JP2007308984A - Spacer for constructing reinforced concrete - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spacer for constructing a reinforced concrete easily manufacturable, easily mountable to reinforcements, having sufficient strength, not moving without discretion after being mounted to the reinforcements, capable of clearly obtaining covering dimensions, and eliminating foreign matters between the reinforcements and a mold member. <P>SOLUTION: A part of a sheet metal reinforcement holding member 2 with spring property is integrally buried in a concrete or mortar space body part 1. A short recessed groove 4 with a curved recess 5 engageable with the reinforcement 3 is formed in the body part. Arm parts 8a, 8b for mounting to the side are formed on a pair of reinforcement holding parts 2a, 2b of the same shape. Each mounting arm part is buried in both inplane side walls 9a, 9b of the short recessed groove. The reinforcement held between the reinforcement holding parts and pressed by reinforcement holding pieces 7a, 7b is brought into direct contact with the bottom end surface of the curved recess, and can be held without allowing foreign matters to interpose between the reinforcement and a mold member 11. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a spacer used to hold a reinforcing bar in order to ensure a constant interval between a reinforcing bar and a formwork plate during construction of a reinforced concrete structure.

  When constructing highway bridge girders, side walls, building slabs, etc. with concrete, when the concrete is poured into the formwork for construction, the reinforcing reinforcing bars bend or move due to its weight, pressure, etc. The structure does not have sufficient strength, and the reinforcing bar is exposed from the structure.

  Therefore, even when concrete is poured into the construction formwork, the reinforcing bar is supported and the distance from the formwork plate is kept constant so that the reinforcing rebar does not bend or move due to its weight or pressure. Need to hold on. Therefore, a reinforced concrete construction spacer is used to support the reinforcing bars. Various types of spacers for constructing reinforced concrete have been proposed in the past. For example, there are the following.

B) Made of concrete or mortar, with a trapezoidal shape when viewed from the side, that is, a rectangular pyramid-shaped spacer with a short concave groove for placing reinforcing bars on the upper surface.
Japanese Patent Laid-Open No. 6-14679

B) Consists of a spacer body made of concrete or mortar, and a reinforcing bar support plate made of an elastic metal plate and having a cross-section with an inverted Ω shape at the center. The plate is centered on the spacer body. And fitted with both shoulders so that a slight gap is left.
JP-A-6-16556

C) Consists of a spacer body made of concrete or mortar and a reinforcing bar support arm made of elastic metal wire. The central part of the reinforcing bar support arm is embedded and fixed on the top surface of the spacer body, and both sides are the length of the reinforcing bar. In a non-orthogonal direction and extending in opposite directions, both sides are orthogonal to the longitudinal direction of the reinforcing bar and the outer peripheral surface of the reinforcing bar is folded in a hook shape so as to be sandwiched from the relative direction.
Japanese Patent Laid-Open No. 2000-145041

D) It has a main body part and a steel catcher (rebar holding part) attached to the main body part, and the main body is made of a cement-based material and has a predetermined fog in order to regulate the thickness of concrete placement. The catcher includes a receiving recess for fitting with a reinforcing bar, and at least a pair of legs projecting laterally from the receiving recess, and the catcher includes the pair of legs. Is attached to the main body by abutting on one surface of the main body and embedding a part of the cement-based material forming the main body thereon.
JP 2005-325545 A

However, the conventional spacer for reinforced concrete construction has the following problems.
In the above-mentioned Patent Document 1, since the reinforcing bar is simply engaged in the short concave groove, the spacer is easily misaligned with the reinforcing bar in the form plate having a vertical surface or an inclined surface. I can't use it. It is necessary to prepare a different type of spacer, or it takes time and effort to wind the vertical reinforcing bar around the horizontal reinforcing bar with a wire.

  The thing of the above-mentioned patent document 2 is that the internal reinforcing bars are simply sandwiched between the side plate portions by the spring force from both sides at the inverted Ω-shaped portion, so the holding force is weak, and concrete placement When an external force such as (pouring) is applied, this spacer easily turns around in the outer circumferential direction and slides along the longitudinal direction of the reinforcing bar. This is especially true for vertical and inclined bars.

