Net hanging concrete construction method

Abstract

The invention relates to the field of building construction, in particular to a net hanging concrete construction method which specifically comprises the steps of base surface cleaning, mortar stone wall and slope protection maintenance, hole drilling and cleaning, bar anchoring, steel bar binding, curved surface formwork supporting, concrete pouring and concrete curing. Differentiated concrete construction modes are carried out on the net hanging construction working faces of the twisted face and the inclined face, the targeted formwork supporting and concrete pouring construction method is carried out, self-compacting concrete is applied to the twisted face construction working face, the dependence of concrete pouring on manual vibration is reduced by means of the self-flowing performance of the self-compacting concrete, and the construction efficiency is improved. A traditional vibrating hole is converted into a concrete pouring hole, and reutilization of a traditional formwork is achieved. And continuous pouring of the slip-form machine is carried out on the inclined plane, so that high-altitude operation of workers is reduced, the compactness of a concrete structure is ensured, and the construction safety is improved.

Description

Technical Field

[0001] The present invention relates to the field of building construction, and in particular to a construction method for shotcrete with wire mesh. Background Art

[0002] The construction technology of shotcrete with wire mesh is widely used in the field of building construction such as slope protection. Its core is to enhance the stability of the base surface through the composite structure of the wire mesh and concrete.

[0003] The traditional construction process of shotcrete with wire mesh mostly adopts ordinary formwork support combined with manual vibration. However, when facing special-shaped structures such as twisted surfaces and curved surfaces, the formwork is prone to formwork displacement or deformation due to uneven stress, resulting in poor concrete forming quality and lack of targeted construction for the construction work surfaces with different curvatures. At the same time, the vibration in the area with dense steel bars is not sufficient, and defects such as honeycombs and cavities are likely to appear, affecting the structural density and durability. Summary of the Invention

[0004] In view of the problem in the above or the prior art that the degree of targeting for the construction work surface to be constructed is relatively low, and the structural density in the area with dense concrete steel bars is likely to decrease, the present invention is proposed.

[0005] Therefore, the object of the present invention is to provide a construction method for shotcrete with wire mesh.

[0006] To solve the above technical problems, the present invention provides the following technical solutions, including the following steps:

[0007] Base surface cleaning, cleaning and leveling the construction area; base surface maintenance, repairing the walls in the construction area to ensure the integrity of the masonry base surface; drilling and hole cleaning, using a drilling machine to open holes for anchor bars on the base surface of the construction area, and checking the hole depth and aperture after drilling; anchoring the bars and tying the steel bars, curing the steel bars with anchoring glue; formwork support, erecting the basic framework required for concrete pouring in the construction area, and reserving vibration ports on the support formwork; concrete pouring and curing, pouring on the erected concrete framework, and curing after pouring;

[0008] Among them, the working area to be constructed with wire mesh is divided into a twisted construction work surface and an inclined construction work surface;

[0009] For the twisted construction work surface, in the formwork support step, the surface of the twisted construction work surface is supported by phenolic plywood or bamboo plywood. Before formwork support, the top formwork bars and tie rods arranged on the twisted construction work surface are welded first. The top formwork bars are arranged between the twisted construction work surface and the formwork. Holes are drilled on the concrete floor of the twisted construction work surface to insert positioning steel bars and then welded to the original anchor bar steel bars; in the concrete pouring and curing step, self-compacting concrete is used to achieve the pouring between the anchor bar steel bars and the support formwork;

[0010] For the inclined construction working face, in the formwork support step, the sides of the inclined construction working face are supported with side formwork, and the side formwork includes two square steel bars of 8 cm * 4 cm; in the concrete pouring and curing step, a slipform machine is used for pouring. The slipform machine includes four 20-channel steels, the width of the slipform machine is 80 cm, the stroke length of the slipform machine is 6 m, a 3-kW winch is installed on each side, the machine cover of the slipform machine is arranged on the side formwork on both sides of the inclined construction working face, and the upper part of the slipform machine is hung on the steel piles at the top of the inclined construction working face through the winch.

[0011] As a preferred embodiment of the construction method of the shotcrete with wire mesh of the present invention, wherein: in the formwork support step, vibration ports are arranged on the formwork, one vibration port is arranged every 2 m, and the size of each vibration port is set to 50 cm * 50 cm.

