The mixing step of low cement castable is the key link to ensure the construction quality. The following are detailed mixing methods and precautions:

I. Mixing step of low cement castable

(1) Prepare equipment and tools:

Forced mixer or mortar mixer.

Bucket, scale, tool shovel, trolley, etc.

The mixer should be cleaned in advance and must not be mixed with lime, sediment, portland cement and other sundries.

(2) Dry mixing stage:

Pour the low cement castable into a blender and dry mix it first, and the mixing time is not less than 1 minute.

The purpose of dry mixing is to make aggregate and powder fully and evenly mixed to avoid uneven particle size distribution.

(3) adding water and stirring:

Clean drinking water should be used, and the water temperature should be 10 ~ 25℃.

Add water in strict accordance with the mixture ratio given in the product manual, first add 90% of the reference water, and then gradually add the remaining water according to the actual situation.

The wet mixing time shall not be less than 5 minutes, so as to ensure uniform mixing and no caking.

(4) judging the water content:

The method of "kneading by hand" can be used to test: if the pellet is deformed and flows out from the hand seam, it means that the water content is too high; If the pellets are cracked and scattered, it means that the water content is too small.

(5) controlling the stirring time:

The stirring time should be controlled within 5 ~ 10 minutes, and it is recommended not to exceed 10 minutes.

(6) Quick use:

The mixed castable should be transported to the pouring site quickly, and it must be used within 30 minutes from the beginning of adding water.

Wet materials that have been initially set shall not be mixed with water again.

II. Precautions

Strictly control the water addition: the water consumption of low cement castable is generally lower than that of traditional castable, and too much water will reduce the strength and increase the porosity.

Ambient temperature: the construction ambient temperature should be between 5℃ and 30℃. If it is lower than 5℃, measures should be taken to raise the temperature; if it is higher than 30℃, measures should be taken to lower the temperature.

Tool cleaning: all mixing tools should be kept clean to avoid mixing impurities.

Through the above steps and precautions, the mixing quality of low cement castable can be ensured, and the subsequent construction and service life can be guaranteed.