What is the advantages of amorphous calcium aluminate in underwater non-dispersible concrete?
by acacem.com
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Keywords
Amorphous calcium aluminate, underwater non-dispersible concrete, flocculant, anti-dispersant, silica fume, metakaolin, viscosity-reducing enhancer, polycarboxylate superplasticizer
Underwater non-dispersible concrete refers to the concrete in which the anti-dispersion agent is added to the fresh concrete so that it can be poured underwater without the separation of aggregate and mud under the action of water. It has the advantages of self-leveling, self-compacting viscosity without vibration.
At present, the composition of underwater non-dispersible concrete materials mainly includes:
Flocculant (anti-dispersant), fly ash, silica fume, metakaolin, viscosity-reducing enhancer, polycarboxylate superplasticizer, etc.
Amorphous calcium aluminate is a kind of non-crystalline special cement material, which has extremely high hydration activity due to the disordered molecular arrangement inside. Therefore, using amorphous calcium aluminate as the main material of underwater non-dispersible concrete has great advantages, which are mainly reflected as follows:
1. Very short setting time, high early strength, stable late strength, and basically no shrinkage.
Due to its extremely short setting speed, it can prevent the concrete from dispersing and resisting erosion during underwater construction; and the early strength and later strength are stable, which can make the concrete structure more stable. Due to its own characteristics, there is no shrinkage phenomenon in the later stage, so the concrete structure will not produce cracks; thus greatly improving the strength and durability of the concrete structure.
2. Self-compacting, impermeability, corrosion resistance and erosion resistance
Due to the reaction characteristics of amorphous calcium aluminate, it has fast setting, early strength and no shrinkage; therefore, it can make the concrete structure more compact, enhance the performance of concrete, and solve the problems of anti-permeation, anti-corrosion and anti-scouring. These characteristics can perfectly make up for the disadvantages of underwater concrete construction.
3. High underwater activity and low temperature activity
Amorphous calcium aluminate also has high reactivity underwater and can adapt to underwater low temperature construction. Therefore, the problem of underwater construction in winter is solved.
