Small-stroke continuous construction process of hydraulic slip form in high-temperature dry environment

Abstract

The invention relates to a small-stroke continuous construction process for a hydraulic slip form in a high-temperature dry environment, which comprises a small-stroke continuous lifting technology, an atomizing spraying circulating assembly and a concrete retarding measure. The concrete is lifted by about 20 mm every 5 minutes, the lifting speed is basically matched with the construction speed of the reinforced concrete, and by adopting a small-stroke continuous lifting technology, the situation that the friction resistance is increased due to the factors such as overlong relative standing time between the concrete and the formwork, concrete bleeding and concrete strength value increase, and the concrete is cracked when lifted again can be effectively avoided.

Description

Technical Field

[0001] The invention relates to the field of environmentally friendly construction of hydraulic sliding formwork, in particular to a small-stroke continuous construction process of hydraulic sliding formwork in a high-temperature dry environment. Background Art

[0002] The hydraulic sliding formwork construction process is an advanced construction process widely used in vertical reinforced concrete structures such as bridge piers, chimneys, water towers, large silos, and core tubes of high-rise buildings. This process mainly uses hydraulic devices to drive the formwork system to rise. The GYD60 split ball jack in the commonly used hydraulic device has a maximum lifting stroke of 50mm at a time. The lifting height each time (6 to 8 jack strokes) is equal to the thickness of a concrete pouring layer (250 to 300mm). The construction time of each reinforced concrete pouring layer is about 1 to 1.5 hours. Through reciprocating cycle lifting, the purpose of continuous concrete pouring is achieved, thereby greatly improving the construction efficiency, ensuring the quality of the project, and also reducing labor intensity and construction costs. The best construction conditions for the traditional hydraulic sliding formwork process are an ambient temperature of 15 to 25°C, a temperature difference between day and night of no more than 10°C, and a humidity of 40% or above.

[0003] For areas with high temperatures, large temperature differences between day and night, and relatively low humidity, the application of hydraulic sliding formwork construction technology will result in excessive strength of the concrete being pulled apart, and the concrete becoming loose and weak after early water loss, which will seriously affect the construction quality and project safety. In addition, the large amount of construction waste after rework will also cause environmental pollution. Nowadays, the temperature in most areas during the high temperature period of the year is far above 25℃, even reaching above 50℃. Under such high temperature and dry environmental conditions, the application of traditional hydraulic sliding formwork construction technology is gradually shrinking. If other construction methods are used, the cost is relatively high.

[0004] Therefore, we propose a hydraulic slipform small-stroke continuous construction process in a high-temperature dry environment. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art, adapt to actual needs, and provide a hydraulic sliding formwork small-stroke continuous construction process under a high-temperature dry environment to solve the current high-temperature dry environment conditions, coupled with unforeseen factors such as the difficulty in accurately predicting the future ambient temperature during construction, the concrete retarding measures are inevitably ineffective (the amount of concrete retarder determines the retarding time of concrete within a certain range, and the amount of retarder varies with the rise and fall of the concrete construction environment temperature). It is difficult to ensure that the strength value of the demolding concrete is exactly within the optimal range of 0.2 to 0.4 MPa. Using conventional lifting methods, it is inevitable that cracks will appear on the surface of the demolding concrete, and even the sliding formwork operation cannot be carried out normally. Technical problems.

[0006] In order to achieve the purpose of the present invention, the technical solution adopted by the present invention is: designing a hydraulic slipform small-stroke continuous construction process under a high-temperature dry environment, including a small-stroke continuous lifting technology, an atomizing spray circulation component and a concrete retarding measure, wherein the small-stroke continuous lifting technology includes the following steps:

[0007] S1. Hydraulic system pressure test: Test the hydraulic system pressure to ensure that the system pressure is stable and meets the design requirements;

[0008] S2. Inspection and acceptance of hydraulic sliding formwork device: Conduct a comprehensive inspection of the hydraulic sliding formwork device, including structural integrity, fastening of connectors, etc. The next step can be carried out only after the acceptance is qualified;

[0009] S3. Inspection and acceptance of other systems: Inspection and acceptance of other systems related to the hydraulic sliding formwork, such as electrical system, control system, etc.;

