An admixture that has both air-entraining and water-reducing functions is an air-entraining and water-reducing agent.
The main feature of air-entrained water-reducing admixture is that it not only improves the durability of concrete due to air-entraining, but also improves concrete strength due to water reduction, and also contributes to the increase in tensile strength.
Secondly, there are many varieties of high-efficiency air-entraining water-reducing admixtures that can well maintain the slump and workability of fresh concrete, so that its excellent operability can be maintained for several hours without significant changes.
The water-reducing rate of air-entraining water-reducing agents is required to be medium, not less than 10%. As for ordinary water-reducing agents, air-entraining agents can slightly reduce water and expand mobility, which is not difficult to achieve. This requirement, as far as high-efficiency water-reducing agents are concerned, the water-reducing rate index is not high.
Since the air-entraining agent can effectively eliminate concrete bleeding and improve workability, the bleeding rate ratio is required to reach a lower value of 70-80%, while the relative durability index, namely the dynamic elastic modulus, remains The value is higher and should reach 80%-60%.
The concrete strength requirement is to reach 115% of the strength of the benchmark concrete of the same period in 3 days, and not lower than the strength of the benchmark concrete in the same period in 28 days.
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