The use of composite Portland cement, what are the advantages of composite Portland cement

Characteristics and applications of Portland cement: (1) High strength Portland cement sets and hardens quickly, has high strength, especially the early strength growth rate is large, especially suitable for projects with high early strength requirements, high-strength concrete structures and prestressed concrete projects. (2) High heat of hydration Portland cement clinker has high content of C3S and C3A, which makes the early heat release large, fast heat release speed, and high early strength, and can often avoid frost damage when used in winter construction.

However, high heat release is not good for large-volume concrete projects, and should not be used for large-volume concrete projects if there are no reliable cooling measures. (3) Good frost resistance Portland cement mixture is not easy to leak water, and the hardened cement stone has a higher density, so the frost resistance is better than that of other general cements. It is suitable for concrete engineering in severe cold areas subject to repeated freeze-thaw action.

4) High alkalinity and strong carbonization resistance The hardened cement stone of silicate cement shows strong alkalinity, and the steel bar buried in it generates a gray passivation film on the surface of the alkaline environment, which can keep the steel bar from rusting for decades. Portland cement has strong alkalinity, high compactness, and strong carbonization resistance, so it is especially suitable for important reinforced concrete structures and prestressed concrete projects. (5) Dry shrinkage Portland cement forms a large amount of hydrated calcium silicate gel during the hardening process, which makes the cement stone dense, less free water, and not easy to produce dry shrinkage cracks, which can be used in concrete projects in dry environments.

7) Good abrasion resistance Portland cement has high strength, good wear resistance, and dry shrinkage, which can be used for pavement and ground engineering. (8) Poor corrosion resistance Portland cement stone has a large amount of Ca(OH)2 and calcium aluminate hydrate, which is easy to cause the erosion of soft water, acids and salts. Therefore, it should not be used in projects that are attacked by flowing water, pressure water, acids and sulfates.

9) Poor heat resistance Portland cement stone at a temperature of 250 when the hydrate begins to dehydrate, the strength of the cement stone decreases, when the heat is more than 700, the cement stone begins to destroy. Therefore, Portland cement should not be used alone for heat-resistant concrete projects.

10) Poor damp heat curing effect Portland cement hardens quickly and has high strength under conventional curing conditions. However, after steam curing, the compressive strength measured after natural curing to 28 days is often lower than that measured after 28 days without steam curing.

Generally, Portland cement is mainly used in ordinary civil buildings or non-structural places of engineering in the market.

Composite Portland cement is actually a composite cement made of mixed cement, which has a wide range of applications in our lives. Let me introduce its advantages. Composite Portland cement has strong frost resistance, is not easy to produce soapy water, and the relative density of cement stone after hardening is high, so the frost resistance is better than that of other ordinary concrete.

It is suitable for concrete works with continuous freezing and thawing in cold areas. Composite Portland cement has high toughness, cement hardening and high compressive strength. In particular, the initial compressive strength is high.

It is suitable for engineering projects with high initial compressive strength, high-strength concrete structures and prestressed reinforced concrete construction projects.

Composite Portland cement not only has high acidity, but also has strong carbonization ability. The cement stone after the solidification of composite Portland cement shows strong alkalinity, and the surface of the building steel bar buried in it will turn into a dark gray passivation film in the alkaline natural environment, which can keep the building steel bar from being corroded for decades. 4.

Composite Portland cement has high strength wear resistance, Portland cement not only has high hardness, but also has good wear resistance, and can be basically used for road and ground construction.

What are the characteristics of Portland cement, and the advantages of Portland cement are. High initial strength. Condensation hardening fast jujube plum.

Good cold tolerance. The lack of stools regrets late is that the hydration heat is high. Poor heat resistance.

Acids, bases, and sulfates are less chemically attacked. Dissolvable ** etching differences. The advantages of ordinary Portland cement are:

High initial strength. Condensation hardens quickly. Good cold tolerance.

The disadvantage is that the heat of hydration is high. Poor heat resistance. Dissolution ** erosion is not good.

The advantage of slag cement is its low heat of hydration.

