Pre-installed mechanical anchoring device and method

Abstract

mm. Because the present invention first assembles a pre-installed mechanical anchoring device in an open space to ensure that the end face of the end of the rebar can be against the innermost side of the screw hole of the anchoring head, and the end of the rebar is completely fixed in the screw hole of the anchoring head before the subsequent anchoring procedure is carried out, the present invention does not require bolts at all. Since the wall surface does not need to be penetrated by the bolt, the thickness of the wall surface can be controlled to be less than

Description

Technical Field

[0001] This invention relates to an anchoring device and method, and more particularly to a pre-installed mechanical anchoring device and method. Prior Technology

[0002] Reinforced concrete structures possess excellent mechanical strength due to the combination of the compressive strength of concrete and the tensile strength of steel reinforcement, and are therefore widely used in various construction projects or infrastructure projects such as buildings, houses, bridges, roads, and slopes.

[0003] When constructing reinforced concrete structures, the construction unit needs to pre-bundle multiple steel bars into structural forms such as beams and columns according to the building design, and then prepare the formwork before pouring concrete. At the joints of beams and columns, the steel bars usually need to be securely attached to the dried concrete using anchoring structures. A common steel bar hook anchoring structure involves bending the ends of the steel bars into L-shaped or U-shaped hooks, which are then anchored to the concrete after pouring and drying.

[0004] However, the conventional rebar hook anchoring structure has several problems: First, because the length required to form the hook is reserved, the required rebar length is relatively long, increasing the cost of rebar materials, especially for larger rebar gauges and longer lap lengths, which further increases the cost; Second, after forming hooks, the numerous rebars are bound within the rebar structure, increasing the congestion of the rebars and thus restricting the flow of concrete between the coarse aggregates. This is particularly true in reinforced concrete buildings, where beam-column joints are among the most congested areas for rebar configuration, subject to numerous restrictions during construction; Third, hooks inhibit the arrangement of rebars, increasing rebar handling costs; Fourth, before concrete is poured, the hooks of the rebars bound into the rebar structure are in a protruding outward state, and the exposed rebars increase the danger of the construction site.

[0005] Beam-column joints are the points where column and beam members meet, and are among the most complex elements in reinforced concrete structures, especially edge columns, corner columns, top-floor columns, and beam-column joints of discontinuous beams or columns. In traditional construction methods, to meet seismic design requirements, the ends of the reinforcing bars are anchored with hooks, and these hooks are all anchored towards the core of the intersection zone. This results in a more crowded arrangement of reinforcing bars in the intersection zone, making construction difficult, leading to poor concrete pouring quality, and unstable strength of the beam-column joint.

[0006] To address the issues associated with conventional rebar hook anchoring structures, manufacturers now commonly replace them with expanded rebar. Expanded rebar not only shortens the length of the embedded rebar but also solves the problem of rebar crowding, thereby improving the construction quality of beam-column joints.

[0007] Furthermore, in recent years, developed countries around the world have generally faced the problem of an aging population, leading to a gradual reduction in the construction workforce. This results in increased direct labor costs and may even cause labor shortages, leading to increased indirect time costs and greater uncertainty in project schedules. This issue can currently be improved through precast construction methods, particularly in terms of improving project timelines. The application of precast construction methods is extremely diverse. Considering the convenience of component transportation, column and beam components are precast in factories, then transported to the construction site for assembly. Reinforcing steel is then tied at the beam-column intersection, and concrete is poured on-site. This method is the most commonly used combination method in precast construction.

