Use | Air-entraining agent, also known as air-entraining agent, is a kind of hydrophobic surfactant, dissolved in water and added to the concrete mixture, in the mixing process can produce a large number of tiny bubbles. |
Air-entraining agent can improve the fluidity, cohesiveness and water retention of concrete mixture, improve the fluidity of concrete, and introduce a large number of uniformly distributed, closed and stable admixtures of tiny bubbles in the mixing process of concrete mixture.
The main varieties of air-entraining agents include rosin resins, alkyl and alkyl aromatic sulfonic acids, fatty alcohol sulfonates, saponins, protein salts, petroleum sulfonates, etc. The common dosage is 50 ~ 500ppm of cement weight. Air-entraining agents are mainly used for structures with high frost resistance requirements, such as concrete dams, pavements, bridge decks, airport pavements and other large areas that are susceptible to freezing.
due to the introduction of a large number of bubbles, the effective area of concrete under compression is reduced, and the strength and wear resistance of concrete are reduced. when the water cement ratio is kept unchanged, the air content increases by 1%, and the concrete strength decreases by about 3% ~ 5%. therefore, when air entraining agent is used to improve the frost resistance of concrete, attention should be paid to controlling the air content of concrete to avoid a large amount of causes leading to a substantial decrease in concrete strength.