KR101492812B1 - Hollowed Precast Column And Constructure Method Thereof - Google Patents

Abstract

A hollow precast column according to one aspect of the present invention includes a concrete portion having a hollow portion formed in a cylindrical shape at a central portion thereof, a first upper screw portion partially buried in a peripheral portion of the concrete portion and having an upper portion formed in a spiral shape, At least one first reinforcing bar having a first lower thread portion formed in a helical shape and an auxiliary reinforcing bar formed at a predetermined distance between at least one of the first reinforcing bars and a second reinforcing bar formed between the first reinforcing bar and the upper And a splice sleeve for splicing a second lower thread portion of a second cast iron root joined to the second lower thread portion.

Description

Technical Field [0001] The present invention relates to hollow precast columns,

The present invention relates to a hollow precast column and a method of constructing the column, and more particularly, to a hollow precast column capable of firmly joining a plurality of columns and a method of constructing the column.

Generally, in the case of building construction, firstly, foundation concrete is laid on the ground in a state where the ground is chipped, and a reinforcing bar, which is a column, is connected to the reinforcing bars laid on the foundation concrete. The concrete frame is laid by pouring concrete inside the mold.

However, in such a construction method, the work process is often dependent on manual work, and it is very difficult to secure the homogeneous quality of the concrete frame, and it is inevitable that the construction is inevitable because it is affected by the external temperature condition and the weather .

Therefore, in order to solve this problem, a method of constructing a precast concrete column at a factory and transferring the precast concrete column to a site has been used.

In other words, after making molds (molds) using iron or wood, reinforcing bars are placed in the molds, concrete is laid, and concrete pillar is produced by curing in a steam curing furnace.

However, since the column is a solid solid column, it has a large weight, which makes it difficult to carry it in the field, increases the transportation cost, and has a problem of using a heavy-duty heavy machine for piling the concrete column in the field assembly.

In addition, there is a problem in that a beam is installed on the column or the connection portion connecting the column and the column is low in strength and not rigid, resulting in shear failure.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a hollow pre-cast structure capable of strengthening and strengthening a joint portion by simultaneously using a mechanical joint and a double joint, And a method of constructing the column and the column.

According to an aspect of the present invention, there is provided a hollow precast column, comprising: a concrete portion having a first hollow portion formed in a cylindrical shape at a central portion thereof; At least one first main steepener having a first upper screw portion and a first lower screw portion formed at a lower portion in a spiral shape, an auxiliary reinforcing bar formed at a predetermined interval between at least one of the first main steels, And a splice sleeve for splicing a threaded portion and a second lower threaded portion of a second cast iron muscle coupled to an upper portion of the first casted steel root.

The reclaimed concrete using the recycled aggregate can be filled in the first hollow portion.

The splice sleeve includes a body having a filling hole for receiving the second lower threaded portion and filling the filler material, the upper portion of the outer side surface being formed in a spiral shape, and a second threaded portion extending from the lower portion of the body, And a fastening portion having a fastening hole.

The splice sleeve has a cap hole having a diameter larger than that of the second main iron core to prevent the second main iron core from being loosened by being spirally connected to the upper side of the outer surface of the main body and to secure the fluidity of the main iron core, As shown in FIG.

The second lower threaded portion may include a retaining plate to be engaged with the cap so that the second lowered threaded portion is engaged with the cap. When the fillet material is cured in the body, And a separation preventing plate for separating the liquid from the liquid.

The first cast iron core may be formed so that an upper portion of the splice sleeve coincides with an upper portion of the bottom slab when the first upper screw portion and the splice sleeve are engaged.

Wherein the auxiliary reinforcement comprises a first extension portion extending from the upper portion of the concrete portion to the first hollow portion side and a second extension portion extending from the first extension portion so as to correspond to the position of the first hollow portion, And a second extending portion that extends vertically so as to be inserted into the inside of the two hollow portions.

According to another aspect of the present invention, there is provided a method of constructing a hollow precast column, comprising: vertically setting a first column having a support portion whose upper outer circumferential surface is wider than the lower outer circumferential surface; A step of placing a precast beam on an upper portion of the support portion and providing a mold for forming a bottom slab; placing reinforcing bars on the precast beam and the upper portion of the formwork; Placing a concrete into a first hollow portion formed in the first pillar, the precast beam and the bottom slab, bonding the splice sleeve to an end of the first slab, Inserting into the sleeve a second cast iron extending to a lower portion of the second column; It can include binary.

