Pumped concrete is the type of concrete that is transported up to heights via pumping using concrete pumps. Pumped concrete is used when an enormous amount of concrete is required at a higher elevation and where other techniques of transport are not simple to accomplish.
Concrete pumping has been around for over 50 years. Today massive amounts of concrete are transported via pipelines for long distances, usually to construction sites which may be difficult to access by other delivery methods.
The method of pumping concrete is based on an hopper in which the concrete is released from the mixer. The mixer will then feed the concrete pump and, finally, the pipelines that deliver the concrete through which concrete is transported.
The capacity of concrete pumps and pumping capacities
Typically concrete pumps are placed on a truck or on the trailer. The pumps can be electric or diesel powered. Concrete is pumped via the pipe with a diameter ranging from 100mm and 180mm. The most well-known and ideal diameter for pumping normal is 125mm.
Portable concrete pumps that are modern made in other countries are currently in their fifth generation, with a huge power, high capacity and a completely solid hydraulic system. The pumps can lift concrete up to an elevation of 500 meters or extend horizontally of up to 2000m. They have an hydraulic system that can handle create concrete pressures as high as 200 bar. The output of the pump ranges from 19m3 to 150m3 each hour. Different companies have come up with various types of valves or systems. A rock valve the ‘C valve system flat gate valve and the ‘S’ trunk systems are all commonly used, based on the preference of the buyer and preference, or the manufacturer’s own patent-pending method.
But, it should be mentioned it is believed that the valve was named in Germany. According to the German language, rock is the skirt of a woman and because the valve shares similar shapes and movements, it’s referred to as a rock valve.
Concrete pumps are usually built with enough protection to withstand unfavourable usage. They are not sensitive to harsh treatment and operate on construction sites. They are constructed with an extremely durable construction, and are simple to maintain.
The gate valve is able to cut through concrete and is lined with extremely wear-resistant steel and is easily replaced when it wears out. Rams are made from special vulcanized rubber that is covered with steel core and they are simple to replace since they feature fast detachable connectors. The core of the metal is completely covered to stop cement adhesion.
Control systems for every concrete pump are compact, hydraulic and dirt-sensitive. This pump’s hydraulic settings are output controlled which optimizes motor power use at the optimal speed and pressure. Instrument panel nicely organized and displays the pressure of the system. It also has operating controls.
The outlet of the pump consists of a taper as well as an instrument for clamping with the pipe. It’s simple and quick to clean and features an easy side swing. The agitator assists in keeping it in its agitated shape in between the two concrete batches that are fed to the bin. The high-torque drive guarantees that the agitator is always rotating, even when there are tough and rough mix.
The concrete pump conveying device is set up on the chassis of a truck. The hydraulic drive of the pump is directly driven by the engine of the truck. A water pump that is hydraulically driven is connected to the tank. It is employed to flush the pipeline using pressured water as well as to clean of the pump’s concrete. The swivel-pipe system developed by Rock Chieber is typically mounted in the pump mounted on a truck instead of the gate valve system.
The most notable feature of this swivel pipe is the absolute and perfect movement balancing in any conditions. This keeps the bearing and shaft unaffected from wear. Swivel pipe technology improves the pumping capability even over longer distances and with higher vertical reaches since they are more expensive than flat gate valves for high-rise construction sites. However, flat valves are a good choice for poor, hard aggregate concrete or over-sized aggregate concrete needs to be pumping.
Concrete pump manufacturers typically provide the theoretical maximum output or pumping volume in cubic meters of water per hour. This is dependent on the distance at the pump it is able to pump, the length of the line and the pressure of the line.
Input to Pumps for Pumped Concrete
The concrete pump’s output is dependent on a variety of factors, including:
The length of horizontal pipe.
Longness of vertical pipe.
Many bends, particularly bent in a particular shape.
Diameter of the pipeline for delivery.
The length of the flexible hose.
Changes in line diameters or reducers.
The concrete’s working capacity is determined by the slump.
The concrete’s cohesiveness.
The type of aggregate that are used in concrete.
The following figure illustrates the line pressure and pumping rate depending on the diameter of the line as well as pumping distance and the slump. Once the desired pumping speed is established, the line’s diameter can be determined together with the pumping distance and slump, and then the expected line pressure is easily determined. For instance, if the required pumping rate is 25m3/hr, then the line diameter, the pumping distance and the slump are determined as 125mm, 300m and 80mm, respectively. Thus, the line pressure is 36.40 bars.
Concrete pump performance estimator
In reality, the pump is unlikely to be running continuously.
It is important to note that the maximum pressures listed in the manuals and leaflets are not able to be utilized as the safety valves that are pre-controlled are opened at 90 percent of the set pressure.
For all pumps driven by hydrostatic force, it is required that the working pressure do not exceed 90 percent of the pressure stated by the manufacturer, i.e. the set pressure. Along with the above details, the dimensions of the line, layout of the job concrete properties, and the output of the pump calculated from estimates of downtime are considered when determining the needed pumping pressure.
The mixture of the output and the pressures required for pumping could be utilized to determine the ideal pump for the task.
