JP5138009B2 - Mortar connecting spacer for PC - Google Patents

Description

  The present invention relates to a cover securing spacer used in making a prestressed concrete structure typified by a road pier, a railway pier, a bridge and the like.

  For example, a railway bridge portion is generally made of so-called post-tensioned prestressed concrete. In this construction process, first, reinforcing bars that form the skeleton of the bridge are assembled in the formwork. When the reinforcing bars are assembled, a spacer is disposed between the reinforcing bars and the mold so that the reinforcing bars in the vicinity of the mold are arranged at positions away from the mold by a predetermined dimension. Reinforcing bars are assembled, and shelf bars are attached to the assembled skeletal reinforcing bars. The shelf bars are for placing a sheath, which is a tube for passing PC steel, and are horizontally attached to a predetermined height position. Then, the sheath is placed on the attached rack bars, and then concrete is placed.

After the concrete is solidified, the PC steel material is inserted into the sheath, the inserted PC steel material is tensioned, and the grout material is filled in the sheath and solidified, thereby completing a prestressed concrete bridge. (See paragraph [0002] of Patent Document 1)
In such a construction process, when reinforcing bars are assembled in a formwork, it is necessary to interpose a spacer between the formwork and the reinforcing bars to ensure the cover against the reinforcing bars. When the concrete building is a long building such as a bridge, for example, a plurality of reinforcing bars called through bars are arranged in parallel with the length direction along the bottom surface of the formwork. At that time, in order to secure a predetermined cover between the reinforcing bar and the bottom surface of the formwork, the reinforcing bar must be arranged in a state where it is lifted from the bottom surface of the formwork by a spacer with a certain dimension.

  In addition, a spacer must also be arranged between the side surface of the formwork and the reinforcing bar so that the reinforcing bar embedded in the side surface of the building is located on the inner side of the predetermined dimension from the side surface.

JP 2006-159447 A JP 2007-308984 A

By the way, as for the conventional reinforced concrete construction spacer, as disclosed in Patent Document 2, for example, the spacers are each constituted by a single piece, and normally, a locking metal fitting is provided so as not to move with respect to the reinforcing bar. What you have is normal.
When using these conventional spacers to create a skeletal rebar within a formwork to make a prestressed concrete building, a number of spacers must be interposed between the bottom of the formwork and the skeleton rebar. However, there were problems such as poor assembly workability of the skeletal rebar.

Similarly, a large number of spacers must be interposed between the side surfaces of the formwork and the skeletal reinforcing bars, which causes problems such as poor assembly workability of the skeletal reinforcing bars.
The present invention has been made based on such a background, and a reinforcing bar (such as a reinforcing bar, etc.) arranged along the bottom surface of the mold has a predetermined dimension with the bottom surface of the mold. The main object is to provide a spacer that can be secured and easily arranged, and that can secure a cover between the reinforcing bar and the bottom of the formwork.

The present invention can further easily arrange reinforcing bars (reinforcing bars or the like referred to as through bars) arranged along the side surface of the formwork while ensuring a predetermined dimension with the side face of the formwork. Another object of the present invention is to provide a spacer that can ensure a cover between the mold and the side of the formwork.
It is still another object of the present invention to provide a mortar connecting spacer for prestressed concrete (PC).

In order to achieve the above object, the invention according to claim 1 is characterized in that a plurality of spacer portions arranged in a line at predetermined intervals and a connecting rod portion for connecting the plurality of spacer portions linearly. The spacer portion and the connecting rod portion are integrally formed of mortar, and the connecting rod portion includes a round rod made of stainless steel or PC steel that extends in the length direction of the connecting rod portion. Is embedded so as to penetrate from one end to the other end, and the round bar is embedded in a state in which a tensile tension is applied and is solidified by a mortar forming the connecting rod part, It is a mortar connecting spacer.
According to a second aspect of the present invention, each of the plurality of spacer portions protrudes from the connecting rod portion to the connecting rod portion by a predetermined dimension in the crossing direction, and a contact protrusion is integrally formed with the mortar at the protruding tip. The mortar connection spacer according to claim 1, wherein the mortar connection spacer is formed.