  In the above-mentioned Patent Document 3, when the support arm is fitted into the reinforcing bar, the tips of both hook-like portions for locking are applied to the outer peripheral surface of the reinforcing bar obliquely with respect to the longitudinal direction of the reinforcing bar, Thus, it is necessary to twist (turn) the spacer main body portion and insert and lock both hook-shaped portions into the outer peripheral surface of the reinforcing bar. Further, at that time, it is necessary to push the both hook-shaped portions sequentially from the back direction with the fingertips of the other hand to assist the torsional rotation operation. Furthermore, the work of twisting the spencer body with support arm inserted between the reinforcing bar and the formwork plate is not easy when the distance between the reinforcing bar and the formwork plate is narrow, and workability is improved. However, it takes a considerable amount of time to install a large number of spacers.

  Since the thing of the said patent document 4 has embedded the leg part of the catcher in the main body in the thing before that, the dimension which determines the thickness of the concrete with which the outer side of the reinforcing bar 3 is filled and covered, in other words, the wall surface (at the time of construction) The distance from the formwork material surface) to the nearest metal object, that is, the fog dimension in the strict sense could not be confirmed from the appearance, or even if the main body dimension was large, the substantial fog dimension might be small. It is an attempt to solve the problem.

  However, spacers that are in contact with the formwork material are, in principle, made of either concrete or mortar (for example, “Concrete Standard Specification (Construction)” P133, P134 edited by Japan Society of Civil Engineers, edited by Japan Civil Engineering Association) (Refer to “Spacer Design and Construction Guidelines for Reinforcement Construction” on page 4.) In addition, even if the spacer is made of a corrosion-resistant metal, it must not cause the problem of contact decay between dissimilar reinforcing bars (see Standard Specification P134), or the corrosion of the reinforcing bars or the ends of the reinforcing bars or grips are in the fog. It is necessary to be careful not to enter (see the guideline P30).

  Even if the catcher is made of steel, if rusting occurs, the strength between the reinforcing bar, the spacer body and the placed concrete may be weakened, and the strength of the structure may be weakened or damaged. Because there is. Judging from this point, there are foreign objects / impurities other than concrete or mortar in the spacer body between the reinforcing bar and the formwork material during construction, in other words, between the reinforcing bar after construction and the wall of the structure. It must not be. However, the thing of the said patent document 4 is a structure with the baseplate part of the catcher made from steel still interposing between the reinforcing bar and the receiving recessed part of a spacer main-body part. Therefore, the fog dimension in a strict sense has not been obtained yet, and another problem of foreign matter / impurities remains.

  The catcher has a structure in which an opposing receiving recess for supporting a reinforcing bar and leg portions projecting to both sides in the lateral direction are integrally formed, which is, in other words, an integral object having a symmetrical shape. In this case, it is necessary to prepare several types of catchers with different sizes corresponding to the case where the outer diameter of the reinforcing bar is different or the size of the main body is different, which is inefficient in manufacturing and management. Is.

  Furthermore, as far as the figure is concerned, the catcher has leg portions protruding laterally from the curved portion as it is embedded in both walls of the receiving recess of the main body. Therefore, when the catcher is opened to push in the reinforcing bar or when external force is applied by placing concrete, the stress due to deformation concentrates on the position of the leg part in front of the wall, so it breaks at that part. There is also a possibility that it is easy to do.

  An object of the present invention is to solve the problems of the conventional spacer for reinforced concrete construction. That is, the object of the present invention is easy to manufacture and not costly, has good workability in fitting into a reinforcing bar, has sufficient strength, and once attached to the reinforcing bar, it is misaligned and rotated in the outer circumferential direction. In addition, there is a clear fog dimension between the reinforcing bar and the wall surface, and there is no foreign matter / impurities between the reinforcing bar and the formwork (wall surface after completion). An object of the present invention is to provide a reinforced concrete construction spacer that can suppress generation as much as possible.