[0008] The application of extended-end reinforcing bars in precast concrete splicing includes both vertical and horizontal laps. In beam-column joints, extended-end reinforcing bars effectively alleviate the problem of reinforcing bar congestion caused by the hooks at the ends, thus improving concrete pouring quality, and also facilitate the application of precast concrete methods. Therefore, in precast concrete construction, replacing the rebar hook anchoring structure with expanded-end rebar has the following advantages: First, it helps to alleviate the rebar congestion caused by hooks at beam-column joints, improving the quality of concrete pouring; second, the tying operation of expanded-end rebar is simple, reducing labor time; third, if used with large-diameter rebar, the manufacturing cost of expanded-end rebar is lower than that of the rebar hook anchoring structure; fourth, it can shorten the embedded length of the rebar, making the size of concrete components and rebar configuration more flexible; fifth, during the manufacturing process of expanded-end rebar, it must be cut flat with high precision, and due to the convenience of on-site construction, the widespread use of expanded-end rebar helps to improve the construction accuracy of concrete structures; sixth, it improves the construction quality of beam-column intersection areas in on-site pouring of precast concrete structures.

[0009] Because the expanded end of the reinforcing bar is T-shaped, it can be called a T-shaped reinforcing bar. Common manufacturing methods for expanded end reinforcing bars in the construction industry include welded expanded end reinforcing bars, hot-rolled expanded end reinforcing bars, and grouted expanded end reinforcing bars.

[0010] Because welded flared rebar is made by welding a rebar and a flared end, high-strength rebar with a high carbon equivalent (CE) is not suitable for electric welding. Generally, rebar with a strength exceeding SD490 is not suitable for welding into welded flared rebar. Based on the form of the flared end, welded flared rebar includes plate welded flared rebar and screw welded flared rebar. Plate welded flared rebar is made by directly friction welding a steel plate of appropriate thickness to the rebar. The friction between the two steels generates high temperatures, allowing them to melt and fuse within tens of seconds, without the need for additional welding materials. The steel plate is usually circular or rectangular. Screw welded flared rebar uses a screw with external threads, directly welded axially to the rebar. The steel plate has a through hole with internal threads, and the screw is fixed to the through hole.

[0011] Hot-rolled expanded-head steel bars are produced by heating the end of the steel bar to a molten state using equipment, and then forging the end to form an expanded head, resulting in a one-piece expanded head design. Special attention must be paid to the adverse effects of heat treatment on high-strength steel bars during the manufacturing of the expanded head ends.

[0012] Grouting-type expanded head steel bars are suitable for threaded section steel bars. Grouting-type expanded head steel bars are made by locking a coarse-toothed sleeve containing an expanded end plate with the threaded section steel bar, and then injecting high-strength mortar to fill the gap between the steel bar and the sleeve. The high consolidation strength of the mortar enables the formed expanded head steel bar to provide repeated tensile and compressive anchoring strength, preventing slippage between the steel bar and the sleeve.

[0013] However, regardless of the type of expanded steel bar, the manufacturing process is relatively complicated and the manufacturing cost is high. Summary of the Invention

[0014] The main objective of this invention is to provide a pre-installed mechanical anchoring device and method that can form an enlarged head on the reinforcing bar in a simple and low-cost manner, and provide excellent firmness between the enlarged head and the reinforcing bar.

[0015] To achieve the aforementioned objectives, the present invention provides a pre-installed mechanical anchoring device, comprising a reinforcing bar and an anchoring head. The reinforcing bar includes an end with external threads. The anchoring head has a first end and a second end and a threaded hole extending through the first end of the anchoring head and having internal threads. The end of the reinforcing bar is fixed to the threaded hole, and the end face of the end of the reinforcing bar abuts against the innermost side of the threaded hole. A wall surface is formed between the innermost side of the threaded hole and the second end of the anchoring head, and the thickness of the wall surface is less than 10 mm.

[0016] In some embodiments, the thickness of the wall is less than 10 mm and greater than or equal to 5 mm.

[0017] In some embodiments, a through hole is formed in the wall surface, the diameter of which is smaller than the diameter of the screw hole.

[0018] In some embodiments, the screw hole is a blind hole.

