Construction method of large-span special-shaped hyperboloid fair-faced concrete

Abstract

This invention provides a construction method for large-span irregular hyperboloid fair-faced concrete, belonging to the field of concrete construction technology. The method includes the following steps: construction preparation; modeling the large-span irregular hyperboloid structure and exporting two-dimensional drawings; on-site positioning and layout; assembling and adjusting the inner and outer formwork on-site; installing exposed joint strips at the construction joint location on the inner side of the outer formwork; binding and fixing the inner and outer formwork with reinforcing bars and ties; continuously pouring fair-faced concrete between the inner and outer formwork; sequentially removing the reinforcing bars and ties, the outer formwork, the exposed joint strips, and the inner formwork; and curing and surface treating the formed fair-faced concrete. This invention solves the problem of uneven demolding force due to improper operation during formwork removal, which can easily lead to edge cracking at exposed joints, and avoids increasing construction difficulty and affecting construction efficiency by filling the edge gaps.

Description

Technical Field

[0001] This invention belongs to the field of concrete construction technology, and specifically relates to a construction method for large-span irregular hyperboloid surface fair-faced concrete. Background Technology

[0002] Chinese invention patent (application number: CN201710483032.5) with publication number CN107100363B discloses a formwork template for exposed concrete joints in an elevator test tower and a method for constructing exposed joints. The template includes a template body, with an upper exposed joint strip fixedly connected to the upper part and a lower exposed joint strip fixedly connected to the lower part. The spacing between the upper and lower exposed joint strips is the same as the spacing of the exposed joint to be constructed. The cross-sectional shape and size of the lower exposed joint strip match the exposed joint to be constructed, and the cross-section of the upper exposed joint strip is larger than that of the lower exposed joint strip. During construction, a hydraulic climbing formwork system is used to move the template to the next construction position. The lower exposed joint strip is then aligned and embedded in the upper exposed joint position. During pouring, the concrete naturally flows down to fill the gap between the lower and upper exposed joint strips, thus ensuring the quality of the exposed joint construction.

[0003] Exposed joints in fair-faced concrete refer to the filling of pre-existing gaps (also known as visible joints) with sealant during the construction of the concrete surface layer. This enhances the aesthetics and waterproofing performance of the concrete surface. This design of pre-existing visible joints is used in the exterior wall cladding and floor decoration of many buildings. It offers advantages in terms of appearance, water tightness, crack prevention, and maintenance, thereby improving the appearance quality and aesthetics of fair-faced concrete.

[0004] Because the tensile strength of the concrete surface around the exposed joint is low, the exposed joint construction method in the above invention is prone to uneven demolding force due to improper operation when removing the formwork, which can cause edge cracking at the exposed joint. It is also necessary to fill the gap at the edge of the exposed joint, which increases the construction difficulty and affects the construction efficiency. Summary of the Invention

[0005] In view of this, the present invention proposes a construction method for large-span irregular hyperboloid surface fair-faced concrete, which can solve the problem that uneven demolding force caused by improper operation during formwork removal can easily lead to edge cracking at the exposed joints, and avoids increasing the construction difficulty and affecting construction efficiency by filling the gaps at the edges.

[0006] This invention is implemented as follows:

[0007] This invention provides a construction method for large-span irregular hyperboloid surface fair-faced concrete, comprising the following steps:

[0008] S10: Construction preparation, prepare the necessary materials and tools for use;

[0009] S20: Model a large-span irregular hyperboloid structure and export two-dimensional drawings;

[0010] S30: Perform on-site positioning and layout based on the aforementioned two-dimensional drawings;

[0011] S40: Assemble and adjust the inner and outer formwork on site;

[0012] S50: Install exposed joint strips at the location of the construction joint on the inner side of the outer formwork;

[0013] S60: Use steel bars and binding wire to tie and fix the inner formwork and the outer formwork;

[0014] S70: Continuously pour fair-faced concrete between the inner formwork and the outer formwork;

[0015] S80: Sequentially remove the reinforcing bars and binding wires, the outer formwork, the exposed joint strips, and the inner formwork to cure and surface-treat the formed fair-faced concrete.