  The invention according to claim 3 includes a plurality of spacer portions arranged in a line at a predetermined interval, and a connecting rod portion for connecting the plurality of spacer portions in a straight line. The part and the connecting rod part are integrally formed of mortar, and each of the plurality of spacer parts protrudes from the connecting bar part to the connecting bar part by a predetermined dimension in the connecting bar part. A stainless steel strip has a longitudinal direction of the strip extending from one end to the other in the connecting rod portion, a width direction thereof is directed to a protruding direction of the plurality of spacer portions, and a thickness direction thereof is the plurality of the plurality of spacer portions. It is a mortar connection spacer, characterized in that it is embedded in a state in which it faces in a direction orthogonal to the protruding direction of the spacer portion.

According to this invention, the spacer is formed of mortar, and has a plurality of spacer portions and a connecting rod portion for connecting the plurality of spacer portions, so that the predetermined length extending linearly by the plurality of spacer portions. Reinforcing bar cradle is formed.
For this reason, the spacer which concerns on this invention is arrange | positioned on a formwork bottom face, and arrange | positions a reinforcing bar (through bar) in the direction orthogonal to the length direction (length direction of a connecting rod part), The said reinforcing bar (through bar) ) Can be surely arranged at a predetermined distance from the bottom surface of the mold by a simple operation. Therefore, it is possible to reliably ensure the covering of the thread through the bottom of the formwork.

In the connecting spacers according to claims 1 and 2, since a round bar to which a predetermined tension is applied is embedded in the connecting rod portion, the bending strength of the connecting rod portion made of mortar is strong and the reinforcing bar is supported reliably. Can do.
In the invention described in claim 3, a stainless steel belt-like plate is embedded in the connecting rod portion. The width direction of the strip-shaped plate faces the protruding direction of the plurality of spacer portions. Therefore, in the state where the connecting spacer is arranged so that the protruding tips of the plurality of spacer portions are in contact with the bottom surface of the mold, for example, the stainless steel strip embedded in the connecting spacer with respect to the bottom surface of the mold has a width of The direction exists in the connecting rod portion so that the direction is perpendicular to the bottom surface of the mold. For this reason, even if a reinforcing bar or other load is applied to the connecting rod portion, the connecting rod portion has sufficient strength to withstand that load, and can reliably support the reinforcing bar.

1 is a front view (FIG. 1A), a plan view (FIG. 1B), a bottom view (FIG. 1C), and a side view of a mortar connecting spacer 10 according to an embodiment of the present invention. FIG. 1D). FIG. 2 is a diagram illustrating a state in which the reinforcing bars 16 are arranged with a predetermined cover dimension from the bottom surface of the mold (not shown) using the bottom surface mortar connection spacer 10. 3 is a front view (FIG. 3 (A)), a right side view (FIG. 3 (B)), a left side view (FIG. 3 (C)), and a mortar connecting spacer 20 according to another embodiment of the present invention. It is a top view (Drawing 3 (D)). FIG. 4 is a diagram showing a state in which the reinforcing bars 26 are arranged with a predetermined cover dimension from the mold side surface 27 using the side mortar connecting spacer 20. FIG. 5 is a diagram showing a state in which the reinforcing bar 16 is arranged by opening a mold bottom (not shown) and a predetermined cover size using a bottom mortar connecting spacer 30 according to another embodiment of the present invention. 6 is a front view (FIG. 6A), a plan view (FIG. 6B), a bottom view (FIG. 6C), and a side view of a mortar connecting spacer 30 according to another embodiment of the present invention. (FIG. 6D). FIG. 7 is a partially enlarged view of FIG. 6 (A), in which an embedded stainless steel strip is indicated by a broken line. FIG. 8 is an enlarged view of FIG. 6D, in which the embedded stainless steel strip is represented by a broken line.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 is a front view (FIG. 1A), a plan view (FIG. 1B), a bottom view (FIG. 1C), and a side view of a mortar connecting spacer 10 according to an embodiment of the present invention. FIG. 1D). The mortar connection spacer 10 is a bottom mortar connection spacer for securing a cover between the reinforcing bar and the formwork bottom, that is, a cover on the bottom of the building.