Spacer A for reinforced concrete construction according to the present invention is
A part of the reinforcing bar holding part 2 made of a metal plate having a spring property is embedded in the spacer body part 1 made of concrete or mortar and integrated.
The main body 1 has a short concave groove 4 having a curved concave portion 5 with which a reinforcing bar 3 to be held can be engaged at the center of one surface,
The reinforcing bar holding part 2 is a pair of two pieces 2a and 2b having the same shape. The reinforcing bar holding pieces 7a and 7b opposed to each other on the main body part 1 and mounting arm parts 8a and 8b extending sideways are provided. Have
By attaching the mounting arm portions 8a and 8b to the inner side walls 9a and 9b of the short concave groove 4 of the main body portion 1,
The reinforcing bar 3 engaged in the curved concave part 5 is pressed by the tips of the reinforcing bar holding pieces 6a and 6b to be brought into direct pressure contact with the back end surface 6 of the curved concave part 5, and a spacer is provided between the reinforcing bar 3 and the mold plate 10. It can be held without any object other than the main body 1.

  Further, in the above-described one, the pair 2a and 2b having the same shape as the reinforcing bar holding part 2 is connected to the main body part 1 corresponding to the difference in the outer diameter of the reinforcing bar 3 in accordance with the difference in the outer diameter of the reinforcing bar 3. The distance between the two 2a and 2b is changed and attached.

  Further, in the above, the reinforcing bar holding pieces 7a, 7b of the reinforcing bar holding parts 2a, 2b have a pointed tip.

  Moreover, in the above, each of the reinforcing bar holding portions 2a and 2b has a "<"-shaped portion in the support plate portions 10a and 10b between the reinforcing bar holding pieces 7a and 7b and the arm portions 8a and 8b, It is bent substantially at a right angle and continues to the arms 8a and 8b.

  In the above, the dimension from the back end face 6 of the curved concave part 5 of the spacer main body 1 to the tip part in contact with the mold plate 11, in other words, the dimension between the reinforcing bar 3 and the mold plate 11 at the time of construction, or the reinforcing bar after construction The dimension from 3 to the wall surface of the structure, that is, the fogging dimension H in a strict sense, usually has various sizes from about 50 m to about 130 mm.

  Since the reinforced concrete construction spacer A according to the present invention is configured as described above, the following effects are produced.

    B) The spacer A of the present invention is manufactured separately from the spacer main body 1 in advance, by forming a pair of reinforcing bar holding portions 2a and 2b having the same shape, and having the same shape as the outer shape of the main body 1. After pouring concrete or mortar C into a formwork B having a peripheral wall surface (for example, see FIGS. 7 and 8), a pair of reinforcing bar holding portions are inserted into both inner side walls 9a and 9b of the short groove 4 of the main body portion 1. By inserting 2a and 2b oppositely (see, for example, FIG. 9) and curing and curing them, a spacer A in which both are integrated is produced (see, for example, FIGS. 2, 5, and 6). Therefore, it is easy to manufacture and the manufacturing cost is low as in the conventional case.

    B) In the case of mounting the spacer A of the present invention, in the case of the horizontal rebar 3, the rebar 3 is lifted and the spacer A of the present invention is placed on the form plate, and the opposing reinforcing bar holding of the spacer A is held. It is only necessary to place the rebar 3 on the opening opened upward between the use parts 2a and 2b and push it down by hand or step on it with feet. Thus, the reinforcing bar 3 is further pushed open against the spring force between the pair of opposing reinforcing bar holding parts 2 a and 2 b and is engaged in the curved recess 5 of the main body 1.

  When attaching to the vertical reinforcing bar 3, the opening between the opposing reinforcing bar holding portions 2a and 2b of the spacer A is applied from the side of the reinforcing bar 3 so that the main body 1 is directed to the vertical reinforcing bar side. What is necessary is just to press. Thus, the opposing reinforcing bar holding portions 2 a and 2 b are engaged with the reinforcing bar 3 from the opening further opened against the spring force, and the curved concave portion 5 of the main body 1 is one of the outer peripheral surfaces of the reinforcing bar 3. It is engaged so that it may contact | abut to a part.

  In either case, the rebar holding portion 2a, 2b is closed to the original state by the restoration by the spring force and the rebar 3 is prevented from being detached. At the same time, the rebar 3 is connected to the reinforcing bar holding pieces 7a, 7b. It is pressed at the tip and is held in direct contact with the back end surface 6 of the curved recess 5, so that the mounting operation can be completed easily and quickly. (See, for example, FIG. 1).

