KR20010074069A - Reinforcements for bending-moment and shear in the part of reinforced concrete footings and construction method of its using - Google Patents

Abstract

PURPOSE: A bending and shearing stiffener and a constructing method thereof are provided to easily conduct a bar arrangement, to reduce footing thickness in case of the lower footing of a bearing wall and to apply an angle, a flat bar and a wire mesh as well as a reinforcement without an additional welding process. CONSTITUTION: A bending and shearing stiffener consists of; a bending stiffener(1) arranged in the lower portion; a position fixing material(2) arranged in the upper portion; a shearing stiffener(3) connecting the latticed points of the bending stiffener and the latticed points of the position fixing material; a shear connector(4) extended from the shearing stiffener under the bending stiffener at the cross point between the shearing stiffener and the bending stiffener; and a connecting bar arrangement material(5) connecting a bar arrangement around a footing and bar arrangement of an upper structure. Then, a footing lower bar(6) is arranged and the bending and shearing stiffener is put on the footing lower bar. Finally, a footing upper bar(7) is placed on the bending and shearing stiffener to be a reinforced concrete footing.

Description

Reinforcements for bending-moment and shear in the part of reinforced concrete footings and construction method of its using}

The present invention relates to a flexural / shear combined reinforcement that can be used universally in reinforced concrete foundation (footing) and a construction method of the foundation using the reinforcement.

Generally, for reinforced concrete foundations, shear reinforcement is referred to in Section 7.10 of Korea's Ministry of Construction and Transportation Concrete Structural Design Standards (1999).

Take a form that bears a part of the shear force by using the girder used for the beams laid out in the form of tie girder, or cross the lower part of the column if the column is steel or steel-reinforced concrete Flexural stiffeners are being used to install steel frame pedestals so that the steel can bear the bending stress on the foundation. (Reinforced Concrete Slabs, 1999, 2nd Edition, John Wiley & Sons, Robert Park / William L. Gamble, p567 )

However, the tie girder, which is often used for shear reinforcement in the foundation of general reinforced concrete structures, should be fitted with all the bottom bars of the base beam to the base reinforcing bar. Since it has to be installed through the top, the working speed in the field is lowered and the work fatigue is raised, which is causing the workers to avoid shear reinforcement.

On the other hand, if the upper member of the foundation is a pillar, shear reinforcement may be performed in the form of underground beams. However, if the upper member is a bearing wall, such shear reinforcement of such ground reinforcement cannot be applied. The concrete is designed to bear more of the shear stress acting on the foundation by increasing its thickness.

In steel reinforcement,

If the steel aggregate is installed as a composite member after placing the lower part of the foundation on the foundation, additional welding is applied to the steel frame to prevent the sliding phenomenon caused by the stress acting between different materials (steel and concrete). It is necessary to install the shear connector through the method, and when designing only the steel reinforcement, the concrete is designed without any stress burden, resulting in waste of concrete.

The present invention has been developed to solve the above problems, first, the construction method using a separate reinforcement to enable the field workers easy and quick reinforcement work, and second, the reinforcement to facilitate shear reinforcement even in the case of the lower foundation of the bearing wall The shape was developed to reduce the foundation thickness compared to the existing case where shear reinforcement was not possible. Third, it was developed to use not only rebar but also flat steel, angle, and wire mesh without additional welding work. The material can be selected.

1 is the final completeness of the "bending / shear combined reinforcement"

Figure 2 is an embodiment of the "bending / shear combined reinforcement"

Figure 3 is an example of the basic reinforcement using the "flexible / shear combined reinforcement"

Figure 4 is a production chart for each material used as flexural reinforcement

Figure 5 is a production chart for each material used as a shear reinforcement

6 is an upper position fixing member for binding the shear stiffener

7 is an embodiment of the binding operation using the binding line and the clip

8 is an embodiment when the base and the column using the present invention contact

9 is an embodiment when the foundation and the bearing wall using the present invention in contact

