Prefabricating device applied to UHPC prestressed simply supported beam

Abstract

The invention discloses a prefabricating device applied to a UHPC (Ultra High Performance Concrete) prestressed simply supported beam, which comprises a pouring preset path configured to be provided with a pouring cavity for UHPC simply supported beam pouring liquid to flow, and the peripheral side of the pouring cavity is provided with a prefabricating template for UHPC simply supported beam pouring molding; the prefabricating moving mechanism is configured to be provided with a prefabricating pouring tank located on a pouring preset path, the prefabricating pouring tank is provided with a moving support driving the prefabricating pouring tank to move along the pouring preset path, and the bottom of the prefabricating pouring tank is provided with a discharging pipe extending towards the interior of the pouring cavity; the UHPC simply supported beam raw materials which are quantitatively weighed in the prefabricated pouring tank are proportioned through the discharging pipe and are automatically stirred and mixed, and the UHPC simply supported beam is formed after the UHPC simply supported beam raw materials are poured and maintained into the pouring cavity through the discharging pipe. According to the method, material saving and environmental protection are achieved, the construction efficiency is improved, the construction period is shortened, and good social benefits are obtained.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, and in particular to a prefabrication device for UHPC prestressed simply supported beams. Background Technology

[0002] my country's road and bridge construction industry is booming with high quality and speed. However, traditional concrete materials, due to their heavy weight, susceptibility to cracking, insufficient durability, and high maintenance costs, are no longer able to meet the stringent requirements of environmental protection, energy conservation, and sustainable development. Against this backdrop, ultra-high performance concrete (UHPC), as a new generation of cement-based materials, has emerged. It possesses ultra-high mechanical properties of 120MPa to 200MPa and excellent durability, directly breaking through the industry bottlenecks of lightweighting, long service life, and full-cycle cost optimization at the material level, and becoming a core technological force driving bridge engineering towards high quality.

[0003] Currently, based on ultra-high performance concrete (UHPC), our company has applied UHPC to road network construction projects. For the first time, we have used high-precision intelligent weighing combined with efficient and uniform automated mixing intelligent facilities to precast UHPC prestressed simply supported beams. This ensures that the UHPC prestressed simply supported beams can stably achieve their design performance, realizing material conservation and environmental protection, improving construction efficiency, and saving construction time, thus achieving good social benefits. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a prefabrication device for UHPC prestressed simply supported beams, which applies ultra-high performance concrete (UHPC) to road network construction projects. For the first time, it integrates high-precision intelligent weighing with efficient and uniform automated mixing intelligent facilities to prefabricate UHPC prestressed simply supported beams, ensuring that the UHPC prestressed simply supported beams can stably achieve their design performance. This achieves material conservation and environmental protection, improves construction efficiency, saves construction time, and achieves good social benefits.

[0005] The prefabrication device of the present invention for use in UHPC prestressed simply supported beams includes:

[0006] The casting preset path is configured to have a casting chamber for the flow of casting liquid for the UHPC simply supported beam, and the periphery of the casting chamber has a prefabricated template for casting and shaping the UHPC simply supported beam.

[0007] A prefabricated moving mechanism is configured to have a prefabricated casting tank located on a preset casting path. The prefabricated casting tank has a moving support that drives it to move along the preset casting path. The bottom of the prefabricated casting tank has a discharge pipe extending toward the casting chamber. The discharge pipe dispenses UHPC simply supported beam raw materials weighed in the prefabricated casting tank according to a quantitative ratio, automatically mixes them, and then pours them into the casting chamber for curing to form UHPC simply supported beams.

[0008] This invention employs a factory-prefabrication method for UHPC simply supported beams to solve the problems of difficult transportation and hoisting of traditional concrete components and excessive on-site wet work. Furthermore, during the prefabrication process, a pre-set pouring path guides the process, with prefabricated templates serving as the pouring molds for the UHPC simply supported beams. Therefore, the prefabricated templates surround the pouring chamber and obstruct the flow of the pouring liquid within the chamber, allowing the pouring liquid to gradually form the UHPC simply supported beam.

[0009] During the formation of the UHPC simply supported beam, the prefabricated moving mechanism cooperates with the casting chamber to allow the prefabricated casting tank inside the prefabricated moving mechanism to weigh the raw materials of the UHPC simply supported beam in a quantitative proportion and automatically mix them before pouring them into the casting chamber through the discharge pipe. At the same time, during the pouring process in the casting chamber through the discharge pipe, the moving support is driven to move the prefabricated casting tank along the preset pouring path. During the movement, quantitative weighing, automatic mixing, and material filling into the casting chamber in the prefabricated template are carried out simultaneously.

[0010] Therefore, this invention applies ultra-high performance concrete (UHPC) to road network construction projects. For the first time, it integrates high-precision intelligent weighing with efficient and uniform automated mixing intelligent facilities to precast UHPC prestressed simply supported beams, ensuring that the UHPC prestressed simply supported beams can stably achieve their design performance. This achieves material conservation and environmental protection, improves construction efficiency, saves construction time, and obtains good social benefits.

[0011] Furthermore, a vertical steel bar is arranged along its axial direction in the casting chamber, and the vertical steel bar coincides with the axis of the casting chamber. Several horizontal steel bars are arranged along its axial direction in the casting chamber, and all horizontal steel bars are located above the vertical steel bar. Each horizontal steel bar is perpendicular to the vertical steel bar in the horizontal direction and is welded to the inner side of the vertical steel bar at 40cm intervals.