[0012] As a preferred embodiment of the construction method of the shotcrete with wire mesh of the present invention, wherein: in the concrete pouring and curing step for the distorted construction working face, the surface of the distorted construction working face is wetted by sprinkling water before pouring.

[0013] As a preferred embodiment of the construction method of the shotcrete with wire mesh of the present invention, wherein: in the concrete pouring and curing step for the inclined construction working face, a vibrating rod is used manually to compact the concrete in the vibration port, the winch drives the slipform machine to move up 70 cm, and then concrete is poured and vibrated, and so on until the slipform machine reaches the highest point of the inclined construction working face.

[0014] As a preferred embodiment of the construction method of the shotcrete with wire mesh of the present invention, wherein: for the base surface cleaning step, the working area to be constructed with wire mesh is cleaned and leveled, and the loose soil and floating slag on the wall slope are removed by manual labor and pneumatic pick, especially the mortar in the loose pointing is removed.

[0015] As a preferred embodiment of the construction method of the shotcrete with wire mesh of the present invention, wherein: for the base surface maintenance step, after the wall in the construction area is cleaned, the missing grouted stones inside the wall are repaired and the loose stones on the wall are reinforced to ensure the integrity of the grouted stone base surface.

[0016] As a preferred embodiment of the construction method of the shotcrete with wire mesh of the present invention, wherein: for the step of drilling and hole cleaning, the positions and sizes of the holes to be drilled in the construction area are marked according to the design requirements, and waterproof treatment is carried out in the holes to avoid water accumulation.

[0017] As a preferred embodiment of the construction method of the shotcrete with wire mesh of the present invention, wherein: for the step of installing anchor bars and tying steel bars, the anchor bar steel bars are set as threaded steel bars with a diameter of 25 mm, and the intersection points of every two anchor bar steel bars are tied, and at the same time, the intersection points of the anchor bar steel bars and the positioning steel bars are tied.

[0018] As a preferred embodiment of the construction method of the lath concrete of the present invention, in which: for the steps of concrete pouring and curing, the formwork or side formwork on the poured concrete is disassembled, and after watering, a tarpaulin is covered to keep the concrete moist, and water is sprinkled regularly to keep the surface of the concrete wet.

[0019] The beneficial effects of the construction method of the lath concrete of the present invention: Differentiated concrete construction methods are carried out for the lath construction working surfaces of the twisted surface and the inclined surface, and targeted formwork support and concrete pouring construction methods are carried out. Self-compacting concrete is applied to the twisted construction working surface, and the self-flowing performance of the self-compacting concrete is utilized to reduce the dependence of concrete pouring on manual vibration. The traditional vibration holes are transformed into concrete pouring holes, realizing the reuse of the traditional formwork; continuous pouring of a slipform machine is carried out on the inclined surface, reducing the high-altitude operation of workers, ensuring the compactness of the concrete structure, and improving the construction safety. The present invention uses a technical combination of "taking measures according to local conditions", matches the optimal plan according to the different requirements of the twisted surface and the inclined surface, and improves the service life, stability and compactness of the concrete after forming. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0021] Figure 1 It is a schematic diagram of steel bar bundling for a construction method of lath concrete of the present invention for a twisted construction working surface.

[0022] Figure 2 It is a schematic diagram of the working of a slipform machine for a construction method of lath concrete of the present invention for an inclined construction working surface.

[0023] In the figure: 1. Twisted construction working surface; 11. Anchor bar; 12. Positioning bar; 2. Inclined construction working surface; 21. Slipform machine; 22. Winch. Detailed Embodiments

[0024] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention will be made in conjunction with the drawings of the specification.

[0025] Example 1, referring to Figure 1, which is the first embodiment of the present invention. This embodiment provides a construction method for shotcrete on wire mesh, which is specifically constructed for the distorted construction working surface 1, and can achieve the effects of improving the compactness of the concrete forming layer and reducing the dependence on manual vibration during the concrete forming process. The specific process includes base surface cleaning, repair of masonry walls and slopes, drilling and hole cleaning, installation of anchor bars, steel bar binding, support of curved surface formwork, concrete pouring, and concrete curing. Among them, self-compacting concrete is used during the concrete pouring process to improve the compactness of the concrete forming layer and reduce the dependence on manual vibration during the concrete forming process. The traditional vibration holes are transformed into concrete pouring holes, realizing the reuse of traditional formwork.

