Issues to note when using concrete expansion agents

(1) Expansion must be coordinated with strength development. Obviously, expansion while the concrete is in a fluid state is ineffective expansion. If large expansion occurs when the strength is very low, it will also lead to the destruction of the concrete structure. Therefore, the development of expansion must be coordinated with the development of strength in order to make full use of the expansion energy.

(2) Expansion must be under sufficient control. If the expansion of concrete exceeds the control of the limiting conditions, it will become a destructive force. In this case, expansion will not only fail to improve the performance of concrete, but will also significantly reduce the performance of concrete. Therefore, there must be sufficient control over the expansion generated by the expansive agent, so that the expansion develops in a favorable direction.

In concrete, the expansive agent must be evenly distributed. First, the mixing time should be extended; second, segregation should be prevented, as segregation will destroy the uniformity of the concrete.

(3) Concrete with expansive agent must be strengthened curing. The hydration of the expansion component requires a large amount of water. Without water, the expansion component cannot be well hydrated, and therefore cannot play its role well. Therefore, concrete with expansive agent must be strengthened curing. After the concrete hardens, not only should water be sprayed in time, but also sufficient curing time is required.

Note: Concrete containing expansive agents requires strict water curing conditions! If the construction unit does not provide sufficient humid curing conditions, the expansive agent is equivalent to "useless". After use, it not only does not play the corresponding role, but also brings other negative impacts. Mineral admixtures have the effect of inhibiting expansion.