Elements made of concrete and reinforced concrete are key parts of many buildings and structures responsible for transferring the static and dynamic loads arising in them. Concrete shows excellent resistance to mechanical impact, especially compression, and after reinforcement with reinforcement, also to bending. To increase its durability, however, it is necessary in many cases to use concrete coatings that can protect it against external factors, especially corrosion and fire. Let's find out how these threats affect concrete and how they can be eliminated.
Corrosion of concrete and possibilities of its reduction
Concrete corrosion is a process that damages the structure of the material by destroying the reinforcing steel or its components. Concrete corrosion is chemical corrosion that leads to progressive degradation and reduction of load resistance. It can take the form of alkaline corrosion, due to the reaction between the aggregate used and the cement, resulting in the production of a swelling gel, as well as carbonation, meaning a change in pH, and thus acceleration of corrosion of the reinforcement, as well as chloride corrosion similar to it. Sulfate corrosion may also be a problem, as it causes the intumescing of gypsum compounds that disintegrate the concrete. The way to reduce the risk of concrete corrosion is to use appropriate protections.
Destruction of reinforced concrete by fire
Concrete is a non-flammable material with very good heat and flame resistance. However, it is dangerous that the rapid increase in temperature associated with the outbreak of a fire leads to the loss of the properties of the reinforcement used, and thus the reduction of the resistance of the entire elements to loads. A way to prevent such problems is to use coatings that will separate individual elements from the effects of a fire. They can be intumescent coatings as well as mortars constituting a permanent thermal insulation.
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