As the "tallest building in Qingdao", the vertical transportation of concrete is particularly vital." We have optimized the pumping system and presented the concrete pump with the largest stress in China, and the pressure can reach 50Mpa, while the concrete pump used in regular housing projects is just 10Mpa." With the ultra-high pressure ground pumps, it can easily bring tens of thousands of lots of concrete to hundreds of meters high.
Not only that, the building and construction group additionally enhanced the concrete sharing pipe," the higher the pumping elevation, the longer the size of the straight pipe, so we made a structure buffer layer in the height of 150 meters, after the barrier layer and after that up and down increased to more than 300 meters of functioning surface area." With this whole set of devices, the concrete resembles remaining on the" elevator ", and also has actually accomplished a pump to the top.
Ultra-high pumping of concrete modern technology
Ultra-high pumping concrete innovation, usually describes the contemporary concrete pumping technology with a pumping elevation of more than 200m. In recent years, with the development of economy and also culture, there are a growing number of construction jobs of ultra-high pumping concrete, so the ultra-high pumping concrete technology has actually turned into one of the essential technologies in modern building construction.
A pump to the top, is the method of conveying concrete with high pressure pump truck, its functioning concept is similar to the pump, utilizing the huge stress created by the pump body, the concrete is pushed right into the pump pipe, with the vertical erection pipeline, the concrete pump to the working face several hundred meters high. At the beginning of China's construction of skyscraper and high-rise building, concrete generally by crane transport, with the quick advancement of China's economic climate, incredibly high-rise buildings in various cities, China's manufacturing of pumping tools, gradually replaced international products, in 2015, Shenzhen sound a financial center construction site, utilizing the sany hefty industry production pump, success will high strength concrete pump to the elevation of 1000 meters, it marks the China's construction sector has the ability to build 1000 meters incredibly skyscraper. Because of the large viscosity of concrete, as well as there are rock accumulation inside, the pumping pressure of extremely high-rise building is large. So, exactly how can we ensure that the concrete from the bottom layer to the height of 452 meters? In order to satisfy this elevation, designers placed a lot of effort on tools selection. The last choice is the ultra-high pressure pump, its pumping pressure is 48 mpa. MPa is a sensible pressure device in design, at about 10 kg per square centimeter, which suggests that the uHV pump vehicle like the size of the nail of a human hand can get to 480 kg.
Ultra-high pumping concrete modern technology is a thorough technology, consisting of concrete prep work innovation, pumping specification calculation, pumping devices option as well as debugging, pump pipeline format and also pumping procedure control, and so on 1. Choice of basic materials
Cement with high C2S web content must be picked, To boost the fluidity of concrete and also minimize the downturn loss has a considerable effect; The crude aggregate needs to be continually graded, The needle sheet material ought to be regulated, And additionally wish to think about the optimum particle size range; Penalty accumulation ought to be selected as tool sand, Because great sand can make the concrete sticky, And also the coarse sand is easy to make the concrete partition; Using the mineral admixtures with outstanding buildings, Such as mineral powder, 1 grade fly ash, 1 quality composite admixture or simple circulation type composite admixture, silicon ash, etc, High-strength pumping concrete must be preferred to choose mineral admixtures and also chemical admixtures that can reduce the thickness of concrete, Mineral admixtures can be picked viscosity lowering reinforcement, Chemical admixtures can be picked to reduce the viscosity as well as water reduction agent, Can make the concrete to obtain a good working efficiency; Water decreasing representative needs to be provided top priority to choose high water decreasing rate, long plastic preservation time of polycarboxylic acid system water minimizing representative, If necessary, include air introducer, The water-reducing representative must have a good compatibility with the cement and also the admixture.
2. Prep work of concrete
Via the optimization of resources, mix proportion design and process actions, the prepared concrete has great workability, high fluidity, although the viscosity is little, however no partition water sensation, so there is a little flow resistance, very easy to pump.
3. Selection of pumping devices and design of pump pipe
The choice of pumping devices will describe the technical demands specified in the Technical Laws for Concrete Pump Construction. Initially, the pumping criteria will be examined, including the model as well as pumping ability of concrete communicating pump, pressure loss of straight pipeline, pressure loss of vertical pipeline, pressure loss of special pipeline as well as pumping effectiveness, etc. The requirements for pumping equipment and also no tubes are:
- It is suggested to choose high power, ultra-high pressure S valve structure concrete pump, the concrete outlet stress satisfies the needs of extremely high-rise concrete pumping resistance
- Concrete conveying pipelines with high pressure resistance and also high wear resistance should be selected
- High-pressure-resistant pipe cards and also their seals ought to be chosen
- High wear-resistant S pipeline shutoff and also glasses plate should be made use of
- The concrete pump structure must be cast securely as well as securely fixed to stand up to the significant reaction pressure, and also the concrete outlet pipe circulation ought to contribute to decreasing the bearing ability of the pump head
- The conversion length of the ground horizontal pipeline of the sharing pump pipe should not be less than 1/ 5 of the size of the vertical pipeline, and must not be less than 15m
- The communicating pump pipe will be fixed with assistance assistance, which need to be strongly attached, and also the lower high pressure area will be geared up with unique support or concrete structure to endure the weight of the pipe as well as the influence pressure during pumping
- Establish a hydraulic or electrical stop shutoff near the pump electrical outlet
Refine control of the pumping building and construction
The downturn, growth as well as gas material of the concrete, and the procedures will be taken, including the stress modification of pump truck, water seepage, slurry leak and the problem of attaching parts, which shall be managed in time. Pump building and construction control needs are:
- Practical organization, constant building, to avoid disturbance
- Purely control concrete fluidness and also its changing worth
- Extend the preliminary setting time suitably according to the pumping height
- Strictly manage the concrete drainage rate under high pressure problems
- Take insulation or cooling actions to manage the pipeline temperature, stop concrete friction, sunshine and various other elements trigger pipeline overheating
- Enhancing precaution should be set up in the simple using parts such as curves
- When cleaning up the pump pipe, the concrete in the pipeline should be properly recovered to stay clear of air pollution or material waste. The waste concrete generated in the process of pumping and also cleaning shall be correctly treated in time according to the pre-determined therapy methods and locations, and also will not be utilized for pouring architectural elements
Technical index of ultra-high pumping concrete:
1. Concrete combination excellent working, no segregation, slump should be higher than 180mm, the concrete downturn loss must not impact the regular construction of concrete, the loss needs to not be greater than 30mm/ h, concrete inverted collapse cylinder emptying time should be less than 10s. Pump height over 300m, over 550mm; Pump elevation over 400m, over 600mm; Pump height over 600m, more than 650mm; pump height over 600 m, greater than 700mm.
2. The physical as well as mechanical residential properties of hardened concrete satisfy the style requirements
3. The concrete communicating variation, sharing pressure and pump pipe design should be based on the exact calculation, and a detailed execution plan need to be developed to mimic the skyscraper pumping examination.
4. Various other technical indicators will comply with the stipulations of the Technical Laws for Concrete Pump Building and also the Construction Code for Concrete Framework Engineering.
