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 in situations where different methods of transportation aren’t simple to accomplish.
Concrete pumping has been around for over fifty years. Today massive amounts of concrete are transported via pipelines for long distances, frequently to construction sites that might not be accessible via other methods of delivery.
The method of pumping concrete includes an hopper in which the concrete is pumped out of the mixer. This, 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. They are electrically or diesel-powered. Concrete is pumped through the pipeline with a diameter of 100mm and 180mm. The most widely used and most suitable diameter for pumping normal is 125mm.
Portable concrete pumps that are modern made in other countries are in the fifth generation, with a huge power, high capacity and a highly robust hydraulic systems. Pumps can move concrete up to the height of almost 500m or reach horizontal distances of up to 2000m. They are equipped with hydraulic systems that can manage create concrete pressures as high as 200 bar. The output of the pump ranges from 19m3 to 150m3 each hour. Different manufacturers have created different kinds of valves and systems. Rock valves the ‘C valve system flat gate valve and the ‘S’ trunk system are all commonly used, based on the preference of the buyer and the manufacturer’s own patent-pending method.
It is mentioned it is believed that the valve has its origins in Germany. The German language, the word rock refers to the skirt of a woman and because the valve shares similar shapes and movements, it is referred to as that.
Concrete pumps are usually constructed with sufficient protection against unfavourable usage. They are not sensitive to the rough treatment that can occur 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 fully lined with extremely wear-resistant steel and can be replaced quickly in the event of wear and tear. Rams are made of a special vulcanized rubber and covered with steel core and they are simple to replace since they feature quick-release connectors. The core of the metal is completely covered to stop the adhesion of concrete.
Control systems in every concrete pump are hydraulic, compact and dirt-sensitive. Hydraulic pumps are output controlled which means it optimizes motor power usage at the ideal speed and pressure. Instrument panel nicely organized and displays the pressure of the system. It also has operating controls.
The outlet of the pump is comprised of a taper as well as an attachment device that clamps to pipeline. It’s quick and simple to clean and features an easy side swing. The agitator keeps that concrete’s agitated state in between the two concrete batches that are fed through the hopper. The high-torque drive guarantees that the agitator is always rotating, even when there are tough and rough mix.
The conveying unit for concrete pumps is set up on the truck chassis. The hydraulic drive of the pump is directly derived from the engine of the truck. A water pump that is hydraulically driven is attached 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 can be mounted in the pump mounted on a truck the place of the gate valve system.
The main feature of this swivel pipe is the flawless and complete balance of the movements in any conditions. This ensures that the bearing and shaft unaffected from wear. Swivel pipe technology improves pumping efficiency even at longer distances and with higher vertical reaches since they cost less than flat gate valves on building sites with high rises. However, flat valves can be used in the case of rough, poor aggregate concrete or over-sized aggregate concrete needs to be to be pumped.
Concrete pump manufacturers typically provide the theoretical maximum output or pumping volume in cubic meters of water per hour. This is based on the distance over the pump it is able to pump, the length of the line and the pressure of the line.
The output of the pump for pumped Concrete
The concrete pump’s output is dependent on a variety of factors, including:
The length of horizontal pipe.
The length of the vertical pipe.
Many bends, particularly designed bends.
Diameter of delivery pipeline.
Length of flexible hose.
Variations in the diameter of lines or reducers.
Concrete’s workability is measured by the slump.
The strength of concrete is its cohesiveness.
The type of aggregate used in concrete.
The following figure illustrates the pressure of lines and pumping rates depending on the line’s diameter as well as pumping distance and the slump. Once the desired pumping speed is determined, the line’s diameter can be calculated together with the pumping distance as well as slump, and the probable line pressure can 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. So, the pressure of the line will be 36.40 bars.
Concrete pump performance estimator
In reality, the pump is unlikely to be running continuously.
It is to be noted that the maximum pressures stated in the manuals and leaflets cannot be utilised since the safety valves that are pre-controlled are opened at 90 percent of the set pressure.
Get in touch with North West Ready Mix for your next pumped concrete delivery.
For all pumps that are driven by hydrostatics, it is mandatory that the working pressure is not more than 90 percent of the pressure stated by the manufacturer, i.e. the set pressure. In addition to the previous details, the dimensions of the line, layout of the job concrete properties and the output of the pump calculated from estimates of downtime are also considered when determining the needed pumping pressure.
The mixture of the output and the pressures required for pumping is a good way to determine the ideal pump for the task.
It should be kept of the fact that, unless the area has the infrastructure in place to produce concrete of consistent quality at a reasonable speed, no attempts should be made to carry out the pumping as it could result in catastrophic outcomes.
