KR101693551B1

KR101693551B1 - Flat-tie for formwork

Info

Publication number: KR101693551B1
Application number: KR1020150060056A
Authority: KR
Inventors: 고영곤; 김철환; 천경식; 황재웅
Original assignee: 주식회사 포스코건설
Priority date: 2015-04-28
Filing date: 2015-04-28
Publication date: 2017-01-06
Also published as: KR20160128152A

Abstract

There is provided a flat tie improved for a flat tie for molding that maintains a spacing between a first foam panel and a second foam panel that are disposed to face each other, absence; And two projecting members each extending along the longitudinal direction from both ends of the intermediate member, wherein a side surface of the projecting member is provided with a projecting portion for projecting the side surface of the first foam panel Wherein a hole for receiving a support pin for supporting the first foam panel or the second foam panel is formed and the inner circumferential surface of the hole is formed in a portion where a tensile load of the support pin due to the side pressure is applied, A load acting surface formed so as to be in surface contact with the surface; A curved expansion surface which is curved and expanded from both ends of the load acting surface; And two guide surfaces for guiding the upper surface and the lower surface of the support pin, respectively, so that a reaction force of the support pin acts on the load acting surface.

Description

{FLAT-TIE FOR FORMWORK}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat tie used as a long-form payment such as a euro form.

Formwork tie is used to maintain the spacing of the form panels during the construction of the concrete structures and to support the side pressure of the concrete.

Formwork long-term payment can be divided into a concrete type and a concrete type, and a long type and a long type, and a buried type tie can be divided into a flat type and a detached type. Among these, flat tie is a long settlement used in the formwork of a structure such as a wall having a constant thickness, and is widely used in a construction site.

FIG. 1 is a side view of a conventional flat tie, and FIGS. 2 (a) and 2 (b) schematically show a state in which a conventional flat tie is installed.

1, 2A and 2B, a flat tie 800 is formed between the first foam panel 310 and the second foam panel 320 by the side pressure 510 generated when the concrete 500 is poured, Thereby preventing the occurrence of the gap g. 2B, the flat tie 800 may be installed in a manner that the support pin 400 is inserted into the hole 810 formed in the flat tie 800. [

2A, if the concrete 500 is placed between the first and second foam panels 310 and 320, as shown in FIG. 2B, the lateral pressure 510 of the concrete 500 Is transmitted to the support pin 400 through the first foam panel 310 or the second foam panel 320 so that the support pin 400 acts on the flat tie 800 to act as a tensile load 410 do. That is, the flat tie 800 can resist the tensile load due to the side pressure 510 of the concrete 500, and can maintain the wall thickness so that the concrete is not collapsed during the curing of the concrete 500.

However, the conventional flat tie 800 has a problem that a shearing stress concentrates at a part (corner portion) of the hole 810 to which the support pin 400 is fastened. In other words, when the lateral pressure 510 of the concrete 500 is increased by a predetermined amount or more due to an increase in the height of the concrete slip, shear cracks are generated from the edges of the holes 810 and propagate rapidly in the horizontal direction, Causing sudden brittle fracture.

Especially, in case of high strength concrete with high fluidity, which has been used recently, the lateral pressure of the concrete is drastically increased due to its high fluidity. However, when the conventional flat tie 800 is used in response to the installation of the high-flowable concrete, the flat tie 800 is brittle and fractured due to the side pressure 510 acting at a considerably higher level than that of the conventional concrete, It was difficult to rule out the possibility of sudden collapse during this concrete pouring.

In order to prevent the brittle fracture due to abrupt shear cracks, the thickness of the flat tie 800 is adjusted to a predetermined value, There is a limitation that it is difficult to arbitrarily change. In addition, in terms of securing the productivity of the flat tie 800, it is difficult to arbitrarily change only the thickness of the portion where the flat tie 800 is generated.

It is an object of the present invention to solve the above-mentioned problems of the prior art, and it is an object of the present invention to prevent abrupt shear cracking and brittle fracture on the flat tie when the side pressure of the poured concrete is increased by more than a predetermined amount, The present invention also provides a flat tie for a dice.

As a technical means for achieving the above technical object, the molding flat tie according to the first aspect of the present invention is a flat tie for molding that maintains a space between a first foam panel and a second foam panel arranged to face each other An intermediate member having a length across the gap; And two projecting members each extending along the longitudinal direction from both ends of the intermediate member, wherein a side surface of the projecting member is provided with a projecting portion for projecting the side surface of the first foam panel Wherein a hole for receiving a support pin for supporting the first foam panel or the second foam panel is formed and the inner circumferential surface of the hole is formed in a portion where a tensile load of the support pin due to the side pressure is applied, A load acting surface formed so as to be in surface contact with the surface; A curved expansion surface which is curved and expanded from both ends of the load acting surface; And two guide surfaces for guiding the upper surface and the lower surface of the support pin, respectively, so that a reaction force of the support pin acts on the load acting surface.