The reclaimed concrete using the recycled aggregate can be filled in the first hollow portion.

The reinforcing bars may include a hook reinforcement for reinforcing a joining force between the first post and the precast beam, the vertical portion being inserted into the first hollow portion and the horizontal portion being laid on the bottom of the precast beam.

A method of joining a first cast iron muscle using the splice sleeve, the method comprising the steps of: coupling a fastener formed on a lower portion of the splice sleeve to a first upper thread portion formed on an upper portion of the first cast iron muscle; A step of inserting a cap into a second lower thread portion formed at a lower portion of the splice sleeve, and a step of spirally coupling the stopper plate and the separation preventing plate to the second lower thread portion, Filling the filling hole with the filler, and covering the cap on the outer surface of the body.

The first cast iron muscle may extend so that the upper portion of the splice sleeve coincides with the upper portion of the bottom slab when the first upper thread portion and the splice sleeve are engaged.

According to the method of constructing a hollow precast column and its columns according to the present invention, a mechanical joint for joining the first cast iron of the upper and lower columns and a reinforcing bar are bent by using a splice sleeve to form a first hollow portion It is possible to securely join the connecting portions by increasing the strength of the connecting portions.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a precast beam joined to a hollow precast column according to an embodiment of the present invention; FIG.
2 is a perspective view of a hollow precast column according to an embodiment of the present invention;
3 is a perspective view showing a state in which a hollow precast column according to an embodiment of the present invention is joined.
4 is a cross-sectional view showing a construction of a hollow precast column according to an embodiment of the present invention.
FIG. 5 is a cross-sectional view illustrating a splice sleeve joined with a column according to an embodiment of the present invention; FIG.
6 is a flowchart showing a method of constructing a hollow precast column according to another embodiment of the present invention.
FIG. 7 is a perspective view illustrating a method of constructing the hollow precast column shown in FIG. 6. FIG.
8 is a front view illustrating a method of joining a hollow precast column using a splice sleeve according to another embodiment of the present invention.

Hereinafter, a hollow precast column and a method of constructing the column according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view showing a precast beam joined to a hollow precast column according to an embodiment of the present invention, and FIG. 2 is a perspective view illustrating a hollow precast column according to an embodiment of the present invention.

1 and 2, a hollow precast column 10 according to an embodiment of the present invention includes a concrete part 100 having a first hollow part 110 formed in a cylindrical shape at a center part thereof, A first reinforcing bar 400 formed at a predetermined interval between at least one of the first reinforcing bars 200 and a second reinforcing bar 400 formed at a predetermined distance between the first reinforcing bars 200, And a splice sleeve 500 which splices the splice sleeve 500 and the splice sleeve 500 together.

The hollow precast column 10 can be produced in a factory using centrifugal force. The hollow precast column 10 may be formed by arranging the first main iron core 200 and the auxiliary reinforcing bars 400 and then pouring concrete to rotate the first hollow core precursor column 10 to form the first hollow portion 110 therein. Since the hollow precast column 10 utilizes the centrifugal force, a cylindrical first hollow portion 110 can be formed therein.

The concrete part 100 may have a first hollow part 110 formed into a cylindrical shape by centrifugal force. The cross section of the concrete part 100 may be formed into various shapes such as a square shape and a circular shape . Also, the concrete part 100 is formed of high-strength concrete so that even if the first hollow part 110 is provided therein, it can be structurally prevented from being influenced by strength or the like. The first and second columns 12 and 14 may be arranged so as to align the first and second columns 12 and 12 before the concrete is poured into the concrete section 100, Can be increased.

The upper portion of the concrete section 100 is extended with the first reinforcing steel rope 200 and the second reinforcing rope 12 and the outer side of the first reinforcing rope 200 and the second reinforcing rope 12, A space in which the cast second post 12 is stacked can be formed.

The first cast iron 200 is partially buried in the peripheral portion of the concrete part 100 and has a first upper screw part 210 formed in a spiral shape and a first lower screw part 220 formed in a spiral shape in a lower part, .

The first cast steel 200 may have a diameter larger than that of the second column 12 to increase the resistance against the vertical load of the hollow precast column 10, And may be formed to have a length protruding from the lower portion.

