Cement knowledge Complete book cement basic knowledge

Cement is a powdery hydraulic inorganic cementing material. The concrete made of cemented gravel with it not only has high strength after hardening, but also can resist the erosion of fresh water or salt water. For a long time, as an important cementing material, it has been widely used in civil construction, water conservancy, national defense and other projects.

1.Cement terminology:

2.Cement is divided into three categories according to its use and properties.

1, general cement, the cement usually used in general civil construction projects. General purpose cement mainly refers to the six categories of cement stipulated by GB175-1999, GB1344-1999 and GB12958-1999, namely Portland cement, ordinary Portland cement, Portland slag cement, volcanic Portland cement, Portland fly ash cement and composite Portland cement.

2, special cement, special purpose cement. Such as: G class oil well cement, road Portland cement.

3, characteristic cement, a kind of cement with outstanding performance. Such as: fast hard Portland cement, low heat slag Portland cement, expanded sulphoaluminate cement.

Second, cement according to its main hydraulic substance name is divided into

(1) Portland cement, commonly known abroad as Portland cement;

(2) aluminate cement;

(3) sulfoaluminate cement;

(4) ferric aluminate cement;

(5) fluoroaluminate cement;

(6) Cement with volcanic ash or potential hydraulic materials and other active materials as the main components.

3. Cement is divided into the main technical characteristics indicated in the cement naming according to the need:

(1) Fast hard: divided into fast hard and express hard two categories;

(2) heat of hydration: divided into medium heat and low heat two categories;

(3) Sulfate resistance: divided into medium sulfate corrosion resistance and high sulfate corrosion resistance two categories;

(4) Expansibility: divided into two categories of expansion and self-stress;

(5) High temperature resistance: The high temperature resistance of aluminate cement is graded by the alumina content in the cement.

4. the general principles of cement naming:

The name of cement is based on the main hydraulic minerals, mixed materials, uses and main characteristics of cement according to different categories, and strive to be concise and accurate, and if the name is too long, it is allowed to have short names. General purpose cement is named after the main hydraulic mineral name of cement by the name of the mixed material or other appropriate name. Special cement is named for its specific use and can be referred to in different models.

Cement with pozzolanic or potentially hydraulic materials and other active materials as the main component is named by the name of the main component followed by the name of the active material, and may also be named by the characteristic name, such as gypsum slag cement, lime pozzolanic cement, etc.

5. Definition of main cement products

1, cement: add water and mix into a plastic slurry, can cement sand, stone and other materials can be hardened in the air and can be hardened in water powder hydraulic cement material.

2, Portland cement: by Portland cement clinker, 0%~5% limestone or granulated blast furnace slag, a moderate amount of gypsum ground fine made of hydraulic cementitious material, known as Portland cement, P.I and P.I, that is, foreign commonly known as Portland cement.

3, ordinary Portland cement: by Portland cement clinker, 6%~15% of the mixed material, a moderate amount of gypsum ground fine made of hydraulic cement material, called ordinary Portland cement (referred to as ordinary cement), code: P.O.

4, slag Portland cement: by Portland cement clinker, granulated blast furnace slag and an appropriate amount of gypsum grinding made of hydraulic cementing material, called Portland slag cement, code: P.S.

5, volcanic Portland cement: by Portland cement clinker, volcanic ash mixed material and an appropriate amount of gypsum grinding made of hydraulic cementation material. Known as pozzoline Portland cement, code: P.P.

6, fly ash Portland cement: by Portland cement clinker, fly ash and an appropriate amount of gypsum grinding made of hydraulic cement material, called fly ash Portland cement, code: P.F.

7, composite Portland cement: by Portland cement clinker, two or more specified mixed materials and an appropriate amount of gypsum grinding made of hydraulic cementing material, called composite Portland cement (referred to as composite cement), code P.C.

8, medium heat Portland cement: with the appropriate composition of Portland cement clinker, adding an appropriate amount of gypsum ground fine made with moderate hydration heat of hydraulic cementing material.

9, low heat slag Portland cement: with the appropriate composition of Portland cement clinker, adding an appropriate amount of gypsum ground fine made with low hydration heat of hydraulic cementing material.

10, fast hard Portland cement: by Portland cement clinker to add an appropriate amount of gypsum, ground fine made of early strength high to 3 days compressive strength of the cement label.

11, sulfate resistant Portland cement: by Portland cement clinker, adding an appropriate amount of gypsum grinding made of good sulfate corrosion resistance cement.