[0012] The vertical and several horizontal reinforcing bars designed in this invention are checked against the length, quantity, and model of various specifications of reinforcing bars in the construction drawings before being cut. The installation of the horizontal reinforcing bars achieves stress positioning, prestressed anti-collapse, and tension end reinforcement, giving the UHPC simply supported beam a strong prestress. At the same time, in the actual operation of this invention, the two ends of the vertical reinforcing bars in the casting chamber are tied to the casting template respectively. All horizontal reinforcing bars are located above the vertical reinforcing bars, and each horizontal reinforcing bar is perpendicular to the vertical reinforcing bar in the horizontal direction and welded to the inner side of the vertical reinforcing bar at 40cm intervals. This can enhance the overall strength of the UHPC simply supported beam.

[0013] Furthermore, slide rails are provided on both sides of the precast template, and the axial direction of the slide rails is parallel to the axial direction of the casting chamber. The movable support includes sliding feet embedded in the slide rails, and the bottom of the sliding feet has rollers that move along the axial direction of the slide rails. A protective rail is installed on the side of the slide rails away from the casting chamber.

[0014] The slide rail designed in this invention is matched with a movable support, allowing the movable support to move along the axis of the slide rail. The axis of the slide rail is parallel to the axis of the casting chamber. Therefore, the sliding feet embedded in the slide rail, in cooperation with the rollers, drive the precast casting tank to move along the preset casting path. The cooperation between the movable support and the slide rail maintains the stability of the precast casting tank's movement, thus ensuring the uniformity of the UHPC casting liquid being poured through the precast casting tank's discharge pipe. The protective guardrail installed on the side of the slide rail away from the casting chamber is to protect inspection personnel and improve overall construction safety.

[0015] Furthermore, the precast casting tank includes a mixing drum and a discharge hopper located below the mixing drum. The top of the mixing drum has a sealing plate for sealing the mixing drum. Below the sealing plate is a proportioning column located in the mixing drum for weighing the various raw materials of the UHPC casting liquid. Below the proportioning column are two sets of stirring components for the various raw materials of the UHPC casting liquid. The stirring components extend into the discharge hopper. The discharge hopper is connected to the discharge pipe and is equipped with a handwheel to start the discharge pipe, so that the proportioning column delivers quantitatively weighed UHPC casting liquid raw materials into the mixing drum step by step, and the stirring components stir the UHPC casting liquid raw materials and discharge them through the discharge pipe.

[0016] This invention combines weighing and proportioning with automated mixing to deliver quantitatively weighed raw materials of UHPC casting liquid into the mixing drum via a proportioning column. Two sets of mixing components are used to mix the raw materials of UHPC casting liquid and then discharge them through a discharge pipe. The discharge process adopts a step-by-step feeding technology to solve the problems of large fluctuations in traditional concrete mix proportions and uneven distribution of steel fibers. This avoids steel fiber clumping and strength dispersion, ensuring that the compressive strength of UHPC reaches a stable level of over 150MPa, thereby improving the uniformity of component quality from the source.

[0017] Furthermore, a proportioning column is installed below the sealing plate, located within the mixing drum, for weighing the various raw materials of the UHPC casting liquid. These raw materials include a premix, a water-reducing agent, a crack-resistant and shrinkage-reducing agent, steel fibers, and water. The premix has a concentration of 2170 kg / m³. 3 The polycarboxylate superplasticizer is 30 kg / m³. 3 The phosphate crack-resistant agent is 30 kg / m³. 3 The steel fiber has a strength of 160 kg / m³. 3 And the water content is 145 kg / m³ 3 The premixed material includes 1200 kg / m³ of 52.5 grade silicate cement. 3 240kg / m³ of mineral powder 3 356 kg / m³ of fly ash 3 Silica fume 260kg / m 3 Quartz sand 114kg / m 3 .

[0018] This invention uses 52.5 grade silicate cement as high-strength silicate cement, silica fume (activity ≥10%), and graded quartz sand / powder and other fine-particle materials. Based on the densest packing theory, the particle size distribution is optimized (0.16mm~1.25mm gradient gradation) to reduce porosity to its limit. Simultaneously, highly active powders (silica fume, spherical fly ash) are incorporated to trigger a secondary hydration reaction, generating low-calcium-silica ratio CSH gel, achieving microstructural densification. Combined with a high-efficiency water-reducing agent (water reduction rate >30%), the water-cement ratio is controlled to ≤0.20, significantly reducing capillary porosity.

[0019] During the mixing stage, ultrafine steel fibers (tensile strength ≥2000MPa, aspect ratio 60-100) with a volume fraction of not less than 2.0% and not more than 3.5% are incorporated, and the fibers are uniformly dispersed through high-speed forced mixing. During stress, the fibers inhibit the propagation of microcracks through the bridging effect, changing the material failure mode from the brittle fracture of ordinary concrete to pseudo-ductile behavior with multiple crack propagation. The tensile strength is increased to 7.2MPa, significantly enhancing the impact resistance and fatigue performance.

[0020] Meanwhile, the UHPC high-performance concrete in this invention has a low water-cement ratio, and the use of covering and steam curing in the factory significantly reduces water consumption compared to traditional reinforced concrete structures, achieving water conservation. UHPC precast beams enable low-carbon, green, environmentally friendly, sustainable, and high-quality development construction.

[0021] Furthermore, the proportioning column has a weighing chamber for weighing the raw materials of the UHPC casting liquid. Several weighing sensors are evenly distributed at the bottom of the proportioning column and facing the weighing chamber. The bottom of the proportioning column has a discharge port for discharging the raw materials of the UHPC casting liquid and facing the discharge hopper. A control valve for opening and closing the discharge port is installed in the discharge port. Several feed ports are opened along the circumference of the proportioning column, and all feed ports face the weighing chamber. Inclined feed channels are evenly distributed along the circumference of the proportioning column. The position of each feed channel corresponds one-to-one with the position of the weighing sensor. One end of the feed channel is connected to the discharge port, and the other end of the feed channel is connected to the feed port opened on the side wall of the mixing drum.