[0016] The technical effects of the construction method for large-span irregular hyperboloid fair-faced concrete provided by this invention are as follows: By using this construction method for large-span irregular hyperboloid fair-faced concrete, auxiliary vibration is applied to the installation location of the exposed joint strip to achieve air release, which helps eliminate air bubbles generated during pouring at the transverse exposed joint strip location, ensuring the quality of the concrete pouring at the exposed joint strip location. Furthermore, by using a dedicated exposed joint strip removal device to remove the exposed joint strip after the concrete has formed, the exposed joint area can be protected, preventing edge chipping due to improper demolding operations. This reduces the difficulty of demolding, decreases the workload of subsequent repairs, and helps improve the construction quality and efficiency of the exposed joint.

[0017] Based on the above technical solution, the construction method of large-span irregular hyperboloid surface fair-faced concrete of the present invention can be further improved as follows:

[0018] The specific steps of step S70 are as follows: when pouring the fair-faced concrete, it is poured in layers and vibrated in layers. The thickness of each layer of fair-faced concrete is 500mm. The thickness of each layer is controlled by a ruler. After the vertical structure is poured, the horizontal structure is poured immediately. The pouring direction is to advance parallel from the periphery to the center. At the same time as pouring, an immersion vibrator is used for internal vibration, and an auxiliary air venting device is used to assist in vibration at the horizontal open joints on the outside of the template to eliminate air bubbles at the horizontal open joints.

[0019] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: Since a large number of air bubbles are easily generated at the bottom of the horizontal exposed joint strip during construction, which will reduce the overall appearance of the exposed joint, the use of an auxiliary air venting device to vibrate on the outside of the template at the horizontal exposed joint area helps to strengthen the vibration at the horizontal exposed joint area, vent the air from the horizontal exposed joint strip, and improve the construction quality of the horizontal exposed joint area.

[0020] Furthermore, the specific steps for removing the exposed seam strip in step S80 are as follows: removing the exposed seam strip using an exposed seam strip removal device.

[0021] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: by using the exposed joint strip removal device, the demolding strength of each part of the exposed joint strip can be made equal, thereby making the demolding force on the exposed joint strip uniform, reducing the phenomenon of exposed joint edge breakage caused by improper demolding and uneven force during the removal of the exposed joint strip, and ensuring the appearance neatness and aesthetic performance of the exposed joint of fair-faced concrete.

[0022] Furthermore, step S20 specifically includes the following steps:

[0023] The first step is to establish a model of the large-span irregular hyperboloid structure and a template model of the fair-faced concrete that matches its shape as a BIM model, and reserve space for the arched doorway.

[0024] The second step is to divide the BIM model into different elevations and to divide the arc-shaped doorway into planar projections separately.

[0025] The third step is to fine-tune and refine the local curvature of the irregular arc shape on the facade of the large-span irregular hyperboloid structure, and adjust the template model accordingly.

[0026] Step 4: Collect spatial data at different elevations of the large-span irregular hyperboloid structure from the BIM model, generate two-dimensional drawings, and export them.

[0027] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: by using drawing software to divide the arc-shaped doorway into planar projections, the rationality of each segment is observed after the division, ensuring that there are appropriate segment sizes, avoiding errors in the projected shape and design size caused by excessively long segments, and avoiding unfavorable scaffolding erection caused by excessively short segments.

[0028] Furthermore, step S30 specifically includes the following steps:

[0029] The first step is to analyze the coordinate system in the two-dimensional drawing, and identify the primary and secondary coordinate axes and the positions of each elevation control point;

[0030] The second step is to prepare the necessary tools for setting out the lines according to the requirements of the positioning and setting out. These tools include a line setting gun, a protractor, a rangefinder, a line marking pen, and nails.

