What Is A Concrete Pump?
A Concrete Pump is used in conveying freshly mixed concrete from the containers to where it needs to be filled at the construction site and thus, it is an important part of any construction project.
Concrete Pumps are the most favored method of transferring liquid concrete nowadays and are a common appliance on building sites now. The invention of the concrete pump has increased the efficiency of building projects, especially when it comes to high-rises buildings.
- The concrete pumps lead to less consumption of water as compared to other ordinary concrete pouring techniques. Thus, when the concrete is poured, it won’t show shrinking and cracking properties at all and it will maintain its strength.
- The use of concrete pumps assure that the concrete is placed easily at inaccessible or congested sites. So, whether you want to place the concrete on the top floor of a high rise building or in a foundation slab, concrete pumps can transfer the concrete mix to almost any area and at any height without leaving spills and lumps on the way.
- Concrete pump is also feasible in complex locations like high-rise buildings or insulated concrete walls, concrete pumps are used to increase pouring accuracy.
- Placing of concrete by the concrete pump gives higher accuracy with little or zero material wastage.
- Also, the concrete placing is not affected by any weathering actions or conditions.
Types of Concrete Pumps
There are mainly three types of concrete pumps that are used in building construction
- Boom or Truck mounted pump
- Trailer, line, or stationary pump
- Specialized usage pump
How Does A Concrete Pump Work
A concrete pump is a tool mainly used for conveying freshly mixed concrete to the location on a construction site where it is needed to be placed. It works using a valve system and the basic fundamental of hydraulics.
- The pumping operation starts with the discharge of the concrete, usually from a ready-mix truck that mixes concrete mix within its rotating drum.
- Then the truck pours the fresh concrete into a hopper, which is continuously rotating so concrete will not solidify. In the hopper of the pump, an agitator maintains the fresh concrete flowing smoothly into the pumping cylinders.
- From there, the concrete pump sucks the liquid concrete mix out of the hopper, through a valve system, and into the area where it needs to be laid down. Sometimes with the use of auxiliary hoses.
- Pistons of concrete pumps utilize the same principle as a twin-cylinder work with the reciprocating engine, in which the one cylinder draws concrete from the hopper on the return stroke and another cylinder pushes mix on the forward stroke into the pipeline.
- A twin-cylinder hydraulic pump’s internal workings typically consist of two parallel cylinders. The cylinders have driven pistons inside them that move them backward and forward in opposite directions. As the first cylinder moves forward, the second one moves back.
- Pistons in both cylinders operate in inverse directions so there is constant pressure applied on the concrete mix in the pipeline and uninterrupted flow. The pistons in the concrete pump are operated by hydraulic cylinders powered by a hydraulic pump.
- A synchronized valve permits concrete from the two cylinders to go into one pump discharge line. This valve is frequently used to differentiate one type of pump from another.
- The 1st cylinder, also known as the material cylinder, pulls concrete out of the hopper. The 2nd cylinder known as the discharge cylinder thrust the concrete out of the pump in the location where it is needed to be placed on the site.
- The two working pistons, alternately pulling in and pushing out their volumes of liquid concrete. The hydraulic flow created by the continuous flow of concrete is important to prohibit the liquid concrete from solidifying.
Read More: 15+ Types of Admixtures and Their Uses
Quality Requirements of Pumped Concrete
Many factors like length, number of bends in the line, type of pipe, size of a line, height to which the concrete is being pumped, and the concrete mixture influence the working capacity of a concrete pump.
1) Pump Lines
Pipelines used in concrete pumps are generally a combination of rigid pipe and heavy-duty flexible pipe. The acceptable rigid pipe can be made of steel or plastic and is available in sizes from 3 to 8 inches in diameter.
The aluminum alloy pipe should not be used as a pump line. The flexible hose is made of rubber, spiral wound flexible metal, and plastics. If possible, the pipeline should be of one size and laid out to contain a minimum number of bends.
2) Mixture Proportions
Proportions of concrete ingredients of pumpable mixtures are essentially the same as those to be placed by other methods. Concretes which are pumped must be cohesive.
Harsh mixtures do not pump well. The pressure exerted by the pump can force the mortar away from the coarse aggregate causing a blockage in the line if the mixture is not proportioned properly.
