Aluminum sulfate and liquid alkali-free accelerator
Key words
Liquid alkali-free accelerator, aluminum sulfate, shotcrete, accelerator, concrete
The aluminum ions in aluminum sulfate can significantly improve the quick-setting effect of cement.
The main component of the accelerator is aluminum sulfate. The quick-setting effect of this quick-setting agent is mainly aluminum ions, but its solubility is small, the solution is relatively active, most of them have high dosage, low early strength and later strength will be lost. shortcoming.
Aluminum sulfate and sodium aluminate as the main components of the accelerator. Under certain conditions, it can react to form polyaluminum sulfate, so that the content of aluminum ions in the solution increases, but the stability of polymerization is poor. Now, the method of adding stabilizers and adjusting the pH value is mainly used to inhibit the hydrolysis of aluminum ions. Increase its storage period. This kind of accelerator has little effect on the later strength of cement and has good adaptability to different types of cement. But in essence, sodium ions will inevitably be introduced when sodium aluminate is added, which is contrary to the tendency of accelerators to develop towards alkali-free.
Accelerator with aluminum sulfate and aluminum hydroxide as the main components. It can directly react to generate polyaluminum sulfate, shorten the reaction process, and introduce aluminum ions to a certain extent. The advantage is that no alkali metal ions are generated, and the disadvantage is that the proportion of aluminum hydroxide used is relatively large, the cost is high, and this type of accelerator has poor stability, easy precipitation and crystallization, and is not suitable for long-term storage.
Aluminum sulfate is an inorganic substance, which is a white crystalline powder.
Chemical formula: Al2(SO4)3
Molecular weight: 342.15
CAS: 10043-01-3
EINECS: 233-135-0
Melting point: 770C
water solubility: soluble
Density: 2.71 g/cm3
