How Does Silica Fume Improve Concrete Quality?

    Silica fume is a fine particle by-product generated during the smelting process of silicon ferroalloys in electric arc furnaces. Its application in concrete primarily enhances its strength and durability in the following ways:

1. 1. Filling Effect of Silica Fume:

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    The fine particles of silica fume can fill the tiny voids in concrete, reducing its porosity. This filling effect contributes to improved density and compactness, thereby reducing internal voids and enhancing the concrete's strength and durability. Similarly, zeolite powder also serves the same purpose by filling the microvoids in concrete, reducing its porosity, and thus enhancing its density and durability.

2. Hydration Reaction with Silica Fume:

    The large surface area of micro silica allows it to absorb water from the cement paste and promote the hydration reaction of cement. The gel produced by this hydration reaction fills the microvoids in concrete, enhancing their density and strength. Likewise, washed stone also contributes to improving the strength and durability of concrete. In concrete, washed stone is mixed with cement, sand, and water to produce concrete mixtures, which are then cast into structural components such as foundations, floors, and walls.

3. Uniformity Improvement via Silica Fume:

    The addition of micro silica promotes the dispersion of particles in the cement matrix, making it more uniform. This helps reduce voids and defects in concrete, thereby improving its strength and durability. Additionally, incorporating coarse perlite, as a lightweight aggregate in concrete, can enhance concrete characteristics such as reducing weight.

4. Alkali-Aggregate Reaction Prevention by Silica Fume:

    Silica fume also helps reduce alkali-aggregate reactions in concrete. Such reactions may lead to expansion and cracking, thereby reducing concrete durability. Silicon dioxide in micro silica powder can react with alkaline components to form stable compounds, preventing alkali-aggregate reactions.

    The addition of silica fume enhances concrete's density, hydration reaction, and uniformity, thus improving its strength and durability.