What are the technical points of using air entraining agents in concrete

The bubble structure is good, the bubble radius is small, and the frost resistance index is high, which is used for high durability concrete structures, such as dams, high-grade highways, thermal power station cooling towers, pool hydraulics, ports, etc.

2. Concrete roads and bridges sprinkled with de-icing salt.

3. High and workable concrete engineering.

4. Pumping concrete.

The addition of air entraining agent is to obtain more closed pores, and the permeability of concrete is to use open holes and the kind of penetrating holes, and these closed pores water not only progressively can also block the penetration of water, so the impermeability will be improved, and the addition of air entraining agent will affect its compactness to a certain extent, but compared with other properties, it is still good, and when the air content is 5%, its strength is not only not reduced but also increased. And its pumping effect is also better.

The purpose of adding air-entraining agent to ordinary concrete is to increase the frost resistance of concrete, improve the durability of concrete, improve the toughness of concrete, and reduce the shrinkage rate of concrete.

1. Increase the frost resistance of concrete: the addition of air-entraining agent will produce many small pores in the concrete, which can buffer the shrinkage pressure of the concrete and change the microstructure of the concrete, thereby increasing the frost resistance of the concrete and reducing the cracking caused by eccentric torsion at low temperature.

2. Improve the durability of concrete: The air entrainment effect of the air-entraining agent can change the pore structure of the concrete, so that its density is moderate and the porosity is reasonable, thereby greatly improving the durability of the concrete and prolonging the service life of the concrete structure.

3. Improve the toughness of concrete: the air-entraining agent can change the microstructure of concrete, thereby increasing the damage tolerance of concrete and improving its toughness and seismic performance.

4. Reduce the shrinkage rate of concrete: the addition of air-entraining agent can reduce the free shrinkage rate of concrete, thereby reducing the stress state of concrete and reducing the cracking tendency of concrete.

The addition of air-entraining agent can effectively improve the comprehensive performance of ordinary concrete, improve the durability, toughness, spalling resistance and other aspects of the performance of concrete, so it is widely used in construction.

Definition of air-entraining agent

Air-entraining agent, also known as microbubble agent, is a class of chemical additives, which refers to a chemical admixture added to concrete or mortar, which can increase the number of air pores in it. Air-entraining agent is essentially a surfactant, which is able to form a stable foam system in cement slurry, refine and disperse the bubbles generated in the concrete in the concrete, thereby changing the pore structure of the concrete, increasing its porosity and volume, thereby improving the properties and properties of the concrete.

Air-entraining agents are widely used in concrete production and construction, and can generally be divided into two types: chemical air-entraining agents and physical air-entraining agents, among which chemical air-entraining agents are mainly some surfactants or other substances with redox properties, which can promote the reaction of hydrogen oxide in concrete and produce gas, thereby forming fine bubbles. The physical air-entraining agents are mainly some foaming agents, which are pumped and transported by the hydraulic power of the bubbles, so as to achieve the air-entraining effect on the concrete.

Answer] :d This question examines cement concrete. The air-entraining agent is a hand-forest admixture that can introduce a large number of evenly distributed stable and sealed imitation medium and micro bubbles in the mixing process of mixing large acres of concrete, so as to reduce the water segregation of the mixture, improve the workability, and significantly improve the freeze-thaw durability of hardened concrete.

Answer]: b, c, d

The air-entraining agent mainly improves the fluid deformation performance, durability and early strength of the concrete mixture.

Summary. The addition of air-entraining agents can improve the strength, compressive properties and durability of concrete. Air-entraining agent can improve the fluidity of concrete, make concrete easier to smooth, reduce the occurrence of shrinkage cracks, improve the compressive strength of concrete, improve the durability of concrete, and make concrete more durable and durable.

In addition, air-entraining agents can also improve the frost resistance of concrete, making concrete more frost-resistant and heat-resistant, and more durable. Air-entraining agents can also improve the impermeability of concrete, making it more waterproof and durable. In short, air-entraining agents can improve the strength, compressive performance and durability of concrete, making concrete more durable, more frost-resistant and heat-resistant, and more waterproof and durable.

The addition of air-entraining agents can improve the strength, compressive properties and durability of concrete. The air-entraining agent can improve the fluidity of mixed chain field concrete, make the concrete easier to smooth, reduce the occurrence of shrinkage cracks, improve the compressive strength of concrete, improve the durability of concrete, and make the concrete more durable. In addition, air-entraining agents can also improve the frost resistance of concrete, making concrete more frost-resistant and heat-resistant, and more durable.

Air-entraining agents can also improve the impermeability of concrete, making it more waterproof and durable. In short, air-entraining agents can improve the strength, compressive performance and durability of concrete, making concrete more durable, more frost-resistant and heat-resistant, and more waterproof and durable.

You've done a great job! Can you elaborate on that?