  Referring to FIG. 1, the mortar connecting spacer 10 for the bottom surface will be described based on the direction when it is installed. A plurality of spacers (four in the drawing) arranged in a row in the left-right direction with a predetermined interval. It has the part 11 and the connection rod part 12 which connects the four spacer parts 11 linearly. Both the spacer portion 11 and the connecting rod portion 12 are integrally formed of mortar.

  The feature of the bottom surface mortar connecting spacer 10 is that a stainless round bar 13 extending in the length direction of the connecting rod portion 12 is embedded in a connecting rod portion 12 that connects a plurality of spacer portions 11. . By embedding the round rod 13 made of stainless steel, the strength of the connecting rod portion 12 made of mortar, particularly the bending strength applied in the cross direction in the length direction can be significantly improved.

In order to manufacture the bottom surface mortar connecting spacer 10, a manufacturing mold is made, and a stainless steel round bar 13 is first placed in the mold. At that time, force in a direction away from each other is applied to both ends of the round bar 13 to bring the round bar 13 into a tension application state. Then, the mortar is poured into the mold, and the mortar is solidified, whereby the bottom surface mortar connecting spacer 10 according to this embodiment is completed.
At the time of production, the mortar may be poured into a mold without applying tension to the stainless steel round bar. Further, the number of stainless steel round bars arranged in the mold may be two, three, or the like instead of one.

As shown in the side view, the connecting rod portion 12 of the bottom surface mortar connecting spacer 10 has a flat shape with a top surface and a side surface (cross-sectional shape) that is convex downward.
On the other hand, the spacer portion 11 has a substantially rectangular shape that is slightly long in the vertical direction in a side view, and the width is wider than the width of the connecting rod portion 12 (side view shape). It is overhanging. Moreover, it has a rectangular parallelepiped shape having a predetermined thickness.

For example, a pair of hemispherical protrusions 15 project from the lower surface of the spacer portion 11. The projection 15 constitutes a contact portion that contacts the bottom surface of the mold.
Strictly speaking, the cover size of the mortar connecting spacer 10 is a distance D1 from the round bar 13 embedded in the connecting rod portion 12 to the projection tip of the spacer portion 11.
However, since the stainless steel round bar is a rust-proof metal, the fogging dimension can be regarded as the distance D from the upper surface of the connecting bar part to the protrusion of the spacer part 11.

FIG. 2 is a diagram illustrating a state in which the reinforcing bars 16 are arranged with a predetermined cover dimension from the bottom surface of the mold (not shown) using the bottom surface mortar connection spacer 10.
As shown in FIG. 2, the bottom surface mortar connecting spacer 10 can be stably formed on the bottom surface of the mold. For this reason, by arranging a plurality of bottom surface mortar connection spacers 10 at regular intervals, the plurality of bottom surface mortar connection spacers 10 constitute a receiving table for a plurality of reinforcing bars 16.

Therefore, unlike the conventional spacer, it is not necessary to attach the spacers individually to the reinforcing bars.
By arranging the bottom surface mortar connecting spacer 10 on the bottom surface of the formwork and placing the reinforcing bars, the reinforcing bars can be surely arranged while securing a predetermined cover.
The form of the bottom surface mortar connecting spacer 10 according to the present invention is not limited to that of the embodiment, and various modifications can be made within the scope of the claims.

3 is a front view (FIG. 3 (A)), a right side view (FIG. 3 (B)), a left side view (FIG. 3 (C)), and a mortar connecting spacer 20 according to another embodiment of the present invention. It is a top view (Drawing 3 (D)). The mortar connection spacer 20 is a side mortar connection spacer for securing the cover between the reinforcing bar and the side surface of the formwork, that is, the cover on the side surface of the building.
Referring to FIG. 3, the side mortar connecting spacer 20 will be described based on the direction when it is installed. A plurality of (three in the figure) spacers arranged at predetermined intervals in a vertical direction. It has the part 21 and the connection rod part 22 which connects the three spacer parts 21 linearly. Both the spacer portion 21 and the connecting rod portion 22 are integrally formed of mortar.

