KR20080108880A - Trench forme method for the steel concrete column - Google Patents

Abstract

A trench form method of construction for making a steel concrete column is provided to pre-arrange columns to meet on a straight line without being open or going crisscross in case of bringing two half columns into contact with each other to weld. A trench form method of construction comprises is used to make a steel concrete column by laying down a trench form and precasting concrete(5) in the trench form, and welding the space between the outer sides of upper flanges where a pair of precasted half columns are brought into contact with each other and meet each other, thereby completing a column, or, and putting a pair of trench forms into contact with each other and welding to form a permanent column form, and then erecting and post-placing column concrete.

Description

Trench Form Method for Steel Concrete Columns-TF Column Method {Trench Forme Method For the Steel Concrete Column}

It is difficult to obtain formwork carpenter and reinforcing steel fabricator, and developed a composite column that makes full use of the tensile strength and the compressive strength of cheap concrete. It is aimed at making it possible.

In 1999, the TSC beam, which was developed by the applicants for the first time in the world, combining only the advantages of reinforced concrete structures and steel structures, combining the principles and developing them, is now widely applied to the domestic construction industry, making a significant contribution. In other words, it is possible to construct at the same construction period as steel frame with similar construction cost than TSC. However, the structure is formed only by attaching to the pillar to be framed. The typical types of pillars used so far are 9 types from A to I of FIG. 6 and J and K have recently been developed by the applicant. The pillars A to I are not suitable for use with existing TSC beams due to poor construction and economic feasibility.J and K are small pillars originally developed for use in apartment underground parking lots or low-rise buildings with five stories above ground. Since the company signed an exclusive production contract with a single factory (considering the burden of upfront investment in facilities costs), the market ripple effect will be limited for the time being. For reference, J and K can be manufactured in 1,000mm square and 600mm cylinders, respectively. Therefore, the column size can be freely adjusted, so it can be applied to multi-storey buildings or large-scale construction, and there is a need for a steel concrete composite pillar that can be easily produced by anyone without a specific factory.

The cost of the columns in the frame is less than that of the beams. For example, if a column is arranged at a floor area of 10m × 10m, the length of the beam is about 40m, whereas the length of the column is only 3 ~ 4m (one floor height), that is, 1/10 of the beam length. Therefore, even if there are many ready-made members, the cross-sections which are manufactured and marketed only for pillars are not common (there are H-shaped steels of 300 and 400 mm series). Therefore, in the present invention, by using the TSC III, IV beam cross-sections already developed and produced as a trench form for the production of pillars, it is not necessary to invest additional manufacturing equipment.

The stress advantage of steel aggregates is that they have a large bearing capacity for both compressive and tensile forces. It is more common to use cheaper concrete than expensive steel as a compressive material, so it is common to design large columns with steel reinforced concrete. A frequently used column is to wrap the outside of H-beams with reinforced concrete (Fig. 6 I) and sometimes use CFT (Concrete Filled Tube) such as C or D in Fig. 6 (J in Figure 4) is a kind of CFT in a broad sense). The following explains why each of the nine existing pillars is expensive.

■ A, B (reinforced concrete band column, round column); It is the most commonly used column, and the construction cost and air increase due to lack of formwork and reinforcement workers, and the durability is poor due to cracking and neutralization of concrete.

■ C, D (CFT); Structural theory seems to be the most reasonable, but large steel pipes that can be used as pillars are very expensive pillars because they are produced only when a certain amount is more than a certain amount by a large specific company. As shown in FIG. It is cumbersome and expensive to use the method of injecting concrete at high pressure by drilling or injecting concrete into the hose from the top of the column or by drilling a hole in the bottom of the column. In addition, it is impossible to attach diaphragm or stiffener to molded steel pipe, and large steel pipe manufactured by welding steel plate should have special facility called CES welding that attaches diaphragm to steel pipe, but there are not many cases of application due to excessive production cost. It is not common to design CFTs on large CES welded large steel pipes, as there is a high probability that the concrete will not fill well under the diaphragm --- e.g. 63 building, COEX, etc.

