TWI809329B - Bar anchoring system and method - Google Patents

Abstract

A steel bar anchoring system and method, comprising: a steel bar, at least one end of which is formed with an external thread; The other end of the anchor head is formed with a second through hole that extends into the interior of the anchor head and communicates with the first through hole. The inner surface of the first through hole is formed with a first internal thread that matches the external thread of the steel bar. The inner surface of the second through hole is formed with a second internal thread, and one end of the anchor head is matched with the external thread through the first internal thread to be installed on the end of the steel bar; and the bolt has a connection with the anchor head The screw rod matched with the second internal thread, the screw rod is locked into the second through hole from the other end of the anchor head, and the end of the screw rod resists the end of the steel bar with an active force. After the steel bar structure composed of multiple steel bar groups is poured with concrete, the anchor head will produce an anchoring effect in the concrete.

Description

Bar anchoring system and method

The invention relates to the field of construction engineering, in particular to a system and method for anchoring steel bars.

Reinforced concrete structures have excellent mechanical strength due to the combination of the compressive properties of concrete materials and the tensile properties of reinforced materials, so they are widely used in various constructions such as buildings, houses, bridges, roads, slopes, ... engineering or infrastructure.

When building a reinforced concrete structure, it is necessary to bundle multiple steel bars into structural forms such as beams and columns in advance according to the design of the building, and perform concrete grouting after matching the formwork. Rebars at junctions of structures such as beams, columns, etc. need to have anchoring structures to firmly bond the rebars to the cured concrete. The conventional steel bar anchoring structure is shown in Figure 1A and Figure 1B, which is bent at the end of the steel bar A to form an L-shaped hook A1 or a U-shaped hook A2. Hook A1 or A2 is anchored to concrete and fixed.

However, there are the following disadvantages in the aforementioned known steel bar hook anchoring method:

1. Due to the need to reserve the length to form the hook, the length of the steel bar required is longer, which increases the cost of the steel bar material, especially the larger the number of the steel bar, the longer the lap length, and the higher the cost.

2. Most of the steel bars form hooks and are bound in the steel bar structure, which will increase the congestion of the steel bars, thereby limiting the fluidity of the concrete poured between the coarse aggregates. In particular, the beam-column joint is one of the most congested parts of the reinforcement configuration in reinforced concrete buildings, and it is subject to many restrictions during construction.

3. The curved hook will inhibit the arrangement of the steel bars and increase the operating cost of the steel bars.

4. Before the concrete is poured, the hooks of the steel bars bundled into the steel bar structure are in a protruding state, and the exposed steel bars increase the danger of the construction site.

The beam-column joint is the intersection point of the column member and the beam member. When the construction method wants to meet the seismic design requirements, because the ends of the main reinforcement are anchored by hooks, and the hooks of the steel bars are all anchored towards the core of the intersection area, the reinforcement configuration in the intersection area is more crowded, and it is easy to cause concrete damage due to construction difficulties. Poor pouring quality has further raised doubts that the strength of beam-column joints cannot be guaranteed.

In order to solve the lack of the above-mentioned steel hook anchoring structure, it is known that the expansion head steel bar has been used to replace the traditional hook anchoring form. In addition to shortening the embedding length of the steel bar, it can also reduce the damage caused by reducing the end of the hook. To improve the construction quality of the beam-column joints.

In addition, in recent years, with the population aging in Taiwanese society, the labor force for construction projects has gradually decreased, resulting in an increase in direct labor costs, and may even result in a lack of work, resulting in an increase in indirect time costs and increased uncertainty in the construction period. This issue is currently It can be improved by adopting the 預鑄 construction method, which is especially helpful to the improvement of the construction period. The application of the 預鑄 construction method is extremely diverse. Considering the convenience of component transportation, the column and beam components are produced in the factory using the 預鑄 method, and then transported to the construction site for assembly, binding the steel bars in the beam-column intersection area, and Concrete is poured on site. This method is the most commonly used combination method in the 預鑄 construction method.

