Concrete Pumping Explained
The main goal of concrete pouring is to place it to its final destination. Some construction sites have obstacles that may make it difficult to pour concrete to the point of placement.
This is now where pumping of the concrete is needed. Pumping is the most reliable and economical way of bringing concrete to the required locations.
Movement of Concrete Through the Pump Line
During concrete pumping, concrete is normally separated from pump line walls by a greasing layer of water, sand and cement.
The concrete should have enough water to enable it to move smoothly through the reducers and bends of the hose pipes.
You should make sure all concrete mixes are pumpable to avoid clogging of pump lines.
Proper Configuration of Pump Lines and Equipment
To have a good concrete pumping process, the system should be configured correctly. The correct pump line pressure should be known and at what pressure to push the wet concrete. The length and diameter of the pipeline should also be identified.
Pipeline pressure can be affected by the following factor:
- Line length
- Line diameter
- Pumping rate
- Distances, horizontal and vertical
To determine the line pressure, the below factors should be considered first:
- The vertical rise
- Severity of bends
- The quantity of flexible hose to be utilised in the line
The line Diameter
The line diameter of the pipe will also affect the pumping pressure. This means the larger the diameter the less pumping pressure required.
There are disadvantages associated with using large conduits like increased blocking, bracing and extra Labour.
The ACI standards state that one-third of the diameter should be equivalent to the maximum size of aggregates.
The Line Length
When concrete is being pumped through the line, it creates friction along the pipes internal walls. When the pipes are long, there’s an increase in friction.
However, if you have to pump for a long distance you can use a smooth-walled steel pipe which lowers the friction.
Horizontal and Vertical Pumping
When pumping concrete horizontal or vertical a lot of pressure is needed for the concrete to reach the desired place. If the horizontal pumping distance is long, you can use two pumps and two lines. The first pump will be connected to the hopper meaning it will feed on the second pump. This process may be more economical as compared to a single long-distance line.
Bends in the Line
The pipeline configurations should be designed to accommodate a few bends to reduce the friction involved.
When the diameter of the pipe is reduced, there’s going to be an increase in friction where concrete passes. With this in mind, the diameter should remain the same.
In case you need reducers, then it is recommended to use long reducers that will lessen the friction involved. An eight-foot reducer will use less force to pump concrete as compared to a four-foot reducer.
There are two different types of concrete pumps used in the construction industry
- Line Pumps
Line pumps are used to pump concrete, grout, mortar, shotcrete, sludge, wet screeds and foamed concrete. There are different line pumps for different needs.
- Boom Pumps
Boom pumps are mounted on a truck and are used to pump concrete. They are mostly used for concrete slabs, high-rise buildings and large scale projects. They are the best in placing concrete in confined areas. There are different varieties of boom pumps depending on the chassis and the size of the pump.
Proper precautions should be taken when working with concrete pumps. Keep the machinery in working condition and with proper maintenance.