The first upper threaded portion 210 formed at the upper end of the first main iron core 200 and the first lower threaded portion 220 formed at the lower end of the first main iron core 200 are formed in a spiral shape to increase the binding force by spirally joining other devices. The spiral shape of the first upper thread portion 210 and the first lower thread portion 220 may be formed to have a predetermined length at the end of the first main spindle 200 to bind other devices for a predetermined length.

The reinforcing rods of the second pillar 12 may be disposed at a predetermined interval between at least one of the first reinforcing rods 200. Although not shown in the drawing, the reinforcing bar of the second pillar 12 can be fixed by wrapping the reinforcing bar before pouring the concrete into the concrete part 100. The band reinforcing bars 400 may be wound around the auxiliary reinforcing bars 400 in various shapes such as spiral or rhombus in order to fix the auxiliary reinforcing bars 400 and increase the binding force.

In addition, the auxiliary reinforcing bars 400 may be arranged at a predetermined interval between the first main reinforcing bars 200, but may be arranged in a circle in the same manner as the first hollow portions 110, .

The auxiliary reinforcing bar 400 includes a first extending portion 410 extending from the upper portion of the concrete portion 100 toward the first hollow portion 110 and a second extending portion 410 extending from the end of the first extending portion 410 And a second extending portion 420 extending upwardly from the second extending portion 420.

After the auxiliary reinforcing bars 400 are folded, the recycled aggregate 50 made of recycled aggregate formed by crushing waste concrete in the first hollow portion 110 is filled to reduce the construction cost .

The use of the recycled concrete (50) makes it possible to use a recycled concrete (50) because the concrete part (100) is made of high strength concrete and therefore the concrete filled in the first hollow part (110) Construction costs can be saved.

The splice sleeve 500 includes a body 510 for receiving the primary iron core 200 of the upper hollow precast column 10 when a plurality of the hollow precast columns 10 are stacked, And a fastening portion 520 extending from the lower portion and helically engaged with the first upper thread portion 210 of the lower hollow precast column 10.

FIG. 3 is a perspective view showing a state in which a hollow precast column according to an embodiment of the present invention is joined, and FIG. 4 is a sectional view showing a construction of a hollow precast column according to an embodiment of the present invention.

3 to 4, the hollow precast column 10 according to an embodiment of the present invention can be joined to another hollow precast column 10 stacked on top by a splice sleeve 500 have.

The pre-cast beam 20 may be laminated on the concrete part 100 of the hollow precast column 10 to form the bottom slab 600. When the precast beam 20 is stacked on the upper part of the concrete part 100, the precast beam 20 is stacked on the concrete part 100 to prevent the precast beam 20 from being deviated downward due to the vertical load, can do.

The precast beam 20 may be structured such that the upper part thereof is opened by the half precast beam 20 and the inside thereof is empty. When the bottom slab 600 is formed by laminating the precast beam 20 on the upper portion thereof, the hook reinforcement 30 is bent vertically at the end to increase the bonding strength between the precast beam 20 and the hollow precast column 10, The first hollow portion 110 and the precast beam 20 may be in contact with each other at the same time.

When the hook reinforcement 700 is installed, the concrete is poured into the first hollow portion 110 of the pre-cast beam 20 and the hollow precast column 10 to form the pre-cast beam 20 and the hollow pre- It is possible to increase the bonding force of the base 10.

The fastening part 520 of the splice sleeve 500 is formed by spirally coupling to the first upper threaded part 210 formed at the end of the first cast iron core 200 extending on the upper part of the hollow precast column 10 .

The upper portion of the splice sleeve 500 may be the same as the upper portion of the bottom slab 600 or the upper portion of the splice sleeve 500 A portion formed in a spiral shape on the outer surface of the body 510 of the main body 510 may extend upward.

When the length of the first cast iron muscle 200 is short or long, the coupling depth of the first upper screw part 210 and the coupling part 520 is adjusted so that the upper part of the splice sleeve 500 is connected to the bottom slab 600 ). ≪ / RTI >

3 to 4, the auxiliary reinforcement 400 includes a first extension part 410 and a second extension part 420 so that the first extension part 410 and the second extension part 420 are embedded in the bottom slab 600, The second hollow portion 120 can be vertically extended so as to enter the second hollow portion 120. Therefore, the end of the second extension part 420 can be inserted into the second hollow part 120 of the column stacked on the upper part of the hollow precast column 10.

