JP4149117B2 - Method for performing column base concrete splicing and driving form for a splicing portion used in the method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a method capable of preventing a depression S due to sedimentation of concrete occurring in a stigma (Fig. 1) 1 'of a reinforced concrete structure (hereinafter referred to as RC), and for each floor of an RC building, the top end face of the beam The present invention relates to a method for making a column base concrete joint and a casting form for a column base joint used in this method.
[0002]
[Prior art]
In the present invention, the RC building has an integral structure by piercing the column base concrete at the top end surface of the beam for each floor, but the horizontal connection portion of the column base concrete is accompanied by the separation of the aggregate. A large amount of latency (a white muddy substance that does not harden due to the low specific gravity in the cement powder) is generated in the depression S due to the settling of the bean plate or the stigma concrete 1 ′. In addition, discontinuities are likely to occur due to the presence of sawdust and other debris from the work on the formwork, so the weight from the top and the compressive force due to the large shearing force and bending moment during the earthquake are applied, and the axial force and shearing force There is a question of durability as well as transmission, and it is the most anxious part of the body.
[0003]
Conventionally it is pouring by dividing concrete 1 Kaibun two layers (Fig. 1) h _2, but the pillar has a large height implantation when compared to the surrounding beams and floor, generate concrete after casting Breathing water (a phenomenon in which the water inside the concrete moves upward in fresh concrete) and air bubbles in the concrete are degassed, so that the concrete sinks and a dent S is formed at the top as shown in FIG. Easy (Refer to Photo 1.18-2 on page 8 of “RC Construction Body Construction Supervision Checklist” edited by Japan Building Construction Engineers Association). In the subsidence of the stigma concrete, it is shown that after leveling the concrete, it sinks about 30 mm from the surrounding beams, and a depression is formed in the part that becomes the column base 1 ″ on the upper floor. Even if the latency is removed, the formwork and bar arrangement are washed to prevent sudden water absorption of the formwork after the formwork and bar arrangement work is completed and the concrete is placed. Sawdust and other debris dispersed inside gathers on the column base, and the cleaning water slightly flows out from the contact surface with the joints of the formwork and concrete, but the remaining cleaning water and debris remain in the recesses in the joint surface. If concrete is thrown in from the top, ignoring this phenomenon, impurities such as saw dust will be sandwiched between the column bases, and the integrity will be lost. -1 includes ripples appearing on the surface of the column base and water It shows the state of the column base with sawdust sandwiched between the joint surfaces.
[0004]
If the column base that contains the defect encounters a large earthquake, the shearing force acts on the main bar of the column because the shearing force cannot be expected from the axial force from the top. In addition to the axial force due to the bending moment that should be borne by the main reinforcement, a shearing force is also applied, and an alternating repeated load is applied where the main reinforcement yields and the main reinforcement yields, so it is determined that the column base concrete will collapse.
[0005]
Since the concrete of the pillar is introduced from the floor reinforcement via the beam formwork, the concrete is separated by hitting a hoop or formwork separator arranged in the horizontal direction during free fall. Therefore, a bean plate with a large amount of coarse aggregate and a small amount of mortar tends to be generated on the column base. In addition, it is difficult to reach the rod-shaped vibrator from the floor bar arrangement, and the form vibrator is difficult to attach at the bottom. There is no method other than hitting the surface of the formwork with a wooden mallet, and bean boards are likely to be generated near the floor.
[0006]
[Problems to be solved by the invention]
The object of the present invention is to eliminate the above-mentioned joint defect of RC column base concrete, to add shear strength to the column base, and to easily perform vibration compaction to prevent the bean plate of the column base concrete. It is an object of the present invention to provide a construction method and a casting mold for a joint used in the construction method.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a method for performing column-base concrete jointing according to the present invention includes a hoop that surrounds a column main reinforcement of a column base that becomes a concrete joint surface on an upper floor after the assembly of the column formwork and bar arrangement is completed. A column form for a column-base joint formed by a strip-shaped plate that extends in the circumferential direction with a contour that fits in the column main bar surrounded by a hoop, at the top of the beam main bar inside the bar. When placing concrete in a frame consisting of beam main bars, column main bars, and hoops, a formwork for a column base joint is formed so that a protrusion is formed above the column base joint surface of the column. When filling concrete into the upper floor and passing over the upper floor concrete, stop the concrete injection at a position slightly higher than the joint surface of the column base, and start from the strip plate of the cast formwork for the column base joint Vibration transmission protruding around Strike the bolt head with a hammer, characterized in that so as to span went mortar to coarse aggregate of the column base near the surface by applying vibration to the driving formwork for striking Joint.
[0008]
The connecting part driving form is formed by a belt-like plate extending in the circumferential direction with a contour that fits in a column main reinforcement surrounded by a hoop, and is formed at an outer corner of the belt-like plate. The vibration transmitting bolt is screwed.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.
[0010]
In RC buildings, concrete is formed by joining concrete at the top of the beam for each floor, but as described above, a depression S is likely to occur in the joint. FIG. 1 shows a phenomenon in which when a concrete is placed, even if the floor height is divided into halves, a depression S is generated in the stigma due to sedimentation of fresh concrete.
[0011]
In the method of casting column base concrete according to the present invention, a unique casting form made of steel for the joining portion is used.
[0012]
