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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