■ E (H section steel); Representative steel structure column is 300, 400mm series for H type cross section for column. H-beams are uneconomical because they are weak in sciatica about the y-axis and their ability to resist bending moments. The H-shaped steel of the thick 400mm series can bear up to 1,000tf of axial force, and more than that, weld the ultra-thick steel plate or use H (CROSS H) or I (steel reinforced concrete).

■ F, G (steel pipe); It is a hollow steel pipe that is used as a material for CFT and cannot be used when the axial force is large. Installing diaphragm inside or outside is burdensome and construction cost is very expensive (63 building, COEX, and Myeongdong Royal Hotel).

■ H (CROSS H); Complementing the shortcomings of E (H-beam), which is theoretically strong in both directions of bending moment, it is reasonable but it is expensive to use due to the high production cost (used in earthquake country Japan).

■ I (steel reinforced concrete); The most common application for heavy load buildings is the expensive construction method of adding reinforced concrete construction to steel construction. After joining the steel column and the steel beam, the reinforced concrete column construction outside the column should be added. Therefore, the steel is disconnected from the bottom of the steel beam end of the column and the concrete is not filled well.

More than nine types of pillars can be divided into four types of reinforced concrete (A, B), steel structure (E, F, G, H), steel reinforced concrete (I) and steel concrete structure (C, D) Reinforced concrete tanks can be categorized into cast-in-place concrete and precast concrete tanks. Precast concrete columns have a heavy burden of transporting heavy materials (carrying and assembly costs are high, and repairing when concrete is broken due to impact during transportation) There is a difficulty in joining the beam and the joint of the upper and lower pillars in the field. It is an object of the present invention to develop a column that is well suited to TSC beams by inexpensive, easy to construct, and ensures structural strength by supplementing the disadvantages of the existing pillar methods.

Unlike other precast concrete columns, this TF column is a lightweight steel frame with a thickness of 10 mm or less of the trench form corresponding to the formwork. Therefore, it is desirable to reduce the transport cost of heavy materials by precasting concrete inside the trench form at the construction site. In order to weld the half pillars of dogs, it is a technical task to pre-align them so that they can meet in a straight line without gaps or gaps. TSC beams are manufactured in half by welding due to the limited size of the forming rolls held in Korea because the beam tends to be deformed due to the deformation of the beam due to the heat of welding. Fortunately, when using it as a beam, the deformed shape is a chamfer, that is, the center of the beam rises upwards, so it functions well, but the column is not to bend. Therefore, it is necessary to develop a method that can correct heat deformation without special equipment or difficult work. In addition, if a closed steel pipe is used as a steel concrete column, a diaphragm or stiffener cannot be attached to the inside of the steel pipe.

As shown in FIG. 1, a suitable distance between the upper flanges 11 of various trench foams (determined by checking the structural calculation whether the length of the upper flange is within the allowable width thickness ratio according to the height of the trench foam web 13 and the thickness of the steel sheet is determined. By welding the flat iron (4) to maintain the width of the opening of the trench form, and precast the concrete (5) inside the trench form in the state of welding the molten steel sheet (7) to the both ends of the trench length and closed. Half pillars such as When precasting concrete, the vibrator is operated evenly while the trenchforms (1a to 1e) are laid down, and the dense concrete is obtained. 3 is a TF column welded to each other with the half pillar of FIG.

As shown in Fig. 1, the upper part of the trench form has an opening (standard size of TSC III and IV) having a width of 120 mm or more in total length as shown in Fig. 1, and thus, it is used as a work tool. 8) or the stiffener 9 can be easily welded. As shown in Fig. 3 and Fig. 9, the schematic shape of the column cross section is a quadrilateral or fat H type. Therefore, the strength of resisting bending moments in both X and Y directions is large, and the buckling length in the Y-axis (weak axis) direction is also significantly increased compared to general H-beams.

