JPH0816346B2 - Precast concrete pillar construction method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of constructing a precast concrete column, and more particularly, to a column rebar joint by using a joint sleeve for connecting upper and lower column rebars and filling a grout material into the sleeve. It relates to a construction method for forming a.

[0002]

2. Description of the Related Art FIGS. 16 and 17 show an example of a conventional method for constructing a precast concrete column, in which a grout material G is injected into a sleeve 8 after the precast concrete column 1 has been built. This is a method of joining the upper and lower column reinforcing bars 3A, 7A (3B, 7B). Hereinafter, the method will be described step by step.

(1) At the time when the work on the lower floor is completed, as shown in FIG. 1, from the column mounting surface 6, the column reinforcing bars 3A, 3 on the lower floor side are provided.
B is protruding. In FIG. 2, pillar rebars 3A, 3B
Are arranged, for example, in a square shape, and the column rebars at the four corners are indicated by reference numeral 3A, and the remaining middle column rebars are indicated by reference numeral 3B.

(2) The mounting surface 6 is shown in FIG.
A quadrilateral stakeout line 5 corresponding to the outer shape of the column is drawn as shown in FIG. 3, and a level liner 14 for determining the installation height H of the column 1 is attached as shown in FIG. The level liner 14 is arranged by selecting a well-balanced place at the time of construction as shown in FIG. 17, and as the material to be used, steel plates are laminated in layers, cement-based or other materials that can withstand the weight of the column itself are used. Has been done.

(3) Before the precast concrete columns 1 are built, the mortar 30 is laid according to the height of the level liner 14. The spread area of the spread mortar 30 may be the entire surface within the marking wire 5 as shown in the figure, but it may also be spread in the shape of a cylinder around each pillar rebar. The laying mortar 30 needs to have a strength equal to or higher than that of the pillar, and in order to close the lower end opening of the sleeve 8 of the precast concrete pillar 1, the mortar 30 is laid more in a raised shape than the height of the level liner 14.

(4) After laying the mortar 30, the precast concrete columns 1 are hung up and set on the level liner 14 in line with the marking lines 5 before solidification progresses. At this time, the pillar reinforcing bars 3A and 3B on the lower floor side enter the sleeve 8 from the lower end opening of the sleeve 8 as shown in FIG.
It is pressed against the upper surface of 0 and is thereby closed.

(5) Next, while confirming the verticality of the precast concrete pillar 1, a support 37 as shown in FIG.
Then, adjust the verticality and temporarily fix it.

(6) In FIG. 16, the kneaded grout material G is press-fitted into the sleeve 8 from the lower injection port 10 of the sleeve 8 by a press-fitting pump or the like.

(7) When it is confirmed that the grout material G begins to overflow from the upper discharge port 11, the discharge port 11 is sealed with the cap 12, and then the injection port 10 is sealed with the cap 12. As a result, the joining of the upper and lower column reinforcing bars is completed, and subsequently, concrete is poured into the hollow of the precast concrete column 1, for example.

[0010]

As described above, in the method of laying the mortar before laying the precast concrete columns, since it solidifies relatively quickly after mixing,
The following issues arise.

(1) When the height H of the level liner 14 is, for example, 30 mm or more and the usage amount of the floor mortar 30 is increased, if a large amount of mortar is kneaded and prepared in advance, it will increase with time. The solidifying action proceeds more than necessary, resulting in a decrease in the strength of the column base. On the other hand, if you are planning the necessary amount each time, it will take time to build and
In addition to the erection workers, a dedicated worker for kneading the mortar in parallel with the erection work is required, and improvement in work efficiency and labor saving cannot be achieved.

(2) Although the lower end opening of each sleeve 8 is closed by the upper surface of the spread mortar 30, the upper surface of the spread mortar 30 is relatively uneven, and the lower end openings of all the sleeves are completely installed when the pillar is installed. It is very difficult to close it, and even if the grout material leaks from the gap between the lower end opening and the mortar upper surface, it is very difficult to find it from the outside, so even if there is a leak, it will be compensated for. Is impossible.

[0013]

[Means for Solving the Problems] A precast concrete column having built-in column reinforcing bars of the same arrangement as the lower floor side reinforcing bar is installed on the column member mounting surface where the lower side pillar reinforcing bar projects upward, through a level liner. By arranging it at a predetermined height and inserting the lower floor pillar rebar into the lower end opening joint sleeve fixed to the lower end of the upper floor pillar rebar, and filling the grout material in the sleeve. In the construction method of the precast concrete column that joins the column rebars, the spring members and washers that can bend in the vertical direction are inserted into the lower column side column rebars, and when the precast concrete columns are arranged on the column member mounting surface, for each joint The lower end opening of the sleeve is closed by a washer that is elastically pressed upward by a spring member, and the grout material is injected into the sleeve in the closed state to join the column rebars.