[0031] The third step is to determine the positioning benchmark of the template. Using the line-laying tool, the axis of the building's side column or wall is measured and the axis is used as the starting point to determine the center of the semi-ellipse. The starting point and ending point of the semi-ellipse arc segment are determined through the center. Finally, the planar projection of the semi-ellipse top plate is determined and marked and recorded.

[0032] The fourth step is to use the cross-correlation method or closed loop test to check the accuracy of the layout and confirm the layout results and marking positions.

[0033] Furthermore, step S40 specifically includes the following steps:

[0034] The first step is to pre-assemble the template using sheet materials to ensure the curvature of the ellipse;

[0035] The second step is to erect a steel pipe support frame on site to form the formwork support system of the template.

[0036] The third step is to assemble the inner template and the outer template on the formwork support system.

[0037] The steel pipe support frame consists of 48x3.5mm plain pipes and fasteners. The steel pipes are connected by fasteners to form a temporary stable structure. Tie bolts are installed between the inner and outer steel pipe supports to withstand the lateral pressure of the cast-in-place concrete. The tie bolts are arranged in a neat and symmetrical manner to ensure the surface effect of the fair-faced concrete.

[0038] Furthermore, step S50 specifically includes the following steps:

[0039] Step 1: Process the visible seam strip according to the shape of the visible seam;

[0040] The second step is to perform a demolding treatment on the exposed seam strip before installation by wiping the exposed seam strip with a clean towel soaked in release agent 1 to 2 times.

[0041] The third step is to smoothly install the exposed joint strip on the inner side of the outer template at the construction joint, ensuring that the lines of the exposed joint strip are straight, flat and smooth.

[0042] By performing a demolding treatment on the exposed joint strip before installation, the purpose is to reduce the adhesion between the concrete and the exposed joint strip by using the release agent, thereby reducing the risk of the exposed joint edge breaking during the formwork removal process. The amount of release agent applied should be such that only a trace amount adheres to the surface of the exposed joint strip, and there should be no dripping or sagging.

[0043] Furthermore, step S60 specifically includes the following steps:

[0044] The first step is to process the required steel reinforcement materials on site according to the design requirements;

[0045] The second step is to use the binding wire to tie the reinforcing bars to the surface of the template, and to adjust the binding wire to ensure that the reinforcing bars are tied stably and the template is in the correct position.

[0046] The third step is to use bolts to firmly fix the reinforcing bars to the template.

[0047] Reinforcing bars and binding wires must not touch the concrete surface to be poured inside the formwork. Each binding wire must be tied in the reverse direction, and each point must be fully tied. Special plastic spacers for reinforcing bars should be used during tying. The positioning of reinforcing bars should avoid the position of tie bolts. For multi-curved walls and where the wall meets the arc of the wall surface, single-sided formwork should be erected before tying the reinforcing bars. Temporary fixing measures should be taken when tying the reinforcing bars to ensure that the protective layer of the reinforcing bars and the formwork is consistent.

[0048] Furthermore, the specific steps for curing the formed fair-faced concrete in step S80 are as follows: cover the surface of the fair-faced concrete with a film for curing, tightly compact the edges and joints, and then cover it with geotextile for curing to avoid direct sunlight. The curing time shall not be less than 14 days.

[0049] Furthermore, the specific steps for surface treatment of the formed fair-faced concrete in step S80 are as follows: sealing the plug holes, repairing air bubbles, repairing the wall base, repairing the leakage at the external corners and the misalignment of the fair-faced concrete.

[0050] Compared with existing technologies, the beneficial effects of the construction method for large-span irregular hyperboloid fair-faced concrete provided by this invention are as follows: This method utilizes auxiliary vibration at the installation location of the exposed joint strip to achieve air release, which helps eliminate air bubbles generated during pouring at the transverse exposed joint strip location, ensuring the quality of the concrete pouring at the exposed joint strip location. Furthermore, the use of a dedicated exposed joint strip removal device after concrete molding protects the exposed joint area, preventing edge chipping due to improper demolding operations. This reduces demolding difficulty, decreases subsequent repair work, and helps improve the construction quality and efficiency of the exposed joints. Attached Figure Description

[0051] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0052] Figure 1A flowchart illustrating a construction method for large-span, irregularly shaped, hyperboloidal surface-finished fair-faced concrete.