If the wire is required for the light switch for the pillar, etc., as shown in Figure 9 can be utilized in the wire pipe space A or B of the trench form manufactured by welding the expansion steel plate 6 inside the a-shaped projection (2) of the TSC III. It can also be used as a building design by wrapping it with a finish along the contour of the cross section. The reason why the TF column has excellent resistance to bending moment is because the steel is located on the outermost surface of the cross section. As shown in FIG. 7, the diaphragm 8 or the stiffener 9 welded to the inside of the trench form in the panel zone prevents the column opening effect due to the tensile stress caused by the upper flange of the beam joined to the column as shown in FIG. 8. Play a role. On the other hand, even if the existing cross-section (H-shaped steel, CROSS H) that can reinforce the panel zone with continuous openings on the side as shown in FIG. 6, when the diaphragm 8 or the stiffener 9 is welded, they are exposed to the outer surface. While it feels rough enough to be used in a building column, this TF pillar has the advantage that it does not appear in appearance because the diaphragm or stiffener is hidden inside the cross section. (The diaphragm attached inside the steel pipe is expensive special CES welding. CES welding is possible only with large columns with a steel pipe thickness of 16 mm or more).

If the two half pillars are bent due to the welding heat during the fabrication of the trenchform, precasting the concrete in that state will make it impossible to forcibly correct the rigidity of the concrete in the hardened trenchform. Therefore, the trenchform must correct the bend in the X and Y directions before pouring the concrete. FIG. 10A shows two half French forms when pre-casting a bent trench form (generally deformed as shown in FIG. 10A due to welding heat during fabrication, which has a net function of acting as a camber of a beam). Pour concrete one by one in half with bolts or hydraulic jacks tightened at both ends. If there is no work space at the construction site, the precast concrete can be imported into the factory and welded with half pillars, so the unit weight of the pillar to be transported is reduced to half. There is also an advantage that is less concerned. However, if you want to pour concrete in the site instead of precasting the trench form, as shown in Fig. 10b, two trench forms are faced with two trench forms facing each other with two bolts or hydraulic jacks. Weld with pillar form (permanent formwork).

If the above work to control the deformation of the welding heat is cumbersome, the trench form manufacturing method can be changed to the bolt tightening method as shown in Figure 1, in that case, it is used to change the expanded steel sheet (6a) instead of the expansion steel sheet (6).

In the case of welding two trenches to one column, both sides should be carried out at the same time to prevent the cross-section of the column. Columns large enough to pour the concrete from the mold will attach the expansion plate (6) or the expansion (6a), so withhold the expansion steel sheet (6) attachment or expand the expansion steel (hole) for each floor. You can cut a portion of the web in 6a), pour concrete, and close the opening in the field.

The reason why this TF pillar is more economical and shorter than the other nine pillars is that the outer steel sheet constituting the trench form, which is a formwork, is a permanent formwork and concrete reinforcement for pouring concrete. Unlike concrete columns, the steel is placed on the outermost side of the cross section (the farthest position from the neutral axis of the cross section), maximizing stress efficiency and utilizing the various cross-sections that are currently being produced for TSC beams without additional investment in production facilities. This is because it is possible to manufacture pillars. In addition, unlike ordinary CFT, the method of pouring concrete inside the cross section (precasting or on-site pouring) is simple and can be easily manufactured by anyone. It is simple and if the difference in the specification of the upper and lower pillars is severe, the ribs may be welded and reinforced between the upper pillar steel sheet and the outer surface of the upper pillar trench form.

If you prefer a square pillar of a specific standard outside the range of TSC IV fabrication, you can replace the TSCIV beam trench form by pressing a thick steel sheet with a c-beam or by welding the steel sheet. At this time, various manufacturing details are the same as when the TSCIV beam trench form is used as the permanent formwork of the column. In Figure 7, the diaphragm is used when precasting the concrete in the trench form and the stiffener (9) is used to pour the pillar concrete in the field to ensure that the concrete is smoothly filled.