[0026] In the base surface cleaning step, construction workers first clean and level the construction area, use manual labor and pneumatic picks to clean the loose soil and floating slag on the distorted construction working surface 1, especially the loose mortar joints must be cleaned, and the wall surface is rinsed with high-pressure water and kept at a certain humidity.

[0027] In the step of repairing masonry walls and slopes, after cleaning the walls and slopes of the distorted construction working surface 1, the missing masonry stones are repaired and the loose stones are reinforced to ensure the integrity of the masonry base surface.

[0028] In the drilling step, mark the drilling positions and types according to the design requirements of the construction working surface. If there are other factors on the base surface affecting drilling, the drilling positions can be adjusted appropriately. The drilling is carried out using a modified drilling machine. For places where the machine cannot reach, manual labor uses an electric hammer or pneumatic drill to form holes. The modified drilling machine drills to a depth of 50 - 60 cm and can complete one hole in half a minute. The modified drilling machine is convenient to transfer, has a high drilling efficiency, reduces the safety risks of workers working at heights, and does not require scaffolding erection, saving expenses. Drill holes more densely in places where the formwork is under great stress, and the hole spacing is 60 - 80 cm.

[0029] In the hole cleaning step, after drilling is completed, the staff checks the hole depth and diameter to be qualified, then blows the dust in the hole out with an air compressor, then brushes the hole wall with a brush, and blows the hole with compressed air again. This should be repeated 3 to 5 times until there is no dust debris in the hole. Finally, wipe the hole wall with a cotton cloth dipped in acetone and temporarily seal the hole opening. If there are waste holes, fill them with anchoring glue after cleaning. Protect the holes in time after hole cleaning to prevent rainwater and sundries from falling in. Pay attention to the weather forecast in time and cover the holes with rainproof cloth before rain. If rainwater enters, it must be cleaned up, otherwise it will affect the bonding effect of the anchoring glue. Use a thin strip of sponge to clean the accumulated water in the hole after water enters.

[0030] In the step of anchoring the steel bars, the anchoring steel bars use threaded steel bars with a diameter of 25. The rust and oil stains within the anchoring length of the steel bars are cleaned and polished to a metallic luster. The steel bars are inserted into the hole by rotation or hammering. When hammering, one hand should hold the steel bar or bolt to ensure centering and avoid rebound. The amount of anchoring glue filling should ensure that a small amount of glue overflows around the steel bar after insertion. The exposed part of the anchor bar 11 should be reserved in length according to the laid line. The mortar masonry base surface is uneven and cannot be reserved based on it. The anchoring glue needs to be cured. The anchor bar 11 must not be disturbed within 12 hours when the daily average temperature is above 25°C, and the anchor bar 11 must not be disturbed within 24 hours when the daily average temperature is below 25°C. If there is a large disturbance, the anchor bar 11 should be relocated.

[0031] In the process of steel bar binding, the steel bar binding is strictly constructed according to the drawings, especially the reservation of the protective layer. The height of the horse stool is adjusted according to the laid line, and the activity space of the vibrator is reserved for the subsequent concrete pouring. All the intersections of the steel bars must be tied, and no skipping is allowed. The anchor bar 11 on the torsion surface will inevitably be trampled during the formwork support process, and skipping is more likely to be trampled and deformed. The intersection of the anchor bar 11 and the positioning steel bar 12 must also be tied.

[0032] In the step of curved surface formwork support, the twisted surface formwork support uses bakelite or bamboo plywood. Before the formwork support, the top rod and the tension screw are first welded. The tension screw is welded to the anchor steel bar 11 located at the top of the construction surface for positioning. The main tension of the formwork during the working process is provided by it, and the welding stability of the anchor steel bar 11 must be guaranteed. The welding of the top rod is mainly to ensure the thickness of the protective layer between the formwork and the binding steel bars, so the top rod must be placed with a good line for welding. The key point is the reinforcement at the bottom of the formwork, where the formwork is subjected to the greatest force and the formwork is most likely to run. The positioning steel bar 12 can be inserted into the concrete bottom plate through a hole, and then welded to the anchor steel bar 11 to reinforce the formwork. The support formwork should reserve a vibration port in the middle part, one every two meters, with a size of 50*50cm. The main function is to insert a pump pipe into the vibration port to pour concrete, and to insert a vibrating rod into the vibration port to vibrate the concrete, reducing the dependence of the concrete on manual vibration, while reducing the existence of the vibration blind area and reducing the bubbles and honeycombs inside the concrete forming layer.