[0053] Figure 2 This is a schematic diagram of an auxiliary exhaust device in a construction method for large-span, irregularly shaped, hyperboloidal surface fair-faced concrete.

[0054] Figure 3 This is a schematic diagram of a device for removing exposed joint strips in a construction method for large-span, irregularly shaped, hyperboloidal surface-finished fair-faced concrete.

[0055] Figure 4 This is a schematic diagram of the exposed joint strip in a construction method for large-span irregular hyperboloid fair-faced concrete.

[0056] The attached diagram lists the components represented by each number as follows:

[0057] 10. Seam forming part; 11. Connecting part; 12. Fixing strip; 20. Handle; 201. Connecting rod; 202. Spherical joint; 21. Vibration chamber; 211. Spherical groove; 22. Fixing plate; 30. Slide rail; 31. Slider; 311. Hinge block; 32. Swing rod; 321. First hinge end; 322. Second hinge end; 33. Pull-out rod; 331. Crossbar; 332. Insert strip; 34. Rotating shaft. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0059] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0060] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0061] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0062] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0063] like Figure 1 The diagram shown is a flowchart of a construction method for large-span irregular hyperboloid surface fair-faced concrete provided by the present invention, which specifically includes the following steps:

[0064] S10: Construction preparation, prepare the necessary materials and tools for use;

[0065] S20: Model a large-span irregular hyperboloid structure and export two-dimensional drawings;

[0066] S30: Conduct on-site positioning and layout based on two-dimensional drawings;

[0067] S40: Assemble and adjust the inner and outer formwork on site;

[0068] S50: Install exposed joint strips at the location of the construction joint on the inner side of the outer formwork;

[0069] S60: Use steel bars and tie wire to tie and fix the inner and outer formwork;

[0070] S70: Continuous pouring of fair-faced concrete between the inner and outer formwork;

[0071] S80: Sequentially remove the reinforcing bars and binding wires, outer formwork, exposed joint strips, and inner formwork, and then cure and surface-treat the formed fair-faced concrete.

[0072] Furthermore, in the above technical solution, step S20 specifically includes the following steps:

[0073] The first step is to create a model of the large-span irregular hyperboloid structure and a fair-faced concrete formwork model that matches its shape as a BIM model, and reserve space for the arched doorway.

[0074] The second step is to divide the BIM model into different elevations and to divide the planar projection of the arched doorway separately.

[0075] The third step is to fine-tune and refine the curvature of the irregular arc shape on the facade of the large-span irregular hyperboloid structure, and adjust the template model accordingly.

[0076] Step 4: Collect spatial data at different elevations of the large-span irregular hyperboloid structure from the BIM model, generate two-dimensional drawings, and export them.

[0077] It should be noted that BIM (Building Information Modeling) is essentially a virtual 3D model of a building project. Its core is to utilize digital technology to create a complete and accurate database of building information for this model. BIM technology is characterized by its high degree of visualization, coordination, simulation, optimization, and drawing capabilities. It can effectively visualize, coordinate, simulate, and optimize large-span, irregularly shaped, hyperboloid-surfaced exposed concrete structures, and generate various professional drawings and detailed drawings, making the project more detailed.

[0078] Furthermore, in the above technical solution, step S30 specifically includes the following steps:

[0079] The first step is to organize the coordinate system in the two-dimensional drawing, and clarify the primary and secondary coordinate axes and the positions of each elevation control point;

[0080] The second step is to prepare the necessary tools for setting out the lines according to the requirements. These tools include a line-laying gun, a protractor, a rangefinder, a line-marking pen, and nails.

