UHPC (Ultra High Performance Concrete) anti-gravity pressure pouring device and construction process thereof

Abstract

The invention relates to the technical field of constructional engineering, and discloses a UHPC anti-gravity pressure pouring device and a construction technology thereof.The device comprises a formwork system, a pouring system and a pouring system, the formwork system comprises an outer formwork arranged on a bottom formwork table, and an inner formwork is correspondingly and fixedly arranged in the outer formwork; the pressurized grouting equipment comprises a hopper used for loading UHPC mixing materials, a thrust oil cylinder used for driving grouting and a control module used for controlling the grouting pressure and the grouting speed of the thrust oil cylinder. The inlet end of a grouting connecting hose is connected with a grout outlet of the thrust cylinder, at least one outlet end of the grouting connecting hose is connected with the bottom of the outer formwork, and grouting is conducted on a cavity between the inner formwork and the outer formwork. In order to solve the problems of difficulty in pouring, incompactness in pouring and poor surface quality of existing UHPC thin-wall components and complex-shape components, the negative pressure pumping vibration technology is adopted, the pouring process is convenient and easy to operate, the pouring is compact, the surface quality is high, and high-quality construction forming of the UHPC thin-wall components and the complex-shape components is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of construction engineering, and in particular to a UHPC anti-gravity pressure casting device and a construction process thereof. Background Art

[0002] At present, there are mainly two traditional molding processes for the construction of ultra-high performance concrete (UHPC) components:

[0003] (1) For large concrete components with large casting surfaces, such as slabs, beams, and rectangular blocks, UHPC is generally transported to the top of the component mold by a pump truck or hopper for pouring. Gravity (sometimes vibration is required) allows the UHPC to flow downward and become dense. This method is currently the most common forming process for concrete components.

[0004] (2) For hollow tubular components such as pipe piles, centrifugal molding can be used. This construction method rotates the component at high speed to generate huge centrifugal force, so that the UHPC inside the component is squeezed against the inside of the mold and the excess water is discharged. This method is widely used in the production of tubular UHPC components, and the component molding quality is good.

[0005] The above two traditional UHPC casting methods have certain limitations, the main disadvantages are as follows:

[0006] (1) The method of using a pump truck or hopper to cast on the top of the component mold will become very difficult for thin-walled components (thin-walled hollow boxes, large-diameter round tubes) that need to be cast vertically. ① Due to the small casting surface on the top, the insufficient casting construction operation area will greatly extend the casting time. Since the UHPC water-cement ratio is extremely low (generally not more than 0.2), the casting surface is prone to water loss and form a hard shell. The long interval between each batch of material casting will cause multiple casting cold joints in the component, which seriously affects the structural strength and durability; ② The amount of cementitious material in UHPC is roughly the large adhesion between the mixture and the mold and steel mesh. The large adhesion makes it difficult for reinforced UHPC structures, especially thin-walled structures, to achieve complete self-flowing density by relying solely on gravity or vibration, making the final product more likely to have quality problems such as voids and poor surface quality.

[0007] (2) Although the centrifugal method has better molding quality, it can only be applied to the construction and molding of tubular components, and is difficult to apply to components with more complex shapes.

[0008] In view of the shortcomings of the above-mentioned traditional UHPC casting methods, some studies have proposed some innovative measures for improvement, which are listed as follows:

[0009] The existing Chinese patent with publication number CN116104309A discloses a UHPC thin-wall structure casting device, the main principle of which is to install a large hopper on the top of the thin-wall component, thereby solving the problem of small construction area and long construction time of thin-wall components. However, the patent fails to solve the problem that the internal space of the thin-wall component is small and UHPC is difficult to flow and compact only by gravity or vibration.

[0010] The existing Chinese patent with the publication (announcement) number CN 117513642 B provides a prefabricated UHPC-HPC composite hollow thin-walled component and a manufacturing method. The main principle is to use the HPC hollow thin-walled component as an inner mold to centrifuge the UHPC material on the basis of traditional centrifugal construction equipment, so as to realize the casting of a layer of UHPC outside the HPC hollow thin-walled component, thereby realizing the molding of the UHPC-HPC composite hollow thin-walled component by centrifugal method. This invention solves the construction difficulties of composite structure pipe piles, but it can only be used for the construction and molding of tubular components, which is difficult to apply to components with complex shapes.