[0033] In the concrete pouring step, sprinkle water before pouring to moisten the warehouse surface. Use self-compacting concrete, which has better fluidity and can flow better between the steel bars and the formwork, reducing the phenomenon of stone overhead. The concrete pouring speed must be slow, and a fast speed can easily lead to mold explosion. As long as there is no cold joint, the speed can be set to the slowest. When pouring at the vibration port, the vibration port can be closed in advance.

[0034] After the concrete pouring is completed and the concrete is tensely removed from the formwork, it can be sprinkled with water and covered with tarpaulin to keep it warm and moist. A designated person should sprinkle water frequently to keep the concrete surface moist. The maintenance of the concrete determines its later service life.

[0035] Example 2, reference Figure 2 , which is the second embodiment of the present invention. Different from the previous embodiment, this embodiment provides a mesh concrete construction method for the inclined construction working surface 2, which solves the problem of slipform concrete pouring on the conventional inclined construction working surface 2. The specific process includes base surface cleaning, mortar stone slope protection maintenance, drilling, hole cleaning, anchor reinforcement, steel bar binding, side formwork support, concrete pouring and concrete curing.

[0036] The workflow different from Example 1 is as follows: The template support process mainly supports the side template. The side template is made of two 8*4cm square steels spliced together and fixed in the position determined by the layout.

[0037] The concrete pouring step uses a slipform machine 21. The slipform machine 21 is welded with four 20 channel steels, 80cm wide and 6 meters long, with a 3kW winch 22 installed on each side. The slipform machine 21 is covered on the side molds on both sides, and the upper part is hung on a fixed steel pile using a winch 22. The concrete is poured under the slipform machine 21, and the vibrator rod is used to vibrate and compact it manually. The switch of the winch 22 is pressed to move the slipform machine 21 up 70cm, and then the concrete is poured and vibrated, and it is repeated until the top of the slope. This technology has high requirements for the control of the slump of concrete. The slump is controlled at 90-120mm. If the slump is too large, it is easy for the concrete to overflow from the bottom of the slipform machine 21; if the slump is too small, it is not easy to vibrate and compact it, so that the quality of the concrete cannot be guaranteed.

[0038] Furthermore, in the specific working process, the models of the anchor drilling equipment include WG-45A, WG-45B, WG-45C, and WG-45D. The equipment of these four models is applicable to rocks with a hardness of f = 6-18, the single rod drilling depth is 3.2 meters, and the total machine weight is 1000 kg. The rock drill models matched with the equipment of these four models include HYD200, HYD300, HC20, and DF530. Among them, the equipment manufacturers of HYD200 and HYD300 are China Lianshan, the impact powers are 7kW and 15kW respectively, the impact frequencies are 34-67Hz and 50Hz, the impact pressures are 16-19MPa, and the impact flows are 45L / min and 65L / min. The equipment manufacturer of HC20 is France MONTABERT, the impact power is 4.5kW, the impact frequency is 50Hz, the impact pressure is 14MPa, and the impact flow is 45L / min. The equipment manufacturer of DF530 is Finland DOOFOR, the impact power is 10kW, the impact frequency is 60Hz, the impact pressure is 10-13MPa, and the impact flow is 45-55L / min. The slag discharge gas volume of the above four kinds of equipment is 3.0m³ / min, the slag discharge air pressure is 6-10bar, the practical drill rod specifications include radii of 25mm, 32mm, and 28mm, the drilling diameter covers 32mm-64mm, and the excavator volume used is greater than 8 tons. During the construction of the slip form machine 21, rock drilling equipment such as the WG-45 series can be optionally equipped, which is applicable to rocks with a hardness of f = 6-18 and a drilling depth of 3.2m. The specific parameters are adjusted according to the project requirements.

