Silica fume is often used in concrete and refractory materials, and the main purpose is to use the very fine particles of silica fume to fill the pores between the particles of cement and other materials, thus making the concrete more dense. Most of the general particle size of cement is 3~30μm, how much finer is the silica fume than it?

The fineness of silica fume and its role

Silica fume, also known as silica fume, as a gray particle agglomerates, the fineness of its particles less than 1μm can account for more than 80%, the average particle size are 0.1μm to 0.3μm, its fineness is about 80 to 100 times that of cement. So when the concrete is mixed with silica fume, the silica fume particles can basically fill the pores between cement particles, cement hydrate and aggregate pores, and other inter-aggregate pores, making the concrete more dense, thus improving the hardness of concrete, impermeability and other properties.

In the actual use of the process, the fineness of silica fume is not constant, mainly because the use of concrete or refractory products sometimes do not require a high degree of compactness, although it can be controlled by reducing the amount of silica fume, but the reduction in the amount of silica fume may cause the strength of the silica fume to improve the effect is not obvious. So generally in the preparation of concrete or refractory materials, will first select different content, different fineness of silica fume, with different admixture into the material specimens for mixing and hardening experiments, to determine the material preparation of the choice of silica fume specifications.

The common fineness of silica fume specifications