A steam curing construction device for precast box girders and its construction technology

Abstract

The present invention discloses a steam curing construction device for precast box girders and its construction process, belonging to the technical field of precast box girders. A steam curing construction device for precast box girders includes a steam curing box with an intelligent temperature and humidity control system arranged inside, and further includes: a main steam pipeline, the main steam pipeline is arranged at the bottom of the steam curing box, the main steam pipeline is connected with a plurality of sub-steam pipelines placed inside the steam curing box, and a plurality of equally spaced steam nozzles are arranged on each sub-steam pipeline; a main spray pipeline, the main spray pipeline is arranged at the bottom of the steam curing box, and the main spray pipeline is connected with a plurality of sub-spray pipelines placed inside the steam curing box; The present invention solves the problem that the strength and elastic modulus of the box girder in outdoor natural curing take a long time to increase. After demoulding, the tensioning condition can be quickly achieved, greatly improving the construction efficiency. Moreover, the stable curing environment of this application ensures the uniformity during the hydration reaction of concrete, effectively improving the appearance quality of the box girder.

Description

Technical Field

[0001] The present invention relates to the technical field of precast box girders, and particularly to a steam curing construction device for precast box girders and its construction technology. Background Art

[0002] With the continuous growth of the operating mileage of expressways in China, the construction of expressway bridges is gradually developing towards the direction of assembly, standardization, and industrialization. The construction of bridges mostly adopts the method of centralized prefabrication of standard beams and beam erection by a bridge erection machine, which improves the construction quality of bridges, shortens the construction time, and is energy-saving and efficient.

[0003] Before concrete is shaped, since it is sensitive to changes in temperature and humidity, it is necessary to cure the concrete before shaping to avoid too rapid loss of surface moisture of the concrete, resulting in cracks on the concrete surface, thereby affecting the strength and durability of the box girder. Traditional precast beam yards are restricted by the natural environment and the tensioning age of box girders. The curing time is long. At least 7 days of curing are required after demoulding before prestress can be applied and the beam can be moved. The curing of box girders is greatly affected by the surrounding weather, and the appearance quality is uneven. Moreover, a large number of precast pedestals are required, which further increases the floor area of the precast beam yard. Summary of the Invention

[0004] The purpose of the present invention is to solve the problems existing in the prior art, and to propose a steam curing construction device for precast box girders and its construction technology.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A steam curing construction device for precast box girders includes a steam curing box internally provided with an intelligent temperature and humidity control system, and further includes:

[0007] A main steam pipeline, the main steam pipeline is arranged at the bottom of the steam curing box, the main steam pipeline is connected to a plurality of sub-steam pipelines arranged in the steam curing box, and a plurality of steam nozzles are equidistantly distributed on each sub-steam pipeline;

[0008] A main spray pipeline, the main spray pipeline is arranged at the bottom of the steam curing box, the main spray pipeline is connected to a plurality of sub-spray pipelines arranged in the steam curing box, and a plurality of spray nozzles are equidistantly distributed on each sub-spray pipeline; and a steam boiler, the steam boiler is fixedly arranged outside the steam curing box, the gas outlet end of the steam boiler is connected to the main steam pipeline, the water inlet end of the steam boiler is connected to a water inlet pipe, and the water inlet pipe is connected to the main spray pipeline.

[0009] Preferably, the structures of the sub-steam pipelines and the sub-spray pipelines are the same. Each sub-steam pipeline and sub-spray pipeline includes three sections of conduits, and adjacent two sections of the conduits are vertically arranged, and a connecting pipe is arranged between adjacent two sections of the conduits.

[0010] Preferably, a mounting plate is fixedly provided on the connecting pipe, a driving motor is fixedly provided on the mounting plate, an output shaft of the driving motor is connected to a driving shaft, a driving gear is arranged on the driving shaft, and a driven gear meshing with the driving gear is fixedly provided on the conduit.

[0011] Preferably, the conduit includes a sleeve rotatably connected to the connecting pipe and a pipe body slidably connected to the sleeve. The connecting pipe is sleeved outside the pipe body. A first slider is fixedly provided at one end of the sleeve, an arc-shaped groove for the first slider to slide is formed on the connecting pipe, a first elastic element is arranged between the arc-shaped groove and the first slider, and the driving gear is arranged as an incomplete gear.