    C) In the above case, if the tip of each of the pair of reinforcing bar holding pieces 7a, 7b is sharpened, the reinforcing bar 3 has a spring force in a state in which the reinforcing bar 3 is engaged with the curved recess 5 of the main body 1. The pointed ends of the pieces 7a and 7b bite into a part of the outer peripheral surface, and the rebar 3 can be held more firmly. Therefore, even if an external force is applied during pouring of the concrete, the position of the spacer A on the reinforcing bar 3 is not shifted or the outer periphery of the reinforcing bar 3 is not rotated.

    D) Further, each of the reinforcing bar holding portions 2a, 2b has "<"-shaped portions 10a1, 10b1 at the support plate portions 10a, 10b between the reinforcing bar holding pieces 7a, 7b and the arm portions 8a, 8b. If the arm portions 8a and 8b are bent at a substantially right angle and continue, the reinforcing bar holding portions 2a and 2b can be bent with spring force and elasticity with their boundary portions as fulcrums.

  For this reason, the reinforcing bar holding portions 2a and 2b can be sufficiently expanded with a margin when the reinforcing bar 3 is fitted, and can easily cope with a difference in the outer diameter of the reinforcing bar 3. Therefore, there is no need to manufacture and manage various types of spacers and reinforcing bar holding parts according to the difference in the outer diameter of the reinforcing bars as in the past, and the mounting legs are close to the embedded part due to the concentration of stress due to external force. It won't be damaged.

    E) In addition to these, the spacer A of the present invention is particularly emphasized that the reinforcing bar holding part 2 is a separate part 2a, 2b on each side, and each mounting arm part 8a extending to the side is provided. , 8b are embedded in both inner side walls 9a, 9b of the short groove 4 of the main body 1 and are attached. Thus, unlike the case of Patent Document 4, the metal reinforcing bar holding part 2 is not interposed in the curved recess 5 or inside thereof, and the reinforcing bar 3 is in direct contact with the inner end face 6 of the curved recess 5. (See, for example, FIG. 1).

  Therefore, there is only a spacer body 1 made of concrete or mortar between the reinforcing bar 3 and the formwork 11 (the reinforcing bar and the wall surface of the structure after construction), and no other foreign matter is interposed. Therefore, in this spacer A, the distance from the mold material surface (wall surface after construction) to the nearest metal object, that is, the fog dimension H in a strict sense can be easily confirmed in appearance, and a predetermined fog is obtained. The dimension H can be obtained easily and quickly. Even if the size of the main body is large, there is no spacer that the fog size is small in a strict sense.

  In addition, even after construction, there is no other foreign material between the rebar 3 and the wall surface, only the spacer body A made of concrete or mortar. It will also be minimal.

  The spacer main body 1 has various shapes, and the same applies to the spacer main body 1 in the present invention. For example, when viewed from the longitudinal direction of the supported reinforcing bars, trapezoidal shape, inverted trapezoidal shape, the portion that comes into contact with the formwork plate is rounded, the one having two or more rounded portions, the planar one, There are other shapes (see, for example, FIGS. 10 and 11, Japanese Patent Application Laid-Open Nos. 2000-145021 and 2001-173159).

  In the above, the dimension from the back surface 6 of the curved concave part 5 of the spacer main body 1 to the tip part contacting the formwork plate 11, in other words, the dimension from the reinforcing bar 3 to the formwork material 11 during construction, or after construction There are various sizes of the dimension from the reinforcing bar 3 to the wall surface of the structure, that is, the fogging dimension H in a strict sense, from about 50 m to about 130 mm, for example.

  On one side of the main body 1 where the reinforcing bar holding portion 2 is provided, as seen from the front view, a substantially semicircular curved concave portion 5 in which the reinforcing bar 3 is engaged with the central portion, and a slightly wider interval on both outer sides thereof. It is preferable to form a short groove 4 having inner walls 9a and 9b.

  The arm portions 8a, 8b extending to the side of each reinforcing bar holding portion 2a, 2b are inserted into both the inner side walls 9a, 9b of the short groove 4 so as not to enter the curved recess 5 of the main body 1 or the inside thereof. It is to be buried.

