The construction of stone has certain functions of sound insulation and fire prevention,which can satisfy many needs of users and is an indispensable material for construction and decoration!Here we introduce what is the construction of plaster and its functions!

　　Build gypsum

　　The materials produced by gypsum are mainly natural gypsum containing calcium sulfate(also known as raw gypsum)or chemical by-products containing calcium sulfate and waste residues such as phosphogypsum,fluorogypsum and boron gypsum.Its chemical formula is CaSO4.2H2O,also known as gypsum dihydrate.Different types of gypsum can be obtained by calcining natural dihydrate gypsum at different temperatures.If the natural dihydrate gypsum is heated under the dry condition of 107~1700c,the gypsum can be constructed.

　　After adding water to the construction gypsum,it is mainly dissolved in water,and then the dihydrate gypsum is generated and separated.As the hydration progresses,the generated dihydrate gypsum colloid particles continue to increase.These particles are finer than the original,larger than the outer surface,and absorb a lot of water;together,the free water in the slurry is constantly due to hydration and transpiration Cut,the consistency of the slurry is continuously added,the adhesion between the colloidal particles is gradually increased,and friction and adhesion between the particles occur,so that the slurry gradually loses its plasticity,that is,the slurry gradually coagulates.Continuous hydration,the colloid turns into crystals.The crystalline particles gradually grow,so that the slurry completely loses its plasticity,and strength occurs,that is,the slurry hardens.This process continues until the slurry is completely dry and the strength is not added.At this moment,the slurry has hardened to form stone.

　　The main function of building gypsum

　　(1)Cohesion and hardening fast.After the construction gypsum is mixed with water,the slurry begins to lose plasticity within a few minutes,and the plasticity is completely lost within 30 minutes,resulting in strength.

　　(2)The volume expands slightly when condensing and hardening.The gypsum slurry will swell slightly in the early stage of aggregation and hardening.The appearance of this type of gypsum product is lubricated,delicate,accurate in size,full-bodied and good in decoration.

　　(3)The porosity is large.When mixing the building gypsum,in order to make the slurry have the plasticity required for construction,it is necessary to participate in the water consumption of 60%~gypsum,and the theoretical water requirement for building gypsum hydration is 18.6%,so when a lot of free water is transpiration,Many capillary pores are formed inside the built gypsum products.The thermal conductivity is small and the sound absorption is good,which is attributed to the lightweight insulation material.

　　(4)has certain humidity control.Because many capillary pores inside the gypsum product have a strong ability to adsorb water vapor in the air,it has a certain adjustment effect on the indoor air humidity.

　　(5)Good fire resistance,durability,water resistance,impermeability and poor frost resistance.