According to the above-mentioned problem solving means of the present invention, since the holes are formed so as to have the curved expansion surface gradually curved from the load acting surface, sudden shear cracking and brittle fracture are caused in the flat tie when the side pressure of the poured concrete is increased by a predetermined amount or more Thereby making it possible to achieve more stable construction of the concrete structure.

Further, through the shape of the hole having the load acting surface and the curved expansion surface curved therefrom, the conventional shear stress generation can be converted into tensile stress, and even if unexpected excessive side pressure of concrete is applied to the flat tie, Since ductile fracture can be induced, the operator can obtain adequate response time before the flat tie is destroyed or sufficient time to safely evacuate.

In addition, even if the shape of the flat tie is changed without changing the thickness of the flat tie, the conventional shear stress excess generation can be sufficiently converted into tensile stress to avoid brittle fracture, and the shape of the hole can be changed within a range The compatibility with the form panel structure such as the Euroform and the accessory unit used therein can be maintained as it is.

1 is a side view of a conventional flat tie.
2A and 2B are views schematically showing a state in which a conventional flat tie is installed.
3A is a side view of a flat tie for a mold according to one embodiment of the present application.
FIG. 3B is a side view of a portion of the die flat tie according to one embodiment of the present invention, as viewed in a partially enlarged view.
3C is an enlarged perspective view of a part of a form flat tie according to an embodiment of the present invention.
FIG. 3D is a conceptual diagram showing a state in which a support pin inserted in a hole of a flat tire for molding according to an embodiment of the present invention exerts a tensile load on a load acting surface of the hole.
FIG. 3E is a schematic view illustrating a state where the flat tie for molding according to one embodiment of the present invention is installed on the first foam panel and the second foam panel.
4A is a side view of another embodiment of a form flattie according to one embodiment of the present application.
FIG. 4B is a three-dimensional conceptual view enlargedly showing a part of another embodiment of the formwork flat tie according to the embodiment of the present invention.
FIG. 4C is a conceptual diagram showing a state in which a support pin inserted in a hole of another embodiment of a formwork flat tie according to an embodiment of the present invention applies a tensile load to a load acting surface of the hole.
5A is a diagram showing a model for numerical analysis of a conventional flat tie.
FIG. 5B is a diagram illustrating a model for numerical analysis of a flat tie for molding according to an embodiment of the present invention.
5C is a diagram illustrating a model for numerical analysis of another embodiment of the die for flat according to one embodiment of the present application.
6A is a view showing a state of shear stress among numerical analysis results of a conventional flat tie.
6B is a view showing a shear stress state in a numerical analysis result of a flat tie for a work according to an embodiment of the present invention.
FIG. 6C is a view showing a shear stress state among numerical analysis results of another embodiment of the molding flat tie according to the embodiment of the present invention. FIG.
FIG. 7A is a conceptual diagram showing a state in which a coating layer is formed on the surface of a projecting member of a molding flat tie according to an embodiment of the present invention. FIG.
FIG. 7B is a conceptual diagram for explaining that a tensile strain or a crack generated in a protruding member can be easily confirmed through a coating layer formed on a surface of a protruding member of a molding flat tie according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. It should be understood, however, that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, the same reference numbers are used throughout the specification to refer to the same or like parts.

Throughout this specification, when a part is referred to as being "connected" to another part, it is not limited to a case where it is "directly connected" but also includes the case where it is "electrically connected" do.

Throughout this specification, when a member is " on " another member, it includes not only when the member is in contact with the other member, but also when there is another member between the two members.

Throughout this specification, when an element is referred to as "including " an element, it is understood that the element may include other elements as well, without departing from the other elements unless specifically stated otherwise. The terms "about "," substantially ", etc. used to the extent that they are used throughout the specification are intended to be taken to mean the approximation of the manufacturing and material tolerances inherent in the stated sense, Accurate or absolute numbers are used to help prevent unauthorized exploitation by unauthorized intruders of the referenced disclosure. The term " step "or" step of ~ " used throughout the specification does not mean "step for.

Hereinafter, a flat tie for molding (hereinafter referred to as a "flat tie") according to an embodiment of the present invention will be described.