[0014]

The washer is pressed against the opening surface of the lower end of the sleeve by the elastic force of the spring member, thereby preventing the grout material from leaking. Further, when the grout material is injected, it can be confirmed whether or not the grout material is leaking from the outside. Therefore, even if the grout material is leaked, it can be easily compensated.

[0015]

Embodiments (1) FIGS. 1 and 2 are the same as the contents described in the prior art, and at the time when the work on the lower floor side is completed, from the pillar mounting surface 6 to the lower floor side. The pillar rebars 3A and 3B project upward. The pillar reinforcements 3A and 3B on the lower floor are shown in Fig. 2.
The square-shaped marking lines 5 for attaching the precast concrete pillars 1 on the upper floor are drawn on the outer side thereof. It should be noted that, although it will be described repeatedly, the column reinforcing bars located at the four corners are indicated by reference numeral 3A, and the column reinforcing bars between them are indicated by reference numeral 3B.

(2) As the column rebars 3A at the four corners, as shown in FIG. 9, so-called threaded bar deformed bar material having a spiral outer peripheral projection is used, and as an intermediate column rebar 3B, an ordinary round bar is used. Shaped rebar material is used.

(3) As shown in FIG. 3 and FIG. 4, nuts 20 for level are respectively screwed into the pillar rebars 3A at the four corners, and washers 22 are fitted on the nuts 20 for leveling.
Then, the coil spring 21 is fitted and the washer 22 is fitted thereon. Each washer 22 is fitted on the outer periphery of the column reinforcing bars 3A and 3B so as to be vertically movable.

(4) As shown in FIG. 9, the pillar installation height H is adjusted by rotationally adjusting the level nut 20. Further, as shown in FIG. 10, each coil spring 21 is
The one with appropriate rigidity is selected and the height is set higher than the column installation height.

(5) On the other hand, as shown in FIGS. 5 and 6,
Precast concrete columns 1 have lower floor side reinforcement 3
A column rebar 7A, 7B having the same arrangement as A, 3B is built in, and a joint sleeve 8 having a lower end opening is fixed to the lower end of the column rebar 7A, 7B.

(6) The precast concrete pillar 1 having the above structure is suspended on the pillar mounting surface 6 as shown in FIG.
Perform the placement work. That is, as shown in FIGS. 5 and 6, the precast concrete pillar 1 is placed on the washer 22 while being aligned with the marking line 5. At this time, the pillar reinforcing bars 3A and 3B on the lower floor side are connected to the sleeve 8 from the lower end opening of the sleeve 8.
Get in. Further, the installation height of the precast concrete pillar 1 is such that the level nuts 20 at the four corners and the washers 2 on the level nuts 20 are provided.
Determined by 2.

(7) Coil spring 2 mounted on the pillar rebar 3B in the middle when the precast concrete pillar is installed
5 is compressed by the weight of the precast concrete column 1 as shown in FIG. 5, and the repulsive force presses the washer 22 against the lower end surface of the sleeve 8 to seal the inside of the sleeve 8. The height of the washers 22 at the four corners is
It is possible to adjust those variations. That is, the lower end opening surface of the sleeve 8 to which the washers 22 at the four corners correspond can be finally and tightly sealed.

(8) As shown in FIG. 13, while confirming the verticality of the precast concrete column 1, the degree of verticality is adjusted by the support 37 and temporarily fixed.

(9) In FIG. 5, the grout material G kneaded is mixed with the lower injection port 1 of the sleeve 8 by a press-fitting pump or the like.
Press into the sleeve 8 from 0. In this case, whether or not the grout material G is leaking can be easily confirmed from the outside and can be compensated for.

(10) Grout material G from the upper outlet 11
When it is confirmed that the liquid begins to overflow, first, the upper discharge port 11 is sealed with the cap 12, and then the lower injection port 10 is sealed with the cap 12, as shown in FIG. 7. This completes the joining of the upper and lower column reinforcing bars.

(11) Formwork 24 is attached so as to surround the space for the column base portion formed between the column 1 and the mounting surface 6, and concrete is poured into the hollow precast concrete column 1. As a result, the column base portion and the hollow portion are integrally molded with concrete of specified strength. At this time, the coil spring 2
Although 1 is embedded in concrete, it functions as a reinforcing material.

[0026]

[Another embodiment]

(1) In the above-mentioned embodiment, the hollow structure is used as the precast concrete columns, but the present invention can be applied to the case where solid precast concrete columns are used. In this case, only a space for the column base below the column is generated, but a form is attached around this, as in FIG. 7, and concrete or mortar of specified strength is pressed into the space by a pressure pump or the like.