[0010] S4. Pour concrete layer by layer until the formwork is full: Pour concrete layer by layer according to the design requirements until the full formwork height designed for the formwork is reached. During the pouring process, pay attention to controlling the pouring speed and vibration intensity of the concrete;

[0011] S5. Trial lifting: When the strength of the first layer of concrete reaches 0.2-0.4MPa, conduct a trial lifting operation. During the trial lifting process, pay attention to the changes in the formwork and concrete to ensure smooth lifting;

[0012] S6. Critical lifting pressure measurement: During the trial lifting process, the critical lifting pressure is measured to provide a reference for subsequent lifting;

[0013] S7, continuous uniform lifting: according to the critical lifting pressure measurement results, adjust the lifting speed and pressure, and carry out continuous uniform lifting. During the lifting process, pay attention to record the lifting data, such as lifting height, lifting speed, etc.;

[0014] S8. Layered concrete pouring: While continuously and evenly lifting, continue pouring concrete in layers to ensure that the concrete fits tightly to the formwork;

[0015] S9, oil circuit oil quantity adjustment: During the lifting process, adjust the oil circuit oil quantity according to the equipment operating status and lifting requirements to ensure stable operation of the equipment;

[0016] S10, Steel bar binding: During the lifting process, steel bar binding should be carried out in a timely manner to ensure that the steel bars are positioned accurately and firmly;

[0017] S11. Lifting speed adjustment, when the temperature is lowest at night: When the temperature is lowest at night, adjust the lifting speed according to the ambient temperature changes to avoid the impact of temperature on concrete and formwork;

[0018] S12, continuous uniform speed lifting: continue to lift at a continuous uniform speed until the designed height is reached or the entire lifting process is completed;

[0019] S13, end of lifting: when the designed height is reached or the whole lifting process is completed, the lifting is stopped and the equipment is cleaned and maintained.

[0020] Preferably, the atomizing spray circulation component is arranged on the outer surface of the steel formwork, and the atomizing spray circulation component includes a water collection and purification tank, a high-pressure water pump, a first high-pressure hose, a water storage tank, a booster pump, a check valve, a water volume regulating valve, a nozzle, a second high-pressure hose and a third high-pressure hose.

[0021] Preferably, a high-pressure water pump is installed inside the water collection and purification tank, and a first high-pressure hose is connected between the high-pressure water pump and the water storage tank.

[0022] Preferably, a second high-pressure hose is connected between the water storage tank and the booster pump, between the booster pump and the check valve, and between the check valve and the water volume regulating valve.

[0023] Preferably, a third high-pressure hose is connected between the water volume regulating valve and the spray head.

[0024] Preferably, the concrete retarding measures include the following steps:

[0025] S1. According to the temperature range of the slipform operation environment, pre-prepare the slow-setting concrete mix ratio with a gradient of 5°C to ensure that the initial setting time of the concrete reaches 6±0.5 hours under different temperature conditions;

[0026] S2. If the predicted ambient temperature of the next concrete pouring layer exceeds 5°C, the corresponding concrete mix ratio should be replaced in advance;

[0027] S3. By adding modified retarder enhancer into concrete, the initial setting time of concrete can be delayed without affecting the lifting operation, and the strength of the concrete out of the mold is not less than 0.2MPa and the design strength of the concrete.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The present invention controls the pressure and flow of the hydraulic system, and tries to lift to obtain the critical lifting pressure as the formal lifting working pressure. The height is lifted by about 20mm every 5 minutes. The lifting speed is basically matched with the construction speed of reinforced concrete. As the lifting trend is closer to continuous and uniform speed, the friction between the concrete and the formwork is smaller during lifting, and the possibility of concrete being cracked is also smaller. The use of small-stroke continuous lifting technology can effectively avoid the increase of friction caused by factors such as the long relative static time between the concrete and the formwork, the bleeding of concrete, and the increase of concrete strength value, which may cause the concrete to be cracked when it is lifted again.

[0030] 2. The curing water system in the existing hydraulic sliding formwork construction technology only cures the concrete removed from the formwork. The atomized spray circulating water in the present invention has the triple functions of lowering the ambient temperature, increasing the ambient humidity, and curing the concrete; when the ambient temperature is too high, adding ice cubes to the water tank can more effectively lower the ambient temperature; the atomized spray circulating water method is more energy-saving and environmentally friendly.