In the details of the lap joint arrangement of the expanded steel bar applied to the 預鑄 method, it can be divided into two types: vertical lap joints and horizontal lap joints. Expanding the steel bar in the beam-column joint can not only effectively reduce the congestion of the steel bar caused by the hook at the end of the steel bar to improve the quality of concrete pouring, but also help the application of the 預鑄 construction method. Therefore, in the 預鑄 construction method, the use of expanded steel bars to replace traditional hooked steel bars has the following advantages: 1. It helps to reduce the congestion of the steel bars caused by the bent hooks at the joints, and improves the quality of concrete pouring; 2. The binding operation of expanded steel bars is simple , can reduce man-hours; 3. If it is applied to large steel bars, the production cost of head expansion is more economical than that of hooked steel bars; 4. It can shorten the embedding length of steel bars, making the size of concrete members and the configuration of steel bars more flexible; 5 .Because the steel bar must be cut flat during production, the precision is high, and because of the convenience of on-site construction, it is helpful to improve the construction accuracy of the concrete structure when it is widely used; The construction quality of the intersection area.

Expanded bars are called T-head bars because of their shape. Commonly expanded steel bars in the engineering field are shown in Figure 3, and can be divided into three types according to the production method of the expanded head, including:

1. Welded expanded steel bar: Because the steel bar is welded to the expanded head by welding, high-strength steel bars with high carbon equivalent (CE) are not suitable for electric welding processing. Generally, steel bars with a strength exceeding SD490 are not suitable for welding processing. Welded head-expanding steel bars can be divided into steel plate-welded head-expanding steel bars and screw-welded head-expanding steel bars according to the form of objects welded to the steel bars. Among them, as shown in Figure 2A, The steel plate type expanded head steel bar adopts steel plate B of appropriate thickness to be directly joined with steel bar A by friction welding. The high heat generated by the friction between the two steel materials can be melted and joined within tens of seconds without using additional welding consumables. The shape of the expansion head steel plate is usually round or rectangular. As shown in Figure 2B, the screw welded expanded head steel bar is directly welded to the steel bar A in the axial direction with the screw C having external threads, and the expanded head steel plate B is machined with internal threads to lock with the screw C. The expanding process of the welded expanding steel bars is complicated and costly.

2. Hot-rolled head-expanding steel bar: as shown in Figure 2C, it uses equipment to heat the end of steel bar A to a molten state, and then extrudes the end of the steel bar by forging to form head-enlarging A3, which is integrally formed Expander style. The manufacture of the end of the expanded head requires special attention to the adverse effects of heat treatment on the high-strength steel bars, and the expanded process is complicated and costly.

3. Grouting-type expanded head reinforcement: This type of expanded head reinforcement is suitable for threaded section steel bars. After locking the threaded section steel bars with the coarse-threaded sleeve containing the expanded head end plate, high-strength mortar is poured and filled with mortar. The gap between the steel bar and the sleeve, and the high consolidation strength of the mortar, so that the formed expanded steel bar can provide the anchoring strength of repeated tension and compression, and avoid sliding between the steel bar and the sleeve. However, the manufacturing process of this kind of expanded steel bar is relatively cumbersome and costly.

The object of the present invention is to provide a steel bar anchoring system and method which can easily and cost-effectively form an expansion head on a steel bar, and provide excellent firmness between the expansion head and the steel bar.

