Test procedures:
1. Wet the slump cylinder and bottom plate, and there is no clear water on the inner wall and bottom plate of the slump cylinder. The bottom plate should be placed on a solid (non-absorbent) horizontal plane, and the cylinder should be placed in the center of the bottom plate, and then the foot pedal on both sides should be stepped on. The slump cylinder should be kept in a fixed position when loading.

2. Put the concrete sample obtained according to the requirements into the cylinder evenly with three layers of ploughstaff, so that every level height after compaction is about one third of the height of the cylinder. Insert and pound 25 times with a tamping stick on each layer.

3. Use ploughstaff to smooth the top of the cylinder, clear the concrete on the bottom plate of the cylinder side, and lift away from the slump cylinder vertically balanced. The lifting process of the slump cylinder should be completed within 5-10 seconds; The whole process from starting loading to lifting the slump cylinder should be carried out continuously and should be completed within 150 seconds.

4. After lifting the slump cylinder, the height difference between the height of the measuring cylinder and the highest point of the concrete test body after slump is the slump value of the concrete mixture.

5. Observe the cohesion and water retention of concrete test body after slump.