[0012] Preferably, a rotating rod is rotatably connected to the mounting plate, a driven bevel gear is arranged on the rotating rod, a driving bevel gear meshing with the driven bevel gear is arranged on the driving shaft, a rotating rod is arranged at one end of the rotating rod away from the mounting plate, a movable ring is movably connected to the rotating rod, a connecting rod is arranged on the movable ring, and a collar is movably connected to one end of the connecting rod away from the movable ring. The collar is rotatably arranged with the pipe body.

[0013] Preferably, a second slider is fixedly provided at the top of the pipe body, a sliding groove for the second slider to slide is formed on the inner wall of the sleeve, and a second elastic element is arranged between the sliding groove and the second slider.

[0014] Preferably, an elastic telescopic rod is fixedly provided on the inner wall of the steam curing box, a fixing rod is fixedly provided on the elastic telescopic rod, the fixing rod is rotatably connected to one end of the pipe body, the fixing rod is connected with an arc-shaped plate fitting with the inner wall of the pipe body through a connecting rod, and a concave hole matching with the steam nozzle is formed on the arc-shaped plate.

[0015] Preferably, the intelligent temperature and humidity control system includes a PLC controller, a fixed touch screen, an electric actuator, a temperature sensor, a humidity sensor, and valves arranged on the main steam pipeline and the main spray pipeline. Three temperature sensors and three humidity sensors are respectively arranged at the front end, the terminal end, and the rear end inside the steam curing box in sequence.

[0016] Preferably, the steam curing box includes a galvanized square pipe frame and a heat preservation rock wool board coated outside the galvanized square pipe frame.

[0017] The present invention also discloses a construction process of a steam curing construction device for precast box girders, including the following steps:

[0018] S1: After the box girder is cast and the formwork is removed, it is placed on a mobile pedestal. The mobile pedestal walks on the rail track to send the box girder into the steam curing box, and the same-condition strength test block and elastic modulus test block are cured together with the beam body.

[0019] S2: One - key start the steam curing program, generate high - temperature steam through a steam boiler, and use the main steam pipeline and branch steam pipelines to transport the steam to the steam curing box, and use the main spray pipeline and branch spray pipelines to transport the purified water to the steam curing box;

[0020] S3: The generated steam enters the steam curing box through the steam nozzles, and the purified water enters the steam curing box through the spray nozzles. Control the driving motor to operate, so that the branch steam pipelines and branch spray pipelines rotate and traverse horizontally during the movement, increasing the spraying range of the steam nozzles and spray nozzles;

[0021] S4: After the curing starts, the curing information is transmitted to the intelligent temperature - humidity control system in real - time through the temperature sensors and humidity sensors set inside the steam curing box. The intelligent temperature - humidity control system automatically adjusts the release amount of steam and purified water according to the temperature curve preset by the PLC controller, and then automatically adjusts the temperature and humidity inside the steam curing box. The steam curing is divided into three stages: heating - constant temperature - cooling. The heating and cooling do not exceed 10 degrees per hour, the constant - temperature is controlled at 55℃±5, and the humidity inside the steam curing box is maintained at 99%.

[0022] Compared with the prior art, the present invention provides a steam curing construction device for precast box girders and its construction technology, which has the following beneficial effects:

[0023] 1. For the steam curing construction device for precast box girders and its construction technology, by placing the box girder after form removal in the steam curing box and cooperating with the intelligent temperature - humidity control system to regulate the temperature and humidity inside the steam curing box, it solves the problems of long strength and elastic modulus improvement time in outdoor natural curing of box girders. After form removal, the tensioning condition can be quickly achieved, greatly improving the construction efficiency. Moreover, the stable curing environment of this application ensures the uniformity during the concrete hydration reaction process, can effectively prevent early cracking of concrete, ensure the later strength and durability of concrete, and effectively improve the appearance quality of box girders.