10 is an embodiment in the case where the pile is installed in the lower base using the present invention

<Description of the code | symbol about the principal part of drawing>

1: Lower flexural stiffener (rebar, flat steel, angle)

2: Upper position fixing material (bar, wire mesh)

3: vertical / inclined shear stiffener (rebar)

4: shear connector (rebar)

5: connecting rod (pillar or wall reinforcement of the upper part of the foundation reinforcement)

6: basal lower muscle 7: basal upper muscle

8: combined column type reinforcement 9: combined wall type reinforcement

10: hole 11: pile

12: clip 13: ties

In order to achieve the above object, the present invention, the reinforcing bar 6 is commonly laid on the lower part of the foundation, and the present invention is used to produce a bending / shear combined reinforcement (8 or 9) to move the device (for example, tower crane) Move to the required position by using and install it on the lower reinforcement (6) already installed, or install the combined bending / shearing reinforcement material (8 or 9) at the position where reinforcement is needed in the state where the foundation lower part (6) is laid. Finally, the upper part of the foundation (7) is placed in the upper part of the reinforcement and the concrete is poured to complete the basic structure.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a final completeness using the binding means for the present inventors bending / shear combined reinforcement. The upper figure (8) shows the case of pillar reinforcement on both the bending and shearing stiffeners, and the lower figure (9) shows the case of wall reinforcement on the bending and shearing stiffeners.

2 illustrates an example of a work procedure for producing a bending / shear combined reinforcement. According to this, as shown in Fig. 2a, first, the outermost frame 1, 2, 3 is assembled using the binding means according to the size of the designated reinforcement range.

Then, the lower flexural stiffener 1 and the upper position fixing member 2 in one direction as shown in Figure 2b is temporarily bonded to the outermost frame assembled.

Then, as shown in Fig. 2c, the lower stiffener (1) and the upper position fixing member (2) are placed one by one in the 90 ° direction, and the shear stiffeners (3) required in the row are vertical or vertical as shown in Fig. 2d. Bind inclined and proceed to shear reinforcement work in this way as shown in Figure 2e to complete the reinforcement. In this case, when there is a connecting bar (5) for connecting between the upper part of the base portion to be installed in the reinforcement to the reinforcement as shown in Figure 2f or 2h, when the shear reinforcement (3) In parallel to the stomach.

FIG. 3 is a graphical representation of an example of the basic reinforcement work using the flexural / shear combined reinforcements 8 and 9 manufactured as in FIG. 1. First, as a 1st step, the reinforcing bar 6 which reinforces in common in the lower part of a foundation is laid. As the second step, the present invention provides the bending / shear combined reinforcement materials 8 and 9 at the position where reinforcement is required. As a method of installation, the inventors of the present inventors may use the bending / shear combined reinforcement material separately and move to a position requiring reinforcement using a moving device (for example, a tower crane) to install on the lower reinforcement 6 laid in step 1 or There is a method of directly binding the flexural / shear combined reinforcement at the required position. In this way, after the installation of the bending / shear combined reinforcement in all the positions that need to be reinforced, when the upper part near the base (7) is placed on it, all the reinforcement process of the foundation is finished, and after the concrete casting is completed, the foundation structure forming work is completed.

In the case where the upper part of the foundation is a column, after laying the common lower root (6), one bending / shear combined reinforcement (8) is installed at the position of the pillar and the upper upper root (7) is finally placed thereon. In the case where the reinforcement work is performed and the upper part of the foundation is a bearing wall, after laying the common foundation root (6), the bending / shear combined reinforcement (9) made of a constant unit length (2-3 m) is arranged one by one along the wall row. Subsequently, the reinforcement work is carried out by installing and finally placing the upper upper part 7 on it.

In this way, the reinforcement can be installed separately from the lower part of the foundation work or the upper part of the work. It is possible to prevent the decrease in the work speed and increase the fatigue of work in the installation).

