Analyze the cause of pipe blocking in concrete pumping and preventive measures

 Concrete pumping is usually affected by many factors, such as site conditions, operators' non-compliance with operating regulations, etc. However, pipe blockage is likely to occur during the concrete pumping process. If it is not handled quickly and effectively, it will not only delay the overall construction Progress and cannot ensure the quality of construction. So we write this article for your reference.

1.Operation error may cause pipe blockage

First, operators are distracted in actual operations. Second, the choice of pumping speed lacks rationality. In the pumping process, the speed (that is, the pumping displacement) must be selected reasonably, and the operator cannot just pay attention to the speed. Sometimes the speed is not a good thing. When pumping for the first time, because the pipeline resistance is quite large, in this case, it is necessary to pump at a low speed. After ensuring that the pumping is normal, the pumping speed can be adjusted appropriately. The third remaining material control is unscientific. During the pumping process, the operator needs to carefully observe the remaining material in the hopper. If the remaining material is too small, it is likely to inhale air and cause pipe blockage. And the material in the hopper should not accumulate too much, and must be lower than the protective fence, so that it is convenient to quickly clean the super-large aggregate and coarse aggregate on the protective fence. Fourth, when the concrete sag is too small, the pump truck operator needs to make an accurate judgment. If the normal pumping cannot be satisfied, the concrete needs to be discharged from the bottom of the hopper immediately. If you want to save trouble, the pumping is mandatory , It is likely to cause blockage. It is forbidden to add water to the hopper for mixing. Fifth, the downtime deviation. When shutting down, the pump needs to be turned on every five to ten minutes, but the specific time must be determined based on factors such as the temperature of the day and the concrete slump to avoid pipe blockage. For some concrete that has been completely set and has a long downtime, pumping must be stopped. Sixth, there is debris or concrete residue in the pipeline. After the last pumping, the pipeline must be carefully cleaned and inspected in time.

2. Pipe blockage caused by pipe connection

Improper pipe connection method is likely to cause pipe blockage. The principles that need to be followed in the pipeline connection process are specifically manifested in the following points: In the pipeline layout process, the transmission resistance must be reduced as much as possible according to the largest, smallest elbow and shortest distance, which can reduce the probability of pipe blockage. At the pump outlet stacking position, the elbow pipe cannot be directly connected. It is necessary to connect a straight pipe over 500 mm before connecting the elbow pipe (as shown in Figure 1). When connecting pipes in the middle of pumping, only one pipe can be added at a time, and water should be used to fully lubricate the inner wall of the pipe and ensure that the inner wall of the newly connected pipe is clean and free of debris, otherwise it is likely to cause pipe blockage. As far as the vertical downward pipeline is concerned, the upper bend of the riser must be raised, and the outlet position must be equipped with an anti-segregation device, which can prevent pipe blockage. In addition, in the high-level pumping process, usually the length of the horizontal pipeline must be 15% greater than the length of the vertical pipeline, and the pipeline stop valve must be connected to the horizontal pipeline. If the downtime is more than five minutes, the shut-off valve must be closed in time to avoid backflow and back pressure of concrete, causing pipe blockage.

3. Pipe blockage caused by segregation of concrete or mortar

Generally speaking, if concrete or mortar touches water, it is likely to cause segregation. In most cases, the key reason for the phenomenon of pipe blockage in the process of umping mortar is that after the mortar directly contacts the water in the pipeline, it is caused by the segregation of the mortar. Then, for this kind of pipe blockage, the preventive measure is to use clean water to soak the pipes before the pump, loosen the pipe joints at the lowest point of the pipe, and drain all the remaining water in the pipe, or contact the pump before pumping the mortar. After the water, put in the sponge ball, separate the water and the mortar. After the pumping is over, when cleaning the pipeline, you must also put a sponge ball in to separate the concrete and water, otherwise it is likely to cause blockage.

4. Pipe blockage caused by local leakage

5. Pipe blockage caused by substandard pumped concrete

Totally, the reasons for the pipe blockage caused by pumped concrete in actual construction are reflected in many aspects, but as long as the operating procedures are strictly implemented in actual operation, the experience from the pipe blockage is summarized in time to ensure the construction quality. In addition, scientifically formulate preventive measures against the causes of pipe blockage in concrete pumping, so as to prevent or reduce the occurrence of pipe blockage.