[0024] 2. For the steam curing construction device for precast box girders and its construction technology, since both the branch steam pipelines and branch spray pipelines are composed of three sections of conduits, and a connecting pipe is arranged between adjacent two conduits. Control the driving motor to operate, so that the driving motor drives the conduits to rotate and traverse relative to the connecting pipe, with a wider curing area and uniform curing of the surface of the precast box girder, ensuring the curing quality of the box girder. Brief Description of the Drawings

[0025] Figure 1 It is a structural schematic diagram of the present invention;

[0026] Figure 2 It is a structural schematic diagram of the longitudinal section of the steam curing box of the present invention;

[0027] Figure 3 It is a structural schematic diagram of the cross - section of the steam curing box of the present invention;

[0028] Figure 4 Schematic structural diagram of the catheter of the present invention;

[0029] Figure 5 Schematic sectional structural diagram of the catheter of the present invention;

[0030] Figure 6 Of the present invention Figure 5 Schematic diagram of the partial enlarged structure of part A in;

[0031] Figure 7 Schematic sectional structural diagram of the pipe body of the present invention;

[0032] Figure 8 Working block diagram of the intelligent temperature and humidity control system of the present invention.

[0033] In the figure: 1, steam curing box; 101, galvanized square pipe frame; 102, thermal insulation rock wool board; 2, main steam pipeline; 201, steam nozzle; 3, main spray pipeline; 301, spray nozzle; 4, steam boiler; 401, water inlet pipe; 5, catheter; 501, sleeve; 5011, first slider; 502, pipe body; 5021, arc groove; 5022, first elastic element; 6, connecting pipe; 7, mounting plate; 701, driving motor; 702, driving shaft; 7021, driving bevel gear; 703, driving gear; 704, driven gear; 8, rotating rod; 801, driven bevel gear; 802, rotating rod; 803, movable ring; 804, connecting rod; 805, collar; 9, second slider; 901, chute; 902, second elastic element; 10, elastic telescopic rod; 11, fixed rod; 111, arc plate; 112, concave hole; 12, temperature sensor; 13, humidity sensor. Specific embodiments

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention; obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0035] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "top / bottom end", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0036] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, terms such as "installation", "provided with", "sheathed / connected", "connection", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components; for those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0037] Example: Refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 8 , a steam curing construction device for precast box girders, including a curing box 1 with an intelligent temperature and humidity control system installed inside, and further including:

[0038] The main steam pipeline 2 is arranged at the bottom of the curing box 1. The main steam pipeline 2 is connected with a plurality of sub-steam pipelines placed inside the curing box 1, and a plurality of steam nozzles 201 are arranged at equal intervals on each sub-steam pipeline;

[0039] The main spray pipeline 3 is arranged at the bottom of the curing box 1. The main spray pipeline 3 is connected with a plurality of sub-spray pipelines placed inside the curing box 1, and a plurality of spray nozzles 301 are arranged at equal intervals on each sub-spray pipeline; and

[0040] The steam boiler 4 is fixedly arranged outside the curing box 1. The air outlet end of the steam boiler 4 is connected with the main steam pipeline 2, and the water inlet end of the steam boiler 4 is connected with a water inlet pipe 401, and the water inlet pipe 401 is connected with the main spray pipeline 3.

[0041] Furthermore, the intelligent temperature and humidity control system includes a PLC controller, a fixed touch screen, an electric actuator, temperature sensors 12, humidity sensors 13, and valves arranged on the main steam pipeline 2 and the main spray pipeline 3. There are three temperature sensors 12 and humidity sensors 13 respectively, and the three temperature sensors 12 and humidity sensors 13 are sequentially arranged at the front end, the terminal end, and the rear end inside the curing box 1.