FIG. 3A is a side view of a molding flat tie according to one embodiment of the present invention, and FIG. 3B is a side view of a portion of a molding flat tie according to an embodiment of the present invention, as viewed from a partial enlarged view. FIG. 3C is a perspective view enlargedly showing a part of a work flat tie according to an embodiment of the present invention. FIG. 3D is a cross-sectional view illustrating a state in which a support pin inserted into a hole of a work flat tie according to an embodiment of the present invention, FIG. 3E is a schematic view illustrating a state in which a flat tie for molding according to an embodiment of the present invention is installed on a first foam panel and a second foam panel. FIG.

The present flat tie 100 relates to a flat tie for molding that maintains the gap g between the first and second foam panels 310 and 320 facing each other.

The flat tie 100 includes an intermediate member 1 and two projecting members 2.

3A and 3E, the intermediate member 1 may have a length transverse to the gap g between the first foam panel 310 and the second foam panel 320. For example, the intermediate member 1 may have a length corresponding to the thickness of a concrete wall to be installed through a form panel such as a Euroform. As a specific example, referring to FIG. 3A, the length of the intermediate member 1 (the length between the two side notches 3) plus 6 mm on both sides may be the thickness of the concrete wall to be installed. That is, the length of the intermediate member 1 can be set so that the notch 3 is slightly immersed in the concrete.

3A, the two projecting members 2 may extend from both ends of the intermediate member 1 along the longitudinal direction, respectively. For reference, the longitudinal direction may refer to the 9 o'clock -3 o'clock direction (left-right direction) of FIG. 3A.

3A and 3E, a side pressure 510 of the concrete 500 laid between the first and second foam panels 310 and 320 is formed on the side surface of the protrusion member 2, A hole 21 into which a support pin 400 for supporting the first foam panel 310 or the second foam panel 320 is inserted may be formed.

Further, the intermediate member 1 and the two protruding members 2 may have the same and constant thickness. Since the intermediate member 1 and the protruding member 2 are provided so as to have the same and constant thickness, the mass production of the flat tie 100 at the time of manufacturing can be ensured.

3A, a notch 3 may be formed between the intermediate member 1 and the protruding member 2. As shown in FIG. For example, the notch 3 may have a groove shape that is recessed at a depth of 3 mm. After completion of the curing of the concrete placed between the first and second foam panels 310 and 320, the notch 3 is placed in the concrete and the protruding member 2 is placed in the concrete, (1). Since the notch 3 is self-explanatory to a person skilled in the art, a detailed description thereof will be omitted.

3B and 3C, the inner circumferential surface of the hole 21 formed in the protruding member 2 may include a load acting surface 211, a curved extension surface 212, and two guide surfaces 213 have.

The load acting surface 211 is brought into contact with the thickness surface 400a of the support pin 400 at a portion where the tensile load 410 of the support pin 400 due to the side pressure 510 of the concrete 500 is applied . Referring to FIG. 3D, the width of the load acting surface 211 (the length in the direction of 12 o'clock to 6 o'clock in FIG. 3d) can be set to be equal to or greater than the thickness t of the support pin 400.

For example, when the thickness t of the support pin 400 is 6 mm, the width of the load acting surface 211 can be set to 6 mm or more. If the width of the load acting surface 211 is smaller than the thickness t of the support pin 400, the angled corners of the both ends of the thickness surface 400a of the support pin 400 are not in contact with the curved extension surface 212, (Or point) contact, large stress concentration may be induced.

That is, it is preferable that the load acting surface 211 is formed to have a width capable of covering the entire thickness surface 410 of the support pin 400 that transmits the tensile load through surface contact. For example, for the stress distribution through such surface contact, the thickness surface 400a of the support pin 400 and the load acting surface 211 may be formed as flat surfaces facing each other.

Further, the support pin 400 may have a constant thickness t. The support pins 400 are constructed so as to have a size that interoperates with ancillary units such as a form panel structure such as a Euroform and a flat tie used therein, and is generally made to have a constant thickness. In other words, the present invention aims to provide a flat tie which can reduce the occurrence of shear stress as much as possible while minimizing the cost of the material, while utilizing the conventional support pin 400 without any modification.

Further, the curved expansion surface 212 is curved and expanded from both ends of the load acting surface 211. 3B and 3C, the curved extension surface 212 may be a curved surface. For example, the curved extension surface 212 may be a curved surface having a predetermined radius of curvature. Further, the curved extension surface 212 may be connected to the guide surface 213 to be described later.

Referring to FIG. 1, a conventional flat tie 800 has a rectangular-shaped hole 810 corresponding to the thickness of the support pin 400. However, such a rectangular hole 810 has the following problems.

