Silica Fume has been used as an addition to concrete up to 15 percent by weight of cement, although the normal proportion is 7 to 10 percent. With an addition of 15 percent, the potential exists for very strong, brittle concrete. It increases the water demand in a concrete mix; however, dosage rates of less than 5 percent will not typically require a water reducer. High replacement rates will require the use of a high range water reducer.
Function of adding Silica Fume(microsilica) :• Increase durability
• Reduces concrete permeability
• Improves resistance to corrosion
• Shotcrete - lower rebound
