CRACK RESISTANCE OF REINFORCED CONCRETE STRUCTURES
Crack resistance is the ability of a material to resist various mechanical stresses (internal and external), leading to the development of cracks.
The indicator is characterized by the time before the appearance of cracks under the influence of temperatures, bending forces, compression, tension, chemical processes. Accordingly, the longer the reinforced concrete structure during operation does not lose the integral structure, the higher the crack resistance of the material. Crack growth is observed if the coefficient of intensity and growth of stress exceeds the available threshold values вЂ‹вЂ‹of the material.
A true assessment of crack resistance can only give tests of concrete samples. Research is an effective method for predicting structural stability in the long term.
What affects the crack resistance of concrete?
The rate of formation of cracks in a reinforced concrete structure can be affected by both external factors, such as humidity or temperature, and the quality of the material itself. To determine the value of crack resistance, the parameters of material strength, elasticity, shrinkage, creep, etc. are taken into account. The effect of negative factors can be enhanced due to the characteristics of the structure itself, its shape, size.
Studies show that the quality of cement can significantly affect the rate of cracking. For example, cements with a low hardening rate are in most cases less prone to cracking. Therefore, objectively judging the crack resistance of reinforced concrete structures is possible only in combination.
How to increase the crack resistance of concrete?
Even minimal cracks can provoke structural failure in the future. In the crack zone, the reinforcement is exposed, resulting in corrosion, which leads to even greater expansion of the crack. You can increase the crack resistance of concrete in the following ways:
- Adding special reinforcing additives to the concrete mix.
- Magnetization of water.
- Reduction in the composition of undesirable components.
- Creation of an additional surface layer, the composition of which will prevent the appearance of microcracks.
- The formation of the optimal microstructure of concrete.
The main task in choosing the optimal composition of the concrete mixture is to find a ratio at which it will be possible to achieve maximum strength of the material with minimal negative qualities.
Is there a crack? Quality solution
For proper repair of cracks in reinforced concrete structures, the cause is initially identified. Work to eliminate cracks in reinforced concrete structures can be conditionally divided into 2 directions:
- Repair and restoration of the bearing capacity of reinforced concrete structures.
- The construction of new replacement or unloading structures.
To eliminate cracks in reinforced concrete structures, the injection method is most often used. A special strengthening solution is injected into the problem area under pressure. To restore the protective layer, the method of torquing is used: a pressure repair mixture is applied to the repaired and cleaned surface.
If defects in concrete appeared as a result of shrinkage of the soil, its washing out or decompression, then this problem should be immediately eliminated.
When contacting the specialists of the URETEK company, you will be offered the most modern and effective methods for the restoration and reinforcement of reinforced concrete structures to preserve their durability, strength, reliability.