[0031] 3. The operation of the sliding formwork is affected by many factors such as ambient temperature and humidity, the difficulty of the steel bar project, concrete supply, people, and machines. It is difficult to ensure that the operation time of each concrete pouring layer is completely consistent, which creates obstacles for the allocation of the concrete retarding time. Since the atomized spray circulating water creates a relatively stable concrete construction environment temperature and humidity, the small stroke continuous lifting technology reduces the requirements for the demoulding strength of the concrete, and the temperature gradient preparation method of the retarded concrete is used, the quality of the concrete can be better ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a flow chart of the small-stroke continuous lifting of the hydraulic sliding template of the present invention;

[0033] Figure 2 It is a schematic diagram of the arrangement of the atomizing spray circulation component of the present invention.

[0034] In the figure: 1. Water collection and purification tank; 2. High-pressure water pump; 3. First high-pressure hose; 4. Water storage tank; 5. Booster pump; 6. Check valve; 7. Second high-pressure hose; 8. Water volume regulating valve; 9. Third high-pressure hose; 10. Nozzle. DETAILED DESCRIPTION

[0035] The present invention is further described below in conjunction with the accompanying drawings and embodiments:

[0036] Example 1: Hydraulic sliding formwork small stroke continuous construction process under high temperature and dry environment, see Figure 1 to Figure 2 , including small-stroke continuous lifting technology, atomizing spray circulation components and concrete retarding measures. The small-stroke continuous lifting technology includes the following steps:

[0037] S1. Hydraulic system pressure test: Test the hydraulic system pressure to ensure that the system pressure is stable and meets the design requirements;

[0038] S2. Inspection and acceptance of hydraulic sliding formwork device: Conduct a comprehensive inspection of the hydraulic sliding formwork device, including structural integrity, fastening of connectors, etc. The next step can be carried out only after the acceptance is qualified;

[0039] S3. Inspection and acceptance of other systems: Inspection and acceptance of other systems related to the hydraulic sliding formwork, such as electrical system, control system, etc.;

[0040] S4. Pour concrete layer by layer until the formwork is full: Pour concrete layer by layer according to the design requirements until the full formwork height designed for the formwork is reached. During the pouring process, pay attention to controlling the pouring speed and vibration intensity of the concrete;

[0041] S5. Trial lifting: When the strength of the first layer of concrete reaches 0.2-0.4MPa, conduct a trial lifting operation. During the trial lifting process, pay attention to the changes in the formwork and concrete to ensure smooth lifting;

[0042] S6. Critical lifting pressure measurement: During the trial lifting process, the critical lifting pressure is measured to provide a reference for subsequent lifting;

[0043] S7, continuous uniform lifting: according to the critical lifting pressure measurement results, adjust the lifting speed and pressure, and carry out continuous uniform lifting. During the lifting process, pay attention to record the lifting data, such as lifting height, lifting speed, etc.;

[0044] S8. Layered concrete pouring: While continuously and evenly lifting, continue pouring concrete in layers to ensure that the concrete fits tightly to the formwork;

[0045] S9, oil circuit oil quantity adjustment: During the lifting process, adjust the oil circuit oil quantity according to the equipment operating status and lifting requirements to ensure stable operation of the equipment;

[0046] S10, Steel bar binding: During the lifting process, steel bar binding should be carried out in a timely manner to ensure that the steel bars are positioned accurately and firmly;

[0047] S11. Lifting speed adjustment, when the temperature is lowest at night: When the temperature is lowest at night, adjust the lifting speed according to the ambient temperature changes to avoid the impact of temperature on concrete and formwork;

[0048] S12, continuous uniform speed lifting: continue to lift at a continuous uniform speed until the designed height is reached or the entire lifting process is completed;

[0049] S13, end of lifting: when the designed height is reached or the whole lifting process is completed, the lifting is stopped and the equipment is cleaned and maintained.