[0039] 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. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A construction method for shotcrete with mesh, comprising the following steps: Base surface cleaning: Clean and level the construction area. Base surface maintenance: Repair the walls in the construction area to ensure the integrity of the grouted stone base surface. Drilling and hole cleaning: Use a drilling machine to open holes for anchor bars on the base surface of the construction area. After drilling, check the hole depth and diameter. Installing anchor bars and tying steel bars: Cure the steel bars with anchoring glue. Formwork support: Set up the basic framework required for concrete pouring in the construction area, and reserve vibrating openings on the formwork for support. Concrete pouring and curing: Pour concrete on the erected concrete framework and perform curing after pouring. It is characterized in that: Divide the working area to be constructed with mesh into a twisted construction working surface (1) and an inclined construction working surface (2) for separate construction. Among them, the self-compacting concrete pouring method is used for the twisted construction working surface (1), and the slip form concrete pouring method is used for the inclined construction working surface (2). For the twisted construction working surface (1), in the formwork support step, the surface of the twisted construction working surface (1) is supported with plywood or bamboo plywood. Before formwork support, first weld the top formwork rods and tie rods arranged on the twisted construction working surface (1). The top formwork rods are arranged between the twisted construction working surface (1) and the formwork. Drill holes on the concrete floor of the twisted construction working surface (1) and insert positioning steel bars (12), and then weld them to the existing anchor bar steel bars (11). In the concrete pouring and curing step, use self-compacting concrete to pour between the anchor bar steel bars (11) and the formwork for support. For the inclined construction working surface (2), in the formwork support step, support the side surface of the inclined construction working surface (2) with side formwork. The side formwork includes two square steel bars with a size of 8 cm * 4 cm. In the concrete pouring and curing step, use a slip form machine (21) for pouring. The slip form machine (21) includes four 20-channel steels. The width of the slip form machine (21) is 80 cm, and the stroke length of the slip form machine (21) is 6 m. A 3 kW winch (22) is installed on each side. The machine cover of the slip form machine (21) is arranged on the side formwork on both sides of the inclined construction working surface (2).

2. The construction method of the shotcrete with mesh as claimed in claim 1, characterized in that: In the formwork support step, set vibrating openings on the formwork. One vibrating opening is set every 2 m, and the size of each vibrating opening is set to 50 cm * 50 cm.

3. The construction method of the shotcrete with wire mesh as claimed in claim 1 or 2, characterized in that: In the concrete pouring and curing step for the twisted construction working surface (1), sprinkle water before pouring to moisten the surface of the twisted construction working surface (1).

4. The construction method of the shotcrete with wire mesh according to claim 3, characterized in that: In the concrete pouring and curing step for the inclined construction working surface (2), manually use a vibrating rod to compact the concrete in the vibrating opening. The winch (22) drives the slip form machine (21) to move up 70 cm, then pour concrete and vibrate it. Repeat this process until the slip form machine (21) reaches the highest point of the inclined construction working surface (2).

5. The construction method of shotcrete with wire mesh as claimed in claim 4, characterized in that: For the base surface cleaning step, clean and level the working area to be constructed with mesh, remove the loose soil and floating slag on the wall slope surface, especially remove the mortar in the loose pointing.

6. The construction method of shotcrete with wire mesh as claimed in claim 5, characterized in that: For the base surface maintenance step, after cleaning the walls in the construction area, repair the missing masonry stones inside the walls and reinforce the loose stones on the walls to ensure the integrity of the masonry base surface.

7. The construction method of shotcrete with wire mesh as claimed in claim 6, wherein: For the step of drilling and hole cleaning, mark the positions and sizes of the holes to be drilled in the construction area according to the design requirements.

8. The construction method of shotcrete with mesh as claimed in claim 7, characterized in that: For the step of drilling and hole cleaning, perform waterproof and drying treatment on the formed holes.

9. The construction method of the shotcrete with wire mesh according to claim 8, characterized in that: For the step of installing anchor bars and tying steel bars, the anchor bar steel bars (11) are set as deformed steel bars with a diameter of 25 mm. Tie the intersection points of every two anchor bar steel bars (11), and at the same time tie the intersection points of the anchor bar steel bars (11) and the positioning steel bars (12).

10. The construction method of shotcrete with mesh as claimed in claim 9, characterized in that: For the step of concrete pouring and curing, remove the formwork on the concrete or the side formwork after pouring. After sprinkling water, cover the concrete with a tarpaulin to keep it moist, and sprinkle water regularly to keep the concrete surface wet.

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