How to guarantee the successful construction of concrete pum
Posted On: 18/12/2018 | Posted by: Haomei Concrete Pumps
How to guarantee the successful construction of concrete pumping
1.Pumpability of concrete pumping concrete should meet the requirements of pumpability. If necessary, the mix proportion of pumping concrete should be determined by test pumping.
The ratio of the maximum diameter of coarse aggregate to the diameter of conveying pipe should be as follows: when the pumping height is below 50m, it should not be greater than 1:3 for gravel and 1:2.5 for pebble; when the pumping height is between 50 and 100 m, it should be in the range of 1:3 to 1:4; when the pumping height is above 100 m, it should be between 1:4 and 1:5. The content of needle-like granules should not be more than 10%.
2. After starting the concrete pump, it is necessary to pump proper amount of water to wet the hopper, concrete cylinder and conveyor pipe of the concrete pump directly in contact with the concrete.
After pumping water, one of the following methods is used to lubricate the above parts: pumping cement slurry; pumping 1:2 cement mortar; pumping cement mortar with proportion of other components except coarse aggregate. Cement slurry or cement mortar for lubrication shall be dispersed and shall not be centrally poured in the same place.
3. When starting pumping, the trailer concrete pump should be in a state of slow and uniform operation, and then gradually accelerate. At the same time, we should observe the pressure of concrete pump and the working condition of each system, and pump at normal speed after the system works normally.
4. Concrete pumping machine should be carried out as continuously as possible. The piston of concrete cylinder should keep running with the maximum stroke in order to give full play to the maximum efficiency of concrete pump and make the wear of concrete cylinder uniform in the long direction.
5. If the pressure of concrete pump truck is too high and unstable, the oil temperature will rise. When there are obvious vibration of the conveyor pipe and difficulties in pumping, no forced pumping shall be allowed, and the causes shall be immediately identified and eliminated. You can first hit the conveyor pipe with a mallet to get the elbow. In order to prevent blockage, the taper pipe and other parts should be pumped or pumped back at a slow speed.
6. Pumped concrete should be pre-mixed concrete. Pumping concrete can also be supplied at the concrete batching plant on site, but manual mixing of concrete should not be pumped.
The supplied concrete should be strictly controlled, and the change of slump should be paid attention to at any time. Concrete that does not meet the pumping requirements is not allowed to enter the pump to ensure the effective operation of the schwing concrete pump.
7. The concrete pump hopper should be provided with a screen mesh, and a special person should be set to monitor the feeding to avoid blockage caused by the excessive diameter of the aggregate or foreign matter entering.
8. When pumping, the concrete stock in the hopper should not be lower than the position of the stirring shaft to avoid the air from entering the concrete truck tube and causing the pipe to vibrate.
9. When the concrete pumping process needs to be interrupted, the interruption time should not exceed 1h. The anti-pump and positive pump should be operated every 5 to 10 minutes to prevent the pipe from being blocked due to excessive bleeding or slump loss in the pipe.
10. After the concrete trailer pumping is completed, the hopper and the conveying pipeline system must be carefully cleaned. If the residual concrete in the concrete cylinder is not cleaned, it will solidify on the cylinder wall. When the piston runs again, the piston sealing surface will directly bear the impact of the solidified concrete on the cylinder wall, causing the push piston to partially peel off. This damage is different from the normal wear of the piston seal, and the sealing surface cannot self-compensate under the pressure, resulting in leakage or suction, causing pumping weakness, blockage, and the like.