Calcium formate is a white or slightly yellow liquid powder, which can speed up the hydration speed of cement and avoid the problem of too slow setting speed in winter or low temperature and wet conditions, so as to improve the early strength of mortar. Today I will tell you about calcium formate to accelerate the setting and hardening of concrete what is specific?
Calcium formate accelerates the setting and hardening of concrete by:
1. Shorten the initial setting time
2. Normalize slow setting of cement under low temperature conditions
3. Increase the growth rate of early strength
4. Shorten the closing time in the module in the production of concrete prefabricated parts
5. Shorten the time for concrete to reach its load capacity
For example, Portland cement is generally used in dry mortar, which is characterized by low strength in the early stage and high strength in the later stage, and adding an appropriate amount of calcium formate is beneficial to improve the early strength of the product.
In Portland cement system, calcium formate has the effect of promoting coagulation and early strength, because the formate ions in HCOO- can form the similarities of AHt and AFm (C₃A·3Ca(HCOO)₂·30H₂O C₃A·Ca(HCOO)·10H₂0, etc.), which greatly reduces the setting time of cement.
In addition, calcium formate can promote the hydration of calcium silicate, because HCOO- ions are diffused faster than Ca2+ ions, and can penetrate the hydration layer of C3S and C2S, accelerating the precipitation of Ca(OH)₂ and the decomposition of calcium silicate. HCOO- ions can also further bind silicon atoms to react with OH- through chemical action, so as to cross-link adjacent silicate groups, promote the formation of C-S-H gel, and improve the hardening strength of cement mortar.
Post time: May-31-2024