The steel bar anchoring system provided by the present invention includes: a steel bar, an external thread is formed on the periphery of at least one end of the steel bar; The other end in the axial direction is formed with a second through hole that extends into the anchor head and communicates with the first through hole. The inner surface of the first through hole is formed with a thread that matches the external thread of the steel bar. a first internal thread, the inner surface of the second through hole is formed with a second internal thread, and one end of the anchor head matches the external thread through the first internal thread to be installed on the end of the steel bar; and a bolt, There is a cap head and a screw connected to the cap head, the screw rod is used to match the second internal thread of the anchor head, the screw rod is locked into the second through hole from the other end of the anchor head, and the screw rod The end portion of the screw rod resists the end portion of the steel bar with an active force; wherein, the outer surface of the screw rod is formed with a ring groove around the circumference at a position along its central axis to separate the thread of the screw rod from the cap head groove, and the diameter of the bottom surface of the ring groove is smaller than the outer diameter of the screw rod, and wherein, the radial net cross-sectional area of the anchor head is more than four times larger than the radial cross-sectional area of the steel bar. By means of the anchoring system, when the screw pushes against the end of the bar with a force, the bar The end of the cap will bear an axial pressure, so that the anchor head will generate axial tension on the steel bar relatively, that is, the steel bar will be firmly combined with the anchor head due to pre-stress; When the applied torsion force exceeds a predetermined value, the screw rod can be broken along the ring groove, thereby assisting the construction personnel to quickly judge whether the bolt exerts a predetermined force on the steel bar; The radial cross-sectional area of the reinforcing bar is more than four times, and the anchoring head can have the best anchoring effect on the concrete structure under the principle of economy.

In a preferred embodiment of the present invention, the length of the steel bar with the external thread can be formed in the shape of a round rod or a tapered rod, and the first through hole of the anchor head is formed in a shape similar to that of the round rod or tapered rod. Matching round or tapered hole shape.

Preferably, the first through hole and the second through hole formed at both ends of the anchor head are aligned in a straight line in the axial direction, so that the screw rod can exert force on the end of the steel bar most efficiently.

The present invention also provides a steel bar anchoring method, comprising: providing a steel bar, and forming an external thread on the periphery of at least one end of the steel bar; constructing a steel bar structure by cooperating the steel bar with other steel bars, and making the external thread The steel bar extends into the steel bar structure of the built ditch; an anchor head is provided, one axial end of which is formed with a first through hole extending axially into the anchor head, and the other axial end is formed with an extending A second through hole that enters the interior of the anchor head and communicates with the first through hole. The inner surface of the first through hole is formed with a first internal thread that matches the external thread of the steel bar. The second through hole A second internal thread is formed on the inner surface of the anchor head, and one end of the anchor head is mounted on the end of the steel bar by matching the first internal thread with the external thread; a bolt is provided, and the bolt has a cap head and connects the cap The screw of the head, the outer surface of the screw is formed with a ring groove around the circumference to separate the thread of the screw from the cap head at a position along its central axis, and the diameter of the bottom surface of the ring groove is smaller than that of the screw. The outer diameter of the anchor head, and the radial net cross-sectional area of the anchor head is more than four times greater than the radial cross-sectional area of the steel bar; The other end of the anchor rod is locked into the second through hole, and when the end of the screw rod is pressed against the end of the steel bar, a rotational force is continuously applied to the bolt, so that the end of the screw rod is pressed against the end of the steel bar. A longitudinal pressure is applied, so that the anchor head exerts longitudinal tension on the steel bar relatively, so that the anchor head and the steel bar are fixed to each other, and when the rotational force applied to the bolt reaches a predetermined value, the screw rod breaking along the diameter direction of the ring groove; and grouting, pouring concrete into the steel structure, and anchoring the anchor head after the concrete is dry. In this way, when the torque applied to the bolt exceeds a predetermined value, the screw rod can be broken along the ring groove, thereby assisting construction personnel to quickly judge whether the bolt exerts a predetermined force on the steel bar.

In an embodiment of the steel bar anchoring method, the radial net cross-sectional area of the anchor head is more than four times larger than the radial cross-sectional area of the steel bar. Thereby, the anchoring head has the best anchoring effect on the concrete structure under the principle of economy.

In one embodiment of the steel bar anchoring method, a length of the steel bar with the external thread is formed in the shape of a round rod or a tapered rod, and the first through hole of the anchor head is formed to be in the shape of the round rod or the tapered rod. Round or tapered hole shape matched by taper rod shape.

In an embodiment of the reinforcing bar anchoring method, the first through hole and the second through hole are linearly aligned in the axial direction, so that the screw rod can exert force on the end of the reinforcing bar most efficiently.

