KR20030075131A - beam-column connection detail of long-span pre-cast system - Google Patents

Abstract

PURPOSE: Joint structure of columns and beams for a long-span precast system is provided to make the best use of space by extending the span of the precast system, to improve the durability by reducing the section of the member, and to reduce the construction period by vertically jointing the column and the beam. CONSTITUTION: A joint system of long-span precast columns and beams is composed of a precast column(10) and a precast beam(20). The precast beam is divided into a cantilever beam(21) and a simple beam(22), and connected by jointing simply on the spot. The precast column is composed of a lower precast column(11) and an upper precast column(12) installed in the upper part of the cantilever beam. The cantilever beam is installed in the upper part of the lower precast column, and the simple beam is jointed to the cantilever beam simply. The joint system includes a sleeve inserted to the upper and lower columns, and steel concrete inserted to the sleeve.

Description

Beam-column connection detail of long-span pre-cast system}

The present invention relates to a column-beam joint structure of a long span precast system, and more particularly, in a long span precast system in which a simple beam is installed in a field in a pretension cantilever beam manufactured in a factory, the cantilever beam and It relates to the joining structure of the precast column.

The most important point in the structural design of a building is the choice of a safe structure, in addition to the consideration of air, workability and economics. In particular, in the case of commercial facilities such as large discount stores, air and space utilization are one of the biggest concerns, and in view of this, construction of buildings using precast systems is increasing.

The precast system currently used in Korea is largely classified into the following two methods.

The first is an 8m × 10m module, which is a system in which an inverted T-beam 20 is pin bonded to a precast column 10 as shown in FIG. 1, and the slab is a system using a double tee slab or a hollow slab 30. Lateral loads impart lateral force to the shear walls by placing overlay concrete on top of the slab.

The joining of precast columns and inverted T-beams is done through steel cobells or precast brackets, and the joints, beams, and slabs are easily segmented and simply joined in the field through simple joining.

Therefore, according to this method, longer spans have a difficult problem. This is because the connection between the column and the beam is a pin joint.

The second is an improved system of the first method, in which the moment frame behaviours by rigidly joining the column and the beam. In this system, the Dowel Bar protrudes from the beam and the moment connection is made by using cast-in-place concrete at the joint with the column.

Compared to the first system, the system receives a moment at the end, so that the cross section can be reduced by about 30%.

The second system is a system that is limited to a stadium or a distribution center, and has a disadvantage in that a large amount of field work is required to cast concrete on columns and beams compared to the system described above.

In addition, there is a system in which H-shaped steel is introduced into a precast beam and a joint with a column is used as a moment joint. In addition, among the systems being developed for long spans, a system is being developed in which the beams are segmented in the form of gel-verbo and the posts are integrated with the posts on the side of the columns.

The present invention has been made to overcome the problems such as difficulty in long span due to the pin joining of the precast pillar and beam as described above or an increase in the amount of field work caused by the moment bonding of the pillar and the beam, The purpose of this invention is to provide the column-beam joint structure of the long span precast system, which enables the long span of the precast system to be easily constructed without additional field work by using the moment joint as the moment joint. .

1 is a plan view of a conventional 8m x 10m precast system module

Figure 2 is an elevational view of the column and beam according to the specific sealing example of the present invention

3 is a junction detail view of a cantilever beam and a simple beam according to a specific embodiment of the present invention;

4 is a column-beam connection according to a specific embodiment of the present invention

5 is a flow chart of the column-beam joint construction

<Description of Major Codes in Drawings>

10: pillar 11: lower pillar

12: upper pillar 13: sleeve

20: beam 21: cantilever beam

22: simple beam 23: pressure plate

30: slab

The present invention is a system for improving the economics and constructability of a long span precast structure, in consideration of the lifting capacity of the crane is divided into two precast beams and a simple joint of the gel-verbo method, the most important point of the column and beam It is a system that can improve workability and shorten air in the field by joining cantilever beams on the pillars as a joint and not by transverse joints.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 and 3 is an elevational view of the pillar and beam and the junction details of the pillar and beam according to a specific embodiment of the present invention.

As shown, the long span precast pillar-beam joint structure according to a specific embodiment of the present invention is composed of a precast pillar 10 and a precast beam 20.

Referring to the components in accordance with a specific embodiment of the present invention configured as described above in detail.

The precast beam 20 is divided into two beams of the cantilever beam 21 and the simple beam 22 at a quarter point of the span in consideration of the lifting capacity of the crane, and is joined by simple joining in the field.

Therefore, the precast beam 20 takes the form of a gel-burbo as a whole and enables long spanning. When the beam becomes a long span, the stress in the center of the beam is increased due to the large load transmitted to the beam, and thus the height of the beam may be excessively large, and thus prestress is generally introduced to prevent the beam.

