The hottest is 601 meters and is still climbing

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601 meters, and still rising

Introduction: in early November 2007, the Putzmeister ultra-high pressure concrete pump in the Burj Dubai Tower in the United Arab Emirates reached a record pumping height of 601 meters. Earlier than expected! At this height, in the world's most spectacular skyscraper project, the central big

in early November 2007, the ultra-high pressure concrete pump of Putzmeister in Burj Dubai Tower in the United Arab Emirates reached a record pumping height of 601 meters. Earlier than expected! At this height, in the most spectacular skyscraper project in the world, the core wall of the central building is concreted on the 155th floor. The pumping height is calculated from the length of the riser fixed in the building structure and the length of the vertical transmission pipeline (including tubular columns and fixed distribution rods). The actual concrete pouring is carried out at a height of 585 meters. The pumping of high-rise concrete is not over yet, but it is not far away. At the same time, the ideal pumping height has been moved up to 611 meters, and the concrete pump is working very smoothly at present

in the Burj Dubai Tower in the United Arab Emirates, the extremely professional super high-rise concrete pumping is usually carried out at night

unimix executive Khalid Mohd S. al Bakhit (right) and employees ate cold chocolate together,

to celebrate the new world record 601 meters of super high-rise concrete pumping

the owner Emaar properties (UAE) entrusted a consortium jointly managed by Samsung (South Korea), besix (Belgium) and arabtec (UAE) to be responsible for the construction of the world's tallest building (more than 800 meters high). Turner construction (USA) is responsible for project management

equipped with three Putzmeister concrete pumps, a complex transmission pipeline system, four fixed distribution rods with counterweights and concrete mixtures with special performance, the core cylinder of Burj Dubai Tower in the United Arab Emirates began construction in early 2005. Due to the rapid progress of construction and the higher the building, the narrower the building structure, three of the four fixed distribution poles were removed, and at the same time, a drag pump was removed

pipeline installation of Putzmeister pumping group, concrete receiving area and three cleaning systems

when unimix company (the concrete supplier and pumping service provider of Dubai Tower in the United Arab Emirates) decides to entrust Putzmeister company to supply and install Drag Pumps and boom systems, it needs to have full trust in the technical level and reliability of partners. Through early towing pump test, Putzmeister company has determined to use concrete towing pump and concrete delivery pipe with pumping height of more than 600 meters, and the outlet displacement is 30 m3/h; It is also learned that in order to stabilize, the top of Burj Dubai building will use light steel structure from the 156 floor, and the concrete floor will be poured to the 160th floor (611 meters high)

in the comprehensive preliminary test, simulate the drag pump transmission of super high-rise buildings

at the beginning of 2005, Putzmeister made full preparations and allocated corresponding personnel at the German headquarters and the construction site in Dubai to carry out a series of comprehensive tests on the drag pump and transmission pipeline, and Putzmeister's local agent German Gulf company provided support. The purpose of the test is to convert the simulated pressure of concrete in the transmission pipeline and the friction of concrete into the pumping system of super high-rise buildings. The model of towing pump used in the test is bsa14000 hp-d towing pump for super high-rise buildings and DN125 ZX transmission pipeline

in order to simulate the concrete pumping of super high-rise buildings under extreme conditions, hundreds of meters of transmission pipes were laid in the test stage,

the measured values and coefficients (such as friction coefficient) were determined and converted into the data of super high-rise pumping

at the same time, the foundation slabs of the core tube and the three podiums are constructed by pump trucks with different boom lengths. The 7000 square meter core tube foundation is supported by 200 concrete piles (1.5 meters in diameter) and the podium is supported by 650 piles (0.9 meters in diameter). The depth of the pile reaches 55 meters, and the concrete of the floor of the building is 45000 cubic meters

the plan of Burj Dubai Tower in the United Arab Emirates

includes the platform, three wings and the core tube of the central building

ultra high pressure concrete pump adapted to the extreme conditions

at this time, the details of the new ultra-high pressure concrete pump to be developed have been determined at the German headquarters of Putzmeister company. The pump must be manufactured and delivered in the summer of 2005 for the concrete delivery of the upcoming super high-rise building. BSA 14000 shp-d (ultra high pressure concrete pump), including the components in the frame and hopper, has been strengthened to withstand great pressure. Putzmeister also adjusted the expected pressure of S valve and S valve bearing of our product using computer-aided level adjustment system. BSA 14000 shp-d has a particularly efficient filtration system. The engineers of Putzmeister improved the hydraulic drive system of the concrete pump, and the transmission ratio between the concrete pressure and the hydraulic pressure of the oil cylinder is less than i=1 when the rod free cavity is running. Due to this transmission ratio, high-performance pumps may achieve a concrete pressure of more than 400 bar. Putzmeister's engineers expected the pressure to be much smaller in their later work, thus limiting the pressure of the concrete pump, while the maximum operating pressure of the pipeline was "only" 250 bar

one of the BSA ultra-high pressure concrete pumps is working at night

unimix combined two BSA 14000 shp-d ultra-high pressure pumps from Putzmeister and BSA 14000 hp-d "conventional" high pressure concrete pumps to form a pump group in the test stage. The horizontal distance between the concrete pump and the center of the building is about 70 meters. Ultra high pressure concrete pump is driven by 470 kW Caterpillar diesel engine produced in series

strength grade of concrete used at different heights

in order to minimize the size of floors and load-bearing walls and bear the increasing load with the increase of height, this construction site of Dubai's most spectacular super high-rise building only uses high-strength concrete. According to the original plan, The strength grade of concrete at each height is as follows:

° Foundation: c80a (maximum particle size of crushed stone is 20mm)

° below the 26th floor: (the height can delay the time of fire spread even if it is on fire by 95 meters) wall c80a (maximum particle size of crushed stone is 20mm)

° below the 126th floor: (height 452 meters) wall C80 (maximum particle size of crushed stone is 14mm)

° below the 154th floor: (height 570 meters) Wall C60

° the floor concrete of all floors is C50

although the c80a grade concrete with the maximum particle size of 20 mm of gravel was originally only used for structures below 95 meters high (the 26th floor), the concrete was pumped to a height of 352 meters (the 100th floor) (the paving degree is 50cm, and the water cement ratio is 0.3). When this material is used at this height and there is a rod cavity, when the displacement of concrete is 30 m3/h, the concrete pressure is only 150 bar

the cost saved by increasing the maximum particle size of crushed stone

for the design of concrete grades at different heights, on the one hand, the concrete should be able to be pumped to more than 300 meters; On the other hand, this can obviously reduce the cost, because compared with the concrete with the maximum total particle size of 14 mm, the concrete with the maximum particle size of 20 mm requires much less cement and fine sand

although the strength of this concrete is "only" 80 n/mm2, later tests often show that the strength is greater than 100 n/mm2. This high-strength concrete contains 20 different admixtures that will affect the fluidity and setting performance

test the strength of concrete

add ice to the concrete

due to the high external temperature, the concrete is usually poured in the evening or at night, but the thermometer often shows that the temperature is nearly 40 degrees Celsius. Because the maximum temperature of concrete pouring can only be 35 ℃, the aggregate has been cooled in the concrete plant before being configured into concrete, and part of the water has been replaced with ice (crushed ice). This means that unimix, a concrete supplier, can transport concrete to the construction site of Burj Dubai Tower in the United Arab Emirates at a temperature of about ° C even in summer

part of the water used for mixing concrete is replaced by ice

multiple inspections ensure the quality of concrete

the production of each batch of concrete in the concrete mixing plant is monitored and recorded. Before the concrete is pumped, the temperature and fluidity of the concrete will be checked regularly, and test blocks will be made to check the concrete strength. In addition, the management party on site will take cores to determine the concrete solidification and shrinkage indicators. During each pumping, each delivery pipe is pumped with 2 cubic meters of pumping auxiliary agent, which is collected in a container on the building, and then lifted to the ground with a tower crane

regularly measure the concrete temperature...

slump test

the precise positioning of the formwork is completed through the satellite positioning system. This means that the vertical deviation is only a few millimeters. After 10 to 12 hours, the template is opened; After 24 hours, remove the formwork. One floor (core tube and floor slab of the building) is completed every 3 to 4 days

rigid and flexible tower structure

because the Burj Dubai Tower in the United Arab Emirates has no active damping device, great attention is paid to aerodynamic optimization in the design of three podium buildings. As the height of the building increases, the plane will shrink a little, but in principle, the center will remain the same. This means that this super high-rise building will have extremely high stiffness while maintaining considerable elasticity. This construction method is especially suitable for reversing the wind direction by 180 degrees in the morning and evening, and sometimes the strong wind speed will exceed 100 kilometers per hour. For more powerful storms ("50 year storm"), the swing at 605 meters is calculated to be about 40 to 50 centimeters. This data is based on simulation tests conducted in wind tunnel tests

the construction height of Dubai Tower in the United Arab Emirates has reached 601 meters

complex concrete transmission pipeline system

developing a high-efficiency concrete pump with spectacular pumping height in Burj Dubai Tower in the United Arab Emirates is only one of the tasks of engineers of Putzmeister company. A particular challenge is the transmission pipeline system, its wear resistance, high pressure resistance, and the direction of the pipeline and its fixation in the building structure. Putzmeister has applied for a number of patents in this regard

for the concrete pouring of floor slab, unimix uses Putzmeister standard fixed concrete pump and standard ZX delivery pipe (DN 125). The equipment will pump most of the C50 strength concrete to a height of 452 meters. The same BSA 14000 HP d concrete pump has been used in a series of pumping tests

according to the situation on site, pump pipes with an inner diameter of 150 mm (6 inches) are equipped almost throughout the pumping height for pumping particularly high-strength concrete. Only the general Putzmeister ZX transmission pipe (DN 125) is installed on the top 10 floors (because it is easy to install). In this configuration, the pipe can withstand a pressure of 130 bar

in the central core tube of Dubai Tower in the United Arab Emirates, the two main pipes can be transformed into four risers after several movements, and the risers lead to the Putzmeister boom fixed on three floors and one fixed on the wall template of the building core tube. Some pipelines and all distribution rods have been removed

thick pipelines have advantages and disadvantages

change the cross-section of the pipeline, such as flow, wear resistance, pressure and the time that the concrete stays in the pipeline (assuming the output per hour

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