The content of cement will generally be slightly higher for pumped mixes than those of mixtures placed by conventional methods.
3) Coarse Aggregate
The nominal maximum size of the coarse aggregate is restricted to one-third of the inside diameter of the pump for crushed aggregates or 40 percent of the smallest inside diameter of the pump for well-rounded aggregates.
Oversize particles should be eliminated. Excessive mortar content will be necessary to effectively pump a concrete containing crushed aggregates than for concrete containing rounded aggregates.
4) Fine Aggregate
The properties of fine aggregates as an ingredient in concrete are more critical in proportioning pumpable mixtures than are the properties of the coarse aggregates.
Combined with the cement and water, the fine aggregates compose the mortar which transfers the coarse aggregates in suspension through the pump line.
Both types of aggregate manufactured fine aggregates and natural sands can be used in pumped mixtures.
The necessity of water for optimum slump and to maintain control of that slump throughout a pumping placement are both extremely important factors.
Concretes having slumps less than 2 inches when delivered to the pump are difficult to pump. Concretes having slumps over 6 inches can segregate causing a blockage in the pump line and may require a pumping aid to increase the cohesiveness of the concrete mix.
Materials which enhance workability, such as water-reducing agent, high-range water-reducer, and air-entraining admixtures, as well as pozzolanas, usually improve pumpability.
It is usual to experience a decrease in air content during pumping. The specified air contents essential for the durability of concrete should be obtained at the point of placement on the site.
Therefore, it may be necessary to entrain a higher air content into the concrete mixture before pumping.
Proper arrangement of the whole pumping operation including pump location, line layout, placing sequence, and concrete supply will result in savings of time and expense.
The pump should be feasible as near the placement area as possible. Concrete conveying systems should have easy approaches to the pump.
Pipelines from the pump to the placement area should be made up of rigid pipe and contain a minimum number of bends.
Benifits of Using Concrete Pumping In Construction Comapare to Ordinary Concrete Placing
|Factors to be Considered||Concrete Pumping||Ordinary Concrete Placing|
|Faster concrete placement||Speed of the placing is always an important factor when it comes to a big-sized construction project. The main benefits of concrete pumping are that it is a faster way to pour concrete on-site than other traditional methods.||In ordinary concrete placing more time required in placing of concrete. When a concrete pump is not used on-site the smaller equipment may have to be moved around to different locations to finish one pour.|
|Less labor||Concrete pumping generally requires less in the way of labor than other methods of concrete placing. Also, the site will seem less congested and use labors for other important tasks when the concrete is placed directly.||When it is required to place the concrete manually on-site required more labor and also the quality of pouring concrete depends on the workmanship of laborers.|
|Quality of concrete||With concrete pumping, less water is needed than with other methods. This means that when concrete is placed it won’t shrink and crack at all and it will maintain its strength. Pumping of concrete ensures the strong and durable concrete over its entire life span.||Quality of placing of concrete cannot be maintained by placing concrete manually because it depends on weathering conditions. Also, cause bleeding and shrinkage problems which deteriorate the strength of concrete.|
|Concrete pouring accuracy||For complex locations like high-rise buildings and insulated concrete form walls accuracy is most important, which can be maintained by concrete pumping.||In complex or congested location normal placing of concrete can not be feasible as placing become difficult and also cause segregation of ingredients of concrete.|
|Convenience in placing concrete||The concrete pumping system is just more convenient than the old mix and pours methods. Boom arms can reach over the top of the house or other structures to place the concrete in locations where other types of machinery can’t reach.||It becomes more difficult to pour the concrete if it is required to place the concrete on high-rise buildings which cause more labor force and more wastage of material in conveying from a place of mixing to placing.|
|Faster progress of work||In concrete pumping, the pouring of concrete is done using a pump so discharge or quantity of concrete produced is more which may lead to faster progress in construction work.||In the ordinary placing method, concrete is transporting by labors using pan or buckets which cause delays or consuming more time in concrete.|
|Weathering conditions||Concrete placed by pumping is not affected by atmospheric conditions as it is transferred by means||Water losses may have occurred in the concrete mix while it is placing during hot weather conditions may lead to shrinkage of concrete.|
Watch Video: Concrete Pump Working On Construction Site
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