[0011] The existing Chinese patent with the publication (announcement) number CN117247255A provides a single-layer pre-set coarse aggregate grouting type UHPC board, a functional gradient high-performance cement-based fiber composite board and a preparation method, that is, the coarse aggregate is pre-evenly filled in the mold, and the UHPC is injected into the mold through the grouting pipe, vibrated and compacted, and the functional gradient high-performance cement-based fiber composite board is obtained after curing. This invention application solves the problem that the pre-set coarse aggregate board and the functional gradient high-performance cement-based fiber composite board are difficult to be compacted, but the patent focuses more on the anti-penetration performance of the single-layer pre-set coarse aggregate grouting type UHPC board and the functional gradient high-performance cement-based fiber composite board, and does not propose relevant construction measures for the construction of thin-walled components. Summary of the invention

[0012] In order to solve the shortcomings of traditional UHPC casting methods and existing public technologies, the present invention proposes a UHPC anti-gravity pressure casting device and its construction process. The process uses a method of pressurized grouting at the bottom of the component mold to make UHPC flow from bottom to top through high pressure, thereby discharging the air inside the component from bottom to top. For components with extremely complex shapes, the components can also be placed in a negative pressure sealed container while vibrating and grouting, further solving the problem of difficult air discharge during the casting process of complex components, and feeding from the bottom avoids multiple castings to form cold seams at the UHPC skin hard shell. The high pressure of grouting can make UHPC more compact, solving the problems of casting difficulties, loose casting and poor surface quality in traditional casting methods and existing improved methods for UHPC thin-walled components and components with complex shapes. 。

[0013] The present invention provides the following technical solutions:

[0014] A UHPC anti-gravity pressure casting device, comprising:

[0015] The template system comprises an outer template placed on a bottom template platform, wherein an inner template is fixedly disposed correspondingly inside the outer template;

[0016] The pressurized grouting equipment includes a hopper for loading UHPC mixture, a propulsion cylinder for driving grouting, and a control module for controlling the grouting pressure and grouting speed of the propulsion cylinder;

[0017] The inlet end of the grouting connection hose is connected to the grouting outlet of the propulsion cylinder, and at least one outlet end of the grouting connection hose is connected to the bottom of the outer template to inject grout into the cavity between the inner and outer templates.

[0018] According to some embodiments, a high-frequency vibrator is provided on the outer formwork, the inner formwork or the bottom formwork platform.

[0019] According to some embodiments, an airtight sealing box is provided outside the outer mold plate and the bottom mold platform, and air is evacuated inside the sealing box by a vacuum pump to form a negative pressure.

[0020] According to some embodiments, the grouting connection hose is connected to the bottom of the outer formwork via a connecting device.

[0021] According to some embodiments, lateral self-balancing is achieved by anchoring the inner and outer formworks through several pairs of tie rods; a bottom plate strip that bears the bottom pressure is provided at the bottom of the inner formwork; several tie rods are provided on the bottom formwork platform and outside the outer formwork, a top beam is provided between the tops of the tie rods, and at least one vertical pressure rod is provided between the top beam and the bottom plate strip to achieve anti-floating self-balancing of the bottom plate of the inner formwork; a plurality of inner formwork cross braces are provided in the inner formwork to achieve self-balancing of the formwork all around.

[0022] On the other hand, the present invention also provides a construction process of the above-mentioned UHPC counter-gravity pressure casting device, which comprises the following steps:

[0023] S1: Determine the anti-gravity pressure value:

[0024] Calculate the pressure value of the pressurized grouting equipment. According to the components to be cast, calculate its bottom pressure p1=ρgh, where ρ, g, h are the density of UHPC, gravity constant and component height respectively, and calculate the adhesion stress p2 between UHPC and the pipeline of the pressurized grouting equipment, that is, the actual output pressurization value p=p1+p2, where the adhesion force p2=κS, κ is the pipe wall adhesion force generated by the 1m long pump pipe on the flowing UHPC, determined according to the test or taken as 0.065MPa / ㎡; S is the pipeline expansion area of ​​the pressurized grouting equipment;

[0025] S2: Install the equipment:

[0026] Before making the formwork, a hole is pre-drilled at the installation position at the bottom of the outer formwork; the formwork is installed, and the outer formwork and the vertical plate of the inner formwork are fixed by a tie rod; after the formwork is installed, the connecting device is connected to the bottom of the outer formwork; the panel of the connecting device and the outer formwork are sealed with a rubber gasket; the grouting connecting hose is locked with the propulsion cylinder and the connecting device;