[0081] The third step is to determine the positioning benchmark of the template. Use the layout tool to measure the axis of the building's side columns or walls and use this axis as the starting point to determine the center of the semi-ellipse. Use the center of the circle to determine the starting and ending points of the semi-ellipse arc segment. Finally, determine the planar projection of the semi-ellipse top plate and mark and record it.

[0082] The fourth step is to use the cross-correlation method or closed loop test to check the accuracy of the layout and confirm the layout results and marking positions.

[0083] It should be noted that the cross-correlation method for checking the accuracy of the layout involves performing cross-verification measurements after the initial layout is completed. This means taking multiple measurements of the same point at different locations and in different directions to verify the accuracy of the layout. By analyzing and calculating the data from the cross-measurements, the differences between the measured values ​​are compared to evaluate the accuracy and error of the layout. If there are significant errors in the measurement results, the layout needs to be adjusted accordingly, and the measurements need to be repeated until the requirements are met.

[0084] The closed-loop test method for checking the accuracy of line setting out involves connecting the setting-out points with a string line after measurement, forming a closed loop. The distance and angle between adjacent points are measured sequentially along this loop, and the data are recorded. The measured distance and angle data are then calculated and compared to evaluate the accuracy and error of the line setting out. If significant errors are found, the line setting out needs to be adjusted and the measurements repeated until the requirements are met. Checking the accuracy of line setting out using the closed-loop test method requires strict control and verification of the original data to ensure construction quality.

[0085] Furthermore, in the above technical solution, step S40 specifically includes the following steps:

[0086] The first step is to pre-assemble the template using sheet materials to ensure the curvature of the ellipse;

[0087] The second step is to erect a steel pipe support frame on site to form a formwork support system;

[0088] The third step is to assemble the inner and outer formwork on the formwork support system.

[0089] Furthermore, in the above technical solution, step S50 specifically includes the following steps:

[0090] Step 1: Process the seam strip according to the shape of the seam;

[0091] The second step is to remove the exposed seam strips from the mold before installation by wiping them with a clean towel soaked in release agent 1-2 times.

[0092] The third step is to smoothly install the exposed joint strip on the inside of the outer formwork at the construction joint, ensuring that the lines of the exposed joint strip are straight, flat and smooth.

[0093] like Figure 4As shown, the visible seam strip used in step S50 includes a trapezoidal prism-shaped seam-forming part 10 and a cuboid-shaped connecting part 11 fixedly connected together. The connecting part 11 is connected to the rectangular surface where the long base of the seam-forming part 10 is located. A fixing strip 12 is fixedly connected to each side of the tail of the connecting part 11 along the length direction. The length of the fixing strip 12 is the same as the length of the rectangular surface of the seam-forming part 10. The width of the fixing strip 12 is 1 / 4 to 1 / 5 of the width of the rectangular surface of the seam-forming part 10. The length of the connecting part 11 is the same as the length of the fixing strip 12, the width is 1 / 10 to 1 / 13 of the width of the rectangular surface of the seam-forming part 10, and the height is the sum of the thickness of the template and the height of the fixing strip 12. A threaded hole is provided at the connection part between the fixing strip 12 and the template. A connecting hole for removing the visible seam strip is also provided on the side wall of the connecting part 11. When in use, the connecting part 11 of the exposed joint strip is embedded between two adjacent outer templates. The jointing part 10 is located on the inner side of the outer template that is in contact with the fair-faced concrete. The fixing strip 12 is located on the outer side of the outer template and is fixedly connected to the outer template by screws installed in the threaded holes. The fixing strip 12 is also fixedly connected to the connecting part 11 through the connecting holes, which is used to fix the exposed joint strip structure to the outer template.

[0094] Furthermore, in the above technical solution, step S60 specifically includes the following steps:

[0095] The first step is to process the required steel reinforcement materials on site according to the design requirements;

[0096] The second step is to use tie wire to bind the reinforcing bars to the surface of the formwork, and to adjust the reinforcing bars to ensure they are secure and the formwork is in the correct position.