First, when the rectangular hole 810 is formed in a precisely rectangular shape, angular corners become a starting point at which shear cracking starts, which causes sudden brittle fracture to occur more rapidly. Secondly, when the rectangular holes 810 are formed in a somewhat blunt and gentle manner without being corners due to a machining error or the like, angled corners of both ends of the thickness surface 400a of the support pin 400 are formed in such a blunt There is a problem that a large stress concentration causing shear fracture is caused by gentle contact with a corner and a line (or point).

That is, in the present application, the load acting surface 211 is in surface contact with the thickness surface 400a of the support pin 400, thereby preventing stress concentration due to line (or point) contact and, at the same time, By providing the curved extension surface 212 which is formed by a gently curved extension extending from both ends of the slit 211, the portion that becomes the starting point of shear cracking like the angular edge portion can be removed and the generation of shear stress is minimized Sudden brittle fracture can be prevented.

The two guide surfaces 213 guide the upper surface and the lower surface of the support pin 400 so that the reaction force of the support pin 400 acts on the load acting surface 211, respectively. Referring to FIG. 3D, the distance between the two guide surfaces 213 may be a distance corresponding to a constant thickness t of the support pin 400. Referring to FIG. 3D, one of the guide surfaces 213 is in contact with at least a part of the upper surface of the support pin 400, and the other one of the guide surfaces 213 is in contact with at least a part of the lower surface of the support pin 400 .

Since the two guide surfaces 213 are formed to contact the upper surface and the lower surface of the support pin 400 as described above, the thickness surface 400a of the support pin 400 can be clearly brought into surface contact with the load acting surface 211 have. If the two guide surfaces 213 are not formed, both end edge portions of the thickness surface 400a of the support pin 400 are separated from the load acting surface 211 and are in line (or point) contact with the curved extension surface 212 In a state of being. That is, it is preferable that the two guide surfaces 213 are provided to guide the thickness surface 400a of the support pin 400 so as not to deviate from the load acting surface 211.

That is, according to the present invention, since the tensile load through the support pin 400 stably acts on the load acting surface 211 through the guide surface 213, the effect of preventing brittle fracture through the curved expansion surface 212 is improved And can be reliably and reliably exerted.

4A is a side view of another embodiment of a form flattail according to one embodiment of the present invention. FIG. 4B is a three-dimensional conceptual view enlarging a part of another embodiment of the molding flat tie according to the embodiment of the present invention. FIG. 4C is a perspective view of a flat tie according to another embodiment of the present invention, Is a conceptual diagram showing a state in which a support pin applies a tensile load to a load acting surface of the hole.

4A, in the protruding member 2, the upper surface corresponding to the portion where the curved extending surface 212 is formed can be formed so as to be convex upward, and the upper surface corresponding to the portion where the curved extending surface 212 is formed The lower surface can be expanded and formed to be convex downward. Referring to FIG. 4C, it is possible to reinforce the portion where the tensile stress mainly concentrates due to the tensile load 410 by the support pin 400 through the expansion of the protruding member 2, Which may also prevent or delay ductile fracture. 4B, the protruding member 2 may have a transverse sectional area A1 of the portion where the curved extension surface 212 is formed, which is not less than the transverse sectional area A2 of the portion where the two guide surfaces 213 are formed.

That is, according to another embodiment of the present invention, it is possible to improve the shape of the hole 21 by the organic combination of the load acting surface 211, the curved extension surface 212, and the guide surface 213 without changing the overall thickness of the flat tie It is possible to more stably cover the tensile stress for inducing ductile fracture, which can be slightly increased with decreasing shear stress, while reducing the amount of shear stress generated.

5A is a diagram illustrating a model for numerical analysis of a conventional flat tie, FIG. 5B is a diagram illustrating a model for numerical analysis of a molding flat tie according to an embodiment of the present invention, and FIG. Fig. 5 is a diagram showing a model for numerical analysis of another embodiment of a flat tie for molding according to an embodiment. Fig.

5A to 5C, a conventional flat tie, the present flat tie 100 (hereinafter referred to as 'main flat tie 1') shown in FIGS. 3A to 3E, Numerical analysis of the tensile load of the support pin 400 was performed by modeling (FEM) another embodiment (hereinafter referred to as 'main flat tie 2') of the flat tie 100. The results are as follows.

6B is a view showing a state of shear stress among the numerical analysis results of the present flat tie 1. FIG. 6C is a view showing a result of numerical analysis of a conventional flat tie Fig. 5 is a view showing a shear stress state among numerical analysis results of another embodiment of the tie-2. Fig.

The results of the numerical analysis shown in these drawings are summarized in Table 1 below.