[0042] Specifically, after the box girder is cast and the formwork is removed, it is placed on a movable pedestal. The movable pedestal travels on the rail track to send the box girder into the steam curing box 1. The same-condition strength test blocks and elastic modulus test blocks are cured together with the beam body. The steam curing program is started with one key. The steam boiler 4 burns biomass fuels such as straw, sawdust, bagasse, rice bran, etc. as raw materials to make clean fuels. The high-temperature steam generated by the steam boiler 4 uses the main steam pipeline 2 and the branch steam pipeline to transport the steam to the steam curing box 1, and uses the main spray pipeline 3 and the branch spray pipeline to transport the purified water to the steam curing box 1. After the curing starts, the curing information is transmitted to the intelligent temperature and humidity control system in real time through the temperature sensor 12 and the humidity sensor 13 arranged inside the steam curing box 1. The intelligent temperature and humidity control system automatically adjusts the release amount of steam and purified water according to the temperature curve preset by the PLC controller, and then automatically adjusts the temperature and humidity inside the steam curing box 1. The steam curing is divided into three stages: heating - constant temperature - cooling. The heating and cooling do not exceed 10 degrees per hour, the constant temperature is controlled at 55°C ± 5, and the humidity inside the steam curing box is maintained at 99%; combined with the local temperature and the performance of the concrete itself, and verified by experiments, by heating for 3 hours, keeping the constant temperature for 12 hours, and cooling for 3 hours, it can ensure that the concrete reaches more than 90% of the design strength, and the elastic modulus reaches more than 100% of the 28-day elastic modulus of C50 concrete, meeting the tensioning conditions, and the appearance quality of the box girder is good, with a "mirror" effect. This application solves the problem that the strength and elastic modulus of the box girder in outdoor natural curing take a long time to increase. After the formwork is removed, the tensioning conditions can be quickly reached, greatly improving the construction efficiency. Moreover, the stable curing environment of this application ensures the uniformity during the hydration reaction process of the concrete and effectively improves the appearance quality of the box girder.

[0043] The following figure shows the statistics of the strength and elastic modulus data of the test blocks before and after the steam curing of the box girder:

[0044]

[0045] According to the analysis of the test data results, when the steam curing reaches 15 hours at a constant temperature of 55°C, the average compressive strength of the concrete is 43.6 MPa, reaching 87.2% of the design strength, and the elastic modulus is 3.64 GPa, reaching 105.5% of the 28-day design value; when the steam curing reaches 15 hours at a constant temperature of 50°C, the average compressive strength of the concrete is 53.4 MPa, reaching 106.8% of the design strength, and the elastic modulus is 4.18 GPa, reaching 122.2% of the 28-day design value. When the steam curing reaches 15 hours under both constant temperature conditions, it has met the double-control requirement of "the compressive strength and elastic modulus of the concrete test blocks reach 85% of the design value before tensioning can be carried out".

[0046] Therefore, after the box girder goes through three stages of heating - constant temperature - cooling: the heating and cooling rates during steam curing are controlled at 10°C / h, the constant temperature is 50°C, the humidity is ≥95%, and the constant temperature time is 12h. The concrete strength of the box girder reaches more than 100% of the design strength, and the elastic modulus reaches more than 100% of the 28-day elastic modulus of C50 concrete, meeting the tensioning conditions. It can reach the tensioning conditions as soon as 18 hours after form removal, greatly improving the construction efficiency.

[0047] Refer to Figure 4 、 Figure 5 、 Figure 6 and Figure 7 As a preferred technical solution of the present invention, the structures of the sub-steam pipeline and the sub-spray pipeline are the same. Each sub-steam pipeline and sub-spray pipeline includes three sections of conduits 5. Adjacent two sections of conduits 5 are vertically arranged, and a connecting pipe 6 is provided between adjacent two sections of conduits 5.

[0048] Furthermore, a mounting plate 7 is fixedly provided on the connecting pipe 6. A driving motor 701 is fixedly provided on the mounting plate 7. The output shaft of the driving motor 701 is connected to a driving shaft 702. A driving gear 703 is provided on the driving shaft 702. A driven gear 704 meshing with the driving gear 703 is fixedly provided on the conduit 5.

[0049] Furthermore, the conduit 5 includes a sleeve 501 rotatably connected to the connecting pipe 6 and a pipe body 502 slidably connected to the sleeve 501. The connecting pipe 6 is sleeved outside the pipe body 502. One end of the sleeve 501 is fixedly provided with a first slider 5011. An arc-shaped groove 5021 for the first slider 5011 to slide is opened on the connecting pipe 6. A first elastic element 5022 is provided between the arc-shaped groove 5021 and the first slider 5011. The driving gear 703 is set as an incomplete gear.