When the hollow precast column 10 is installed, the first cast iron 200 supporting the load can be mechanically joined by the splice sleeve 500, assisting the first cast iron 200, The reinforcing bar 400 having a resistance to the second hollow portion 120 is inserted into the second hollow portion 120 of the upper portion so that when the concrete is poured into the second hollow portion 120, have.

Hereinafter, the lower hollow precast column will be referred to as a " first column " and the hollow precast column to be laminated on the upper side will be referred to as a "second column"

FIG. 5 is a cross-sectional view illustrating a splice sleeve joined to a column according to an embodiment of the present invention.

5, a splice sleeve 500 according to an embodiment of the present invention includes a first upper thread portion 210 formed on an end portion of a first cast iron 200 extending on an upper portion of a first column 11, And a second lower thread portion 310 formed at an end portion of the second cast steel 300 extending to the lower portion of the second column 12 can be joined.

The splice sleeve 500 includes a body 510 having a filling hole 511 for receiving the second lower thread portion 310 and filling the filler 540 and having an upper portion formed in a spiral shape, And a fastening portion 520 extending from a lower portion of the body 510 and having a fastening hole 521 for fastening with the first upper screw portion 210.

The splice sleeve 500 may further include a cap 530 coupled to the outer surface of the body 510 to prevent the second main iron core 300 from being detached.

The body 510 may include a filling hole 511 for receiving the second lower thread portion 310 therein. The lower portion of the body 510 may have a fastening hole 521 to be coupled with the first upper screw portion 210 and may include a first upper screw portion 210 coupled to the fastening portion 520, The filler 540 may be filled in the fill hole 511 to increase the bonding force of the second lower screw portion 310.

The second lower threaded portion 310 may include a retaining plate 550 to be engaged with the cap 530 so as to be engaged with the cap 530 and a second main threaded portion 530 when the filler material 540 is cured in the body 510. [ 300 may be detachably coupled to the end of the second lower threaded portion 310 so as not to be released to the outside.

The body 510 may have protrusions on its inner surface so that the filler 540 cured after the curing agent 540 is cured does not separate from the body 510, though not shown in the figure.

For example, if the protrusion is not formed in the body 510, the cured filling material 540 may be separated from the filling hole 511 while receiving the second lower threaded portion 310, so that the filling material 540 Can be prevented from being released to the outside.

The fastening portion 520 may have a fastening hole 521 formed in a side surface thereof so as to be helically engaged with the first upper screw portion 210. The fastening hole 521 may have a diameter equal to that of the first upper thread portion 210 so that the first upper thread portion 210 may be closely contacted with the first upper thread portion 210.

Although not shown in the drawings, the upper portion of the fastening hole 521 may be formed to penetrate through the lower portion of the body 510. The body 510 may be integrally formed with the fastening portion 520, The height of the splice sleeve 500 can be adjusted according to the length of the first main iron core 200.

For example, when the first cast iron 200 is pushed upward in the process of fabricating the first column 11 and extends beyond a predetermined length, the upper portion of the first cast iron 200 should be cut. Since the first upper thread portion 210 is provided on the upper portion of the first cast iron 200 to be coupled with the splice sleeve 500, the upper portion of the coupling hole 521 and the upper portion of the body 510, So that the first column 11 is rotated so that the splice sleeve 500 can penetrate through the first upper threaded portion 210 so that the first cast iron core 200 can be coupled to the first upper threaded portion 210 by a predetermined amount or more And can be engaged with the splice sleeve 500 without cutting when extended.

The cap 530 may be engaged with an upper portion of the outer surface of the body 510 formed in a spiral shape. The cap 530 is inserted into the filling hole 511 before the hooking plate 550 and the separation preventing plate 560 are screwed to the second lower screw portion 310 to cure the filling material 540 And then to the body 510. The cap 530 can prevent the filler 540 from being released to the outside and prevent the second main iron core 300 from being separated from the cap 530.

The cap hole 531 formed at the upper end of the cap 530 is formed to have a larger diameter than the second main iron core 300 so that the second column 12 having the second main iron core 300 can be wind- The load can be made to have fluidity to reduce the construction error.

