Today, there are many different types of concrete that differ in their properties and composition. It is simply impossible to talk about everyone, therefore, this article will consider those types of concrete that are used for construction purposes. The main properties of concrete can be called only three types: thermal conductivity, strength and durability. It is worth noting that durability and strength are those properties that are combined with each other. Indeed, with increasing strength, it is possible to simultaneously improve the durability of the producing material. But with thermal conductivity, everything is completely different. After all, strength and thermal conductivity are constantly contrary to each other. With a decrease in thermal conductivity, the strength of the material will also decrease, and this is completely not desirable. In order for building materials from concrete to have reduced thermal conductivity, it is necessary to increase the porosity of the material. This process can be implemented in two ways: the use of a filler for a concrete mixture of porous materials: slag, expanded clay, pumice and tuff or use materials that have low thermal conductivity for the same purpose: straw, wood sawdust, and use air that will be Enter the cement mixture. As a result of the first method, you can get light concrete – slag concrete, pums concrete, saw -up concrete or the most common expanded clay concrete.
In order to introduce air into the concrete mixture, substances are used that are able to swell aqueous cement solution. But as a gas former, a special aluminum powder is mainly used, which reacts with a hydrate of calcium oxide, forms a swelling mixture, but to obtain it, you must use a special construction tool. The use of foam and gas former allow foam concrete and aerated concrete. Such concrete will have low thermal conductivity, so they are widely used in the construction of low -rise buildings. The negative property of gas-and foam concrete is low moisture resistance. And when moisture hits, an increase in the thermal conductivity of the material, as well as a decrease in the strength of the strength. And if the moisture remains inside the concrete, and the cold season will occur, then the water will freeze, which is in the pores, as a result of which concrete destruction occurs. If you are building a low -rise building from such a material, then it is worth choosing only the material that will be reliably protected from moisture – saturated with a moisture protection composition or plastered with cement plaster. To carry out the plastering of the facade, you need to use only cement plaster, but to carry out internal work, the plaster “Volma-layer” is used