[0050] Furthermore, a rotating rod 8 is rotatably connected to the mounting plate 7. A driven bevel gear 801 is provided on the rotating rod 8. A driving bevel gear 7021 meshing with the driven bevel gear 801 is provided on the driving shaft 702. A rotating rod 802 is provided at the end of the rotating rod 8 away from the mounting plate 7. A movable ring 803 is movably connected to the rotating rod 802. A connecting rod 804 is provided on the movable ring 803. One end of the connecting rod 804 away from the movable ring 803 is movably connected to a collar 805. The collar 805 is rotatably arranged with the pipe body 502.

[0051] Furthermore, a second slider 9 is fixedly provided on the top of the pipe body 502. A sliding groove 901 for the second slider 9 to slide is opened on the inner wall of the sleeve 501. A second elastic element 902 is provided between the sliding groove 901 and the second slider 9.

[0052] Specifically, the steam generated during curing enters the steam curing chamber 1 through the steam nozzle 201, and the purified water enters the steam curing chamber 1 through the spray nozzle 301. Control the driving motor 701 to operate. When the driving motor 701 works, it drives the driving shaft 702 to rotate. The driving shaft 702 drives the driving gear 703 and the driving bevel gear 7021 to rotate. The driving gear 703 is an incomplete gear. When the driving gear 703 rotates, it intermittently meshes with the driven gear 704. When the driving gear 703 meshes with the driven gear 704, the driven gear 704 drives the sleeve 501 to rotate. The sleeve 501 rotates relative to the connecting pipe 6. The first slider 5011 slides in the arc-shaped groove 5021, and the first elastic element 5022 is compressed. When the driving gear 703 does not mesh with the driven gear 704, the first elastic element 5022 recovers and drives the sleeve 501 to reset and rotate through the first slider 5011, so that the pipe body 502 rotates around its central axis, causing the steam nozzle 201 and the spray nozzle 301 to reciprocate up and down, changing the spraying range of steam and purified water;

[0053] When the driving bevel gear 7021 meshes with the driven bevel gear 801 on the rotating rod 8, the driven bevel gear 801 drives the rotating rod 8 and the rotating rod 802 at the bottom of the rotating rod 8 to rotate. The rotating rod 802 drives the collar 805 to move horizontally through the movable ring 803 and the connecting rod 804. The collar 805 drives the pipe body 502 to move back and forth relative to the sleeve 501, thereby causing the steam nozzle 201 and the spray nozzle 301 to reciprocate horizontally, avoiding curing dead spots, making the curing area of the box girder wider, evenly curing the surface of the precast box girder, and ensuring the curing quality of the box girder.

[0054] Refer to Figure 5 and Figure 7 As a preferred technical solution of the present invention, an elastic telescopic rod 10 is fixedly provided on the inner wall of the steam curing chamber 1. A fixing rod 11 is fixedly provided on the elastic telescopic rod 10. The fixing rod 11 is rotatably connected to one end of the pipe body 502. The fixing rod 11 is connected by a connecting rod to an arc-shaped plate 111 that fits the inner wall of the pipe body 502. A concave hole 112 matching the steam nozzle 201 is provided on the arc-shaped plate 111.

[0055] Specifically, when the pipe body 502 moves horizontally, it drives the fixing rod 11 to move synchronously, and the elastic telescopic rod 10 connected to the fixing rod 11 automatically expands and contracts. When the pipe body 502 rotates relative to the connecting pipe 6, the pipe body 502 rotates relative to the fixing rod 11, and the steam nozzle 201 or the spray nozzle 301 on the pipe body 502 deviates from the concave hole 112 of the arc-shaped plate 111, and the steam nozzle 201 or the spray nozzle 301 is partially blocked, making the jet diameter of the steam nozzle 201 or the water spray diameter of the spray nozzle 301 smaller. When the pipe body 502 deflects to expand the spraying range, the spraying distance of steam or water can be automatically adjusted without changing the output frequency of the pump body for transporting steam and purified water, ensuring the spraying and curing effect on the box girder.