[0027] S3: Flushing equipment and pipelines:

[0028] Before the formal anti-gravity pressure pouring, flush the pressure grouting equipment, hopper, grouting connection hose and connection device with water to ensure that the equipment will not affect the water-binder ratio of UHPC;

[0029] S4: Anti-gravity pressure pouring:

[0030] After setting the pressure and flow values ​​in the control module of the pressurized grouting equipment, pour the UHPC wet material with a slump expansion of 700±100mm into the hopper of the pressurized grouting equipment, and push the UHPC mixture to the middle of the outer formwork and the inner formwork by the thrust cylinder. The thrust cylinder automatically servo-controls the pouring flow through the control module, so that the UHPC wet material fills the internal space of the formwork from bottom to top.

[0031] According to some embodiments, in step S2, a high-frequency vibrator is provided on the bottom mold platform, the outer mold plate or the inner mold plate to vibrate the mold plate to accelerate the flow and remove part of the gas inside the UHPC mixture.

[0032] According to some embodiments, in step S2, an airtight sealing box is provided outside the outer formwork and the bottom formwork platform, and before pouring, the inside of the sealing box is evacuated to a negative pressure state by a vacuum pump to remove the gas inside the UHPC mixture.

[0033] According to some embodiments, in step S4, the grouting speed is 1 m 3 / h~10m 3 / h.

[0034] According to some embodiments, in step S4, the top surface concrete is poured 1-10 mm higher than the design height, higher than a specific value Δh=hε, where h is the component height and ε is the UHPC shrinkage strain.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The present invention proposes a UHPC anti-gravity pressurized casting device and a construction process thereof. Aiming at the problems of difficult casting, loose casting and poor surface quality existing in existing UHPC thin-walled components and components with complex shapes, a vacuum pumping and vibrating technology is adopted. The casting process is convenient and easy to operate, the casting is dense, and the surface quality is high, so that high-quality construction and forming of UHPC thin-walled components and components with complex shapes can be achieved.

[0037] 1. Full coverage casting: UHPC thin-walled components cannot be compacted by traditional gravity casting, or even have large areas of no slurry on the bottom plate.

[0038] 2. Good surface quality: The surface of UHPC thin-walled components is free of pores and other honeycomb surface phenomena (traditional gravity-cast UHPC components will have a large number of pores and other phenomena, mainly because UHPC is all powder and there is a lot of gas. Even if vibration is used in gravity casting, only part of the gas can be discharged).

[0039] 3. High pouring efficiency: The pouring speed of anti-gravity pressure is more than 10 times that of traditional gravity pouring. The reason is that UHPC is very viscous and has great viscosity. Traditional gravity pouring must overcome the viscosity, so the flow speed is slow. Anti-gravity pressure pouring relies on pressure to push UHPC to flow, so the pouring speed is relatively fast.

[0040] 4. Friendly to special-shaped components: Anti-gravity pressure casting can cast special-shaped components well, while traditional gravity casting is very difficult for special-shaped components. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A schematic diagram of a UHPC counter-gravity pressure casting device provided in an embodiment of the present invention.

[0042] Figure 2 A schematic diagram of a self-balancing template reinforcement solution provided in an embodiment of the present invention.

[0043] In the figure:

[0044] Outer formwork 1; inner formwork 2; bottom formwork platform 3; pressurized grouting equipment 4; hopper 5; thrust cylinder 6; control module 7; grouting connecting hose 8; connecting device 9; rubber gasket 10; clamp 11; high-frequency vibrator 12; tie rod 13; sealing box 14; vacuum pump 15; wooden bottom plate layer 16; inner formwork cross brace 17; top beam 18; vertical pressure rod 19; pull rod 20. DETAILED DESCRIPTION

[0045] The present invention is described in detail below in conjunction with the embodiments and drawings, but it should be understood that the embodiments and drawings are only used to exemplify the present invention and do not constitute any limitation on the protection scope of the present invention. All reasonable changes and combinations within the scope of the inventive concept of the present invention fall within the protection scope of the present invention.

[0046] The present invention will be further described below in conjunction with the accompanying drawings.