Figure 4 is a diagram representing the reinforcement form by type of material to be used as a flexural reinforcement in the present inventors flex / shear combined reinforcement, Figure 4a is a case of using a commonly used reinforcement in this case reinforcing bars and shear reinforcing materials without additional processing Connect using (use ties or clip together). Figure 4b is a method using a flat steel as a flexural stiffener when using multiple bundles of reinforcing bars can be used instead of rebar as a method that can be used instead of reinforcing bars 10 at the position where the shear reinforcing means meet and penetrate the shear reinforcement Have a certain length or more. This protruding length acts as a shear connector 4 which prevents slippage between the flat steel and the concrete, thereby integrating the flat steel and the concrete. 4c is a representation of a method of using a ready-made angle instead of using flat steel, in the case of flat steel, a hole 10 for penetrating the shear stiffener must be separately drilled, but in the case of an angle, this process can be omitted.

5 is a diagram representing the manufacturing form of each type of material to be used as the shear stiffener (3), (a) is the case of using reinforcing bar, (b) is the case of using flat steel, (c) is the angle. (4) is straight or bent at the end when anchoring is required, or in the form of approximation.

6 is a view showing the position fixing material (2) of the upper portion for binding the shear stiffener (3), because it acts only as a position fixing material (2) for holding the shear stiffener (3) at a certain position using a reinforcement as shown in Figure 6a A wire mesh is used as shown in FIG. 6B.

Figure 7 is a diagram representing an embodiment of the binding operation of the combined reinforcement / bending shear. Figure 7a is a drawing of the binding work for the vertical shear stiffener (3) in the case of using the binding line 13, which is generally used for reinforcing bar binding work, Figure 7b is a binding for the slope shear stiffener (3) Working picture. Figure 7c is to put the horizontal reinforcing bar on the clip by inserting the clip (12) at the bottom to raise the horizontal reinforcement (1, 2) in the binding position of the shear reinforcement (3) to facilitate the worker's reinforcement work This figure is to use (13), and it is the figure that binds the shear reinforcement (3) by using the binding line (13) and the clip (12) together so that the field workers can easily make the combined bending / shear. Where (a) is a picture before the clip 12 is inserted into the shear reinforcing material (3), (b) is a state where the clip is fitted, and (c) is a picture of the state where the clip 12 is tightened by the binding line 13. And (d) is a front view of the horizontal member 1 or 2 placed on the clip 12, and (e) is a side view of (d) in which the binding line 13 is fitted into the hole 10. FIG.

8 is a view illustrating an embodiment of the reinforcement work using the present invention when the base and the column are in contact with each other, compared with the existing reinforcement work. FIG. 8A is a diagram representing the basic reinforcement shape without shear reinforcement, and FIG. 8B is a diagram representing the basic reinforcement shape using the bending / shear combined reinforcement 8. Comparing each of these two pictures

1) Basal root muscle (6) The back muscle process is the same. However, when applying the flexural / shear combined reinforcement, there is a difference in the amount of root muscles near the base.

2) In the existing case, bend reinforcement and column reinforcement under the column. The present inventors use the bending / shear combined reinforcement. The present invention includes the shear reinforcement step (shear reinforcement).

3) Near the upper base (7) The backing process is the same. However, in case of applying both a bending and shearing reinforcement, there is a difference in the amount of muscles near the upper base.

4) Compared with the existing foundation, the thickness of the foundation is reduced when the reinforcement combined with bending / shear is applied.

9 is a view illustrating an embodiment of the reinforcement work using the present invention in the case where the foundation and the bearing wall is in contact with each other, compared with the existing reinforcement work. Figure 9a is a representation of the existing basic reinforcement form that can not be shear reinforcement and Figure 9b is a diagram representing the basic reinforcement form using the combined bending / shear shear (9). In such a case, make a reinforcement for both bending and shearing in the unit of a certain length (2 ~ 3m), and then connect them continuously along the wall position and work as shown in the figure. Comparing each of these two pictures

1) The basal lower abdominal muscle process is the same. However, when the base stiffener combined with bending / shear is applied, there is a difference in the amount of root muscles near the base.