[0056] Reference Figure 2

[0057] As a preferred technical solution of the present invention, the steam curing box 1 includes a galvanized square tube frame 101 and a heat-insulating rock wool board 102 wrapped outside the galvanized square tube frame 101. Specifically, the present invention uses the heat-insulating rock wool board 102 and the galvanized square tube frame 101 to set up a sealed steam curing box 1, providing a stable curing environment for the box girder curing, ensuring the uniformity during the concrete hydration reaction process, solving the problems of long strength and elastic modulus improvement time in the outdoor natural curing of the box girder, and greatly improving the construction efficiency.

[0058] The present invention also discloses a construction process of a construction device for steam curing of precast box girders, including the following steps:

[0059] S1: After the box girder is poured and the formwork is removed, it is placed on the mobile pedestal, and the box girder is sent into the steam curing box 1 by walking on the rail track through the mobile pedestal. The same-condition strength test block and elastic modulus test block are cured together with the beam body.

[0060] S2: Start the steam curing program with one key. High-temperature steam is generated by the steam boiler 4 and the steam is transported to the steam curing box 1 through the main steam pipeline 2 and the branch steam pipeline. The purified water is transported to the steam curing box 1 through the main spray pipeline 3 and the branch spray pipeline.

[0061] S3: The generated steam enters the steam curing box 1 through the steam nozzle 201, and the purified water enters the steam curing box 1 through the spray nozzle 301. Control the operation of the driving motor 701 to make the branch steam pipeline and the branch spray pipeline rotate and traverse horizontally, increasing the spraying range of the steam nozzle 201 and the spray nozzle 301.

[0062] S4: After the curing starts, the curing information is transmitted to the intelligent temperature and humidity control system in real time through the temperature sensor 12 and the humidity sensor 13 arranged inside the steam curing box 1. The intelligent temperature and humidity control system automatically adjusts the release amount of steam and purified water according to the temperature curve preset by the PLC controller, and then automatically adjusts the temperature and humidity inside the steam curing box 1. The steam curing is divided into three stages: heating - constant temperature - cooling. The heating and cooling do not exceed 10 degrees per hour, the constant temperature is controlled at 55°C ± 5, and the humidity inside the steam curing box is kept at 99%.

[0063] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent substitutions or changes, and all should be covered within the protection scope of the present invention.

Claims

1. A steam curing construction device for precast box girders, comprising a steam curing box (1) internally provided with an intelligent temperature and humidity control system, characterized in that, Further comprising: A main steam pipeline (2), the main steam pipeline (2) is arranged at the bottom of the steam curing box (1), the main steam pipeline (2) is connected with a plurality of sub-steam pipelines placed in the steam curing box (1), and a plurality of steam nozzles (201) are arranged at equal intervals on each sub-steam pipeline; A main spray pipeline (3), the main spray pipeline (3) is arranged at the bottom of the steam curing box (1), the main spray pipeline (3) is connected with a plurality of sub-spray pipelines placed in the steam curing box (1), and a plurality of spray nozzles (301) are arranged at equal intervals on each sub-spray pipeline; and a steam boiler (4), the steam boiler (4) is fixedly arranged outside the steam curing box (1), the air outlet end of the steam boiler (4) is connected with the main steam pipeline (2), the water inlet end of the steam boiler (4) is connected with a water inlet pipe (401), and the water inlet pipe (401) is connected with the main spray pipeline (3); The structures of the sub-steam pipeline and the sub-spray pipeline are the same, and each sub-steam pipeline and sub-spray pipeline includes three sections of conduits (5), two adjacent sections of the conduits (5) are vertically arranged, and a connecting pipe (6) is arranged between two adjacent sections of the conduits (5); An installation plate (7) is fixedly arranged on the connecting pipe (6), a driving motor (701) is fixedly arranged on the installation plate (7), an output shaft of the driving motor (701) is connected with a driving shaft (702), a driving gear (703) is arranged on the driving shaft (702), and a driven gear (704) meshing with the driving gear (703) is fixedly arranged on the conduit (5); The conduit (5) includes a sleeve (501) rotatably connected with the connecting pipe (6) and a pipe body (502) slidably connected with the sleeve (501), the connecting pipe (6) is sleeved outside the pipe body (502), a first slider (5011) is fixedly arranged at one end of the sleeve (501), an arc-shaped groove (5021) for the first slider (5011) to slide is formed in the connecting pipe (6), a first elastic element (5022) is arranged between the arc-shaped groove (5021) and the first slider (5011), and the driving gear (703) is arranged as an incomplete gear; A rotating rod (8) is rotatably connected to the installation plate (7), a driven bevel gear (801) is arranged on the rotating rod (8), a driving bevel gear (7021) meshing with the driven bevel gear (801) is arranged on the driving shaft (702), a rotating rod (802) is arranged at the end of the rotating rod (8) away from the installation plate (7), a movable ring (803) is movably connected to the rotating rod (802), a connecting rod (804) is arranged on the movable ring (803), and a sleeve ring (805) is movably connected to the end of the connecting rod (804) away from the movable ring (803), and the sleeve ring (805) is rotatably arranged with the pipe body (502).