Concrete production and the transportation towards the pumps play a crucial function in the pumping process. If the boom for placement isn’t accessible, the managing flexible hoses and other pipelines may be a significant obstacle when calculating downtime.
Concrete compacting requires a sufficient speed to handle the placement rate. Formwork design requires careful consideration as the hydrostatic pressure caused by rapid concrete build-up within the formwork is much higher than that of manual placement of concrete.
The layout of reinforcement also has to be changed in order to allow the lowering of the hose closet that is flexible to the place point. In the beginning, 30m3/hr – 40m3/hr would suffice provided that the factors mentioned above are addressed. 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’s hopper via an on-truck mixer. It should be noted that the correct selection of the mix of different equipment could greatly affect how fast, quality and efficiency of concrete.
Benefits of Pumped Concrete
One of the major advantages of concrete pumped is that it can be transported vertically and horizontally at one move. The typical output of the pump is from 30m3 to 150m3 concrete per hour.
The concrete pump can be among of the most effective tools for quality control. This is the only technique where any deviation in consistency of mix or performance can be readily observed at the pumping point by monitoring the pressures at which the pump is operating. It is a an inconspicuous quality control device and will not handle any concrete that is excessively rough, poorly mixed or non-cohesive. It also refuses to handle concrete that is inconsistently incorrect.
In the UK there is no more easy to organize large gangs of laborers frequently for concrete pours so for concrete pours that are large, it is beneficial to utilize concrete pumps to complete the concrete pouring at a faster speed.
Pumped concrete usually has good cohesion, high workability and consequently, provides a superior quality finish and greater strength in concrete structure. Concrete can be used in areas that are difficult to access. Mass concrete can be done in a short amount of period of time and at a speed that is high with no cold joints.
Concrete pumps can aid in faster completion of contracts, and, in turn, contribute to an increase in cash flow, decrease in the cost of site-overheads and better use of resources.
Pipeline that is used to deliver the concrete takes up very little space , and it can be easily extended or taken down.
Concrete is delivered in continuous streams. If the mobile-boom pump is employed for concrete, both horizontal and vertical moves for placing concrete can be made, getting rid of elephant trunks and drop chutes. Concrete should be placed closer its final location in shape which it is less dragged and shoveled, thus eliminating the possibility of segregation in the concrete mix.
Advantages of Pumped Concrete
The capacity to convey concrete pumps is limited, which means that the distance to convey and the height of concrete is limited. Pumped concrete isn’t suitable for situations where you have a distance that is long and the vertical elevation is too high.
Pumped concrete needs the pumpability of the concrete that is moved, which can increase the water-to-cement ratio of the concrete. This concrete is susceptible to shrinkage and cracks.
The slump of concrete used for the purpose of making concrete in the pumping of concrete is big, and the speed of pouring is extremely quick. Pumping concrete makes the measurement of the concrete’s pressure to grow, and the use of concrete pumped requires more structural requirements in the structure of the work.
Pipeline for pumped Concrete
The concrete pipeline is constructed of seamless pipes made of top-quality precision steel. It consists of bends and straight section, which are connected with disconnectable couplings. The inner diameter of pipelines typically used ranges between 80mm to 180mm and length ranges from 0.5m to 3 meters. Along with 90o bends 15 30, 30o, 45o and 60o bends also are available. The pipe’s diameter is contingent on the following aspects.
Dimension and kind of concrete pumps.
Vertical and horizontal spacing distances.
The quality of the concrete that is to be pumped based on its consistency.
The maximum size of aggregates.
The impact from bends and vertical rise and flexible hoses in a laid pipe is calculated as a percentage of the length of the horizontal pipe. This relationship for 100mm or more internal diameter pipelines 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 bend of 30o = 1m of horizontal length
1m rubber pipe = 2m steel pipe
For UK conditions the 125mm diameter pipe is the most appropriate. But, anything larger than 150mm diameter pipe is not recommended in any circumstance. Pipes of different sizes are available in thicknesses that range from 4- 7 millimeters. For demanding pumping tasks such as buildings with high rises 7mm thick pipes are suggested, while for typical pumping tasks that do not require enormous vertical lifts or hard concrete, 5mm pipes are appropriate.
Typically, at the end of each delivery line an hose that is flexible is stored for easy placing and handling. However, more than 5m of flexible hose isn’t ideal. Flexible hoses with two to four layers of high-tensile steel cable reinforcement is available and are able to handle pressures as high as 50 bars. Tube rubbers are soft and resilient to abrasion.