Although not shown in the drawing, the cap 530 may be coupled to the body 510 to fill the filling material 540, thereby forming a separate space into which the filling material 540 can be inserted, And then fill the filler 540 after the filler 540 is coupled with the filler 510. The separate space may be provided with a plurality of holes in the cap 530.

Hereinafter, a method of constructing a hollow precast column according to another embodiment of the present invention will be described with reference to the same reference numerals as those of the hollow precast column according to the above-described embodiment, and a detailed description thereof will be omitted .

FIG. 6 is a flowchart illustrating a method of constructing a hollow precast column according to another embodiment of the present invention, and FIG. 7 is a perspective view illustrating a method of constructing the hollow precast column shown in FIG.

In step S100, the first column 11 having the support portion 800 whose upper outer circumferential surface is formed wider than the lower outer circumferential surface can be vertically erected. The supporting part 800 of the first column 11 may enlarge the overlapping area of the precast beam 20 at the upper part and may be generated at the ends of the first column 11 and the precast beam 20, It is possible to prevent the destruction.

As shown in FIG. 7, when the support part 800 is manufactured in a factory such that the area of the upper part of the first column 11 is wider than the area of the lower part, the support part 800 can be made wider. The support part 800 may be reinforced by a separate reinforcing bar to increase the resistance against the shear force.

In step S200, the precast beam 20 may be applied to the upper part of the support part 800. [ The precast beam 20 can control the quantity of the precast beam 20 according to the position of the first column 11.

In step S300, a mold 40 may be installed on the precast beam 20 to reinforce the reinforced bar 30. A hook reinforcing bar 700 is installed on the first hollow portion 11 of the first column 11 so as to increase the bonding strength between the precast bar 20 and the first column 11 when reinforcing bars are placed in the mold 40. [ 110 and the precast beam 20 at the same time.

In step S400, the coupling part 520 formed at the lower part of the splice sleeve 500 may be spirally coupled to the end of the first main iron core 200 extending from the upper part of the first column 11. The first cast steel 200 is extended so that the upper portion of the splice sleeve 500 coincides with the upper portion of the bottom slab 600 when the first upper thread portion 210 and the splice sleeve 500 are engaged, .

In step S500, concrete is placed in the interior of the formwork 40 in which the reinforcing bar 30 is laid, the pre-cast beam 20 opened in the upper part, and the first hollow part 110 formed in the first column 11 .

In step S600, when the poured concrete is cured, the second pillar 12 can be loaded on the upper part. The second extension part 420 of the auxiliary reinforcing bar 400 can be inserted into the second hollow part 120 of the second pillar 12 when the second pillar 12 is loaded, The second lower thread portion 310 of the second cast iron 300 extending to the lower portion of the column 12 can be inserted into the body 510 of the splice sleeve 500.

The cap 530, the engagement plate 550, and the detachment prevention plate 560 may be coupled to the second lower screw portion 310 and then inserted into the snap sleeve.

In step S700, the filling member 540 may be filled in the filling hole 511 in which the second lower thread portion 310 is accommodated. The cap 530 may be fixedly coupled to the body 510 by spirally filling the filling hole 511 with the filling material 540.

A small amount of the bottom slab 600 may be removed or the cap 530 may be removed so that the outer surface of the spiral body 510 is visible when the upper outer surface of the spirally formed body 510 is covered with the bottom slab 600. [ ) Can be omitted.

8 is a front view illustrating a method of joining hollow precast columns using a splice sleeve according to another embodiment of the present invention.

As shown in FIG. 8, in the method of joining the hollow precast column 10 according to an embodiment of the present invention through the splice sleeve 500, a first step is formed on the first cast iron 200 The fastening portion 520 formed at the lower portion of the splice sleeve 500 can be coupled to the first upper screw portion 210.

In the second step, the cap 530 is inserted into the second lower screw part 310 formed at the lower part of the second cast iron 300 and the second lower screw part 310 is fastened to the cap 530 And the second lower thread portion 310 is wound on the end portion of the second lower thread portion 310 so that the second main thread 300 is not released to the outside when the filling material 540 is cured in the body 510. [ The detachment preventing plate 560 can be spirally engaged.