2. The precast box girder steam curing construction device according to claim 1, characterized in that, A second slider (9) is fixedly installed at the top of the pipe body (502). A chute (901) for the second slider (9) to slide is provided on the inner wall of the sleeve (501). A second elastic element (902) is arranged between the chute (901) and the second slider (9).

3. The precast box girder steam curing construction device according to claim 2, wherein, An elastic telescopic rod (10) is fixedly installed on the inner wall of the steam curing box (1). A fixed rod (11) is fixedly installed on the elastic telescopic rod (10). One end of the fixed rod (11) is rotatably connected to the pipe body (502). The fixed rod (11) is connected by a connecting rod to an arc-shaped plate (111) that fits against the inner wall of the pipe body (502). A concave hole (112) that cooperates with the steam nozzle (201) is provided on the arc-shaped plate (111).

4. The precast box girder steam curing construction device according to claim 3, characterized in that, The intelligent temperature and humidity control system includes a PLC controller, a fixed touch screen, an electric actuator, temperature sensors (12), humidity sensors (13), and valves arranged on the main steam pipeline (2) and the main spray pipeline (3). There are three temperature sensors (12) and three humidity sensors (13). The three temperature sensors (12) and humidity sensors (13) are sequentially arranged at the front end, the terminal end, and the rear end inside the steam curing box (1).

5. A precast box girder steam curing construction device according to claim 4, characterized in that, The steam curing box (1) includes a galvanized square pipe frame (101) and a heat-insulating rock wool board (102) covering the outside of the galvanized square pipe frame (101).

6. The construction process of the precast box girder steam curing construction device described in claim 5, characterized in that, It includes the following steps: S1: After the box girder is cast and the formwork is removed, it is placed on a mobile pedestal. The mobile pedestal walks on the rail track to send the box girder into the steam curing box (1). The same-condition strength test block and the elastic modulus test block are cured together with the beam body. S2: One-key start the steam curing program. High-temperature steam is generated by the steam boiler (4) and is transported to the steam curing box (1) through the main steam pipeline (2) and the branch steam pipeline. The purified water is transported to the steam curing box (1) through the main spray pipeline (3) and the branch spray pipeline. S3: The generated steam enters the steam curing box (1) through the steam nozzle (201). The purified water enters the steam curing box (1) through the spray nozzle (301). Control the operation of the drive motor (701) to make the branch steam pipeline and the branch spray pipeline rotate and traverse horizontally, increasing the spraying range of the steam nozzle (201) and the spray nozzle (301). S4: After the curing starts, the curing information is transmitted to the intelligent temperature and humidity control system in real time through the temperature sensors (12) and humidity sensors (13) arranged inside the steam curing box (1). The intelligent temperature and humidity control system automatically adjusts the release amount of steam and purified water according to the temperature curve preset by the PLC controller, and then automatically adjusts the temperature and humidity inside the steam curing box (1). The steam curing is divided into three stages: heating - constant temperature - cooling. The heating and cooling do not exceed 10 degrees per hour. The constant temperature is controlled at 55°C ± 5, and the humidity inside the steam curing box is maintained at 99%.

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