[0097] The third step is to use bolts to firmly fix the reinforcing bars to the formwork.

[0098] In the above technical solution, the specific steps of step S70 are as follows: when pouring fair-faced concrete, the concrete is poured in layers and vibrated in layers. The thickness of each layer of fair-faced concrete is 500mm. The thickness of each layer is controlled by a ruler. After the vertical structure is poured, the horizontal structure is poured immediately. The pouring direction is to advance parallel from the periphery to the center. At the same time as pouring, an immersion vibrator is used for internal vibration, and an auxiliary air venting device is used to perform auxiliary vibration at the horizontal open joints on the outside of the formwork to eliminate air bubbles at the horizontal open joints.

[0099] like Figure 2As shown, the auxiliary exhaust device used in step S70 includes a handle 20, a vibration chamber 21, and a fixing plate 22. The handle 20 includes a connecting rod 201 and a ball joint 202. The ball joint 202 has an insertion hole for extending the connecting rod 201 from the outer surface of the ball joint 202 to the center position inside the ball joint 202. The connecting end of the connecting rod 201 is inserted into the insertion hole and fixed at the center position inside the ball joint 202. The upper surface of the vibration chamber 21 is provided with a spherical groove 211, and the lower surface of the vibration chamber 21 is arc-shaped to adapt to the curvature of the template. The fixing plate 22 is provided with a circular through hole, and the diameter of the circular through hole is smaller than the diameter of the ball joint 202. The ball joint 202 is placed in the spherical groove 211, the connecting rod 201 passes through the circular through hole on the fixing plate 22, and the fixing plate 22 is fixed to the top surface of the vibration chamber 21.

[0100] When in use, the user holds the handle 20 and places the vibration chamber 21 on the outer template at the position corresponding to the horizontal exposed joint strip. The vibration chamber 21 has a built-in vibration motor, and the vibration generated by it acts on the outer template through the bottom surface of the vibration chamber 21, and then on the exposed joint strip area. It assists in the vibration of fair-faced concrete from the outside of the template, so as to remove air bubbles in the exposed joint strip area.

[0101] Furthermore, in the above technical solution, the specific steps for removing the exposed seam strip in step S80 are as follows: the exposed seam strip is removed using an exposed seam strip removal device.

[0102] like Figure 3 As shown, the visible seam strip removal device used in step S80 includes a slide rail 30, two sliders 31, two rocker arms 32, and a pull-out rod 33. The two sliders 31 are slidably disposed on the slide rail 30, which has a groove. The two sliders 31 can slide relative to the slide rail 30 along the groove. Each rocker arm 32 has a first hinge end 321 and a second hinge end 322. The first hinge ends 321 of the two rocker arms 32 are respectively hinged to the hinge block 311 of one of the sliders 31. The second hinge ends 322 of the two rocker arms 32 and the top of the pull-out rod 33 are hinged together via a pivot 34. The first hinge ends 321 of the two rocker arms 32 are located on one side of the pull-out rod 33. The first hinge ends 321 of the two rocker arms 32 move relative to the sliding of the two sliders 31, thereby driving the pull-out rod 33 to move upward away from the slide rail 30.

