Some of the most common cement varieties and characteristics in building materials

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Some of the most common cement varieties and characteristics in building materials

At present, in the construction of construction project, cement can not be separated from cement, the packaging of commonly used cement is in bulk or bagged, the large amount of cement on the construction site can be required to provide cement cans, which can be used as site storage. If the dosage is not very large, the general use of bags can be, each bag net content of 50 kg. The cement packaging belt should be marked with: manufacturer name, production license mark and number, factory number, packing date, net content, standard of execution, type of cement, code name of cement, strength grade.

Portland cement is the most commonly used cement in China.

According to the recent national standards: general Portland cement, according to the variety and content of mixed materials, divided into:

  1. Portland cement

Portland cement for short

Cement codes: P ·1, P ·11

Strength grades: 42.5, 42.5 R (early strength), 52.5, 52.5 R (early strength), 62.5 R, 62.5 R (early strength)

  1. Ordinary Portland cement

Cement abbreviation: ordinary cement

Cement code: P. O

Strength grades: 42.5, 42.5 R (early strength), 52.5 R, 52.5 R (early strength)

  1. Slag Portland cement

Cement abbreviation: slag cement

Cement codes P ·S ·A, P ·S ·B

Strength rating: 32.5, 32.5R (early strength), 42.5, 42.5R (early strength), 52.5, 52.5R (early strength)

  1. Volcanic ash Portland cement

Abbreviated as pozzolanic cement

Cement code: P. P.

Strength rating: 32.5, 32.5R (early strength), 42.5, 42.5R (early strength), 52.5, 52.5R (early strength)

  1. Pulverized coal ash Portland cement

Cement abbreviation: fly ash cement

Cement code: P. F

Strength rating: 32.5, 32.5R (early strength), 42.5, 42.5R (early strength), 52.5, 52.5R (early strength)

  1. Composite Portland cement

Cement abbreviation: composite cement

Cement code: P. C.

Strength rating: 32.5R (early strength), 42.5, 42.5R (early strength), 52.5, 52.5R (early strength)

These six kinds of cement should be applied to different places, parts and structures according to their own characteristics in engineering construction. The following are the main characteristics of these six kinds of cement:

  1. Portland cement

(1) Fast setting and hardening, high early strength, (suitable for high strength concrete, underwater concrete, prestressed concrete, winter construction)

(2) the hydration heat is large, (not suitable for mass concrete)

(3) good frost resistance, (suitable for winter construction, cold areas)

(4) poor heat resistance (not suitable for heat resistant concrete)

(5) poor corrosion resistance (not suitable for corrosion environment)

(6) small dry shrinkage, (suitable for impermeable concrete)

  1. Ordinary cement

(1) the setting hardening is faster and the early strength is higher (suitable for underwater concrete, general concrete, winter construction).

(2) the hydration heat is large (not suitable for mass concrete).

(3) the frost resistance is good, (suitable for winter construction)

(4) the heat resistance is poor (not suitable for heat-resistant concrete)

(5) poor corrosion resistance (not suitable for corrosion environment)

(6) dry shrinkage is small, (suitable for impermeable concrete)

  1. Slag cement.

The main results are as follows: (1) setting hardening is slow, early strength is low, and strength increases rapidly in the later stage. (suitable for mass concrete engineering, general concrete, mortar)

(2) the hydration heat is small, (suitable for mass concrete)

(3) poor frost resistance (not suitable for winter construction)

(4) good heat resistance, (suitable for heat resistant concrete)

(5) good corrosion resistance (suitable for corrosion environment)

(VI) small dry shrinkage

(7) the bleeding is large and the impermeability is poor, (not suitable for impermeable concrete)

  1. Pozzolanic cement

The main results are as follows: (1) setting hardening is slow, the early strength is low, and the later strength increases rapidly, (suitable for mass concrete, general concrete, mortar)

(2) the hydration heat is small, (suitable for mass concrete)

(3) poor frost resistance (not suitable for winter construction)

(4) the heat resistance is poor (not suitable for heat-resistant concrete)

(5) good corrosion resistance (suitable for corrosion environment)

(6) dry shrinkage is large.

(7) good impermeability (suitable for impermeable concrete)

  1. Fly ash cement

The main results are as follows: (1) setting hardening is slow, the early strength is low, and the later strength increases rapidly, (suitable for mass concrete, general concrete, mortar)

(2) the hydration heat is small, (suitable for mass concrete)

(3) poor frost resistance (not suitable for winter construction)

(4) the heat resistance is poor (not suitable for heat-resistant concrete)

(5) good corrosion resistance (suitable for corrosion environment)

(6) dry shrinkage is small, (not suitable for impermeable concrete)

(7) High crack resistance, (suitable for crack resistant concrete,)

  1. Composite cement, (the property is not stable due to the content of content)

The main results are as follows: (1) setting hardening is slow, the early strength is low, and the later strength increases rapidly. (surface mortar)

(2) the hydration heat is small.

(3) poor frost resistance

(4) good corrosion resistance

(5) other properties are related to the content of admixture.