  It is desirable that the curved concave portion 5 of the main body 1 and the reinforcing bar holding portion 2 have a shape that can accommodate at least two types of thickness of the reinforcing bar 3 (see, for example, FIGS. 5 and 6). Further, in order to correspond to the outer diameter reinforcing bar 3 that cannot be handled by one spacer A, a curved concave surface 5 having a different width is formed on the main body portion 1 having a different lateral width, thereby holding a pair of reinforcing bars having the same shape as described above. It is preferable to provide the devices 2a and 2b so as to face each other at different intervals (for example, see FIGS. 5 and 6).

  Each of the reinforcing bar holding portions 2a and 2b has a "<"-shaped portion at the support plate portions 10a and 10b between the reinforcing bar holding pieces 7a and 7b and the arm portions 8a and 8b, and is substantially perpendicular. It is preferable to bend and continue to the arm portions 8a and 8b.

  The figure shows an embodiment of a reinforced concrete construction spacer A according to the present invention, which is shown here in the case of holding a horizontally oriented rebar 3 at the top of the main body 1 during construction (see FIG. 1).

  Reference numeral 1 denotes a spacer main body, which may be made of concrete, but here is made of mortar, and its shape is an inverted trapezoidal shape with corners cut off with a roundness when viewed from the longitudinal direction of the reinforcing bar 3 to be held. Yes. Among the sizes, the fogging dimension H in a strict sense is 101 mm here, the overall height is about 119 mm, the lateral width is about 76 mm, and the thickness (front-rear width) is about 32 mm.

  A short groove 4 is formed in the upper part of the main body 1. The short concave groove 4 is formed near the center of the upper portion of the main body 1, and here, a recess having a width of about 36 mm and a depth of about 10 mm is formed, and further, a substantially semicircle having a width of about 22 mm and a depth of about 8 mm. A curved concave portion 5 for supporting a reinforcing bar is formed. 6 shows the back end face.

  Reference numeral 2 denotes a reinforcing bar holding portion, but it is not necessary to prepare a variety of types, and two pairs of the same shape and size are prepared as a pair, and the pair is opposed to each main body 1. (See FIGS. 5 and 6 above). Here, a pair of 2a and 2b made of a steel plate having a spring property with a thickness of about 0.7 mm and pressed into the same shape is used to be opposed to the upper portion of the main body 1.

  The pair of reinforcing bar holding portions 2a and 2b are, here, two bars for holding reinforcing bars 7a and 7b having a length of about 10 mm and about 30 degrees obliquely downward, and an obliquely downward and reverse direction from the upper position. The support plate portions 10a and 10b have a "<" shape that continues to the top, and mounting arm portions 8a and 8b that are horizontally about 15 mm laterally as viewed from the lower end.

  Here, the holding pieces 7a and 7b are pointed at their tips, and the mounting arm portions 8a and 8b have a rectangular frame shape when seen in a plan view, and a part of the holding pieces 7a and 7b is manufactured. The locking pieces 13a and 13b for locking to the mold 12 are formed upward.

  In the above, the width of the main body 1 and the interval between the opposing reinforcing bar holding portions 2a and 2b may be compatible only with the reinforcing bar 3 having a specific outer diameter, but here, the difference in the outer diameter of the reinforcing bar 3 to be held Thus, for example, the outer diameters of 13 mm and 16 mm, 19 mm and 22 mm, 25 mm and 29 mm, and 32 mm and 38 mm can be accommodated with two types of outer diameter reinforcing bars 3.

  For example, in order to correspond to the outer diameter of the reinforcing bar 3 of 19 mm and 22 mm, here, as described above, the short groove 4 on the upper portion of the main body 1 has a width of about 36 mm, a depth of about 10 mm, and the curved concave surface 5 has a width of about 22 mm. It has a substantially semicircular shape with a depth of about 8 mm. Further, the interval between the reinforcing bar holding portions 2a and 2b is set to be approximately 22 mm at the opened upper portion and approximately 13 mm at the lower portion (see FIGS. 5 and 6).

  Since the use state and the operational effect of the spacer A are as described in the section of the effect of the invention (see FIG. 1), they are omitted here to avoid duplication.

  The spacer A is manufactured using a manufacturing mold 12 having a shape as shown in FIG. The mold 12 has an outer peripheral wall and a bottom surface that have the same shape as the outer shape of the main body 1 and is open at the top. The arm portions 8a, 8b of the reinforcing bar holding portions 2a, 2b can be inserted into the outer peripheral wall portions corresponding to the inner walls 9a, 9b of the short concave groove 4 of the main body 1 from above. Slits 14a and 14b having a width of 0.8 mm are formed.