As shown in FIGS. 2, 3 and 4, this column-base joint-forming mold 10 has a belt-like shape extending in the circumferential direction with a contour that fits in a column main reinforcement surrounded by a hoop. It is formed by the plate 12. In this embodiment, the driving form 10 is a quadrangle. A vibration transmission bolt 16 for transmitting vibration can be screwed into the nuts 14 welded to the four outer corner portions of the strip plate 12. As shown in FIG. 5, the concrete cast in the space in the strip-shaped plate 12 of the casting mold 10 for the column base connection portion forms an integral protrusion so that its center 18 is slightly higher. .
[0013]
5, the upper Kaibashira main reinforcement 3 and after assembling the Hashirasujikari assembly consisting hoop 4 surrounding the main reinforcement, within the upper Kaibashira main reinforcement 3 enclosed hoop 4 in the Hashirasujikari assembly, girders 2, 3 and 4 is installed on the upper part of the main bar 5. A vibration transmission bolt 16 having a length of about 300 mm is attached to each nut 14 of the post-joining part 10 for the column base joint.
[0014]
Then place the level adjusting sock angle 7 at four corners before assembling the mold 6 pillars around pillars muscle assembly extending upward from the column base striking joint surface, column base cleaning water outlet 8 (See page 55, photo 3.1-1 of the same book), and the vibration transmission bolt 16 of the column-base-joining part form 10 passes through this gap. After all the formwork and floor / beams have been laid out, the high-pressure cleaning water is used to wash the waste in the formwork, and the dust collected in the pillar formwork 6 together with the cleaning water is a column base that is a gap at the floor angle 7. It is confirmed with a searchlight from the upper part of the pillar that it has flowed out of the cleaning drainage port 8, and then concrete is placed on the frame. While placing the concrete of the frame, the concrete is filled in the casting mold 10 for the column base joint, and the top end of the concrete is leveled so that the center 18 of the column base 10 is slightly higher. And an integral protrusion is formed.
[0015]
In addition, do not throw the column base concrete 1 ″ (Fig. 1) to half the floor height at a time, and stop the concrete feed at a height of about 300 mm from the joint surface of the column base. Since it is easy to separate, the column mold 6 is struck from the outside, and the inside is struck by a hammer 5-6 times with the hammer of the vibration transmission bolt 16 protruding from the column base cleaning drain 8 to make the column base joint part Vibration is applied to the driving mold 10. When the four strikes are carried together, the mortar spreads over the coarse aggregate and the bean plate disappears.After that, the vibration transmission bolt 16 is removed, and the column base cleaning drain port 8 is Cover with left uncut material at the corner angle 7 , and cast the concrete on the top.
[0016]
【The invention's effect】
According to the column-base concrete joining method using the casting form for the column-base joint part of the present invention, the joint part cannot be depressed to cause defects, and shearing is performed by forming an integral protrusion on the joint surface. Because of the added strength, the building will be earthquake resistant. In addition, since the aggregate of the column base is not separated into fragile concrete, vibration can also be applied from the inside to the column base where it is difficult to compact fresh concrete, so it is possible to cast solid concrete and design A high-quality building that guarantees strength can be realized.
[Brief description of the drawings]
FIG. 1 shows a depression due to sedimentation of concrete generated on a reinforced concrete column head by a conventional column-base concrete joining method.
FIG. 2 is a plan view of a casting form for a joining portion used in the column base concrete joining method of the present invention.
FIG. 3 is a side view seen from an arrow III in FIG.
4 is a cross-sectional view taken along line IV-IV in FIG.
[Fig. 5] Installed column form for the column base joint at the top of the main beam inside the hoop that surrounds the upper column main column, and put concrete for the column base joint so that a protrusion is formed on the column head. FIG. 5 is a cross-sectional view in which a water gradient is provided so as to be driven up to the upper end of the driving form and to be slightly higher around the top end surface.
6 is a partial cross-sectional view taken along line VI-VI in FIG. 7, with level adjustment laying angles arranged before assembling the column form with protrusions, and column bases at the four corners. A clearance serving as a part-cleaning drain port is provided, and a vibration transmission bolt is mounted on the driving form for the column-base joint using this clearance.
7 is a plan view taken along the arrow VII-VII in FIG. 6. FIG.
[Explanation of symbols]
1 poster head concrete 1 'pillar of hitting joints stigma concrete 1 "on the upper floor of the column base concrete second beam concrete 3-poster main reinforcement 4 hoop 5 girders main reinforcement 6-post frame 7 spread angle 8 column base cleaning drainage port 10 poster Placing form 10 'for leg joint part Protrusion 12 Strip plate 16 Vibration transmission bolt

Claims (2)

In the method of performing column-base concrete jointing at the top end of the beam for each floor of the RC building,
After completing the assembly of the column formwork and bar arrangement, there is a gap in the column main bar surrounded by the hoop inside the hoop bar that surrounds the column main bar of the column base that will be the concrete connection surface of the upper floor, inside the main bar of the beam. Installed a column form for the pedestal joint, formed by a strip-shaped plate that extends in the circumferential direction with a contour that can be placed
While placing concrete in the frame consisting of beam main bars, column main bars, and hoops, place concrete in the column form for the column base joint so as to form an integral protrusion above the column base joint surface of the column. When filling and overcasting the concrete on the upper floor, stop the concrete injection at a position slightly higher than the joint surface of the column base, and project from the strip plate of the casting form for the column base joint part The head of the vibration transmission bolt is hit with a hammer, and the mortar is spread over the coarse aggregate near the surface of the column base by applying vibration to the driving form for the joint. The casting mold for the column base joint portion according to claim 1 is formed by a belt-like plate extending in the circumferential direction with a contour that fits within a pillar main bar surrounded by a hoop, A casting form for a column-base joint, wherein a vibration transmission bolt is screwed to an outer corner of the plate.

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