[0050] Under normal circumstances, the sliding formwork operation is carried out in two shifts, with a total working time of 12 hours per shift. Excluding other time such as handover and meals, the effective working time is about 10 hours, and a maximum of 10 concrete pouring layers (i.e. 3m height) of concrete pouring can be completed. The small stroke continuous lifting technology can theoretically lift the height by about 20mm every 5 minutes, and can lift the height by 2.88m in 12 hours, but the actual lifting speed can be much greater than the construction speed of concrete; in order to delay the lifting speed to the maximum extent and make it closer to the continuous and uniform lifting trend, it is necessary to control the pressure and flow of the hydraulic system; the hydraulic system pressure control value is generally 0.5~0.7Kn / cm2 (the average load value of the hydraulic jack), and the actual minimum lifting working pressure value required is obtained through on-site trial lifting. The hydraulic system pressure is controlled by a two-position two-way electromagnetic reversing valve set on the oil circuit, and one electromagnetic reversing valve generally controls four sets of jacks. The oil circuit flow is controlled by the regulating main valve set on the oil circuit.

[0051] For details, see Figure 2 The atomizing spray circulation component is arranged on the outer surface of the steel formwork. The atomizing spray circulation component includes a water collecting and purifying water tank 1, a high-pressure water pump 2, a first high-pressure hose 3, a water storage tank 4, a booster pump 5, a check valve 6, a water volume regulating valve 8, a nozzle 10, a second high-pressure hose 7 and a third high-pressure hose 9. A high-pressure atomizing spray device is arranged on the outer surface of the steel formwork. When the ambient temperature is too high, ice cubes can be added to the water tank to lower the water temperature, which plays a triple role of lowering the ambient temperature, increasing the ambient humidity, and curing the concrete after the atomized water converges downward; the atomizing spray circulating water is recycled, precipitated and purified and then reused, which saves water and is environmentally friendly.

[0052] For further information, see Figure 2 A high-pressure water pump 2 is installed inside the water collection and purification tank 1, and a first high-pressure hose 3 is connected between the high-pressure water pump 2 and the water storage tank 4.

[0053] It is worth noting that see Figure 2 A second high-pressure hose 7 is connected between the water tank 4 and the booster pump 5 , between the booster pump 5 and the check valve 6 , and between the check valve 6 and the water volume regulating valve 8 .

[0054] It is worth noting that see Figure 2 A third high-pressure hose 9 is connected between the water volume regulating valve 8 and the nozzle 10 .

[0055] It is worth mentioning that see Figure 1 and Figure 2 , concrete retarding measures include the following steps:

[0056] S1. According to the temperature range of the slipform operation environment, pre-prepare the slow-setting concrete mix ratio with a gradient of 5°C to ensure that the initial setting time of the concrete reaches 6±0.5 hours under different temperature conditions;

[0057] S2. If the predicted ambient temperature of the next concrete pouring layer exceeds 5°C, the corresponding concrete mix ratio should be replaced in advance;

[0058] S3. By adding modified retarder enhancer into concrete, the initial setting time of concrete can be delayed without affecting the lifting operation, and the strength of the concrete out of the mold is not less than 0.2MPa and the design strength of the concrete.

[0059] Since the atomized spray circulating water creates a relatively stable temperature and humidity in the concrete construction environment, and the small-stroke continuous lifting technology reduces the requirements for the demoulding strength of the concrete, and is supplemented by the slow-setting concrete temperature gradient preparation method, the quality of the concrete can be better ensured.

[0060] In addition, the components designed in the present invention are all universal standard parts or components known to technical personnel in this field. Their structures and principles can be known to technical personnel through technical manuals or through conventional experimental methods. They can be fully implemented by technical personnel in this field. Needless to say, the content protected by the present invention does not involve improvements to internal structures and methods.

[0061] The embodiments of the present invention disclose preferred embodiments, but are not limited thereto. A person skilled in the art can easily understand the spirit of the present invention based on the above embodiments and make different extensions and changes. However, as long as they do not deviate from the spirit of the present invention, they are all within the protection scope of the present invention.

