Silcrete Densified micro-silica is highly reactive pozzolan used to improve mortar and concrete. Silcrete micro-silica is amorphous silica with high SiO2 content, extremely small particle size, and large surface area.
Silcrete micro-silica improves concrete in two ways; basic pozzolanic reaction, and a micro filler effect. One pound of Silcrete micro-silica in comparison to Portland cement can yield about three to five times as much compressive strength.
Addition of Silcrete micro-silica improves bonding with concrete. It combines with calcium hydroxide produced in the hydration of Portland cement to improve concrete durability. As micro filler, the extreme fineness of micro silica allows it to fill the microscopic voids between cement particles. This greatly reduces permeability and improves the paste-to aggregate bond resulting very high strength and durability.
Silcrete micro-silica, a co-product of the silicon and ferrosilicon metal industry, generated as a gas in submerged electrical arc furnaces during the reduction of very pure quartz. This gas vapor is condensed in bag house collectors as very fine gray to off-white powder of spherical particles that average 0.1 to 0.3 microns in diameter with a surface area of 17 to 30 m2/g. Micro-silica is used in a variety of cementitious (concrete, grouts and mortars), polymer, refractory and ceramic applications. One of the most beneficial uses for micro-silica is in concrete.
- Sulphate resistant at low and high sulphate concentrations
- Resistant to chloride ion penetration and corrosion propagation (NB chlorides are often present with sulphate)
- Silica fume represents a low proportion of the cementitious system making it
- easy to store
- low cost in relation to SRPC in some locations
- High strength leading to
- low cement content low heat
- low cost
- High early age strength for early formwork and propping removal
- Can be used for waterproofing