[0103] In use, the user first gently taps the connecting part 11 of the exposed joint strip with a wooden hammer to weaken the bond strength between the exposed joint strip and the concrete. Then, the slide rail 30 is placed on the template surface, and the insert 332 on the crossbar 331 at the bottom of the pull-out rod 33 is inserted into the connecting hole on the fixing strip 12 of the exposed joint strip. The crossbar 331 and the pull-out rod 33 are perpendicular to each other, and the insert 332 is located on the outside of the crossbar 331. The spacing between the inserts 332 is equal to the spacing between the connecting holes on the side wall of the connecting part 11 of the exposed joint strip. Subsequently, the user applies two opposing forces to the two swing rods 32 respectively. Under the guidance of the groove in the slide rail 30, The force applied by the user to the two rocker arms 32 is in the horizontal direction, that is, parallel to the length direction of the slide rail. At this time, the first hinge ends 321 of the two rocker arms 32 slide relative to each other through the two sliders 31. Since the second hinge ends 322 of the two rocker arms 32 are hinged to the pull-out rod 33 which is fixed to the exposed seam strip, the relative sliding of the first hinge ends 321 will cause the second hinge ends 322 to move in the direction perpendicular to the sliding of the sliders 31, that is, to move upward along the length direction of the pull-out rod 33. This can drive the crossbar 331 and the exposed seam strip to move upward, so that the exposed seam strip can be slowly pulled out of the exposed seam section, while the pull-out force of each part of the exposed seam strip remains stable. Since both swing arms 32 are hinged between the slider 31 and the pull-out rod 33, the two swing arms 32 and the pull-out rod 33 form an elbow mechanism, which amplifies the force exerted by the user on the two swing arms 32 and applies it to the pull-out rod 33. Therefore, the user can pull out the exposed seam strip with a small force on the swing arms 32, which avoids the difficulty of the user to exert force by hand and the possibility of injury. It also keeps the pulling force of the pull-out rod 33 on various parts of the exposed seam strip balanced, and prevents the exposed seam from chipping after the exposed seam strip is removed.

[0104] Furthermore, in the above technical solution, the specific steps for curing the formed fair-faced concrete in step S80 are as follows: cover the surface of the fair-faced concrete with a film for curing, tightly compact the edges and joints, and then cover it with geotextile for curing, avoiding direct sunlight, and the curing time shall not be less than 14 days.

[0105] Furthermore, in the above technical solution, the specific steps for surface treatment of the formed fair-faced concrete in step S80 are as follows: sealing the plug holes, repairing air bubbles, repairing the wall base, repairing the leakage at the external corners and the misalignment of the fair-faced concrete.

[0106] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A construction method for large-span irregularly shaped hyperboloidal surface fair-faced concrete, characterized in that, Includes the following steps: S10: Construction preparation, prepare the necessary materials and tools for use; S20: Model a large-span irregular hyperboloid structure and export two-dimensional drawings; S30: Perform on-site positioning and layout based on the aforementioned two-dimensional drawings; S40: Assemble and adjust the inner and outer formwork on site; S50: Install exposed joint strips at the location of the construction joint on the inner side of the outer formwork; S60: Use steel bars and binding wire to tie and fix the inner formwork and the outer formwork; S70: Continuously pour fair-faced concrete between the inner formwork and the outer formwork; S80: Sequentially remove the reinforcing bars and binding wires, the outer formwork, the exposed joint strips, and the inner formwork, and cure and surface-treat the formed fair-faced concrete; The specific steps for removing the exposed seam strip in step S80 are as follows: the exposed seam strip is removed using an exposed seam strip removal device; The visible seam strip removal device used in step S80 includes a slide rail (30), two sliders (31), two rocker arms (32), and a pull-out rod (33). The two sliders (31) are slidably disposed on the slide rail (30), which has a groove. The two sliders (31) can slide relative to the slide rail (30) along the groove. Each rocker arm (32) has a first hinge end (321) and a second hinge end (322) opposite to each other. The first hinge end (321) of the two rocker arms (32) The hinge block (311) is hinged to a slider (31) respectively. The second hinge ends (322) of the two rocker arms (32) are hinged to the top of the pull-out rod (33) via a pivot (34). The first hinge ends (321) of the two rocker arms (32) are located on one side of the pull-out rod (33). The first hinge ends (321) of the two rocker arms (32) move relative to each other in the sliding of the two sliders (31), thereby driving the pull-out rod (33) to move upward away from the slide rail (30).

2. The construction method for large-span irregular hyperboloid surface fair-faced concrete according to claim 1, characterized in that, The specific steps of step S70 are as follows: when pouring the fair-faced concrete, it is poured in layers and vibrated in layers. The thickness of each layer of fair-faced concrete is 500mm. The thickness of each layer is controlled by a ruler. After the vertical structure is poured, the horizontal structure is poured immediately. The pouring direction is to advance parallel from the periphery to the center. At the same time as pouring, an immersion vibrator is used for internal vibration, and an auxiliary air venting device is used to assist in vibration at the horizontal open joints on the outside of the template to eliminate air bubbles at the horizontal open joints.