As a result of the above numerical analysis, it can be seen that the present flat tie 1 has a shear stress of 84% compared to the conventional flat tie with respect to the same tensile load, and the present brittle tie 2 has a shear stress of 65 %, Respectively. In other words, as described above, according to the present invention, it is possible to reduce the concentration of stress through improvement of the shape of the hole 21 and to eliminate a step of generation of shear crack (crack), thereby inducing soft fracture progressing slowly rather than sudden brittle fracture .

7A is a conceptual view showing a state in which a coating layer is formed on a surface of a protruding member of a molding flat tie according to an embodiment of the present invention, and FIG. 7B is a cross-sectional view of a protruding member of a molding flat tie according to an embodiment of the present invention A tensile strain or a crack generated in the projecting member can be easily confirmed through the coating layer formed on the surface.

7A and 7B, in the vicinity of the load acting surface 211 and the curved extension surface 212 of the surface of the projecting member 2, a color or lightness which is different from the color or brightness of the projecting member 2 The coating layer 22 may be formed.

For example, when the projecting member 2 is made of a material having a somewhat lower brightness, the coating layer 22 may be formed to have a relatively higher brightness as compared with the surface of the projecting member 2. Conversely, when the protruding member 2 is made of a somewhat bright material, the coating layer 22 may be formed to have a relatively low brightness as compared with the protruding member 2, as shown in FIG. 7B.

As described above, by forming the coating layer 22 so that the difference in the material reference brightness or hue of the protruding member 2 is more than a predetermined value, cracks or deformation occurring around the curved expansion surface 212 of the protruding member 2 can be easily detected . Particularly, when tensile deformation due to the action of tensile stress is generated around the curved expansion surface 212, a part of the coating layer 22 may open to cause a gap, and the protruding member 2 is exposed through the gap . At this time, if the coating layer 22 and the protruding member 2 have a difference in brightness or color by a predetermined amount or more, as shown in FIG. 7B, the gap generated due to the tensile strain can be more easily grasped.

That is, according to the present invention, by forming the coating layer 22, the gradual progress of the soft fracture due to tensile strain can be more easily predicted and prepared, and in addition to the tensile strain, the occurrence of unexpected cracks can be detected in advance .

The coating layer 22 may be easily formed by a dipping method in which at least a part of the protruding member 2 of the present flat tie 100 is dipped into a paint such as a paint and is then taken out and dried. But the present invention is not limited thereto, and various coating methods known in the art may be employed.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or essential characteristics thereof. You can understand that. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

100: Flat tie for dice
1: intermediate member 2: projecting member
21: hole 211: load acting surface
212: curved extension surface 213: guide surface
22: Coating layer 3: notch
310: first foam panel 320: second foam panel
g: the distance between the first foam panel and the second foam panel
400: support pin 400a: thickness of support pin
t: thickness of support pin 410: tensile load of support pin
500: concrete 510: side pressure of concrete
800: conventional flat tie 810: hole

Claims

CLAIMS 1. A flat tie for molding which maintains a gap between a first foam panel and a second foam panel which are arranged to face each other,
An intermediate member having a length across the gap; And
And two projecting members each extending along the longitudinal direction from both ends of the intermediate member,
Wherein the intermediate member and the two protruding members have the same and constant thickness so as to ensure mass productivity at the time of manufacturing the form flat tie,
A hole for inserting a support pin for supporting the first foam panel or the second foam panel against the side pressure of the high strength concrete laid between the first foam panel and the second foam panel is formed on the side surface of the protrusion member And,
The inner peripheral surface of the hole
A load acting surface formed to have a width equal to or greater than the thickness of the support pin so as to be in surface contact with a thickness surface of the support pin at a portion where tensile load of the support pin is applied due to the side pressure;
A curved expansion surface that is a curved surface that is curved and expanded from both ends of the load acting surface so that a portion serving as a starting point of the shearing crack is removed; And
And two guide surfaces for guiding the upper surface and the lower surface of the support pin so that a reaction force of the support pin acts on the load acting surface,
The support pin has a constant thickness,
The distance between the two guide surfaces corresponds to a constant thickness of the support pin so that the thickness plane of the support pin does not deviate from the load acting surface,
Wherein the thickness of the support pin and the load acting surface are formed as flat surfaces facing each other,
Wherein a portion of the surface of the protruding member, which is a starting point of shear cracking due to the curved expansion surface, is removed at the periphery of the load acting surface and the curved expansion surface to detect the progress of ductile fracture due to tensile strain, Wherein a coating layer having a color or brightness different from the hue or brightness of the protruding member is formed.

delete

The method according to claim 1,
Wherein the projecting member has a cross sectional area of a portion where the curved extension surface is formed is equal to or larger than a cross sectional area of a portion where the two guide surfaces are formed.