The role of fly ash in concrete is multifaceted, including reducing the heat of hydration. When fly ash replaces part of the cement, the amount of cement used can be reduced, because the volcanic ash of fly ash reacts more slowly, which makes the heat release rate of the concrete lower, thus reducing the heat of hydration.
The principle of fly ash to reduce the heat of hydration is that the heat of hydration is the heat generated by the reaction of cement and water, and this reaction is an exothermic reaction. The incorporation of fly ash can reduce the heat generation of this reaction. This is because the ash reaction rate of fly ash is slower, and when fly ash replaces part of the cement, the heat release rate of the concrete can be reduced, even if the temperature release time of the concrete is extended and the peak of the temperature increase is reduced.
The advantage of fly ash in reducing the heat of hydration is that it can reduce the temperature rise tendency of large-volume concrete, which is especially suitable for large-volume concrete. At the same time, the more fly ash is added, the more obvious the trend of decreasing temperature increase. This is because the volcanic ash reaction of fly ash can improve the impermeability and later strength of concrete, and improve the durability and stability of concrete.
Overall, fly ash reduces the heat of hydration. The addition of fly ash to concrete reduces the generation of heat of hydration, which is due to the reduction in the amount of cement used. The reaction rate of fly ash is slower, and when fly ash replaces part of the cement, the heat release rate of concrete can be reduced, even if the temperature release time of concrete is extended and the peak of temperature increase is reduced. This is another major advantage of the large application of fly ash in concrete.