrete repair mixes. The range of its positive properties is very wide. The composition is characterized by the absence of shrinkage, calmly transfers the effects of negative temperatures and water. The mixture is layered in 5-35 millimeters. It is plastic due to its viscosity and is able to reliably fill all cracks and cracks, therefore, it is used when working on both horizontal and vertical surfaces.It tolerates mechanical loads, it is used both for internal and external work.
The mixture is applied to cement-sand screeds made no more than a month ago. The age of concrete for the repair of this material should not exceed 3 months. Work is recommended in the temperature range from 5 to 30 degrees.
Since the mixture quickly sets, it must be applied as quickly as possible, maximum within 5 minutes after mixing.
To prepare the composition, water is taken at a temperature of 15-20 degrees, to which the mixture is gradually added. At 3 liters you need about 25 kilograms of the mixture. If the volume of water exceeds the required framework, it may adversely affect the strength and durability of the material. After laying on a moist, pre-prepared layer, the mixture is leveled to smooth out irregularities and defects.
Ceresit compounds have several grades, the main difference of which is their grain. Allocate a mixture of CD 22, 23, 25, 26 and CN 83.
- ICBM - This is a dry gray color. It is based on Portland cement, as sand is used as a filler. About 0.2 liters of water is taken per kilogram of dry mix.The composition is applied with a layer thickness of 50 millimeters. It clings not too quickly, but the work must be completed within an hour. Finally harden the mixture in about a day.
Particularly popular is the composition of the MBR-300 "Mount Crystal". It can be used both in the construction of facilities and in their subsequent repair. Fiber content increases the positive properties of the material. It is used on vertical and horizontal surfaces, has good compatibility with materials from reinforced concrete, brick, stone and concrete.
For work carried out in the cold season, it is recommended to use the composition of the MBR 300M. It consists of antifreeze additives, which is important in the winter.
The material practically does not shrink, has good water resistance, frost resistance, strongly adheres to the surface. This composition can be prepared and applied independently, subject to compliance with the technology. When laying it does not require specialized skills.
The mixture can be used both in the construction process and in the repair. It is not required to be primed and evened out additionally, and the application process usually does not cause problems.The process of curing occurs quickly enough. Also indisputable advantage is relatively low price in comparison with similar materials. It is used both at independently carried out repair, and during the work of professional masters.
- Emaco. The Russian manufacturer of this mixture is deservedly respected in wide circles. Provides a wide range of products for the repair of concrete foundations. Different types of materials are used for damages of varying degrees and cracks ranging in depth from 5 millimeters to more than 25 centimeters. With minimal damage and deformations, it is recommended to use Emaco N 5100. For small chipping and peeling, Emaco N 900 and Emaco N 5200 are used. Cracks up to 2 millimeters wide and up to 40 deep, and the appearance of rust implies applying Emaco S 488 PG compounds , S 5400 and S 488. More severe deformations, characterized by cracks up to 10 millimeters deep, are eliminated with the help of a mixture of Emaco T1100 TIX, S560FR, and also S 466. For the most serious damages, when the reinforcement may be exposed, and corrosion appears, it is recommended to use Nan ocrete AP.
- Bars - a well-known brand, whose products are used in construction and repair works of various specifics.It is even used to renew old concrete surfaces. Bars products are used when working with both horizontal and vertical surfaces. This can be achieved due to the viscous consistency of the material, which makes it convenient to use and does not create additional problems during application. It is made in the form of both bulk and dry mixes. One of the most popular - the thixotropic composition of Bars 102 B45. It is applied on previously prepared base with a layer of 2-4 centimeters thick. Does not shrink, perfectly adheres to the surface. This mixture is in the middle price range.
During the works when it is necessary to eliminate leaks, it is recommended to use structure of Consolit Bars. It is characterized by high strength, but due to the fact that it is a self-expanding mixture, it relieves such problems perfectly.
How to choose
The cement-based repair mix can be made independently, however, a wide choice of materials in the construction market allows you to use ready-made, high-quality material in different price categories.
The fundamental point when choosing the type and brand composition,which is supposed to be used in the work, is the type of defect and its size, as well as how much load on the object will be given in the future. In the case when you need to strengthen the base of the structure, it is advisable to apply a deep penetration primer. For work with vertical surfaces, it is optimal to use dry mixes due to their ease of use.
If you just need to strengthen the surface, it is best to use materials that have the best traction characteristics.
To fill the cracks are perfect mix, having in its composition fiber. Also, when choosing a mixture for work, it will not be superfluous to study the information on the label, which indicates the period for which the composition freezes, its necessary consumption and other useful characteristics.
How to prepare and apply the repair mixture on the example of Ceresit CN83, see the following video.