  Further, a hook 28 made of a wire for hooking (for example, a stainless steel wire having elasticity) is provided at the upper end of the right side surface. The hook 28 is preferably formed of an elastic wire so that it can be engaged with a plurality of reinforcing bars having different thicknesses. By using the hook 28 made of an elastic wire, it can be suitably used even when the thickness (diameter) of the reinforcing bar 26 to be applied is different, and the connecting spacer 20 is connected to the reinforcing bar 26 in an engaged state. It is because it does not shift. Also, when changing the attachment position (hanging position) of the connecting spacer 20, the hook 28 having elasticity can easily cope with the position change.

  The feature of the side mortar connecting spacer 20 is that a stainless round bar 23 extending in the length direction of the connecting rod portion 22 is embedded in a connecting rod portion 22 that connects a plurality of spacer portions 21. . By embedding the stainless steel round bar 23, the strength of the connecting bar portion 22 made of mortar, particularly the bending strength generated in the cross direction in the length direction, can be remarkably improved.

In order to manufacture the mortar connection spacer 20 for the side surface, a mold for manufacturing is made, and a stainless steel round bar 23 is first placed in the mold. At that time, forces in the direction of separating from each other are applied to both ends of the round bar 23 to bring the round bar 23 into a tension application state. Then, the mortar is poured into the mold, and the mortar is solidified, so that the bottom surface mortar connecting spacer 20 according to this embodiment is completed. The hook 28 can be attached so that one end is embedded in the mortar at a predetermined position after the mortar is poured into the mold and before the mortar is solidified.
Also in this embodiment, mortar may be poured into a mold without applying tension to a stainless steel round bar. Further, the number of stainless steel round bars arranged in the mold may be plural instead of one.

As shown in the plan view, the connecting rod portion 22 of the side surface mortar connecting spacer 20 has a flat bar shape (cross-sectional shape) that has a flat right side surface and is curved in the left direction.
On the other hand, the spacer portion 21 has a substantially cylindrical shape in the left-right direction in a plan view, and its diameter is wider than the width of the connecting rod portion 22 (right side view shape), and projects from the connecting rod portion 22 back and forth. .

And the front-end | tip of the spacer part 21 is protrudingly provided as the hemispherical protrusion 25, for example.
The protrusion 25 constitutes a contact portion that contacts the side surface of the mold.
Strictly speaking, the cover size of the mortar connecting spacer 20 is a distance D2 from the round bar 23 embedded in the connecting rod portion 22 to the projection tip of the spacer portion 21.
However, since the stainless steel round bar is a rust-proof metal, the fogging dimension can be regarded as the distance D from the upper surface of the connecting bar part to the protrusion of the spacer part 21.

FIG. 4 is a diagram showing a state in which the reinforcing bars 26 are arranged with a predetermined cover dimension from the mold side surface 27 using the side mortar connecting spacer 20.
As shown in FIG. 4, hooks 28 of side mortar connecting spacers are hooked on rebars (for example, through bars) extending horizontally (for example, through bars) on the uppermost side of the reinforcing bars assembled in the mold, The side mortar connecting spacer 20 is hung on the upper reinforcing bar. As a result, all the reinforcing bars 26 arranged below the reinforcing bars 26 are covered with the mold side face 27 by the side mortar connecting spacer 20.

Therefore, unlike the conventional spacer, it is not necessary to attach the spacers individually to the reinforcing bars.
By the simple operation of suspending the side mortar connecting spacer 20 on the most lateral reinforcing bar, it is possible to reliably arrange the reinforcing bars arranged in the vertical direction on the side part while ensuring a predetermined cover.
The form of the side mortar connecting spacer 20 according to the present invention is not limited to that of the embodiment, and various modifications can be made within the scope of the claims.

