Due to its quick setting and hardening, gypsum is used primarily as a binder in the manufacture of gypsum concrete and concrete products. Gypsum can bind many types of aggregates well: from sawdust and paper to slag. Products based on gypsum binders have a low bulk density - 1000-1200 kg / m3. In order to reduce the bulk density and thermal conductivity of products, gypsum dough is closed with excess water, or pore formers are introduced into it.
Gypsum concrete has a number of weaknesses, which to some extent limit their use: insufficient water resistance, a tendency to volumetric deformation, leading to warping of reinforced gypsum products, and the susceptibility of their reinforcement to corrosion. These disadvantages can be largely eliminated by introducing lime and hydraulic additives into its composition.
By introducing some polymers into the composition of gypsum concrete, it is possible to significantly increase its water resistance, giving the gypsum a non-wettability property, and hydrophobic-plasticizing additives together with vibration compaction can significantly reduce the gypsum ratio and increase not only the water resistance, but also the strength of the products.
Gypsum, sealed with an aqueous solution of urea resin, acquires intense properties, which gives products from such gypsum, dried at a temperature of 60-70 ° C, high strength and water resistance. And as a reinforcing material can be wood, reeds, chopped fiberglass, non-woven fiberglass cloth, glass strands.
In order to reinforce gypsum concrete and gypsum concrete products with metal, it is necessary to pre-coat the reinforcement with corrosion-resistant varnishes.
For the production of gypsum concrete, not only natural gypsum stone mined in quarries is used, but also gypsum and gypsum-containing wastes from the chemical industry, as well as secondary raw materials - used gypsum consumables from construction sites and gypsum products obtained during the dismantling and demolition of buildings and structures.
Gypsum concrete is used in the production of many products, most of which we will discuss in the future: artificial stone, gypsum panels, partition walls, architectural details, thermal insulation products and much more.