[0022] In this invention, each raw material of UHPC casting liquid is sequentially fed into the feeding channel through the inlet. Due to the inclined feeding channel, the raw materials in the UHPC casting liquid are transported to the weighing chamber of the proportioning column. After the raw materials of UHPC casting liquid are collected in the weighing chamber, the weight of the raw materials in the weighing chamber is obtained by each weighing sensor in the weighing chamber. When the pressure values ​​of each weighing sensor are respectively transmitted to the microprocessor, after the pressure values ​​in all weighing sensors are equal, the microprocessor issues a command to start the control valve, opens the discharge port, and transports the quantitatively weighed raw materials of UHPC casting liquid in the weighing chamber toward the discharge hopper. After each raw material of UHPC casting liquid is put into the discharge hopper, the stirring component is started to stir.

[0023] The process of adding each raw material to the UHPC casting liquid is as follows: Each raw material is fed into the discharge hopper via the proportioning column and dry-mixed for 3-5 minutes → approximately 70% water is added, followed by phosphate crack-resistant agent and mixing for 3 minutes → the remaining 30% water and polycarboxylate superplasticizer are added and mixed for approximately 10 minutes until fully fluidized → steel fibers are added and mixed for 5 minutes. The total mixing time is ≥20 minutes to ensure no fiber clumping. Weighing errors are controlled within ±0.5%, ensuring accurate mix proportions from the source. Compared to traditional concrete mixing, the slump spread of UHPC is stably controlled at 650-700 mm, achieving a balance between workability and strength.

[0024] Furthermore, the stirring assembly includes a first stirring element and a second stirring element that operate in conjunction with each other. The first stirring element and the second stirring element are connected to a driving element. The driving element drives the first stirring element and the second stirring element to rotate synchronously for stirring. The first stirring element and the second stirring element are both located inside the stirring drum and the discharge hopper.

[0025] This invention uses a first and second agitator that operate in a linked manner to stir the raw materials of the UHPC casting liquid in the mixing drum and the discharge hopper. At the same time, since the first and second agitators rotate synchronously, the energy output can be reduced. The drive unit drives the first and second agitators to stir the UHPC casting liquid in the mixing drum and the discharge hopper in a linked manner.

[0026] Meanwhile, this invention utilizes a PLC control system integrated into a microprocessor to precisely match the raw material ratio with the weighing sensor, enabling fully digital control to replace manual operation and significantly reduce batching errors. The mixing assembly, featuring a dual mixing system with a first and second agitator, monitors mixing uniformity and weight deviation in real time, achieving both green construction (reducing on-site dust) and quality control objectives.

[0027] Furthermore, the first stirring component includes a long stirring rod near the center line of the stirring drum. The axis of the long stirring rod is parallel to the center line of the stirring drum. Two transverse stirring blades are evenly distributed along the axis of the long stirring rod. The two transverse stirring blades on the long stirring rod located on both sides of the center line of the stirring drum are arranged facing each other. The side of the long stirring rod away from the transverse stirring blades is provided with a first inclined stirring blade, which is located between the two transverse stirring blades. The bottom of the long stirring rod extends towards the discharge hopper, and a tail stirring blade is welded to the bottom of the long stirring rod.

[0028] The long stirring rod designed in this invention stirs the various raw materials of the UHPC casting liquid in the mixing drum and the discharge hopper. Two transverse stirring blades on the long stirring rod located on both sides of the center line of the mixing drum are set facing each other, so that the transverse stirring blades generate transverse shear force on the various raw materials of the UHPC casting liquid, thereby stirring and mixing the various raw materials located in the middle of the mixing drum. At the same time, the first inclined stirring blade, which is inclined away from the side of the transverse stirring blade, stirs the various raw materials in the space between the mixing drum and the discharge hopper.

[0029] Meanwhile, the first inclined stirring blade is located between the two transverse stirring blades, and the bottom of the long stirring rod extends towards the discharge hopper. The bottom of the long stirring rod is welded with a tail stirring blade. The first inclined stirring blade, the two transverse stirring blades and the tail stirring blade can be used to stir the raw materials in the entire discharge hopper. The tail stirring blade can perform fine stirring of the raw materials in the discharge hopper, so that the raw materials of the UHPC casting liquid are stirred evenly.

[0030] Furthermore, the second stirring component includes a short stirring rod located away from the center line of the stirring cylinder. The short stirring rod is located inside the stirring cylinder, and second inclined stirring blades are welded to both sides of the short stirring rod.

[0031] The short stirring rods designed in this invention are located inside the stirring drum and on both sides of the stirring drum away from the center line of the stirring drum. They are used to uniformly stir both sides of the stirring drum. The second inclined stirring blades are used to stir the raw materials of the UHPC casting liquid on the inner periphery of the stirring drum, so that the raw materials of the UHPC casting liquid are stirred more evenly.

[0032] Furthermore, the driving component includes a support plate disposed within the stirring drum. The support plate has a driving chamber for the linked operation of a first stirring component and a second stirring component. The driving chamber is respectively provided with a first spur gear connected to the first stirring component and a second spur gear connected to the second stirring component. The first spur gear meshes with the second spur gear. The first spur gear is sleeved on a long stirring rod inside the first stirring component. The long stirring rod passes through the support plate and is connected to a bearing seat disposed on the upper surface of the support plate. The second spur gear is sleeved on a short stirring rod inside the second stirring component. The short stirring rod passes through the support plate and is connected to a servo motor shaft disposed on the upper surface of the support plate.

[0033] This invention uses a support plate to support the servo motor and bearing housing. The bearing housing can provide stable rotational support force for the long stirring rod. The servo motor is installed in the space between the support plate, the feed channel and the proportioning column. At the same time, there are several vent holes on the side wall of the stirring drum that communicate with this space, so that the heat generated by the servo motor during operation can be dissipated through the vent holes.