[0019] To achieve the aforementioned objective, the present invention provides a pre-installed mechanical anchoring method, comprising the following steps: in an open space, fixing one end of a reinforcing bar to a screw hole of an anchor head, with the end face of the reinforcing bar abutting against the innermost side of the screw hole to obtain a pre-installed mechanical anchoring device, wherein the end of the reinforcing bar has an external thread, the screw hole penetrates a first end of the anchor head and has an internal thread, and the anchor head forms a wall between the innermost side of the screw hole and a second end of the anchor head, the thickness of the wall being less than 10 mm; forming a reinforcing bar structure by combining a plurality of reinforcing bars of a plurality of pre-installed mechanical anchoring devices, and extending the plurality of anchor heads of the pre-installed mechanical anchoring devices into the reinforcing bar structure; and pouring concrete into the reinforcing bar structure, wherein after the concrete dries, the concrete anchors the anchor heads of the pre-installed mechanical anchoring devices.

[0020] In some embodiments, the thickness of the wall is less than 10 mm and greater than or equal to 5 mm.

[0021] In some embodiments, a through hole is formed in the wall surface, the diameter of which is smaller than the diameter of the screw hole.

[0022] In some embodiments, the screw hole is a blind hole.

[0023] The advantage of this invention lies in the fact that, because it first assembles the mechanical anchoring device in an open space to ensure that the end face of the reinforcing bar abuts against the innermost side of the screw hole of the anchoring head, and the end of the reinforcing bar is completely fixed to the screw hole of the anchoring head 20 before proceeding with the subsequent anchoring process, this invention completely eliminates the need for bolts. Since the wall surface does not require bolts to pass through, the wall thickness can be controlled to be less than 10 mm, thereby reducing the manufacturing cost of the anchoring head. Simple Explanation of the Diagram

[0024] Figure 1 is a combined cross-sectional view of the first embodiment of the pre-installed mechanical anchoring device of the present invention. Figure 2 is an exploded view of the first embodiment of the pre-installed mechanical anchoring device of the present invention. Figure 3 is a flowchart of the pre-installed mechanical anchoring method of the present invention. Figure 4 is a schematic diagram of step S20 of the pre-installed mechanical anchoring method of the present invention. Figure 5 is a schematic diagram of step S30 of the pre-installed mechanical anchoring method of the present invention. Figure 6 is a combined cross-sectional view of a second embodiment of the pre-installed mechanical anchoring device of the present invention. Figure 7 is an exploded view of a second embodiment of the pre-installed mechanical anchoring device of the present invention. Implementation

[0025] The following description, in conjunction with the accompanying drawings and component symbols, provides a more detailed account of the embodiments of the present invention, so that those skilled in the art can implement them after studying this specification.

[0026] Figure 1 is a combined cross-sectional view of a first embodiment of the pre-installed mechanical anchoring device 1 of the present invention. Figure 2 is an exploded cross-sectional view of the first embodiment of the pre-installed mechanical anchoring device 1 of the present invention. As shown in Figures 1 and 2, the present invention provides a pre-installed mechanical anchoring device 1, including a reinforcing bar 10 and an anchoring head 20. One end 11 of the reinforcing bar 10 has external threads. The anchoring head 20 has a first end 21 and a second end 22 and a screw hole 23 is formed therein. The screw hole 23 penetrates the first end 21 of the anchoring head 20 and has internal threads. The end 11 of the reinforcing bar 10 is fixed to the screw hole 23, and the end face of the end 11 of the reinforcing bar 10 abuts against the innermost side of the screw hole 23. A wall surface 24 is formed between the innermost side of the screw hole 23 and the second end 22 of the anchoring head 20, and the thickness T of the wall surface 24 is less than 10 mm.