3. The construction method for large-span irregular hyperboloid surface fair-faced concrete according to claim 1, characterized in that, Step S20 specifically includes the following steps: The first step is to establish a model of the large-span irregular hyperboloid structure and a template model of the fair-faced concrete that matches its shape as a BIM model, and reserve space for the arched doorway. The second step is to divide the BIM model into different elevations and to divide the arc-shaped doorway into planar projections separately. The third step is to fine-tune and refine the local curvature of the irregular arc shape on the facade of the large-span irregular hyperboloid structure, and adjust the template model accordingly. Step 4: Collect spatial data at different elevations of the large-span irregular hyperboloid structure from the BIM model, generate two-dimensional drawings, and export them.

4. The construction method for large-span irregular hyperboloid surface fair-faced concrete according to claim 3, characterized in that, Step S30 specifically includes the following steps: The first step is to analyze the coordinate system in the two-dimensional drawing, and identify the primary and secondary coordinate axes and the positions of each elevation control point; The second step is to prepare the necessary tools for setting out the lines according to the requirements of the positioning and setting out. These tools include a line setting gun, a protractor, a rangefinder, a line marking pen, and nails. The third step is to determine the positioning benchmark of the template. Using the line-laying tool, the axis of the building's side column or wall is measured and the axis is used as the starting point to determine the center of the semi-ellipse. The starting point and ending point of the semi-ellipse arc segment are determined through the center. Finally, the planar projection of the semi-ellipse top plate is determined and marked and recorded. The fourth step is to use the cross-correlation method or closed loop test to check the accuracy of the layout and confirm the layout results and marking positions.

5. A construction method for large-span irregular hyperboloid surface fair-faced concrete according to claim 4, characterized in that, Step S40 specifically includes the following steps: The first step is to pre-assemble the template using sheet materials to ensure the curvature of the ellipse; The second step is to erect a steel pipe support frame on site to form the formwork support system of the template. The third step is to assemble the inner template and the outer template on the formwork support system.

6. The construction method for large-span irregular hyperboloid surface fair-faced concrete according to claim 5, characterized in that, Step S50 specifically includes the following steps: Step 1: Process the visible seam strip according to the shape of the visible seam; The second step is to perform a demolding treatment on the exposed seam strip before installation by wiping the exposed seam strip with a clean towel soaked in release agent 1 to 2 times. The third step is to smoothly install the exposed joint strip on the inner side of the outer template at the construction joint, ensuring that the lines of the exposed joint strip are straight, flat and smooth.

7. A construction method for large-span irregular hyperboloid surface fair-faced concrete according to claim 6, characterized in that, Step S60 specifically includes the following steps: The first step is to process the required steel reinforcement materials on site according to the design requirements; The second step is to use the binding wire to tie the reinforcing bars to the surface of the template, and to adjust the binding wire to ensure that the reinforcing bars are tied stably and the template is in the correct position. The third step is to use bolts to firmly fix the reinforcing bars to the template.

8. A construction method for large-span irregular hyperboloid surface fair-faced concrete according to claim 7, characterized in that, The specific steps for curing the formed fair-faced concrete in step S80 are as follows: cover the surface of the fair-faced concrete with a film for curing, and compact the edges and joints tightly. Then cover it with geotextile for curing, avoiding direct sunlight, and the curing time shall not be less than 14 days.

9. A construction method for large-span irregular hyperboloid surface fair-faced concrete according to claim 8, characterized in that, The specific steps for surface treatment of the formed fair-faced concrete in step S80 are as follows: sealing of plug holes, repair of air bubbles, repair of wall base, repair of grout leakage at external corners and repair of misalignment of the fair-faced concrete.

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