The third step includes inserting the second lower thread portion 310 into the filling hole 511 formed in the body 510 of the splice sleeve 500,

In step 4, the filling material 540 may be filled in the filling hole 511 and the cap 530 may be placed on the outer surface of the body 510. The filler 540 may fill the cap 530 and fill the filler 540 with a separate hole formed in the cap 530.

Although the hollow precast column and the column construction method according to an embodiment of the present invention have been described above, the spirit of the present invention is not limited to the embodiments disclosed herein. Those skilled in the art, who understands the spirit of the present invention, can readily suggest other embodiments by adding, changing, deleting, adding, or the like of components within the scope of the same idea, I would say.

10: hollow precast column 20: precast beam
100: concrete part 200: first main steel rope
210: first upper thread portion 220: first lower thread portion
300: second cast iron 400: secondary reinforcing steel
500: splice sleeve 510: body
520: fastening portion 530: cap
540: filling material 550:
560: separation preventing plate 600: bottom slab

Claims (12)

A concrete portion having a first hollow portion formed in a cylindrical shape in a central portion thereof,
At least one first cast iron bar partially buried vertically in a peripheral portion of the concrete portion and having a first upper screw portion having an upper portion formed in a spiral shape and a first lower thread portion formed in a lower spiral shape,
An auxiliary reinforcing bar formed at a predetermined interval between at least one of the first reinforcing bars,
And a splice sleeve for splicing the first upper threaded portion and a second lower threaded portion of a second cast iron core coupled to an upper portion of the first casted steel root,
The splice sleeve includes a body having a filling hole for receiving the second lower thread portion and filling the filler material, the upper portion of the outer side surface being formed in a spiral shape,
A fastening portion extending from a lower portion of the body and having a fastening hole which is helically engaged with the first upper screw portion;
And a cap having a larger diameter than the second main iron core in order to prevent the second main iron core from being loosened by being spirally connected to the upper side of the outer surface of the main body and to secure the fluidity of the main iron core,
Wherein the first cast iron core is formed by extending the upper portion of the splice sleeve to coincide with the upper portion of the bottom slab when the first upper screw portion and the splice sleeve are engaged.
The method according to claim 1,
And a recycled concrete using recycled aggregate is filled in the first hollow portion.
delete delete The method according to claim 1,
The second lower threaded portion may include a retaining plate that is engaged with the cap so as to be engaged with the cap,
And a detachment prevention plate that is coupled to an end of the second lower threaded portion so as to prevent the second main steel muscle from being released to the outside when the filler material is cured in the body.
delete The method according to claim 1,
Wherein the reinforcing bar has a first extension extending from an upper portion of the concrete portion to the first hollow portion,
And a second extension portion extending vertically so that the auxiliary reinforcement extending from the first extension portion can be inserted into the second hollow portion corresponding to the position of the first hollow portion and stacked on the upper portion. Hollow precast columns.
A step of vertically erecting a first column having a support portion whose upper outer circumferential surface is wider than the lower outer circumferential surface,
Placing a precast beam on an upper portion of the support and providing a mold for forming a bottom slab,
Placing reinforcing bars in the precast beam and the upper part of the formwork,
Coupling a fastener formed on a lower portion of the splice sleeve to a first upper threaded portion formed on an upper portion of a first main steel cord extending on an upper portion of the first column,
Placing a concrete in a first hollow formed in the first column, a concrete in the pre-cast beam and the bottom slab,
Inserting a cap into a second lower thread portion formed at a lower portion of the second cast iron root;
Coupling the latching plate and the detachment prevention plate to the second lower threaded portion,
Inserting the second lower threaded portion into the filling hole formed in the body of the splice sleeve,
Filling the filling hole with the filling material,
And covering the cap on an outer surface of the body,
Wherein the first cast iron core is extended such that an upper portion of the splice sleeve coincides with an upper portion of the bottom slab when the first upper screw portion and the splice sleeve are engaged.
9. The method of claim 8,
And a recycled concrete using recycled aggregate is filled in the interior of the first hollow portion.
10. The method of claim 9,
Wherein the reinforcing bars are provided with hook reinforcing bars for reinforcing a bonding force between the first pillars and the precast beams, the vertical reinforcing bars being inserted into the first hollow portions and being horizontally arranged at the bottom of the precast reinforcing bars. Construction method of column.
delete delete

Images