[0034] When in use, the servo motor is started, which drives the short stirring rod to rotate, synchronously driving the first spur gear to rotate. Since the first spur gear meshes with the second spur gear, the first spur gear drives the second spur gear to rotate, and the second spur gear drives the long stirring rod to rotate. Therefore, through the cooperation of the first spur gear and the second spur gear, a stirring force is stably delivered to the long stirring rod and the short stirring rod in the drive chamber of the support plate, so that the long stirring rod and the short stirring rod stir the raw materials of the UHPC stirring liquid in the stirring drum and the discharge hopper.

[0035] The beneficial effects of this invention are as follows: The prefabrication device for UHPC prestressed simply supported beams, applied in this invention, systematically solves the common problems of traditional concrete bridge structures, such as heavy self-weight, easy cracking, poor durability, and high maintenance costs, by utilizing ultra-high performance concrete. The compressive strength of UHPC prefabricated beams can reach 150MPa, which is 3 to 5 times higher than that of ordinary concrete prefabricated beams with compressive strength grades of C30 to C50 (tensile strength standard value 2MPa to 5MPa); the corresponding tensile strength standard value of UHPC150 prefabricated beams can reach 7.2MPa, which is 44% to 260% higher than that of ordinary concrete prefabricated beams; due to the strong crack resistance of UHPC prefabricated beams, the steel reinforcement ratio is also reduced accordingly. Attached Figure Description

[0036] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0037] Figure 1 This is a schematic diagram of the construction structure of the prefabrication device for UHPC prestressed simply supported beams according to the present invention;

[0038] Figure 2 This is a schematic diagram of the prefabrication device for UHPC prestressed simply supported beams according to the present invention;

[0039] Figure 3 for Figure 1 Sectional view of AA.

[0040] Figure label:

[0041] 1. Protective railing; 2. Slide rail; 3. Casting chamber; 4. Horizontal reinforcing bar; 5. Precast template; 6. Vertical reinforcing bar; 7. Mixing drum; 8. Sliding support; 9. Sealing plate; 10. First reinforcing rod; 11. Connecting rod; 12. Handwheel; 13. Discharge hopper; 14. Second reinforcing rod; 15. Feed pipe; 16. Roller; 17. Weighing chamber; 18. Feeding channel; 19. Feed inlet; 20. Conveying port; 21. Servo motor; 22. Weighing sensor; 23. Support plate; 24. Drive chamber; 25. Control valve; 26. Feeding port; 27. Long mixing rod; 28. Tail mixing blade; 29. ​​Horizontal mixing blade; 30. First inclined mixing blade; 31. Second inclined mixing blade; 32. First spur gear; 33. Second spur gear; 34. Bearing seat. Detailed Implementation

[0042] like Figure 1-3 As shown: The prefabrication device for UHPC prestressed simply supported beams in this embodiment includes a pre-casting path and a prefabrication moving mechanism. The pre-casting path is configured to have a casting chamber 3 for the flow of casting liquid for the UHPC simply supported beam. The periphery of the casting chamber 3 has a prefabrication template 5 for casting and shaping the UHPC simply supported beam.

[0043] The prefabrication moving mechanism is configured to have a prefabrication casting tank located in the pre-casting path. The prefabrication casting tank has a moving support that drives it to move along the pre-casting path. The bottom of the prefabrication casting tank has a discharge pipe 15 extending toward the casting chamber 3. The discharge pipe 15 dispenses UHPC simply supported beam raw materials weighed in the prefabrication casting tank according to the specified proportions and automatically mixes them. After pouring and curing, the UHPC simply supported beam is formed.

[0044] This embodiment adopts a factory prefabrication method for UHPC simply supported beams to solve the problems of difficult transportation and hoisting of traditional concrete components and a lot of on-site wet work. At the same time, during the prefabrication process of UHPC simply supported beams, a pre-set pouring path is used as a guide. In the pre-set pouring path, the prefabricated template 5 serves as the pouring mold for UHPC simply supported beams. Therefore, the prefabricated template 5 is arranged around the periphery of the pouring chamber 3 and blocks the pouring liquid of UHPC simply supported beams flowing in the pouring chamber 3, so that the pouring liquid of UHPC simply supported beams gradually forms UHPC simply supported beams.

[0045] During the formation of the UHPC simply supported beam, the prefabricated moving mechanism cooperates with the casting chamber 3 to allow the prefabricated casting tank inside the prefabricated moving mechanism to weigh the raw materials of the UHPC simply supported beam in a quantitative manner and automatically mix them before pouring them into the casting chamber 3 through the discharge pipe 15. At the same time, during the pouring process from the discharge pipe 15 into the casting chamber 3, the moving support drives the prefabricated casting tank to move along the preset pouring path. During the movement, quantitative weighing, automatic mixing, and material filling are carried out simultaneously into the casting chamber 3 inside the prefabricated template 5.

[0046] Therefore, this embodiment applies ultra-high performance concrete (UHPC) to road network construction projects. For the first time, it uses high-precision intelligent weighing combined with efficient and uniform automated mixing intelligent facilities to comprehensively precast UHPC prestressed simply supported beams. This ensures that the UHPC prestressed simply supported beams can stably achieve their design performance, realizing material saving and environmental protection, improving construction efficiency, saving construction time, and achieving good social benefits.

[0047] See Figure 1 As shown, a vertical steel bar 6 is arranged along its axis in the casting chamber 3. The vertical steel bar 6 coincides with the axis of the casting chamber 3. Several horizontal steel bars 4 are arranged at uniform intervals along its axis in the casting chamber 3. All horizontal steel bars 4 are located above the vertical steel bar 6, and each horizontal steel bar 4 is perpendicular to the vertical steel bar 6 in the horizontal direction and is welded to the inner side of the vertical steel bar 6 at intervals of 40cm.

