Brief Introduction of Application of Amorphous Calcium Aluminate in Low Temperature Environment
Keywords
Amorphous calcium aluminate, concrete, low temperature concrete, negative temperature concrete
Concrete construction is in a severe cold environment, and the low temperature environment will affect the cement hydration process, especially in a sub-zero environment, the hydration rate will be significantly slowed down, and the cement paste will have the risk of freezing and cracking. In order to solve the risk of concrete construction under sub-zero temperature conditions, it is necessary to introduce new building materials.
Under low temperature conditions, the admixtures that need to be compatible with concrete mainly include:
Polycarboxylate superpalsticizer, lithium carbonate, antifreeze, retarder, expansion agent, defoamer, etc.
One of the most important new materials is amorphous calcium aluminate. Due to its special amorphous form, amorphous calcium aluminate produces extremely fast condensation speed in the process of cement hydration, even at low temperature and subzero temperature. Under low temperature conditions, its setting speed is also extremely fast, which makes concrete feasible in low temperature construction.
In addition, in the hydration of cement, non-crystalline calcium aluminate not only produces the excellent effect of quick setting and fast setting, but also enhances the compactness of concrete and significantly improves the early strength; at the same time, non-crystalline calcium aluminate fills the tiny pores of cement, It also has remarkable effects in terms of waterproof, cold resistance and crack resistance.
Therefore, amorphous calcium aluminate is an indispensable new material for concrete construction in low temperature environment in winter.