[0047] Example 1

[0048] This embodiment provides a UHPC anti-gravity pressure casting device and its construction process. The schematic diagram of the UHPC anti-gravity pressure casting device is shown in the attached Figure 1 The UHPC anti-gravity pressure casting device includes: an outer formwork 1, an inner formwork 2, a bottom formwork platform 3, a pressurized grouting device 4, a hopper 5, a propulsion cylinder 6, a control module 7, a grouting connection hose 8, a connecting device 9, a rubber gasket 10, a clamp 11, a high-frequency vibrator 12, a tie rod 13, a sealing box 14, and an air pump 15 (wherein the sealing box 14, the air pump 15 and the high-frequency vibrator 12 are optional and not necessary). The bottom of the sealing box 14 at the bottom is provided with a bottom formwork platform 3, and a U-shaped or other configuration outer formwork 1 and an inner formwork 2 are arranged above the bottom formwork platform 3. A high-frequency vibrator 12 for vibration and a plurality of tie rods 13 for fixing the inner and outer formworks are arranged on the side of the outer formwork 1. A pressurized grouting device 4 is provided on one side of the sealed box 14. The pressurized grouting device 4 includes a hopper 5 for loading UHPC materials. The control module 7 on the pressurized grouting device 4 controls the thrust cylinder 6 to adjust the grouting speed to a specific pressure value. One end of the grouting connection hose 8 is connected to the grouting outlet of the thrust cylinder 6 through a clamp 11, and the other end is connected to the bottom of the grouting cavity in the inner and outer templates through a connecting device 9 and a rubber gasket 10, and is locked with a clamp 11. The sealed box 14 is also connected to a vacuum pump 15 for vacuuming the sealed box 14 to form a negative pressure environment. The control module 7 is selected from a PLC controller.

[0049] Attached Figure 1 The component shown is a thin-walled open box. This figure is only for schematically illustrating the construction process of anti-gravity pressure molding. The mold can also be changed into other shapes and structures as needed. The sealing box 14 can be installed as needed or not.

[0050] The UHPC anti-gravity pressurized pouring device provided in this embodiment adjusts the pressure value and the grouting speed respectively through the pressurized pouring equipment control module 7. The pressure value and the grouting speed can be adjusted and controlled respectively, while the existing conventional concrete delivery pump can only adjust the flow rate; the device needs to be connected to the bottom of the inner and outer templates through the connecting device 9 to realize anti-gravity grouting, while the conventional concrete delivery pump flows in freely from the top of the component where there is no template.

[0051] The process includes the following steps:

[0052] S1: Determine the anti-gravity pressurization value: Calculate the pressure value of the pressurized grouting equipment 4: According to the component to be cast, calculate its bottom pressure p1 = ρgh (ρ, g, h are the density of UHPC, gravity constant and component height respectively), and consider the adhesion stress p2 between UHPC and the pipeline of the pressurized grouting equipment 4, that is, the actual output pressurization value p = p1 + p2, where the adhesion force p2 = κS (κ is the pipe wall adhesion force generated by a 1m long pump pipe on the flowing UHPC, which can be determined based on experiments. When no experiment is performed, it can be taken as 0.065MPa / ㎡; S is the pipeline expansion area).

[0053] S2: Install the equipment: place the connecting device 9 on the outer formwork 1: before making the formwork, pre-drill a hole at the installation position of the outer formwork 1; install the formwork, and use the tie rods 13 to fix the outer formwork 1 and the inner formwork 2 vertical plates; after the formwork is installed, connect the connecting device 9 to the outer formwork 1 (if the outer formwork 1 is a steel formwork, the connecting device 9 and the outer formwork 1 are connected by bolts; if the outer formwork 1 is a wooden formwork, a tie rod 13 is required to connect the connecting device 9 to the outer formwork 1 and the inner formwork 2 to form a whole); in order to prevent leakage of slurry, the panel of the connecting device 9 and the outer formwork 1 are sealed with a rubber gasket 10; the grouting connecting hose 8 and the thrust cylinder 6 and the connecting device 9 are all locked with a clamp 11.

[0054] S3: Flushing equipment and pipelines: Before the formal counter-gravity pressure pouring, flush the pressure grouting equipment 4, hopper 5, grouting connecting hose 8, connecting device 9, etc. with water to ensure that the equipment will not affect the water-cement ratio of UHPC.

[0055] S4: Anti-gravity pressure pouring: After the control module 7 on the pressure grouting equipment 4 sets the pressure value p and the flow value, pour the UHPC wet material with a slump expansion of 700±100mm into the hopper 5 of the pressure grouting equipment 4, and the UHPC mixture is pushed to the middle of the outer template 1 and the inner template 2 by the thrust cylinder 6. The thrust cylinder 6 is automatically servo-controlled by the control module 7 to control the pouring flow, so that the UHPC wet material fills the internal space of the template from bottom to top by anti-gravity.