The present invention can quickly combine the anchor head with the steel bar and obtain a firm effect by using the aforementioned steel bar anchoring system and method; in addition, the construction personnel can quickly judge whether the bolt is broken or not according to whether the screw rod is broken or not when the bolt is locked. Apply a predetermined force to the steel bar, thus saving the cost of manpower inspection.

"this invention"

1: Rebar

11: external thread

2: anchor head

21: The first through hole

211: The first internal thread

22: Second through hole

221: Second internal thread

3: Bolt

30: cap head

31: screw

32: ring groove

"Known Technology"

A: Rebar

A1: L-shaped curved hook

A2: U-shaped curved hook

A3: Head expansion

B: steel plate

C: screw

Figure 1A is a schematic diagram showing that the end of a conventional steel bar is bent into an L-shaped hook; Figure 1B is a schematic diagram showing that the end of a conventional steel bar is bent into a U-shaped hook; Figure 2A is a schematic diagram showing the end of a conventional steel bar and a steel plate A schematic diagram of direct welding to form an expanded head; Figure 2B is a schematic diagram showing the end of a conventional steel bar after welding the screw, and then locking the screw into a steel plate to form an expanded head; Figure 2C is a schematic diagram showing the end of a conventional steel bar heated to a molten state , and then extruded by forging to form a schematic diagram of the expanded head; Fig. 3 is a plane sectional exploded view showing the combination relationship of the main components of the steel anchor system of the present invention; Fig. 4 is a structural section showing the steel anchor system of the present invention Fig. 5 is a schematic diagram showing that the bolt of the steel anchoring system of the present invention is applied to a torque exceeding a predetermined value so that the screw breaks; and Fig. 6 shows that the steel anchoring system of the present invention is applied to the T-shaped beam-column junction Example schematic.

The implementation of the present invention will be described in more detail below in conjunction with the diagrams and component symbols, so that those skilled in the art can implement it after studying this specification.

As shown in FIG. 2 and FIG. 3 , the preferred embodiment of the steel bar anchoring system provided by the present invention includes: a steel bar 1 , an anchor head 2 and a bolt 3 .

Wherein, the periphery of at least one end of the steel bar 1 is formed with an external thread 11 through processing.

A preferred embodiment of the anchor head 2 is a circular columnar body, one axial end of which is formed with a first through hole 21 extending axially into the interior of the anchor head 2, and the other axial end is formed with a first through hole 21 extending into the interior of the anchor head 2. The second through hole 22 inside the anchor head 2 and communicated with the first through hole 21 , and the first through hole 21 and the second through hole 22 are preferably linearly aligned in the axial direction. The inner surface of the first through hole 21 is formed with a first internal thread 211 matching the external thread 11 of the steel bar 1, and the inner surface of the second through hole 22 is formed with a second internal thread 221 for locking the bolt 3, so One end of the anchor head 2 is mated and locked with the outer thread 11 of the steel bar 1 through the first internal thread 211 to connect the anchor head 2 to the end of the steel bar 1 .

The bolt 3 has a cap head 30 and a screw rod 31 connected to the cap head 30. The screw rod is used to match the second internal thread 221 of the anchor head 2, so that the screw rod 31 is locked into the second thread from the other end of the anchor head 2. Through hole 22. Preferably, the present invention forms an annular groove 32 around the circumference at a position on the outer surface of the screw 31 along its central axis, and the annular groove 32 separates the thread of the screw 31 from the cap head 30 by a distance, and The diameter of the bottom surface of the ring groove 32 is smaller than the outer diameter of the screw 31 . For example, the ring groove 32 may be located at the root of the screw shank 31 adjacent to the bolt head. More specifically, the net radial cross-sectional area of the anchor head 2 after deducting the radial area of the first through hole 21 is more than four times larger than the radial cross-sectional area of the steel bar 1 .

A length with the external thread 11 of the steel bar 1 can be formed in the shape of a round rod or a tapered rod. When the area of the external thread 11 of the steel bar 11 is in the shape of a round rod, the first through hole 21 of the anchor head 2 is correspondingly formed to be in the shape of a round rod. The shape of the round hole matches the round rod; when the external thread 11 area of the steel bar 11 is in the shape of a tapered rod, the first through hole 21 of the anchor head 2 is correspondingly formed in a shape of a tapered hole matching the tapered rod.