2) In the existing case, flexural reinforcement and wall reinforcement are installed under the wall. The present inventors use the bending / shear combined reinforcement. The present invention includes the shear reinforcement step (shear reinforcement).

3) The basic upper back muscle process is the same. However, in case of applying both a bending and shearing reinforcement, there is a difference in the amount of muscles near the upper base.

4) Compared with the existing foundation, the thickness of the foundation is reduced when the reinforcement combined with bending / shear is applied.

Fig. 10 shows an example of reinforcement work using the present invention when the foundation and the pile are in contact with each other. Fig. 10A is a diagram illustrating an existing basic reinforcement shape without shear reinforcement. Fig. 10b is a figure expressing the shape of the basic reinforcement using the bending / shear combined reinforcement.

Regarding the reinforcement design using the combined bending / shearing reinforcement as above, the cross-sectional area and size of the reinforcement should be separately considered in consideration of the load condition and material strength at the time of design according to the domestic reinforcement concrete structural design standard and each country's structural design standard. Design by the calculation of to determine the specific spacing spacing and reinforcement size.

As described above, the present invention

First, when installing the reinforcing bar, separate from the lower and lower base and upper and lower roots, devised a flexible bending / shear combined reinforcement (Fig. 1) to enable the workers in the field to quickly and easily reinforcement work by creating a manpower and air Second, in order to facilitate shear reinforcement even in the case of the lower foundation of pile or bearing wall, the shear reinforcement (1) and the position fixing material (2) in the upper part and the shear reinforcement (3) and the shear connector (4) therebetween. In order to reduce the thickness of the foundation by devising a bending / shear combined reinforcement (Fig. 1).

Third, as shown in Figure 3, it is designed to utilize not only rebar but also flat steel, angle, and wire mesh without additional welding work, so that the material suitable for the site conditions can be selected.

In this way, the use of the combined bending / shearing shear (FIG. 1) generates the effect of reducing the construction volume by reducing air and manpower and reducing the thickness of the foundation in the construction work.

Claims (7)

In the reinforced concrete foundation structure, Shear stiffener (1) disposed at the lower part, position fixing member (2) disposed at the upper part vertically spaced apart from this, and shear stiffener connecting the lower stiffener lattice points and the upper position fixing member lattice points (3) and a shear connector (4) formed by extending the shear stiffener by a certain length below the flexural stiffener at the intersection of the shear stiffener and the flexural stiffener, and the superstructure ( Bending / shear combined reinforcement composed of connecting rod (5) as a component 2. The flexural / shear combined reinforcement according to claim 1, wherein the flexural stiffener 1 functions as a tension member using rebar, flat steel or angles. 2. The bending / shear combined reinforcement of claim 1, wherein the position fixing member (2) is used for positioning a shear reinforcement using a wire mesh or a bound reinforcing bar. 2. The shear / shear combined reinforcement according to claim 1, wherein the shear reinforcement 3 functions as a shear using reinforcing bars, flat steel or angles. The bending / shear combined reinforcement according to claim 1, wherein the shear stiffener (3) connects the lattice point of the flexural stiffener and the lattice point of the position fixing member at an arbitrary angle (Figs. 7A and 7B). 2. The clip according to claim 1, wherein the shear stiffener (3) is fitted with a clip (12) at the lower part of the intersection where the shear stiffener (3) meets a horizontal member (bending stiffener or position fixing member) and the horizontal member (1,2) is placed on the clip and the ties (13) Bending / shear combined reinforcement connecting horizontal material (1,2) and shear reinforcement (3) by binding In the method of reinforcement work on the reinforced concrete foundation structure, Reinforce the foundation lower muscle 6 common to the entire foundation, bind the bending / shear combined reinforcement of claim 1 on the foundation lower muscle 6, and finally bind the foundation upper muscle 7 thereon. Construction method using bending / shear combined reinforcement which completes reinforcement of foundation structure by putting on and binding