(2) As the spring member, as shown in FIG. 15, it is possible to use a spring member composed of a plurality of leaf springs 27.

(3) In the above-described embodiment, the level nut 20 and the washer 22 are used as the level liner, but spring members are attached to all of the column rebars, and the level liner is shown in FIG. It is also possible to use a stack of steel materials.

(4) As shown in FIG. 14, the pillar member 2 on the lower floor side
Can also be applied to the construction method in which the precast concrete pillar 1 on the upper floor side is installed by forming the precast concrete pillar 1 on the upper floor side with the upper end surface of the upper protruding portion 2a of the pillar member as the mounting surface 6.

[0030]

As described above, according to the present invention, (1) the sleeve 8 for the joint between the upper and lower column reinforcing bars 3B and 7B.
The lower end opening surface of the is sealed by a washer 22 which is biased upward by a spring member such as a coil spring 21, and in that state, the grout material G is injected into the sleeve 8 and the upper and lower pillar rebars 3B,
Since 7B is joined, there is no need to lay the mortar in advance as compared with the conventional construction method, in which the mortar is spread before the pillar is installed and the lower end opening of the sleeve is sealed with the upper surface of the spread mortar. Moreover, it is not necessary to pay attention to the mortar solidification time, and it is possible to shorten the work time for joining the column rebars and save labor.

(2) Since the lower end opening surface of the joint sleeve 8 is closed by the spring member and the washer 22 urged by the spring member, the leakage preventing performance of the grout material G is improved, and even if leakage occurs. Can be confirmed from the outside, so that the treatment can be appropriately performed during the injection work, and the strength at the column reinforcing bar joint can be maintained high.

(3) Concrete filling work, etc., into a space for a column base formed between the column mounting surface and the lower end surface of the column,
Since the work can be performed in a completely different work from the work for injecting the grout material into the sleeve, the work can be facilitated and the quality of the connecting portion such as the column base can be improved.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a column mounting surface portion before a column is installed.

FIG. 2 is a plan view of FIG.

3 is a sectional view taken along line III-III in FIG. 4 of a column mounting surface portion in a spring member and washer mounting step.

FIG. 4 is a plan view of FIG.

5 is a sectional view taken along line VV of FIG. 6 of the precast concrete column in the step of placing the precast concrete column.

6 is a cross-sectional view taken along the line VI-VI of FIG.

7 is a VII-VII sectional view of FIG. 8 of the precast concrete column in the column reinforcing bar connection and concrete filling step.

8 is a sectional view taken along line VIII-VIII of FIG.

FIG. 9 is an enlarged front view of a level nut mounting portion of a column reinforcing bar.

FIG. 10 is an enlarged front view of a spring member mounting portion of a column reinforcing bar.

FIG. 11 is an enlarged cross-sectional view of the same portion as FIG. 10 when the column is mounted.

FIG. 12 is a front view showing the entire precast concrete column hanging operation.

FIG. 13 is a front view showing the whole of a precast concrete column when mounted.

FIG. 14 is an overall front view similar to FIG. 12 showing another working example.

FIG. 15 is an enlarged vertical sectional view showing a modified example of the spring member.

16 is a vertical cross section of a conventional example, which is XVI-X of FIG.
FIG. 6 is a sectional view taken along line VI.

17 is a sectional view taken along line XVII-XVII of FIG.

[Explanation of symbols]

 1 Precast concrete columns 3A, 3B Lower floor side column reinforcement 6 Column mounting surface 7A, 7B Upper floor side column reinforcement 8 Sleeve 20 Level nut (level liner) 21 Coil spring 22 Washer

Claims (2)

[Claims] 1. A precast concrete column having built-in column rebars in the same arrangement as the lower floor column rebars is mounted on a column member mounting surface where the column rebars on the lower floor side project upwards at a predetermined height through a level liner. Placed in, the lower floor pillar rebar is inserted into the lower end opening-shaped joint sleeve fixed to the lower end of the upper floor pillar rebar, and by filling the sleeve with grout material,
In the construction method of the precast concrete column that joins the upper and lower column rebars, the lower-column side column rebar is inserted with a spring member and washer that are flexible in the vertical direction, and when each precast concrete column is arranged on the column member mounting surface, Construction of a precast concrete column, characterized in that the lower end opening of the joint sleeve is closed by a washer that is elastically pressed upward by a spring member, and in the closed state, grout material is injected into the sleeve to join column rebars to each other. Method. 2. The method for constructing a precast concrete column according to claim 1, wherein a coil spring is mounted as the spring member.