Mechanism of action of expanding cement
This is a kind of mounting foam, but for a slightly different purpose. In industry it is customary to call self-expanding cement an astringent. In addition, it is noted that expansion occurs in moderate limits and has an exceptionally positive effect on the construction in which this type of building material is used.
The expansion of the cement mixture can occur under the influence of the internal processes of the following plan:
- 1. by forming during the quenching of a number of bubbles inside the mixture, subsequently affecting its volume;
- 2. by forming inside the crystal lattices a substance of chemical ettringite.
These are the two most commonly used technologies in the manufacture of this binder.
When is this cement used and why?
Expandable gypsum-aluminous cement is widely used in construction. It is made by mixing two main components. The basis for this material is alumina cement, in which the necessary amount of gypsum is added to the production.
Due to the mixing of the two above-described constituents, a mixture is obtained that is able to expand upon solidification and is successfully used in building needs. A distinctive feature of this type of cement is the ability to maintain volume, and not to give a certain percentage of shrinkage after the final drying of the used mixture .
Expanding cement is very successfully used when it is necessary to erect buildings in extremely wet places. This mixture performs work on leveling the erected brick or concrete box, and it is given water repellent and energy-saving properties, due to the capital elimination of cracks and cavities due to the expansion of the drying mass used in the work.
Taking into account GOST, gypsum-aluminous expanding cement can be used in low temperature conditions. Due to what you can be completely confident in the unsurpassed stated qualities that are available for this material.
Features of the behavior of gypsum-alumina cement
Among the indisputable advantages that make it necessary to choose this type of cement is its ability not to lose its properties in the process of frequent and rapid changes in ambient air temperatures. Due to this, it is widely used during the winter erection of both residential and industrial buildings.
The structure of the material allows you not to lose elastic qualities, you can not stop working in a frost below 25 degrees Celsius. But do not forget about the small disadvantages. To negative, if it is possible so to say, qualities loss of properties at high humidity in a compartment with temperature of air exceeding a mark in 35 degrees Celsius concerns.
This must be taken into account if it is necessary to finish deliberately unclear premises in the summer. It is best to transfer work on this site to a cooler time of the year, and then nothing will interfere with the surface treatment of the mixture.
Expandable gypsum-aluminous cement, the technical characteristics of which are listed above, is a popular building material of the reinforced concrete industry. And it is used both on an industrial scale, and for private construction, and finishing premises that need strengthening and acquiring water repellent properties.