[0027] Figure 3 is a flowchart of the pre-installed mechanical anchoring method of the present invention. Figure 4 is a schematic diagram of step S20 of the pre-installed mechanical anchoring method of the present invention. Figure 5 is a schematic diagram of step S30 of the pre-installed mechanical anchoring method of the present invention. The present invention provides a pre-installed mechanical anchoring method, comprising the following steps:

[0028] In step S10, as shown in Figures 1 and 3, in an open space, one end 11 of a reinforcing bar 10 is fixed to a screw hole 23 of an anchor head 20, with the end face of the end 11 of the reinforcing bar 10 abutting against the innermost side of the screw hole 23, to obtain a pre-installed mechanical anchoring device 1. The end 11 of the reinforcing bar 10 has external threads, the screw hole 23 penetrates a first end 21 of the anchor head 20 and has internal threads, and the anchor head 20 forms a wall 24 between the innermost side of the screw hole 23 and a second end 22 of the anchor head 20, the thickness of the wall 24 being less than 10 mm.

[0029] In step S20, as shown in Figures 3 and 4, a plurality of steel bars 10 with a plurality of pre-installed mechanical anchoring devices 1 are used to form a steel reinforcement structure 100, and a plurality of anchor heads 20 of the pre-installed mechanical anchoring devices 1 are inserted into the steel reinforcement structure 100.

[0030] In step S30, as shown in Figures 3 and 5, a concrete 200 is poured into the reinforced concrete structure 100. After the concrete 200 dries, it anchors the anchor heads 20 of the pre-installed mechanical anchoring devices 1.

[0031] Furthermore, in the confined space of a construction site, when the end 11 of the reinforcing bar 10 is attached to the screw hole 23 of the anchor head 20, the anchor head 20 is only held at the end 11 of the reinforcing bar 10. The end face of the end 11 of the reinforcing bar 10 cannot abut against the innermost side of the screw hole 23, causing the end 11 of the reinforcing bar 10 to be unable to be fixed to the screw hole 23 of the anchor head 20. To solve the above problem, a conventional technique involves opening a through hole in the anchor head 20. The through hole penetrates the second end 22 of the anchor head 20 and has internal threads, and the diameter of the screw hole 23 is larger than the diameter of the through hole. In this conventional technique, a bolt is inserted into the through hole, and the head of the bolt is rotated to apply torque to the bolt. This causes the end face of the bolt to press against the end face of the end 11 of the reinforcing bar 10 with an axial pressure. The anchor head 20, screwed onto the reinforcing bar 10, will then exert a reverse tensile force on the reinforcing bar 10. Therefore, the opposing axial pressure and tension acting on the reinforcing bar 10 cause the reinforcing bar 10 to generate preload, thus firmly fixing the anchor head 20 to the reinforcing bar 10 and preventing it from loosening due to external forces such as earthquakes. However, the length of the screw is usually greater than or equal to 10 mm. In order for the screw to contact the end 11 of the reinforcing bar 10 through the through hole, the depth of the through hole is usually also greater than or equal to 10 mm. Therefore, the thickness T of the wall 24 between the innermost side of the screw hole 23 and the second end 22 of the anchor head 20 is usually greater than or equal to 10 mm in order to make a through hole with a depth greater than or equal to 10 mm, which increases the manufacturing cost of the anchor head 20.

[0032] Because this invention first assembles the mechanical anchoring device 1 in an open space to ensure that the end face of the end 11 of the reinforcing bar 10 can abut against the innermost side of the screw hole 23 of the anchoring head 20, and the end 11 of the reinforcing bar 10 is completely fixed to the screw hole 23 of the anchoring head 20 before proceeding with the subsequent anchoring procedure, this invention completely eliminates the need for bolts. Since the wall surface 24 does not need to be penetrated by bolts, the thickness T of the wall surface 24 can be controlled to be less than 10 mm, thereby reducing the manufacturing cost of the anchoring head 20.

