Usage of Microsilica Fume

1. Application in refractory materials

According to the different properties of refractory materials, orthogonal design was carried out, and the optimal formula was selected through comparative test.

2. Application to high performance concrete

Mix ratio design

(1) Compatibility: Microsilica fume has good compatibility with water reducer, fly ash, mineral powder, fiber, etc.

(2) Slump: Due to its interstice effect, concrete has a high viscosity, so the slump design requirement of concrete mixed with microsilica fume is 2~3cm higher than that of ordinary concrete;

(3) Incorporation: for the manufacture of high-strength and shotcrete, the incorporation of microsilica fume is 6-12% of the cement content; For underwater engineering concrete, its content is slightly higher; When using microsilica fume as pump aid, the dosage is reduced to about 2%.

The final mix ratio is determined by mix ratio test.

Feeding and stirring

(1) Densification microsilica fume is usually used in the concrete industry, so manual feeding or automatic feeding can be selected.

(2) Due to the unique ultra-fine characteristics of the microsilica fume, it is required to put the microsilica fume into the aggregate immediately after feeding, and the powdered microsilica fume shall not be added into the properly mixed concrete.

(3) The mixing time of concrete mixed with microsilica fume should be extended by 30~40s compared with ordinary concrete to obtain good uniformity.

(4) There is no special requirement for transportation of concrete mixed with microsilica fume, which is the same as ordinary concrete.

Pouring and curing

(1) Vibration of microsilica fume concrete shall be compacted, without leakage, undervibration or over-vibration. General vibration time for 10 to 30s;

(2) Continuous supply of concrete is required to prevent cold stubble and cause hidden trouble. The stubble time shall not exceed 100min;

(3) It is very important to prevent premature evaporation of moisture in the curing process of microsilica fume concrete. Therefore, after pouring, immediately covered with film, and laid sacks, watering maintenance.

(4) According to the specific conditions of the project, the company will provide a detailed construction plan for the reference of commercial concrete manufacturers and construction units. Meanwhile, the company can arrange field engineers to cooperate with the construction on the site.