24-09-2015
GRC Beton


How to prevent cracks in concrete?

When writing about cracks in concrete, one should remember that they are a natural component of any concrete surface, which is particularly visible in the case of floors. Yes, there is a number of ways to minimise the risk of cracks appearing, but eliminating them completely is very difficult. The presence of cracks can have a negative impact on some parameters of the concrete surface, such as, e.g., waterproofing or soundproofing characteristics, but lack of any kind of reaction to their appearance is significantly more damaging. Besides, the best way to fight against concrete cracks is to simply prevent them from appearing. It can be done in a few ways.
The most important method is, of course, using expansion joints, which, in the case of traditional floors, should be added no later than 48 hours after laying them. Obviously, using a suitably designed and vibrated mixture with not too high water-cement ratio (around 0.55) will undoubtedly be a good solution. Good quality of the individual composite components is also very important – contaminated water or aggregate, the presence of organic or loamy materials or low quality cement will certainly have a negative impact on the strength of the concrete surface.
One should also remember about the proper use of reinforcements, especially near the edges and corners. Proper floor drying speed has just as large of an impact on its strength as smoothing it properly. Furthermore, the laid concrete should be adjusted to service loads no greater than those defined during the design stage. Excessive loads will certainly damage its surface, similarly to curing it ineffectively and improperly.
Let us not forget about the ground either. Concrete structures located on unstable and unhardened ground will certainly feel it. Because of this, the proper preparation of ground is recognised as a prerequisite for the good longevity of concrete floors or walls. Disregarding this problem will certainly put the structure of the concrete surface at risk of cracking.