Although the structural advantages of the TSC beam, which is a steel concrete composite beam, are excellent, there is no column suitable for forming a framework by joining it, but the mass diffusion of the TSC beam is delayed. However, when the TF pillar of the present invention is realized, it is more economical to transport and assemble. We can build building that burden is little and construction period is shortened.

1 is a perspective view of various trench foams,

Figure 2 is a perspective view of a half pillar filled with concrete precast inside the various trench forms,

3 is a perspective view of a TF pillar welded to two half pillars filled with concrete in the trench form,

4 is a plan view and a perspective view of nine representative pillars;

5 is a longitudinal cross-sectional view of one section of three layers of steel or composite columns,

6 is a perspective view of the diaphragm and the stiffener of the representative steel frame,

7 is a perspective view of a diaphragm or a stiffener attached to a typical trench form,

8 is a deformation of the panel zone when there is no diaphragm or stiffener inside the square steel pipe,

9 is a cross-sectional view illustrating a wire piping space of a TF pillar using TSCIII as a trench;

10 (a) and 10 (b) are explanatory diagrams of a method for correcting the welding heat deformation of the trench form, and FIG. 10 (a) shows the case of precasting and two 10 (b) of the cast-in-place concrete.

<Brief description of the symbols in the drawings>

1a ~ 1e: Various trench forms 2: A-shaped protrusions

2a: Y-protrusion 3: bottleneck

4: Flat bar 5: Concrete

6: expanded steel sheet 6a: expanded steel sheet

7: copper sheet 8: diaphragm (Diaphragm)

9: Stiffener 11: Upper Flange

12: lower flange 13: web

* TSC beam; Its appearance is the same as reinforced concrete beams, and when concrete is poured into permanent formwork made of steel sheet, no reinforcement is required. Excellent vibration and sound insulation effect, excellent fire resistance, no cracking, and the height of beam is lower than steel concrete beam as well as steel beam (TSCⅠ, Ⅱ, Ⅲ, Ⅳ four types of beam and trench form used in the present invention TSCIII, IV visible)-see FIG. 1, 'Formed Steel Sheet Concrete Beam (TSCII)'-Patent No. 0617878, 'Bottle Top Flange TSC Beam (TSC III)'-Patent No. 0592398, Shape of TSC Beam-TSCI ; , TSCII; , TSCIII; , TSCIV;

** Panel Zone; The area where the beams are joined at the column.

Claims (3)

Trench form for the production of half pillars, which can be precast or cast in place as a permanent formwork made of steel; The trench form has a vertical steel web 13 attached to the left and right lower flanges 12 and is connected to the upper left and right webs so that the upper flanges 11 protrude into the horizontal direction, respectively; And The diaphragm 8 or the stiffener 9 which prevents deformation of the web and the flange in the panel zone of the trench form 1c formed by attaching the flat iron 4 at regular intervals in the longitudinal direction between the left and right flanges. Attach; And With the French foam lying down, the concrete inside is welded between the outer edges of the upper flanges, which are paired with a pair of precast half pillars, A steel concrete pillar forming trench form method, characterized by welding a pair of trench forms to form a permanent formwork by welding the above tips, and then post-installing the pillar concrete. The left and right c-shaped flanges formed by attaching the wings of the a-beam to the outside in connection with the inner ends of the left and right upper flanges of the trench form are formed in the bottleneck shape (3) cross-section (1a, 1d). Steel concrete pillar making arch trench method. The method of claim 1 or 2, in order to expand and reinforce the lower flange width of the trenchform, the two a-shaped projections 2 are formed on the upper surface of the lower flange (inside the trenchform) by being symmetrically isolated from each other and welded (1d, 1e). Or to form a Y-shaped protrusion (2a) by welding these a-shaped protrusions in close contact with the center of the lower flange and forming a Y-shaped protrusion (2a).