Claims

1. A hydraulic slipform small-stroke continuous construction process under a high-temperature dry environment, including a small-stroke continuous lifting technology, an atomizing spray circulation component and a concrete retarding measure, characterized in that: The small-stroke continuous lifting technology comprises the following steps: S1. Hydraulic system pressure test: Test the hydraulic system pressure to ensure that the system pressure is stable and meets the design requirements; S2. Inspection and acceptance of hydraulic sliding formwork device: Conduct a comprehensive inspection of the hydraulic sliding formwork device, including structural integrity, fastening of connectors, etc. The next step can be carried out only after the acceptance is qualified; S3. Inspection and acceptance of other systems: Inspection and acceptance of other systems related to the hydraulic sliding formwork, such as electrical system, control system, etc.; S4. Pour concrete layer by layer until the formwork is full: Pour concrete layer by layer according to the design requirements until the full formwork height designed for the formwork is reached. During the pouring process, pay attention to controlling the pouring speed and vibration intensity of the concrete; S5. Trial lifting: When the strength of the first layer of concrete reaches 0.2-0.4MPa, conduct a trial lifting operation. During the trial lifting process, pay attention to the changes in the formwork and concrete to ensure smooth lifting; S6. Critical lifting pressure measurement: During the trial lifting process, the critical lifting pressure is measured to provide a reference for subsequent lifting; S7, continuous uniform lifting: according to the critical lifting pressure measurement results, adjust the lifting speed and pressure, and carry out continuous uniform lifting. During the lifting process, pay attention to record the lifting data, such as lifting height, lifting speed, etc.; S8. Layered concrete pouring: While continuously and evenly lifting, continue pouring concrete in layers to ensure that the concrete fits tightly to the formwork; S9, oil circuit oil quantity adjustment: During the lifting process, adjust the oil circuit oil quantity according to the equipment operating status and lifting requirements to ensure stable operation of the equipment; S10, Steel bar binding: During the lifting process, steel bar binding should be carried out in a timely manner to ensure that the steel bars are positioned accurately and firmly; S11. Lifting speed adjustment, when the temperature is lowest at night: When the temperature is lowest at night, adjust the lifting speed according to the ambient temperature changes to avoid the impact of temperature on concrete and formwork; S12, continuous uniform speed lifting: continue to lift at a continuous uniform speed until the designed height is reached or the entire lifting process is completed; S13, end of lifting: when the designed height is reached or the whole lifting process is completed, the lifting is stopped and the equipment is cleaned and maintained.

2. The hydraulic slipform small stroke continuous construction process under high temperature and dry environment as claimed in claim 1, characterized in that: The atomizing spray circulation assembly is arranged on the outer surface of the steel template, and comprises a water collection and purification tank (1), a high-pressure water pump (2), a first high-pressure hose (3), a water storage tank (4), a booster pump (5), a check valve (6), a water volume regulating valve (8), a spray head (10), a second high-pressure hose (7) and a third high-pressure hose (9).

3. The hydraulic slipform small stroke continuous construction process under high temperature dry environment as claimed in claim 2, characterized in that: A high-pressure water pump (2) is installed inside the water collection and purification tank (1), and a first high-pressure hose (3) is connected between the high-pressure water pump (2) and the water storage tank (4).

4. The hydraulic slipform small stroke continuous construction process under high temperature dry environment as claimed in claim 2, characterized in that: A second high-pressure hose (7) is connected between the water storage tank (4) and the booster pump (5), between the booster pump (5) and the check valve (6), and between the check valve (6) and the water volume regulating valve (8).

5. The hydraulic slipform small stroke continuous construction process under high temperature dry environment as claimed in claim 2, characterized in that: A third high-pressure hose (9) is connected between the water volume regulating valve (8) and the spray head (10).

6. The hydraulic slipform small stroke continuous construction process under high temperature dry environment as claimed in claim 1, characterized in that: The concrete retarding measure comprises the following steps: S1. According to the temperature range of the slipform operation environment, pre-prepare the slow-setting concrete mix ratio with a gradient of 5°C to ensure that the initial setting time of the concrete reaches 6±0.5 hours under different temperature conditions; S2. If the predicted ambient temperature of the next concrete pouring layer exceeds 5°C, the corresponding concrete mix ratio should be replaced in advance; S3. By adding modified retarder enhancer into concrete, the initial setting time of concrete can be delayed without affecting the lifting operation, and the strength of the concrete out of the mold is not less than 0.2MPa and the design strength of the concrete.

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