In a humid environment, the strength improvement rate is high in the middle and late stages. Good heat resistance. Sulfate attack and dissolution are better before corrosion.

The disadvantages are: the initial strength is low, and it is more pronounced at low temperatures. Cold hardiness decreases.

It has a large shrinkage and has a soapy water phenomenon. The advantages of fly ash cement are: low heat of hydration.

Sulfate resistance and soluble erosion are better. Shrinkage is small. The growth rate of intensity is larger in the later period.

The disadvantage is the low initial strength. Poor heat resistance. Cold hardiness decreases.

Poor resistance to carbonization.

First, the special pure section is strong, second, it dries quickly, the third can integrate a variety of materials, the viscosity is very strong, the third cement is also relatively cheap, the cost is very low, and so on, these are the advantages of the cement, this cement is very easy to use.

The freezing speed is fast, the strength is high, the wear resistance effect is higher, the adhesion is good, it is more suitable for the cracks, and the good adhesion can be used to dismantle the cracks in the wall of Nian Yutan, and it is heat resistant.

Its advantages are high alkalinity, strong carbonization resistance, high hydration heat, it is used for winter construction, can avoid frostbite, and its frost resistance is also particularly good.

The frost resistance is very good, the ability to carbonize is very strong, the hydration heat is high, the time for agglomeration is fast, and the price is cheap.

1. Strength grade:

The lowest strength grade of ordinary Portland cement is; The maximum grade of composite Portland cement is, which is the difference that can be seen from the data.

2. Content used:

The content of ordinary Portland cement mixture is 5%-20%; The mixed materials of composite Portland cement are at least two kinds, with a content of 20%-50%.

3. Scope of application:

Ordinary Portland cement is generally suitable for most concrete structure projects on the ground, underground and in water, and the early strength is fast, the heat of hydration is high, and the dry shrinkage rate is large, so it can not be used for large-volume projects; Composite cement is determined by the characteristics of its mixed materials, its inherent characteristics, generally only used for wall brushing and mortar mixing and other functions, its concrete energy is low.

1. The production is different.

Ordinary Portland cement is finely ground and mixed by limestone, clay and iron ore powder in proportion, and the mixture at this time is called raw meal. Portland cement mixed with mixed materials is to add other substances to ordinary Portland cement in proportion and certain processing procedures to achieve special effects, such as slag cement, porosyl Portland cement, fly ash Portland cement, composite Portland cement and so on.

2. Different uses.

Ordinary Portland cement is calcined, the general temperature is about 1450 degrees, and the product after calcination is called clinker. Then the clinker and gypsum are ground together and mixed in proportion to be called cement. The raw materials of composite Portland cement are more active mixed materials or inactive mixed materials than the original ordinary Portland cement.

1. The strength grade of cement is different.

Ordinary Portland cement has the lowest strength grade, while composite Portland cement has the highest grade.

2. The content of mixed materials is different.

The content of ordinary Portland cement mixture is 5%-20%, while the mixture of composite Portland cement is at least two kinds with a content of 20%-50%.

3. The scope of application is different.

Ordinary Portland cement is suitable for most concrete structures on the ground, underground and in the water, and the early strength is fast, the hydration heat is high, and the dry shrinkage rate is large, so it cannot be used for large-volume projects.

Composite cement is determined by the characteristics of its mixed materials, its inherent characteristics, only used for brushing walls and mortar mixing and other functions, its concrete energy is low.

The differences between ordinary Portland cement and composite Portland cement are as follows:

1. Ordinary Portland cement

Features: high early strength, fast coagulation and hardening, good frost resistance, strong wear resistance, good construction performance; The heat of hydration is high, the heat resistance is poor, and the chemical attack resistance of acid, alkali and silicate is poor;

The cement is suitable for: above-ground engineering, underground engineering without erosion, engineering without water pressure, freezing engineering in non-corrosive water, early strength engineering, and engineering that needs to develop quickly under low temperature conditions.

The cement is not suitable for the water-in-water part of concrete works, bulk concrete works and chemically attacked works.

