What are the main problems in the use of silica fume and what are the disadvantages?
Silica fume needs to be paid attention to in actual use: it should not be used in the case of high wind speed, which is easy to cause dust. When using encrypted silica fume, the stirring time is extended by about 15 seconds to 30 seconds. Operators should take protective measures to prevent silica dust from entering the respiratory tract.
disadvantages of silica fume in concrete
1. Silica fume concrete is too viscous and difficult to apply.it is not easy to wipe the surface.
2. Silica fume requires a high amount of water and needs to be used with a superplasticizer.
3. The price of silica fume is relatively high compared to cement and fly ash. In unnecessary situations, it does increase the cost; in the case of the value of silica fume, better performance will reduce the overall cost.
4. Silica fume will increase the autogenous shrinkage of the cement slurry, and the amount of inclusion will exceed 5%, which may increase the risk of cracking.It is easy to cause cracks in mortar and concrete and need concrete maintenance.