With the aforementioned steel bar anchoring system, when the anchor head 2 is helically combined on the steel bar 1, the anchor head 2 is actually only held on the steel bar 1 without being fixed; and when the screw rod 31 of the bolt 3 is further locked into When the second through hole 22 of the anchor head 2 is operated and the cap head 30 is applied to apply torque to the bolt 3 so that the end of the screw rod 31 is pressed against the end of the steel bar 1 with an axial pressure, the anchor screwed to the steel bar 1 The fixed head 2 will relatively exert a reverse pulling force on the steel bar 1. Therefore, the opposite axial pressure and tension acting on the steel bar will cause the steel bar 1 to generate a preload, so that the anchor head 2 is firmly fixed on the steel bar 1. , will not be loosened by external forces such as earthquakes.

In more detail, since the radial cross-sectional area of the screw rod 31 at the corresponding ring groove 32 is smaller than the radial cross-sectional area of the screw rod 31, the strength of the radial cross-section of the screw rod 31 at the corresponding ring groove 32 is smaller than that of the complete ring groove 32. The strength of the radial section of the whole screw 31; thereby, when the bolt 3 is locked into the second through hole 22 of the anchor head 2 by the screw 31 and the screw 31 is touched against the end of the steel bar 1, the bolt 3 is continuously applied. When the applied torque exceeds the preset torque value of the screw 31 corresponding to the ring groove 22, it will cause the screw 31 to break along the ring groove 32; with this design, the construction personnel or inspectors can quickly judge the bolt 3 Whether the anchor head 2 has been locked to the steel bar 1. In other words, if the screw 31 is not broken, it means that the torque applied by the screw 31 is insufficient, and it is necessary to continue to apply the torque until the screw 31 breaks to obtain enough torque.

As shown in Figure 6, when the aforementioned steel bar anchoring system is applied to T-shaped beam-column joints or even other construction projects, multiple steel bars 1 are bundled into steel bar structures such as columns or beams. The end of the steel bar 1 has been pre-formed with external threads, and then the internal thread of the first through hole of the anchor head 2 is locked to the external thread of the steel bar 1, and then the bolt 3 is inserted from the second hole of the anchor head 2 with a tool. The through hole is locked to fix the anchor head 2 to the steel bar 1, and then the concrete pouring operation can be performed.

The present invention also provides a steel bar anchoring method, which uses the above-mentioned steel bar anchoring system, and the method includes: providing a steel bar, and forming an external thread on the periphery of at least one end of the steel bar; matching the steel bar with other steel bars Constructed into a steel bar structure, and the steel bar with the external thread is inserted into the steel bar structure of the built ditch; an anchor head is provided, and one axial end thereof is formed with an axially extending into the inside of the anchor head The first through hole, the other axial end is formed with a second through hole extending into the anchor head and communicating with the first through hole, the inner surface of the first through hole is formed with the external thread of the steel bar A matching first internal thread, the inner surface of the second through hole is formed with a second internal thread, and one end of the anchor head is matched with the external thread through the first internal thread to be installed on the end of the steel bar; A bolt is provided, the bolt has a cap head and a screw rod connected to the cap head, the screw rod is used to match the first internal thread of the anchor head, and the screw rod is locked into the second thread from the other end of the anchor head. When the end of the screw is pressed against the end of the steel bar, a rotational force is continuously applied to the bolt, so that the end of the screw exerts a longitudinal pressure on the end of the steel bar, so that the anchor The fixing head exerts longitudinal tension on the steel bar relative to each other, so that the anchor head and the steel bar are fixed to each other; and grouting, pouring concrete into the steel bar structure, and anchoring the anchor head after the concrete is dry.

The above-mentioned are only preferred embodiments for explaining the present invention, and are not intended to limit the present invention in any form. Therefore, all related works of the present invention under the spirit of the same invention Any modifications or changes should still be included in the intended protection scope of the present invention.