It is important to keep of the fact that, unless the location has the infrastructure in place to produce concrete that is consistent and of good quality at a reasonable speed, no attempts should be made to perform the pumping as it could result in devastating outcomes.
Concrete production and the transportation towards the pumps play an essential function in the pumping process. If the boom for placement isn’t accessible, the handling flexible hoses as well as other pipelines may cause a major issue when calculating downtime.
Concrete compacting should be able to accommodate the placing rate. Formwork designs require careful analysis as the hydrostatic pressure caused by rapid concrete build-up in the formwork will be higher than that traditional manual placing of concrete.
The layout of reinforcement also has to be altered in order to allow the lowering of the flexible hose closet down to the place point. For the beginning, 30m3/hr to 40m3/hr would suffice in the event that the points above are taken care of. Besides the selection of concrete pump and pipeline, equipment such as truck/mounted mixer, automatic/manually-controlled batching plant, and placing boom plays a very important role in successful concrete pumping operation.
Concrete is usually fed into the concrete pump hopper by trucks-mounted mixers. It should be noted that the correct selection of the mix of different equipment will greatly impact how fast, quality and cost of concrete.
Benefits of Pumped Concrete from North West Ready Mix
One of the biggest benefits of pumped concrete is the fact that concrete can be moved vertically and horizontally at one step. The output of the pump typically ranges between 30m3 and 150m3 of concrete per hour.
Concrete pumps are among of the best tools to quality control. The most sensitive way that any change in consistency of mix or performance can be readily observed at the pumping point by watching the pressures of the pumping. It is a an inconspicuous quality control device and will not handle any concrete that is excessively hard, unmixed or non-cohesive. It also refuses to handle concrete that is inconsistently incorrect.
In the UK there is no difficult to form large gangs of laborers frequently for concrete pours and, consequently for concrete pours that are large, it is beneficial using concrete pumps for concrete at a more rapid speed.
Pumped concrete usually has good cohesion, high workability and therefore, offers a more attractive appearance and durability in concrete structure. Concrete can be put on areas that are not accessible. Mass concrete can be done within a short period of period of time and at a speed that is high and without cold joints.
Concrete pumps can aid in accelerate the completion of contracts and, in turn, contribute to increased cash flow, a reduction in the cost of site-overheads and better use of resources.
Pipeline to transport the concrete occupies a small area and is easily extended or taken down.
Concrete delivery is continuous streams. If the pump’s mobile boom is employed it is possible to use both horizontal and vertical motions for putting concrete in the ground can be made, getting rid of elephant trunks and drop chutes. Concrete should be placed closer its final location in shape decreasing the shoveling and dragging of concrete, thereby eliminating the possibility of segregation in the concrete mix.
Benefits and disadvantages of pumping Concrete
The capacity to convey concrete pumps is limited. Therefore, the distance to convey and the height of concrete are both limited. Concrete that is pumping is not ideal for situations where you have a distance that is long and the vertical height too high.
Pumped concrete needs the pumpability of the concrete that is transported, which increases the water-to-cement ratio of the concrete. This concrete is susceptible to shrinkage and cracks.
The concrete slump utilized for the purpose of making concrete used for pumping concrete construction is quite large and the pouring rate is extremely quick. Pumping concrete makes the measurement of the concrete’s pressure to grow, and the use of concrete pumped is more structurally demanding in the structure of the work.
Pipeline for pumped Concrete
The concrete pipeline is constructed from seamless pipes made of premium precision steel. It is made up of bends and straight section, which are joined by disconnectable couplings. The inner diameter of pipelines typically used ranges between 80mm to 180mm and lengths range from 0.5m to 3 meters. Apart from 90o bends 15o and 30o bends, as well as 45o, 30o and 60o bends also are available. The pipe’s diameter is contingent on the following elements.
The size and the kind of the concrete pump.
The required horizontal and vertical positioning distances.
The quality of concrete that will be pumped in relation to its consistency.
Maximum aggregate size.
The impact on bends, rises vertically and flexible hoses in a laid pipe is calculated as a percentage of the length of the horizontal pipe. The correlation for more than 100mm internal diameter pipe is as is as follows:
1m vertical climb = 2m up to 3m horizontal length
One 90o bend equals 3m of horizontal length
One 45o bend equals 2m of horizontal length
One 30o bend equals 1m length horizontal
1m rubber pipe = 2m steel pipe
For UK conditions the 125mm diameter pipe is the most appropriate. However, a diameter of more than 150mm pipe is not recommended in any way. Pipes of different sizes are available in thicknesses that range from 4- 7 millimeters. For challenging pumping projects like high-rise structures 7mm pipes are recommended. However, for regular pumping jobs that do without enormous vertical lifts or hard concrete, 5mm pipes will suffice.
Normally, at the conclusion of every delivery line an hose that is flexible is stored for easy placing and handling. But, a length of more than 5m of flexible hose isn’t recommended. Flexible hoses that have two to four layers of high-tensile steel cable reinforcement is available and are able to handle pressures as high as 50 bars. Its tube rubber is soft and resistant to abrasion.
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