2. Composite Portland cement

Features: high strength in the early and late stages, good workability of the product, small water leakage, good water retention, low heat of hydration, the prepared concrete is not easy to crack, good construction performance, normal setting time, and the strength and performance of cement are basically the same as those of ordinary Portland cement.

It can be widely used in urban and rural buildings, and can replace the use of ordinary cement (the new standard for general Portland cement was implemented in 2007, and ordinary Portland cement has been cancelled and grade cement, and is now available and replaced).

Ordinary Portland cement origin cement and composite Portland cement compound cement.

Composite Portland cement is a hydraulic cementitious material made of Portland cement clinker, two or more specified mixed materials, and an appropriate amount of gypsum grinding, which is called composite Portland cement (referred to as composite pure cement), and no more than 8% kiln ash is allowed to replace part of the mixed material in cement.

1. Composite Portland cement has superior performance: composite cement has the characteristics of low water demand, moderate setting time, good water retention, dry shrinkage, low heat of hydration, good corrosion resistance, good crack resistance, large strength increase rate in the later stage, good workability of the configured concrete, and good compatibility with admixtures. Quality rolling pants rotten reliable:

Through advanced process equipment and strict process quality control, the quality of composite cement is stable, and the indicators of the product are better than those in the national standard GB12958-1999.

2. Composite Portland cement use: widely used in various industrial projects, civil buildings, suitable for underground, large-volume concrete engineering, foundation engineering and other projects. It is not suitable for use in engineering parts with water level rise and fall in severe cold areas.

3. It can be used to brush the wall or mix cement mortar, and be used for tiling. Combined with performance characteristics, because of the strong compressive ability, coupled with good wear resistance, it is more suitable for road and ground engineering, and can also be used in a relatively dry and dry environment to prevent cracking and shrinkage.

1. It has very good frost resistance, because the density of this cement mixture is relatively large after hardening, and its frost resistance is better than that of other ordinary cements, so in severe cold areas, this composite Portland cement can be used.

2. It also has very good strength, once hardened, the strong disturbance rent clearance is still relatively high, and the solidification speed is relatively fast at the beginning, so if you want to have a slightly higher strength in the early stage, or want to achieve high strength concrete, you can choose cement of this nature.

3. Its carbonization resistance is also very strong, if it is used to pour steel bars, it can maintain the shape of the steel bars for decades without rusting, mainly because the carbonization ability is good, so it is more suitable for reinforced concrete structures.

4. The wear resistance is also very slow.

5. Another is that the dry shrinkage is relatively small, and this kind of cement will form a colloid on the surface after solidification, so that the compactness of the cement is relatively high, so it will not produce cracks, especially suitable for some places with a relatively dry environment.

1. High cement strength: the coagulation capacity of composite Portland cement is relatively fast and the strength is relatively high. In particular, the growth rate of early strength is relatively large, which is suitable for projects with high strength requirements and high-strength concrete construction structures.

2. High hydration heat of Pachaye: C3S and C3A are added to the composite Portland cement, which makes the early heat release large and faster, and can avoid frost damage even in the severe cold season. However, if the temperature is too high, it is not suitable for large-volume concrete work.

3. Good frost resistance: Portland cement mixture does not worry about the phenomenon of water leakage, and the density of cement stone after hardening is larger, so the frost resistance is better than that of other general cements. It is especially suitable for concrete work in severe cold areas.

4. High alkalinity and strong carbonization resistance: the hardened cement stone is strongly alkaline, and a layer of gray passivation film is produced on the surface of the steel bar buried in the steel bar, so as to keep the steel bar from rusting for decades.

Composite Portland cement is the cement that uses Portland cement and then mixes other cement together is this kind of composite silicate cement, which is also more durable and better than ordinary cement.

Composite Portland cement is a hydraulic cementitious material made of Portland cement clinker, two or more specified mixed materials, and an appropriate amount of gypsum grinding, which is called composite Portland cement (referred to as composite cement).

Composite Portland cement refers to a material made of Portland cement clinker, adding two or more specified mixed materials, adding an appropriate amount of gypsum, and grinding.

It is a cementitious material developed by Portland cement, two or more specified mixed materials, and an appropriate amount of gypsum powder.