1: Rebar

11: external thread

2: anchor head

21: The first through hole

211: The first internal thread

22: Second through hole

221: Second internal thread

3: Bolt

30: cap head

31: screw

32: ring groove

Claims (6)

A steel bar anchoring system, comprising: a steel bar, at least one end of which is formed with an external thread; an anchor head, whose axial end is formed with a first through hole axially extending into the interior of the anchor head, the shaft The other end of the direction is formed with a second through hole extending into the anchor head and communicating with the first through hole. The inner surface of the first through hole is formed with a first inner thread matching the external thread of the steel bar Thread, the inner surface of the second through hole is formed with a second internal thread, and one end of the anchor head matches the external thread through the first internal thread to be installed on the end of the steel bar; and a bolt has a cap head and a screw rod connected to the cap head, the screw rod is used to match the second internal thread of the anchor head, the screw rod is locked into the second through hole from the other end of the anchor head, and the screw rod The end resists the end of the steel bar with an active force; wherein, the outer surface of the screw is formed at a position along its central axis with a ring groove around the circumference to separate the thread of the screw from the cap head by a certain distance groove, and the diameter of the bottom surface of the ring groove is smaller than the outer diameter of the screw rod, and wherein, the radial net cross-sectional area of the anchor head is more than four times larger than the radial cross-sectional area of the steel bar. The steel bar anchoring system as described in claim 1, wherein, a length of the steel bar with the external thread is formed in the shape of a round rod or a tapered rod, and the first through hole of the anchor head is formed to be in line with the round The shape of the rod or taper matches the shape of the round or tapered hole. The steel bar anchoring system as claimed in claim 1, wherein the first through hole and the second through hole are linearly aligned in the axial direction. A reinforcing bar anchoring method, comprising: providing a reinforcing bar, and forming an external thread on the periphery of at least one end of the reinforcing bar; constructing a reinforcing bar structure with the reinforcing bar with other reinforcing bars, and extending the reinforcing bar with the external thread into In the reinforcing bar structure of the built ditch; an anchor head is provided, one axial end of which is formed with a first through hole extending axially into the interior of the anchor head, and the other axial end is formed with a first through hole extending into the anchor head. A second through hole inside the head and communicated with the first through hole, the inner surface of the first through hole is formed with a first internal thread matching the external thread of the steel bar, and the inner surface of the second through hole is formed There is a second internal thread, and one end of the anchor head is passed through the first internal thread The thread is matched with the external thread to be installed on the end of the steel bar; a bolt is provided, the bolt has a cap head and a screw rod connected to the cap head, the screw rod is used to match the first internal thread of the anchor head, and the The screw rod is locked into the second through hole from the other end of the anchor head, and when the end of the screw rod is resisted by the end of the steel bar, a rotating force is continuously applied to the bolt, so that the end of the screw rod is opposite to the applying a longitudinal pressure to the end of the steel bar, so that the anchor head exerts longitudinal tension on the steel bar relative to each other, so that the anchor head and the steel bar are fixed to each other; and grouting, pouring concrete into the steel bar structure, After the concrete is dry, the anchor head is anchored; wherein, the outer surface of the screw rod is formed with a ring around the circumference at a position along its central axis to separate the thread of the screw rod from the cap head by a certain distance groove, and the diameter of the bottom surface of the ring groove is smaller than the outer diameter of the screw rod, when the rotational force applied to the bolt reaches a predetermined value, the screw rod is broken along the diameter direction of the ring groove, and wherein, the The radial net cross-sectional area of the anchor head is more than four times larger than the radial cross-sectional area of the steel bar. The steel bar anchoring method as described in claim 4, wherein, a length of the steel bar with the external thread is formed in the shape of a round rod or a tapered rod, and the first through hole of the anchor head is formed to be in line with the round The shape of the rod or taper matches the shape of the round or tapered hole. The steel bar anchoring method according to claim 4, wherein the first through hole and the second through hole are aligned in a straight line in the axial direction.

Images