After a series of physical and chemical changes, it can solidify and harden, and the block or powdery materials can be cemented together to form a whole material.

Inorganic cementitious materials

Organic cementitious materials (asphalt, polymers)

Raw material CaCO3

Production process - calcination The lime production process is a limestone calcination process. According to the degree of calcination, it can be divided into underfired lime, normalized lime and overfired lime.

①Lumpy quicklime

Lime paste, hydrated lime powder, quicklime powder

The slaking process of lime: quicklime water = slaked lime

Lime slaking method

Treatment of over-fired lime and under-fired lime

Things to note during the aging process

hardening process

Carbonization hardening proceeds slowly "from the outside to the inside" → After the mortar joints of masonry mortar and plastering mortar harden, there is still uncarbonized Ca(OH)2 component.

Thinking: Why is lime mortar plastering prone to cracking, shelling, and peeling in an environment that has been exposed to moisture for a long time? Under the action of moisture in a humid environment, the uncarbonized and hardened Ca (OH)2 dissolves in water, resulting in a reduction in the strength of the structure → resulting in mortar cracking, shell jumping, peeling and other phenomena.

Lime quality grade

Properties of lime

Application of lime

·Do not mix, store or transport with flammable, explosive and other dangerous liquid items.

·The storage time of quicklime should not be too long, generally no more than one month. Achieve "change as you go".

·Hydrated lime must be aged for more than two weeks before use to prevent the damage caused by burnt lime to the building.

Quicklime should be stored in a dry warehouse to protect it from water and moisture. When the storage time is long, it is best to digest it into lime paste in the ash tank, and cover the surface with a permanent film to isolate the air and prevent carbonization.

The production of gypsum cementitious materials is usually made by calcining, dehydrating and then grinding dihydrate gypsum at a certain temperature and pressure.

·Under different calcination temperatures, the products obtained are different. The specific process is as follows:

·Building gypsum is commonly used in construction projects; high-strength gypsum is used to produce building gypsum products.

Condensation of building gypsum: it is a process of dissolution, reaction, precipitation and crystallization;

Gypsum hardening: It is the formation process of the crystal structure network between the dihydrate gypsum crystals.

(Crystals intersect with each other to form a network structure; as the reaction continues, The crystal structure network gradually becomes denser, causing the gypsum crystals to gradually harden. )

Technical properties of construction gypsum

Application of Gypsum

·The modulus n of water glass: refers to the ratio of the number of molecules of silicon oxide and sodium oxide in sodium silicate (Na, OnSiOz), which is generally between 1.5 and 3.5.

Formulate heat-resistant concrete or serve as a setting accelerator for cement

for foundation grouting

For painting material surfaces

Liquid water glass absorbs carbon dioxide in the air to form an amorphous silicate gel, which gradually dries and hardens. The specific reaction formula is as follows:

In order to accelerate the hardening of water glass, it can be heated or mixed with 13% to 15% of the hardening accelerator sodium fluorosilicate.

Properties of water glass

Application of water glass

Cement concrete, clay bricks, silicate products, stone