[0048] In this embodiment, the vertical reinforcing bars 6 and several horizontal reinforcing bars are checked against the length, quantity, and model of various specifications of reinforcing bars in the construction drawings before being cut. The installation of the horizontal reinforcing bars 4 achieves stress positioning, prestressed anti-collapse, and tension end reinforcement, giving the UHPC simply supported beam a strong prestress. At the same time, in the actual operation of this embodiment, the two ends of the vertical reinforcing bars 6 in the casting chamber 3 are tied to the casting template respectively. All horizontal reinforcing bars 4 are located above the vertical reinforcing bars 6, and each horizontal reinforcing bar 4 is perpendicular to the vertical reinforcing bar 6 in the horizontal direction. Adjacent horizontal reinforcing bars 4 are welded to the vertical reinforcing bars 6 at intervals of 40cm inside the vertical reinforcing bars 6, which can enhance the overall strength of the UHPC simply supported beam.

[0049] Meanwhile, slide rails 2 are respectively provided on both sides of the precast template 5. The axial direction of the slide rails 2 is parallel to the axial direction of the casting chamber 3. (See [reference]) Figure 2 As shown, the movable support includes sliding legs 8 embedded in the slide rail 2, connecting rods 11 welded between adjacent sliding legs 8, and a handwheel 12 mounted on the connecting rods 11. A second reinforcing rod 14 is inclined between the connecting rods 11 and the sliding legs 8. One end of the second reinforcing rod 14 is welded to the connecting rods 11, and the other end of the second reinforcing rod 14 is welded to the sliding legs 8. The bottom of the sliding legs 8 has rollers 16 that move along the axis of the slide rail 2. A protective railing is installed on the side of the slide rail 2 away from the casting chamber 3.

[0050] In this embodiment, the slide rail 2 is designed to match the movable support, allowing the movable support to move along the axis of the slide rail 2. The axis of the slide rail 2 is parallel to the axis of the casting chamber 3. Therefore, the sliding support 8 embedded in the slide rail 2, in cooperation with the roller 16, drives the precast casting tank to move along the preset casting path. The cooperation between the movable support and the slide rail 2 maintains the stability of the precast casting tank's movement, ensuring the uniformity of the UHPC casting liquid being poured through the discharge pipe 15 of the precast casting tank. The protective guardrail installed on the side of the slide rail 2 away from the casting chamber 3 is to protect inspection personnel and improve overall construction safety.

[0051] The precast casting tank includes a mixing drum 7 and a discharge hopper 13 located below the mixing drum 7. The upper part of the mixing drum 7 is welded to the upper part of the sliding support leg 8. A first reinforcing rod 10 is provided between the discharge hopper 13 and the sliding support leg 8. One end of the first reinforcing rod 10 is welded to the outer wall of the discharge hopper 13, and the other end of the first reinforcing rod 10 is welded to the sliding support leg 8. The first reinforcing rod 10 strengthens the support of the discharge hopper 13.

[0052] This embodiment refers to Figure 3As shown, in this embodiment, the top of the mixing drum 7 has a sealing plate for sealing the mixing drum 7. Below the sealing plate is a proportioning column located in the mixing drum 7 for weighing the raw materials of the UHPC casting liquid. Below the proportioning column are two sets of stirring components for the raw materials of the UHPC casting liquid. The stirring components extend into the discharge hopper 13. The discharge hopper 13 is connected to the discharge pipe 15 and is equipped with a handwheel 12 to start the discharge pipe 15 to discharge the raw materials, so that the proportioning column delivers the quantitatively weighed raw materials of the UHPC casting liquid into the mixing drum 7 step by step, and the stirring components stir the raw materials of the UHPC casting liquid and discharge them through the discharge pipe 15.

[0053] This embodiment combines weighing and proportioning with automated mixing to deliver quantitatively weighed raw materials of UHPC casting liquid into the mixing drum 7 via a proportioning column. Two sets of mixing components are used to mix the raw materials of UHPC casting liquid and discharge them through the discharge pipe 15. The discharge process adopts a step-by-step feeding technology to solve the problems of large fluctuations in traditional concrete mix proportions and uneven distribution of steel fibers, avoid steel fiber clumping and strength dispersion, and ensure that the compressive strength of UHPC reaches a stable level of over 150MPa, thereby improving the uniformity of component quality from the source.

[0054] More specifically, in this embodiment, a proportioning column is installed below the sealing plate in the mixing drum 7 for weighing the various raw materials of the UHPC casting liquid. These raw materials include premix, water-reducing agent, crack-resistant and shrinkage-reducing agent, steel fiber, and water. The premix has a concentration of 2170 kg / m³. 3 The polycarboxylate superplasticizer is 30 kg / m³. 3 The water-reducing agent is model JGUHPC60-1, and the phosphate crack-resistant agent is 30 kg / m³. 3 The steel fiber content is 160 kg / m². 3 And water is 145 kg / m 3 The premixed material includes 52.5 grade Portland cement at 1200 kg / m³. 3 240kg / m³ of mineral powder 3 356 kg / m³ of fly ash 3 Silica fume 260kg / m 3 Quartz sand 114kg / m 3 .

[0055] This embodiment uses 52.5 grade silicate cement as high-strength silicate cement, 92 grade silica fume (activity ≥10%), and fine-particle materials such as graded quartz sand / powder. The quartz sand is 16-30 mesh, 8-16 mesh, and 30-100 mesh. The particle size distribution (0.16mm to 1.25mm gradient gradation) is optimized based on the densest packing theory to reduce porosity to its limit. Simultaneously, highly active powders (silica fume, spherical fly ash) are incorporated to trigger a secondary hydration reaction, generating low-calcium-silica ratio CSH gel, achieving microstructural densification. Combined with a high-efficiency water-reducing agent (water reduction rate >30%), the water-cement ratio is controlled to ≤0.20, significantly reducing capillary porosity.

