Classification and application range of commonly used concrete admixtures

There are many types of concrete admixtures with different functions. Correct use of concrete admixtures is necessary. “Technical Standards for the Application of Concrete Admixtures” GB50119-2003 stipulates the application fields of admixtures.

1. General admixtures and high-efficiency water-reducing admixtures: can be used for plain concrete, building steel reinforcement concrete, prestressed concrete, and can produce high-strength performance concrete. Generally speaking, admixtures should be used in concrete constructed at a minimum temperature of around 5℃, and superplasticizers should be used in concrete constructed at a minimum temperature of around 0℃.

2. Air-entraining agent and air-entraining water-reducing agent: can be used for cold-resistant concrete, impermeable grade concrete, sulfate-resistant concrete, etc.

3. Retarder, retarder admixture and retarder superplasticizer: can be used for large-volume concrete, rolled concrete, concrete constructed under hot weather conditions, which require long-term parking or long-term operation. Concrete transported by distance, etc.

4. Early strength agent: It is suitable for concrete curing concrete and concrete projects with early strength requirements that are constructed in ultra-low and minimum temperatures above -5℃ at normal temperatures.

5. Antifreeze: Organic concrete antifreeze can be used in plain concrete, building reinforced concrete and prestressed concrete.

6. Expansion agent: used for underground, underwater, tunnel construction and other buildings, large-volume concrete, prefabricated component reinforcement, leakage repair, structural settlement post-pouring belt filling, column-beam connectors, ground The foot screws are fixed, etc. The maximum internal temperature of large-volume concrete mixed with expansion agents should comply with relevant standards, and the temperature difference between the inside and outside of the concrete should be <25°C.

7. Pumping agent: Suitable for concrete in industrial production and industrial buildings and underwater concrete construction of other buildings. It is very suitable for large-volume concrete, high-rise residential and high-rise buildings, guide channel construction, etc.

8. Accelerated setting agent: It can be used for spray concrete constructed by the spray method, and can also be used for other concrete that needs to be set quickly.

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