FIG. 5 is a perspective view showing a state in which the reinforcing bar 16 is arranged by opening a mold bottom (not shown) and a predetermined cover size using a mortar connecting spacer 30 according to another embodiment of the present invention.
As shown in FIG. 5, the mortar connecting spacer 30 for the bottom surface according to this embodiment can also be stably installed on the bottom surface of the mold. For this reason, by arranging a plurality of bottom surface mortar connection spacers 30 at regular intervals, the plurality of bottom surface mortar connection spacers 30 constitute a receiving table for a plurality of reinforcing bars 16.
Therefore, unlike the conventional spacer, it is not necessary to attach the spacers individually to the reinforcing bars. By arranging the bottom surface mortar connecting spacer 30 on the bottom surface of the formwork and placing the reinforcing bars, the reinforcing bars can be surely arranged while securing a predetermined cover.

In the bottom mortar connecting spacer 30, a stainless steel strip 33 extending in the length direction is embedded in the connecting rod portion 12.
FIG. 6 is an overall view of the mortar connection spacer 30 for the bottom surface, and its length (the lateral length in the front view of FIG. 6A) is 1 m, with respect to the connection rod portion 12 of 1 m. Seven spacer portions 11 are arranged at equal intervals and protrude from the connecting rod portion 12. 7 and 8 are (partially) enlarged views of the mortar connecting spacer 30 for the bottom surface.

As shown in FIGS. 7 and 8, a stainless steel strip 33 is embedded in the connecting rod portion 12. The stainless steel strip plate 33 is a plate having a thickness of 2 mm, and is embedded in the connecting rod portion 12 so as to extend in the longitudinal direction. Moreover, the width direction of the strip | belt-shaped board 33 is arrange | positioned so that it may face the protrusion direction of the spacer part 11, ie, an up-down direction in FIG. Accordingly, in FIGS. 7 and 8, the long plate 33 embedded in the connecting rod portion 12 does not bend in the vertical direction, receives the load in the vertical direction applied to the connecting rod portion 12, and makes the connecting rod portion 12 load resistant. Can be a good product.
The configuration of this embodiment can also be applied to the side mortar connecting spacer described above.

  In addition, the mortar connecting spacers 10, 20, and 30 of the present invention can be used in a construction process of a concrete building other than a prestressed concrete building.

10, 30 Bottom mortar connection spacer 11 Spacer portion 12 Connection rod portion 13 Round bar 15 Protrusion 16 Reinforcement 20 Side mortar connection spacer 21 Spacer portion 22 Connection rod portion 23 Round bar 25 Protrusion 26 Reinforcement 27 Formwork side surface 28 Hook

Claims (3)

A plurality of spacer portions arranged in a row at a predetermined interval;
A connecting rod portion for connecting the plurality of spacer portions linearly,
The spacer portion and the connecting rod portion are integrally formed of mortar,
In the connecting rod portion, a round rod made of stainless steel or PC steel extending in the length direction is embedded so as to penetrate the connecting rod portion from one end to the other end,
The mortar connection spacer, wherein the round bar is embedded by a mortar that is embedded in a state in which a tensile tension is applied to form the connection bar part.   Each of the plurality of spacer portions protrudes from the connecting rod portion to the connecting rod portion with a predetermined dimension in the crossing direction, and a contact protrusion is integrally formed with a mortar at the protruding tip. The mortar connecting spacer according to claim 1. A plurality of spacer portions arranged in a row at predetermined intervals;
A connecting rod portion for connecting the plurality of spacer portions linearly,
The spacer portion and the connecting rod portion are integrally formed of mortar,
Each of the plurality of spacer portions protrudes from the connecting rod portion to the connecting rod portion by a predetermined dimension in the crossing direction,
In the connecting rod portion, a stainless steel strip-shaped plate, the longitudinal direction of the strip-shaped plate extends from one end to the other end in the connecting rod portion, the width direction thereof faces the protruding direction of the plurality of spacer portions, A mortar connection spacer, wherein the mortar connection spacer is embedded in a state in which a thickness direction faces a direction orthogonal to a protruding direction of the plurality of spacer portions.

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