[0056] The steel fibers used are ultrafine steel fibers with a nominal diameter of 0.20 mm and a nominal length of 20 mm. During the mixing stage, at least 2.0% and no more than 3.5% by volume of these ultrafine steel fibers (tensile strength ≥ 2000 MPa, aspect ratio 60–100) are incorporated, and the fibers are uniformly dispersed through high-speed forced mixing. During stress, the fibers inhibit microcrack propagation through a bridging effect, transforming the material failure mode from the brittle fracture of ordinary concrete to a pseudo-ductile behavior with multiple crack propagation. The tensile strength is increased to 7.2 MPa, significantly enhancing impact resistance and fatigue performance.

[0057] Meanwhile, in this embodiment, the UHPC high-performance concrete has a low water-cement ratio, and the factory uses covering and steam curing methods, which significantly reduces water usage compared to traditional reinforced concrete structures, achieving water conservation. UHPC precast beams enable low-carbon, green, environmentally friendly, sustainable, and high-quality development construction.

[0058] More specifically, in this embodiment, the proportioning column has a weighing chamber 17 for weighing the raw materials of the UHPC casting liquid. Several weighing sensors 22 are evenly distributed at the bottom of the proportioning column and facing the weighing chamber 17. The bottom of the proportioning column has a discharge port for discharging the raw materials of the UHPC casting liquid and facing the discharge hopper 13. A control valve 25 for opening and closing the discharge port is installed in the discharge port. Several feed ports 20 are opened along the circumference of the proportioning column. All feed ports 20 face the weighing chamber 17. Inclined feed channels 18 are evenly distributed along the circumference of the proportioning column. The position of each feed channel 18 corresponds one-to-one with the position of the weighing sensor 22. One end of the feed channel 18 is connected to the discharge port, and the other end of the feed channel 18 is connected to the feed port 19 opened on the side wall of the mixing drum 7.

[0059] In this embodiment, each raw material of the UHPC casting liquid is sequentially fed into the feeding channel 18 through the inlet 19. Due to the inclined feeding channel 18, the raw materials in the UHPC casting liquid are transported to the weighing chamber 17 of the proportioning column. After the raw materials of the UHPC casting liquid are collected in the weighing chamber 17, the weight of the raw materials in the weighing chamber 17 is obtained by each weighing sensor 22. When the pressure values ​​of each weighing sensor 22 are respectively transmitted to the microprocessor, after the pressure values ​​in all weighing sensors 22 are equal, the microprocessor issues a command to start the control valve 25, opens the outlet, and transports the quantitatively weighed raw material of the UHPC casting liquid in the weighing chamber 17 toward the discharge hopper 13. After each raw material of the UHPC casting liquid is put into the discharge hopper 13, the stirring assembly is started to stir.

[0060] The process of adding raw materials to the UHPC casting liquid is as follows: Each raw material is fed into the discharge hopper 13 via the proportioning column and dry-mixed for 3-5 minutes → approximately 70% water is added, followed by phosphate crack-resistant agent and mixing for 3 minutes → the remaining 30% water and polycarboxylate superplasticizer are added and mixed for approximately 10 minutes until fully fluidized → steel fibers are added and mixed for 5 minutes. The total mixing time is ≥20 minutes to ensure no fiber clumping. Weighing errors are controlled within ±0.5%, ensuring accurate mix proportions from the source. Compared to traditional concrete mixing, the slump spread of UHPC is stably controlled at 650-700 mm, achieving a balance between workability and strength.

[0061] Meanwhile, the mixing assembly includes a first mixing element and a second mixing element that operate in conjunction with each other. The first mixing element and the second mixing element are connected to a driving element. The driving element drives the first mixing element and the second mixing element to rotate synchronously for mixing. The first mixing element and the second mixing element are both located inside the mixing drum 7 and the discharge hopper 13.

[0062] In this embodiment, the first and second agitators operate in a linked manner to stir the raw materials of the UHPC casting liquid in the mixing drum 7 and the discharge hopper 13. At the same time, since the first and second agitators rotate synchronously, the energy output can be reduced. The drive unit drives the first and second agitators to stir the UHPC casting liquid in the mixing drum 7 and the discharge hopper 13 in a linked manner.

[0063] Meanwhile, this embodiment utilizes a PLC control system integrated into a microprocessor to precisely match the raw material ratio with the weighing sensor 22. This fully digital control replaces manual operation, significantly reducing batching errors. The mixing assembly, featuring a first and second mixing element, monitors mixing uniformity and weight deviation in real time, achieving both green construction (reducing on-site dust) and quality control objectives.

[0064] The first stirring component includes a long stirring rod 27 near the center line of the stirring drum 7. The axis of the long stirring rod 27 is parallel to the center line of the stirring drum 7. Two transverse stirring blades 29 are evenly distributed along the axis of the long stirring rod 27. The two transverse stirring blades 29 on the long stirring rod 27 located on both sides of the center line of the stirring drum 7 are arranged facing each other. The side of the long stirring rod 27 away from the transverse stirring blades 29 is provided with a first inclined stirring blade 30, which is located between the two transverse stirring blades 29. The bottom of the long stirring rod 27 extends into the discharge hopper 13, and a tail stirring blade 28 is welded to the bottom of the long stirring rod 27.