The prestressing method is to pre-tension the tensioning material first, and then to pre-tension the concrete by placing the concrete and releasing the tension after curing. There is a post-tensioning method which introduces prestress by tensioning.

In the case of the post-tension method, there is a possibility that the field workload is significantly increased, which may adversely affect the air shortening, which is one of the objectives of applying the precast structure. Improved workability and shorten the air in the field.

Since the cantilever beam 21 has a tensile force generated at the top of the beam, a tension member 23 for pretension is disposed on the upper side, and the length of the lower part is formed longer than the length of the upper part, so that a step is formed at the center portion of the cross section. .

The simple beam 22 is a tension force is generated in the lower part of the beam so that the tension member 23 for pretension is disposed on the lower side, and in contrast to the cantilever beam 21, the length of the upper portion is formed longer than the length of the lower cross section In the central part of the step is formed.

Therefore, the cantilever beam 21 and the simple beam 22 are joined to each other in contact with each other, the stepped portion of the center portion of the cross section, as shown in Figure 3, the pressure plate 24 is installed.

Meanwhile, the precast pillar 10 is divided into two, the lower pillar 11 and the upper pillar 12.

As shown in FIG. 4, a sleeve 13 is embedded in the upper portion of the lower pillar 11 and the lower portion of the upper pillar 12 so that the reinforcing bars 14 may be disposed in the sleeve 13 when the cantilever 21 is installed. This insertion is connected to the lower column 11 and the upper column 12.

As shown in FIG. 4, the column-beam connection details of the present invention, as shown in the most essential part of the present invention, the long-span precast column-beam connection structure of the present invention is not a transverse joint that is generally used, but a longitudinal joint. That is, the beam is not joined to both sides of the pillar, but the pillar 10 is divided into two pillars 11 and 12 at the lower and upper portions, and the cantilever beam 21 is bonded to the lower pillar 11 and the cantilever beam ( The upper pillar 12 is installed using the sleeve 13 on the top of the 21.

In the specific embodiment of the present invention, the sleeve is taken as an example of the joining means of the pillar and beam, but is not limited thereto, and any device capable of joining the pillar and the beam is possible.

This joining method has the following advantages as compared to the conventional joining method.

First, the cantilever beam is not installed separately on both sides of the column, but a beam is installed above the lower column to form cantilever beams extending in both directions, thereby securing the rigidity of the pillar-beam joint which is a structurally weak part.

Second, in order to make the precast structure long span, the connection between column and beam should be moment connection, not pin connection. For this purpose, methods using cast-in-place concrete or post tension at the side of column have been used or proposed. . However, all of the above methods not only increase field workload, but also extend air. However, the column-beam joint of the present invention can solve the problem caused by the reinforcement interference and increase the workability by arranging the sleeve in the column instead of the beam having a large amount of reinforcement.

Construction sequence of the long span precast column-beam joint structure according to the present invention is as follows.

First, as shown in FIGS. 5 (a) and 5 (b), the lower pillar 11 is installed, and the cantilever beam 21 is extended to both sides of the sleeve 13 installed on the lower pillar. The non-contraction mortar is constructed in the gap between the lower end of the 21 and the upper end of the lower pillar 11.

Next, as shown in Fig. 5 (c), the simple beam 22 is installed on the cantilever beam 21 which extends to both sides by simple joining, and the gap between the cantilever beam 21 and the simple beam 22 is joined. Inject mortar between.

After completion of the joining of the beam as shown in Figure 5 (d) using the sleeve 13, the upper pillar 12 is installed on the upper end of the cantilever beam 21 and the upper end of the cantilever beam 21 and The gap between the lower ends of the upper pillars 12 is completed by the non-contraction mortar.

According to the long span precast column-beam joint structure of the present invention, it is possible to increase the space utilization by making the 8m × 10m module precast system mainly used in a parking lot or a large discount store.

In addition, the long span precast column-beam joint structure of the present invention has a good lifting condition by segmenting the beam, and reduces the cross section of the member by pre-tension, thereby providing a precast structure with excellent durability and economy, as well as Since the joining is by longitudinal joining rather than transverse joining, shortening of air is possible and excellent workability.

Claims (4)

Lower precast columns; Cantilever beams extending from both sides of the lower precast column; A simple beam simply joined to the cantilever beam; And An upper precast column installed at an upper end of the cantilever beam; Column-beam joint structure of the long span precast system comprising a. The pillar-beam joining structure of a long span precast system according to claim 1, wherein the joining of the lower precast pillar, the cantilever beam, and the upper precast pillar is longitudinal joining by a joining device installed at the lower and upper pillars. . 3. The pillar-beam joint structure of claim 2, wherein the joining apparatus includes a sleeve embedded in the upper and lower pillars and a rebar inserted into the sleeve. 4. The column-beam joint structure of claim 1, wherein the cantilever beam and the simple beam are prestressed beams by pretension.