Air-entraining agents can improve the strength, crack resistance, and durability of concrete. The reason for adding air-entraining agent to concrete is that the air bubbles in the concrete will affect the strength and crack resistance of the concrete, and the air-entraining belt embedding agent can effectively inhibit the formation of air bubbles, thereby improving the strength and crack resistance of the concrete. Workaround:

1.Add liquid to the concrete and add a suitable air-entraining agent to inhibit the formation of bubbles and improve the strength and crack resistance of the concrete. 2.

When adding air-entraining agent, it is necessary to pay attention to controlling the amount of it so as not to affect the performance of concrete. 3.In the mixing process of concrete, it is necessary to ensure that the concrete is mixed evenly, so as not to affect the performance of the concrete.

Personal Tips:1In the construction process of concrete, it is necessary to pay attention to controlling the amount of air-entraining agent so as not to affect the performance of concrete.

2.In the mixing process of concrete, it is necessary to ensure that the concrete is mixed evenly, so as not to affect the performance of concrete. 3.

In the construction process of concrete, it is necessary to pay attention to controlling the humidity of concrete, so as not to affect the performance of concrete. Related knowledge: Air-entraining agent is an additive that can effectively inhibit the formation of air bubbles, thereby improving the strength and crack resistance of concrete.

There are many types of air-entraining agents, such as silicate, sulfate, phosphate, etc., among which silicate is the most commonly used air-entraining agent.

Summary. The addition of air-entraining agents can improve the compressive strength, flexural strength, impermeability, durability and frost resistance of concrete. Air-entraining agent can improve the fluidity of concrete, reduce the moisture of concrete, improve the slump of concrete, improve the filling of concrete, and improve the compressive strength, flexural strength, impermeability, durability and frost resistance of concrete.

In addition, air-entraining agents can also improve the impact resistance, tensile strength, flexural strength, impermeability, durability and frost resistance of concrete. Air-entraining agents can also improve the flexural properties, impermeability, durability and frost resistance of concrete, as well as the flexural properties, impermeability properties, durability and frost resistance. Air-entraining agents can also improve the flexural properties, impermeability, durability and frost resistance of concrete, as well as the flexural properties, impermeability properties, durability and frost resistance.

Therefore, air-entraining agents can improve the compressive strength, flexural strength, impermeability, durability and frost resistance of concrete, thereby improving the performance of concrete.

The addition of air-entraining agents can improve the compressive strength, flexural strength, impermeability, durability and frost resistance of concrete. Air-entraining agent can improve the fluidity of concrete, reduce the moisture of concrete, improve the slump of concrete, improve the filling of concrete, and improve the compressive strength, flexural strength, impermeability, durability and frost resistance of concrete. In addition, air-entraining agents can also improve the impact resistance, tensile strength, flexural strength, impermeability, durability and frost resistance of concrete.

Air-entraining agents can also improve the flexural properties, impermeability, durability and frost resistance of concrete, as well as the flexural properties, impermeability properties, durability and frost resistance. Air-entraining agents can also improve the flexural properties, impermeability, durability and frost resistance of concrete, as well as the flexural properties, impermeability properties, durability and frost resistance. Therefore, the air-entraining agent can improve the compressive strength, flexural strength, wax scale, impermeability, durability and frost resistance of concrete, so as to improve the performance of concrete in mixed excavation.

Fellow, I really didn't understand, I can be more specific.

The addition of air-entraining agents can improve the strength, compressive properties and durability of concrete. Reason: Air bubbles in concrete will affect the strength and compressive properties of concrete, so air-entraining agents need to be added to eliminate air difference bubbles.

Solution: Adding an appropriate amount of air-entraining agent to the concrete can effectively eliminate the pre-argument bubbles and improve the strength and compressive performance of the concrete. Personal Tips:

When adding air-entraining agent to concrete, the appropriate air-entraining agent should be selected according to the nature of concrete and the use environment to ensure the quality of concrete. Related knowledge: Air-entraining agent is an additive that can improve the performance of concrete, improve the strength, compressive performance and durability of concrete, and the commonly used air-entraining agents are sodium silicate, aluminum silicate, calcium silicate, etc.

Answers]: a, b, c, d

2021 new textbook p53 page.

Knowledge points: the role of air-entraining agents.

Air-entraining agent refers to the admixture that can introduce a large number of evenly distributed, stable and closed tiny bubbles in the process of mixing concrete. The air-entraining agent can significantly improve or change some properties of the concrete: improve the workability of the concrete mixture, significantly improve the impermeability and frost resistance of the concrete, but the concrete strength is slightly reduced.

The air-entraining agent can be used for impermeable concrete, frost-resistant concrete, sulfuric acid erosion-resistant concrete, concrete with serious water leakage, light concrete and concrete with requirements for finishing, but the air-entraining agent should not be used for steam-curing concrete and prestressed reinforced concrete. The dosage of air-entraining agent is usually the mass of cement and is calculated as the dry matter of air-entraining agent).