[0065] In this embodiment, the long stirring rod 27 is designed to stir the raw materials of the UHPC casting liquid in the mixing drum 7 and the discharge hopper 13. The two transverse stirring blades 29 on the long stirring rod 27 located on both sides of the center line of the mixing drum 7 are arranged facing each other, so that the transverse stirring blades 29 generate transverse shear force on the raw materials of the UHPC casting liquid, thereby stirring and mixing the raw materials located in the middle of the mixing drum 7. At the same time, the first inclined stirring blade 30, which is inclined away from the side of the transverse stirring blades 29, stirs the raw materials in the space between the mixing drum 7 and the discharge hopper 13.

[0066] Meanwhile, the first inclined stirring blade 30 is located between the two transverse stirring blades 29, and the bottom of the long stirring rod 27 extends toward the discharge hopper 13. The bottom of the long stirring rod 27 is welded with a tail stirring blade 28. The first inclined stirring blade 30, the two transverse stirring blades 29 and the tail stirring blade 28 can be used to stir the raw materials in the entire discharge hopper 13. The tail stirring blade 28 can perform fine stirring of the raw materials in the discharge hopper 13, so that the raw materials of the UHPC casting liquid are stirred evenly.

[0067] The second stirring component includes a short stirring rod located away from the center line of the stirring cylinder 7. The short stirring rod is located inside the stirring cylinder 7, and second inclined stirring blades 31 are welded to both sides of the short stirring rod.

[0068] The short stirring rods designed in this embodiment are located inside the stirring drum 7 and on both sides of the stirring drum 7 away from the center line of the stirring drum 7. They are used to uniformly stir both sides of the stirring drum 7. The second inclined stirring blades 31 are used to stir the raw materials of the UHPC casting liquid on the inner periphery of the stirring drum 7, so that the raw materials of the UHPC casting liquid are stirred more evenly.

[0069] The driving component includes a support plate 23 disposed inside the mixing drum 7. The support plate 23 has a driving chamber 24 for the linked operation of the first and second mixing components. The driving chamber 24 is respectively provided with a first spur gear 32 connected to the first mixing component and a second spur gear 33 connected to the second mixing component. The first spur gear 32 and the second spur gear 33 mesh with each other. The first spur gear 32 is sleeved on a long stirring rod 27 inside the first mixing component. The long stirring rod 27 passes through the support plate 23 and is connected to a bearing seat 34 disposed on the upper surface of the support plate 23. The second spur gear 33 is sleeved on a short stirring rod inside the second mixing component. The short stirring rod passes through the support plate 23 and is connected to the shaft of a servo motor 21 disposed on the upper surface of the support plate 23.

[0070] In this embodiment, the support plate 23 supports the servo motor 21 and the bearing seat 34. The bearing seat 34 can provide a stable rotational support force for the long stirring rod 27. The servo motor 21 is installed in the space between the support plate 23, the feed channel 18 and the proportioning column. At the same time, there are several vent holes on the side wall of the stirring drum 7 that communicate with this space, so that the heat generated by the servo motor 21 during operation can be dissipated through the vent holes.

[0071] When in use, the servo motor 21 is started, which drives the short stirring rod to rotate and synchronously drives the first spur gear 32 to rotate. Since the first spur gear 32 meshes with the second spur gear 33, the first spur gear 32 drives the second spur gear 33 to rotate, and the second spur gear 33 drives the long stirring rod 27 to rotate. Therefore, through the cooperation of the first spur gear 32 and the second spur gear 33, a stirring force is stably delivered to the long stirring rod 27 and the short stirring rod in the drive chamber 24 of the support plate 23, so that the long stirring rod 27 and the short stirring rod stir the raw materials of the UHPC stirring liquid in the stirring drum 7 and the discharge hopper 13.

[0072] Meanwhile, a feeding port 26 is provided at the position of the discharge port at the bottom of the proportioning column corresponding to the support plate 23. The feeding port 26 is funnel-shaped and faces the mixing drum 7 and the discharge hopper 13. After the control valve 25 opens the discharge hopper 13, the raw materials of UHPC casting liquid are conveyed to the feeding hopper.

[0073] The application of this embodiment in the road network construction project of the Daojiao Town Joint Investment Promotion Base area demonstrates significant maturity and reliability. Specific advantages and effects are as follows:

[0074] 1. Small cross-section: The height of UHPC beams can be reduced by 50% compared to the cross-section height of traditional prestressed concrete beams, and the thickness of the components can be reduced to 1 / 3 to 1 / 2 of that of ordinary concrete. This means that under the same span, UHPC beams require a smaller cross-section, which can increase the navigation or flood discharge height under the bridge.

[0075] 2. Lightweight: Under the same strength load-bearing conditions, the weight of UHPC can be reduced to 40% to 60% of that of traditional structures, effectively reducing transportation difficulties, supporting the rapid erection of large components, and improving the spanning capacity of bridges.

[0076] 3. High durability: UHPC has excellent corrosion resistance, freeze resistance and leak-proof performance, basically achieving maintenance-free operation within the structural design life cycle, which significantly improves the long-term performance and durability of bridges.

[0077] 4. High policy adaptability: The application of UHPC also conforms to the national policy of vigorously developing prefabricated buildings, helps the "supply-side structural reform" in the construction field, and is an important technical path to improve the quality of bridge structure construction in my country.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A precasting device applied to a UHPC prestressed simply supported beam, characterized in that: The application relates to a UHPC simple beam pouring device. The pouring device comprises a pouring preset path configured with a pouring chamber for pouring UHPC simple beam liquid, and the pouring chamber is provided with a prefabricated formwork for pouring the UHPC simple beam; and a prefabricated moving mechanism configured with a prefabricated pouring tank located in the pouring preset path, the prefabricated pouring tank is provided with a moving support for driving the prefabricated pouring tank to move along the pouring preset path, the bottom of the prefabricated pouring tank is provided with a discharging pipe extending into the pouring chamber, and the discharging pipe is used for pouring the UHPC simple beam formed by pouring and curing the UHPC simple beam raw materials proportioned and automatically stirred in the prefabricated pouring tank into the pouring chamber. The pouring chamber is provided with a vertical steel bar along the axial direction of the pouring chamber, the vertical steel bar is coincident with the axial direction of the pouring chamber, and the pouring chamber is provided with a plurality of uniformly spaced transverse steel bars along the axial direction of the pouring chamber, all the transverse steel bars are located above the vertical steel bar, and each transverse steel bar is welded in a horizontal direction perpendicular to the vertical steel bar and spaced 40 cm from the inner side of the vertical steel bar.