[0033] Preferably, the thickness T of the wall surface 24 is less than 10 mm and greater than or equal to 5 mm. Specifically, if the thickness T of the wall surface 24 is less than 5 mm, the thickness T of the wall surface 24 will be too thin to withstand the locking force of the end 11 of the reinforcing bar 10, causing the end 11 of the reinforcing bar 10 to easily break the wall surface 24. Therefore, the thickness T of the wall surface 24 is preferably controlled to be less than 10 mm and greater than or equal to 5 mm, so that the thickness T of the wall surface 24 is sufficient to withstand the locking force of the end 11 of the reinforcing bar 10, and the end 11 of the reinforcing bar 10 will not break the wall surface 24. If manufacturing cost is taken into consideration, the manufacturing cost is lowest when the thickness T of the wall surface 24 is equal to 5 mm, and the thickness T of the wall surface 24 is still sufficient to withstand the locking force of the end 11 of the reinforcing bar 10, which is the best implementation method.

[0034] As shown in Figures 1 and 2, in the first embodiment, a through hole 241 is formed in the wall surface 24, and the diameter of the through hole 241 is smaller than the diameter of the screw hole 23.

[0035] Figure 6 is a combined cross-sectional view of a second embodiment of the pre-installed mechanical anchoring device 1A of the present invention. Figure 7 is a cutaway cross-sectional view of a second embodiment of the pre-installed mechanical anchoring device 1A of the present invention. As shown in Figures 6 and 7, the difference between the second embodiment and the first embodiment is that the wall surface 24A of the anchoring head 20A has no perforation 241, and the screw hole 23 is a blind hole.

[0036] The above description is merely for explaining preferred embodiments of the present invention and is not intended to limit the present invention in any way. Therefore, any modifications or changes made to the present invention under the same inventive spirit should still be included within the scope of protection intended by the present invention.

[0037] 1,1A: Install mechanical anchoring device first. 10: Reinforcing steel bars 11: End 20,20A: Anchor head 21: First end 22: Second end 23: Screw hole 24,24A: Wall 241: Perforation 100: Reinforced concrete structure 200: Concrete S10~S30: Steps T: Thickness

Claims

1. A pre-installed mechanical anchoring device, comprising: A reinforcing bar, including an end having external threads; An anchor head having a first end and a second end and a threaded hole, the threaded hole penetrating the first end of the anchor head and having an internal thread, the end of the reinforcing bar being fixed to the threaded hole, and the end face of the end of the reinforcing bar abutting against the innermost side of the threaded hole; wherein, the anchor head forms a wall between the innermost side of the threaded hole and the second end of the anchor head, the wall having a thickness of 5 mm.

2. The pre-installed mechanical anchoring device as described in claim 1, wherein, A through hole is made in the wall surface, and the diameter of the through hole is smaller than the diameter of the screw hole.

3. The pre-installed mechanical anchoring device as described in claim 1, wherein, The screw hole is a blind hole.

4. A pre-installed mechanical anchoring method, comprising the following steps: In an open space, fixing one end of a reinforcing bar to a screw hole of an anchor head, wherein the end face of the reinforcing bar abuts against the innermost side of the screw hole, thereby obtaining a pre-installed mechanical anchoring device, wherein... The end of the reinforcing bar has an external thread, the threaded hole penetrates a first end of the anchor head and has an internal thread, the anchor head forms a wall between the innermost side of the threaded hole and a second end of the anchor head, the wall having a thickness of 5 mm; a plurality of reinforcing bars with pre-installed mechanical anchoring devices are used to form a reinforcing bar structure, and the plurality of anchor heads of the pre-installed mechanical anchoring devices are inserted into the reinforcing bar structure; and a concrete is poured into the reinforcing bar structure, which, after drying, anchors the anchor heads of the pre-installed mechanical anchoring devices.

5. The pre-installed mechanical anchoring method as described in claim 4, wherein, A through hole is made in the wall surface, and the diameter of the through hole is smaller than the diameter of the screw hole.

6. The pre-installed mechanical anchoring method as described in claim 4, wherein, The screw hole is a blind hole.

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