  After the mortar is filled into the mold 12 from above, the positions of the mounting arm portions 8a and 8b near the base are positioned in the slits 14a and 14b from above so that the reinforcing bar holding pieces 7a and 7b face each other. Put it in. In that case, the mounting arm portions 8a and 8b do not cover the curved recess 5 or the inside thereof in the mortar 13 (see FIG. 9).

  In this state, by curing and hardening the mortar, the main body portion 1 and the pair of reinforcing bar holding portions 2a and 2b are integrated, and then the manufacturing form 12 can be taken out with the front and back reversed. The spacer A according to the present invention is completed (see FIGS. 2, 5, and 6).

It is a front view which shows the example of a use condition of one Example of the reinforced concrete construction spacer which concerns on this invention. FIG. 3 is a partially cutaway front view of the spacer shown in FIG. 1. It is an expansion perspective view of the principal part of the spacer shown in FIG. FIG. 2 is a perspective view of one of a pair of reinforcing bar holding portions used in the spacer shown in FIG. 1. FIG. 2 is a front view showing the spacer shown in FIG. 1 corresponding to two types of reinforcing bars having a narrow outer diameter. FIG. 2 is a front view showing the spacer shown in FIG. 1 corresponding to two types of reinforcing bars having a large outer diameter. It is a cross-sectional top view which shows the manufacturing form used for manufacture of the spacer shown in FIG. It is the II sectional view taken on the line of the manufacturing form shown in FIG. It is a partially notched top view which shows the state at the time of manufacture with the manufacturing form shown in FIG. It is a front view of the other Example from which the shape of a main-body part differs. It is a front view of another Example from which the shape of a main-body part differs.

Explanation of symbols

A-spacer 1-spacer main body part 2,2a, 2b-rebar holding part 3-reinforcing bar 4-short concave groove 5-curved concave part 6-back end face 7a, 7b-rebar holding piece 8a, 8b-arm part 9a, 9b-Inner side wall 10a, 10b-Support plate part 11-Formwork plate 12-Manufacturing formwork 13a, 13b-Locking piece 14a, 14b-Slit 15-Mortar H-Fog size

Claims (4)

A part of the reinforcing bar holding part 2 made of a metal plate having a spring property is embedded in the spacer body part 1 made of concrete or mortar and integrated.
The main body 1 has a short concave groove 4 having a curved concave portion 5 with which a reinforcing bar 3 to be held can be engaged at the center of one surface,
The reinforcing bar holding part 2 is a pair of two pieces 2a and 2b having the same shape. The reinforcing bar holding pieces 7a and 7b opposed to each other on the main body part 1 and mounting arm parts 8a and 8b extending sideways are provided. Have
By attaching the mounting arm portions 8a and 8b to the inner side walls 9a and 9b of the short concave groove 4 of the main body portion 1,
The reinforcing bar 3 engaged in the curved concave part 5 is pressed by the tips of the reinforcing bar holding pieces 6a and 6b to be brought into direct pressure contact with the back end surface 6 of the curved concave part 5, and a spacer is provided between the reinforcing bar 3 and the mold plate 10. A spacer for reinforced concrete construction, characterized in that it can be held without any objects other than the main body 1 interposed. The pair 2a, 2b having the same shape as the reinforcing bar holding part 2 is attached to the main body part 1 corresponding to the difference in the outer diameter of the reinforcing bar 3 by changing the interval between the two parts 2a, 2b. , Spacer for reinforced concrete construction. The spacer for reinforced concrete construction according to claim 1 or 2, wherein the reinforcing bar holding pieces 7a, 7b of the reinforcing bar holding parts 2a, 2b have a pointed tip. Each of the reinforcing bar holding portions 2a, 2b has a U-shaped portion at the support plate portions 10a, 10b between the reinforcing bar holding pieces 7a, 7b and the arm portions 8a, 8b, and is bent at a substantially right angle to form an arm portion. The spacer for reinforced concrete construction according to claim 1, 2 or 3, which follows 8a, 8b.

Images