[0056] Casting process of special-shaped components: For components with more complex shapes, in order to allow the air inside the mold to be discharged more smoothly, a high-frequency vibrator 12 can be installed on the bottom mold platform 3, the outer mold 1 or the inner mold 2 to vibrate the mold to accelerate the flow and discharge part of the gas inside the UHPC mixture.

[0057] Casting process of components with special requirements: For components with strict requirements on surface finish and honeycomb surface, a sealing box 14 can be installed on the periphery of the component. Before casting, the inside of the sealing box 14 is evacuated to a negative pressure state of 5-10Pa by a vacuum pump 15. During casting, a high-frequency vibrator 13 vibrates the template and evacuates the gas inside the sealing box 14, thereby completely eliminating the gas inside the UHPC mixture and further improving the casting quality of the component.

[0058] The specific technical parameters and requirements of this process are as follows:

[0059] (1) The slump expansion range of the UHPC mixture used in this process is generally 600 mm to 800 mm. The specific value needs to be determined by testing based on the complexity of the component's shape and the appearance quality requirements;

[0060] (2) The pressurized grouting equipment 4 is composed of three parts: a hopper 5, a propulsion cylinder 6, and a control module 7. The hopper 5 needs to have a stirring function. The maximum output pressure of the pressurized grouting equipment 4 is not less than twice the required pressure value. The pressurized grouting equipment 4 can be mobile or fixed.

[0061] (3) The adhesion force κ of UHPC mixture is the adhesion force of 1 m long pump pipe on the pipe wall of flowing UHPC, which can be determined based on experiments. If no experiment is performed, it can be taken as 0.065 MPa / ㎡.

[0062] (4) Grouting speed is generally 1m 3 / h~10m 3 / h, which needs to be determined according to factors such as the complexity of the mold shape and the volume of the component. On-site technicians can adjust it appropriately according to the pouring situation;

[0063] (5) The grouting connection hose 8, the connection device 9 and the rubber gasket 10 need to be installed at the bottom of the template. The installation position should allow the UHPC to flow smoothly throughout the entire internal space of the mold. Multiple feed ports can also be set according to the casting speed requirements;

[0064] (6) Since the shrinkage strain of UHPC is not less than 400 με, the top surface of the component will collapse by 1-10 mm due to shrinkage after the curing is completed. Therefore, during the counter-gravity pressure pouring process, the top surface concrete should be 1-10 mm higher than the design height, which is higher than the specific value Δh = hε (h is the component height, ε is the UHPC shrinkage strain).

[0065] Example 2

[0066] Based on Example 1, this example provides another self-balancing formwork solution with a larger pressure range. Since the pressure on the formwork in the pressurized molding construction process is greater than that in the traditional casting process, the formwork bearing capacity and stiffness must be strictly calculated before casting, and the bottom plate of the inner formwork 2 will be damaged due to the large buoyancy generated during the casting of the surrounding side plates UHPC. Therefore, the bottom pressure plate of the inner formwork 2 needs to be designed separately for anti-floating. Figure 2 An optional self-balancing formwork solution is provided, and the specific implementation process is as follows: the outer formwork 1 is directly fixed on the bottom formwork platform 3, and the outer formwork 1 and the inner formwork 2 vertical plates are anchored by tension rods 13 to achieve self-balancing of the side plates; the bottom plate of the inner formwork 2 requires an anti-floating device due to the large buoyancy at the bottom, and a plurality of wooden bottom plate pressure strips 16 are arranged to press the bottom plate of the inner formwork 2, and then a plurality of steel vertical pressure rods 19 are arranged to press the wooden bottom plate pressure strips 16, and the vertical pressure rods 19 are pressed by a top beam 18, and the top beam 18 is connected to the bottom formwork platform 3 through a tension rod 20, thereby achieving self-balancing of the bottom plate of the inner formwork 2 against floating; in order to ensure the stability of the outer formwork 1 and the inner formwork 2 vertical plates, a plurality of inner formwork cross braces 17 can be arranged to achieve self-balancing of the formwork around the component.

[0067] The sealed box 14 can be formed by welding Q235 steel plates to form a closed box body, and the steel plates have a thickness of 1-4 mm.