2. The precasting device for UHPC prestressed simply supported beams according to claim 1, characterized in that: The prefabricated formwork is provided with slide rails on two sides, the axial direction of the slide rails is parallel to the axial direction of the pouring chamber, the moving support comprises slide feet embedded into the slide rails, the bottom of the slide feet is provided with rollers moving along the axial direction of the slide rails, and the side of the slide rails away from the pouring chamber is provided with a protective guardrail.

3. The precasting device for UHPC prestressed simply supported beams according to claim 1, characterized in that: The prefabricated pouring tank comprises a stirring cylinder and a discharging hopper located below the stirring cylinder, the top of the stirring cylinder is provided with a closing plate for closing the stirring cylinder, a proportioning column for weighing each raw material of the UHPC pouring liquid is arranged below the closing plate and located in the stirring cylinder, the bottom of the proportioning column is provided with two groups of stirring assemblies for stirring each raw material of the UHPC pouring liquid, the stirring assemblies extend into the discharging hopper, the discharging hopper is communicated with the discharging pipe and is provided with a hand wheel for starting the discharging of the discharging pipe, and each raw material of the UHPC pouring liquid is proportioned and weighed in the proportioning column and then is fed into the stirring cylinder in steps, so that the stirring assemblies can stir each raw material of the UHPC pouring liquid and the discharging pipe can discharge the UHPC pouring liquid.

4. The precasting device for UHPC prestressed simply supported beams according to claim 3, characterized in that: The proportioning column is provided with a weighing chamber for weighing each raw material of the UHPC pouring liquid, the bottom of the proportioning column is uniformly provided with a plurality of weighing sensors towards the weighing chamber, the bottom of the proportioning column is provided with a discharging port for discharging each raw material of the UHPC pouring liquid and towards the discharging hopper, the discharging port is provided with a control valve for opening and closing the discharging port, the proportioning column is provided with a plurality of feeding ports along the circumferential direction of the proportioning column, all the feeding ports are collectively towards the weighing chamber, the proportioning column is uniformly provided with inclined feeding channels along the circumferential direction of the proportioning column, the positions of the feeding channels correspond to the positions of the weighing sensors one by one, one end of the feeding channel is communicated with the discharging port, and the other end of the feeding channel is communicated with a feeding port arranged on the side wall of the stirring cylinder.

5. The precasting device for UHPC prestressed simply supported beams according to claim 4, characterized in that: The closed plate is installed below the stirring cylinder and is used for weighing the proportioning column of each raw material of UHPC pouring liquid, including premix, water reducer, anti-cracking shrinkage agent, steel fiber and water. 3 , the polycarboxylic acid water reducer is 30kg / m 3 , the phosphate anti-cracking agent is 30kg / m 3 , the steel fiber is 160kg / m 3 , and the water is 145kg / m 3 ; the premix includes 52.5 grade Portland cement 1200kg / m 3 , mineral powder 240kg / m 3 , fly ash 356kg / m 3 , silica ash 260kg / m 3 , quartz sand 114kg / m 3 .

6. The precasting device for UHPC prestressed simply supported beams according to claim 5, characterized in that: ​ 7. The precasting device for UHPC prestressed simply supported beams according to claim 4, characterized in that: The stirring assembly comprises a first stirring part and a second stirring part which are operated in linkage, and a driving part which is in common communication with the first and second stirring parts and drives the first and second stirring parts to rotate synchronously.

8. The precasting device for UHPC prestressed simply supported beams according to claim 7, characterized in that: The first stirring part comprises a long stirring rod which is close to the center line of the stirring cylinder, and the axis of the long stirring rod is parallel to the center line of the stirring cylinder, and two transverse stirring blades are uniformly distributed along the axis of the long stirring rod, and the two transverse stirring blades on the long stirring rod on both sides of the center line of the stirring cylinder are oppositely arranged, and the side of the long stirring rod away from the transverse stirring blades is provided with a first inclined stirring blade which is arranged in an inclined manner, and the first inclined stirring blade is located between the two transverse stirring blades, and the bottom of the long stirring rod extends towards the discharge hopper, and the bottom of the long stirring rod is welded with a tail stirring blade.

9. The precasting device for UHPC prestressed simply supported beams according to claim 7, characterized in that: The second stirring part comprises a short stirring rod which is away from the center line of the stirring cylinder, and the short stirring rod is located in the stirring cylinder, and two second inclined stirring blades which are arranged in an inclined manner are welded on both sides of the short stirring rod.

10. The precasting device for UHPC prestressed simply supported beams according to claim 7, characterized in that: The driving part comprises a support plate which is arranged in the stirring cylinder, and the support plate has a driving chamber in which the first and second stirring parts are operated in linkage, and the driving chamber is provided with a first spur gear which is connected with the first stirring part and a second spur gear which is connected with the second stirring part, and the first spur gear is engaged with the second spur gear, and the first spur gear is sleeved on the long stirring rod in the first stirring part, and the long stirring rod is connected with a bearing seat which is arranged on the upper surface of the support plate, and the second spur gear is sleeved on the short stirring rod in the second stirring part, and the short stirring rod is connected with a servo motor shaft which is arranged on the upper surface of the support plate.

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