The dosage of silica fume in concrete typically ranges from 5% to 10% by weight of cement. However, the optimal dosage can vary depending on the specific application and the desired properties of the concrete.

Factors to consider when using silica fume

• Type of concrete: Silica fume is most commonly used in high-performance concrete, such as self-compacting concrete, high-strength concrete, and ultra-high performance concrete.
• Desired properties: Silica fume can improve a variety of concrete properties, including compressive strength, tensile strength, flexural strength, durability, and resistance to chemical attack.
• Cost: Silica fume is a relatively expensive material, so it is important to weigh the benefits of using it against the cost.

Recommendations for the dosage of silica fume

• High-strength concrete: 5% to 10% by weight of cement
• Self-compacting concrete: 5% to 10% by weight of cement
• Ultra-high performance concrete: 10% to 20% by weight of cement

It is important to note that these are just general recommendations. The optimal dosage of silica fume should be determined through testing and experimentation.

Tips for using silica fume in concrete

• Silica fume is a very fine powder, so it is important to mix it thoroughly with the concrete mix.
• Silica fume can make the concrete mix more viscous, so it is important to use a superplasticizer to improve the workability of the mix.
• Silica fume can also increase the drying rate of concrete, so it is important to cure the concrete properly.

If you are unsure about the dosage of silica fume to use in your concrete project, it is best to consult with a qualified engineer or concrete specialist.