[0068] The above embodiments are only preferred implementations of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A UHPC anti-gravity pressure casting device, characterized in that: It includes: The template system comprises an outer template placed on a bottom template platform, wherein an inner template is fixedly disposed correspondingly inside the outer template; The pressurized grouting equipment includes a hopper for loading UHPC mixture, a propulsion cylinder for driving grouting, and a control module for controlling the grouting pressure and grouting speed of the propulsion cylinder; The inlet end of the grouting connection hose is connected to the grouting outlet of the propulsion cylinder, and at least one outlet end of the grouting connection hose is connected to the bottom of the outer template to inject grout into the cavity between the inner and outer templates.

2. The UHPC counter-gravity pressure casting device according to claim 1, characterized in that: The outer mold plate, the inner mold plate or the bottom mold platform is provided with a high-frequency vibrator.

3. The UHPC counter-gravity pressure casting device according to claim 2, characterized in that: An airtight sealing box is arranged outside the outer mold plate and the bottom mold platform, and air is evacuated inside the sealing box by an air pump to form a negative pressure.

4. The UHPC counter-gravity pressure casting device according to claim 3, characterized in that: The grouting connection hose is connected to the bottom of the outer template through a connecting device.

5. The UHPC counter-gravity pressure casting device according to claim 4, characterized in that: Lateral self-balancing is achieved by anchoring the inner and outer formworks through several pairs of tie rods; a bottom plate strip that bears the bottom pressure is provided at the bottom of the inner formwork; several tie rods are provided on the bottom formwork platform and outside the outer formwork, a top beam is provided between the tops of the tie rods, and at least one vertical pressure rod is provided between the top beam and the bottom plate strip to achieve anti-floating self-balancing of the bottom plate of the inner formwork; a plurality of inner formwork cross braces are provided in the inner formwork to achieve self-balancing of the formwork all around.

6. A construction process for a UHPC counter-gravity pressure casting device according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1: Determine the anti-gravity pressure value: Calculate the pressure value of the pressurized grouting equipment. According to the components to be cast, calculate its bottom pressure p1=ρgh, where ρ, g, h are the density of UHPC, gravity constant and component height respectively, and calculate the adhesion stress p2 between UHPC and the pipeline of the pressurized grouting equipment, that is, the actual output pressurization value p=p1+p2, where the adhesion force p2=κS, κ is the pipe wall adhesion force generated by the 1m long pump pipe on the flowing UHPC, determined according to the test or taken as 0.065MPa / ㎡; S is the pipeline expansion area of ​​the pressurized grouting equipment; S2: Install the equipment: Before making the template, pre-drill holes at the installation position at the bottom of the outer template; Install the formwork, and use the tie rods to fix the vertical plates of the outer formwork and the inner formwork; after the formwork is installed, connect the connecting device to the bottom of the outer formwork; seal the panel of the connecting device and the outer formwork with a rubber gasket; and lock the grouting connecting hose, the propulsion cylinder and the connecting device; S3: Flushing equipment and pipelines: Before the formal anti-gravity pressure pouring, flush the pressure grouting equipment, hopper, grouting connection hose and connection device with water to ensure that the equipment will not affect the water-binder ratio of UHPC; S4: Anti-gravity pressure pouring: After the pressure value p and flow value are set in the control module of the pressurized grouting equipment, the UHPC wet material with a slump expansion of 700±100mm is poured into the hopper of the pressurized grouting equipment, and the UHPC mixture is pushed between the outer formwork and the inner formwork by the thrust cylinder. The thrust cylinder automatically servo-controls the pouring flow through the control module, so that the UHPC wet material fills the internal space of the formwork from bottom to top by anti-gravity.

7. The construction process according to claim 6, characterized in that: In step S2, a high-frequency vibrator is arranged on the bottom mold platform, the outer mold plate or the inner mold plate to vibrate the mold plate to accelerate the flow and remove part of the gas inside the UHPC mixture.

8. The construction process according to claim 7, characterized in that: In step S2, an airtight sealing box is arranged outside the outer formwork and the bottom formwork platform, and before pouring, the inside of the sealing box is evacuated to a negative pressure state by a vacuum pump to remove the gas inside the UHPC mixture.

9. The construction process according to claim 6, characterized in that: In step S4, the grouting speed is 1m 3 / h~10m 3 / h.

10. The construction process according to claim 6, characterized in that: In step S4, the top surface concrete is poured 1-10 mm higher than the design height, higher than a specific value Δh=hε, where h is the component height and ε is the UHPC shrinkage strain.

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