Factors affecting concrete pumping by pump trucks

The influencing factors may include:

1. Aging of the pump truck, including excessive wear of the S valve, discharge pressure that does not meet the design standard, insufficient accumulator pressure, or insufficient engine power, etc.

2. The pump pipe is not cleaned thoroughly, and there is solidified old concrete in the pipe, resulting in increased pump pipe resistance

3. The pump pipe is not lubricated with water or mortar when it is newly opened, resulting in increased resistance

4. The pipeline is too long and there are too many bends. If it is a drag pump, the discharge height may be too large

5. The reasons for concrete materials, including mix ratio, aggregate particle shape, etc. Generally speaking, the resistance of artificial aggregate is greater than that of natural aggregate. Too many slender particles or too large aggregate edges and corners, too large sand modulus, and poor grading all cause increased pumping resistance

6. The influence of admixtures. In order to increase the pumpability of pumped concrete, it is generally required to add plasticizers to increase the slump of the mixed material without separation and control the water seepage of the mixed material

7. The influence of the mix ratio, the proportion of each material component is not appropriate, the mixing time is insufficient, and the slump loss on site is too large, which may also lead to pumping difficulties.