JPS6311737A - Method for bonding steel pipe/concrete pillar - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a method for joining steel pipe concrete columns.

(Prior Art) Figures 6 and 7 show a conventional method of joining steel pipe concrete columns, with (a) being a sectional view and (b) being a front view. As shown in the figure, the joint between the upper and lower steel pipe concrete columns (1) is left unfilled with concrete, and in the case of Fig. ), and then concrete (4) is poured into the joint. In the case of Fig. 7, this steel pipe section is welded on-site using a backing metal (7) (6).
), and then concrete (4) is poured into the joint. Note that (5) is a steel pipe concrete column (1)
This is factory-cast concrete.

[Problem that the invention seeks to solve]

However, the conventional bonding method described above has the following problems.

■ At the joint, concrete or unconnected, steel pipe (1
) and concrete (4) have almost no adhesion, so
Through the concrete of the joint. Stress transmission is not possible.

■ High tensile strength bolts (3) are required to obtain sufficient joint strength.
The number of books will increase.

■ On-site butt welding (6) requires time and effort to process the backing metal (7) at a part of the corner of the square steel pipe, has low reliability, and is prone to welding defects. Also, welding becomes difficult when the steel pipe plates have different thicknesses.

■ When pouring concrete (4) into the joint on site,
There is a possibility that the air will not be released and an air pocket will be formed, which may not be able to fully bear the compression force.

The present invention was made in order to solve the above-mentioned problems of the conventional column joining method, and it is an object of the present invention to provide a joining method with high strength and reliability.

(Means for solving the problem) In order to achieve the above purpose, square steel pipes with internal protrusions filled with concrete are used for the columns, and the lower surface of the factory-cast concrete of the upper column is sloped, and the upper end of the slope is Drill an air vent hole in the steel pipe. Then, a plurality of deformed reinforcing bars are arranged in the longitudinal direction of the columns at the joint, and after connecting the upper and lower columns with high-tensile bolts via battens, concrete is injected into the joint.

(Function) Since the inner surface of the steel pipe column is equipped with projections, it is possible to mechanically transmit stress between the steel pipe and the filled concrete through this projection, and in combination with friction bonding using high-tensile bolts,
Significantly improves the strength and strength of joints. By arranging deformed reinforcing bars at the joint, it is possible to reduce the number of high-tensile bolts, and furthermore, by adjusting the number of reinforcing bars, it is possible to design the optimal joint strength. Furthermore, since the lower surface of the factory-cast concrete of the upper column is sloped, air can be completely vented during on-site pouring of concrete, and a decrease in strength of the joint due to air pockets can be prevented.

(Embodiment of the Invention) Fig. 1 shows an embodiment of the present invention, showing a method for joining steel pipe concrete columns, (a) is a side sectional view, (b) is a plan sectional view,
(c) is a side view, in which (2) and (3) are the same parts as the conventional device, (11) is a steel pipe concrete column, O is its inner protrusion, 03 is the factory-cast concrete, α4)
is the concrete bottom surface of the upper column, (15) is the deformed reinforcing bar, (
I6) is concrete, α7) is concrete! The main population, the scream, is the air vent hole.

As shown in the figure, a square steel pipe (11) filled with concrete and having two protrusions on the inner surface is used for the column, and when joining this column, the lower part α4) of the factory-cast concrete 03 of the upper column is used. An air vent hole was drilled in the steel pipe at the upper end of the slope, and multiple deformed reinforcing bars (L19) were installed at the joints of the upper and lower columns, and high-tensile bolts (L19) were installed through the battens (2).
After connecting the upper and lower columns in step 3), connect the concrete injection hole (17
) Pour concrete (16).

Since the steel pipe concrete columns are joined as described above,
The concrete at the joint is integrated by the protrusion α on the inner surface of the steel pipe, and the reinforcing bars [15] extend in the longitudinal direction of the column.
By arranging reinforcement and connecting the steel pipe sections with high-tensile bolts, the strength and reliability of the joint are significantly improved compared to conventional methods. Also, the lower surface of the factory-cast concrete of the upper column α4
) is sloped, and an air vent hole (18) is drilled in the steel pipe at the upper end of the slope, so when concrete is poured, the internal air is completely removed, preventing the formation of air pockets, and increasing the strength of the concrete due to air pockets. Degradation is prevented.

Figure 2 is a sectional view of the joint showing another embodiment, and shows the lower column (
This shows a method of placing reinforcing bars (one reinforcing bar) at the joint at the same time when pouring concrete α in 1) at a factory.Since the reinforcing bars are placed in advance, the on-site work is reduced accordingly. This reduces the construction period and cost of on-site construction.

3, 4, and 5 show other embodiments in which reinforcing bars have different shapes. (a) is a plan sectional view, and (b) is a side sectional view.

As shown in the figures, the shapes of the reinforcing bars are different. Figure 3 uses a round bar with a head, Figure 4 uses an angle bar with a protrusion, and Figure 5 uses a steel pipe with an external protrusion instead of each reinforcing bar. An example is shown.

Note that in this example, a protrusion was provided on the inner surface of the steel pipe, but
A stud dowel or the like may be fixed instead of the protrusion.

Furthermore, if the stress generated at the joint is small, it is possible to omit the connection using high-tensile bolts.

(Effect of the invention) When joining columns of steel pipes with internal projections filled with concrete, the present invention arranges reinforcing bars in the longitudinal direction of the joint,
By sloping the lower surface of the factory-cast concrete for the upper column, drilling air vents in the steel pipes, and injecting concrete into the joints, we were able to achieve the excellent effects described below.

■Without the need for on-site welding, it is possible to design joints with high reliability and flexibility by combining concrete joints using steel pipes with internal protrusions, deformed reinforcing bars, and steel pipe joints using high-tensile bolt friction welding.

■ The use of steel pipes with internal protrusions enables mechanical stress transmission between concrete, and the use of deformed reinforcing bars can significantly reduce the number of high-tensile bolts used.

■ It is easy to vent air from poured concrete, improving the reliability of joints.

■ It is possible to join even if the steel pipe plate thicknesses of the upper and lower columns are different.

[Brief explanation of drawings]

Figure 1 shows a method for joining steel pipe concrete columns according to an embodiment of the present invention. (a) is a side sectional view, (b) is a plan sectional view, (C) is a front view, and Figure 2 is another embodiment. The side sectional view of the example, and FIGS. 3 to 5 show still other embodiments. (a) is a plan sectional view, (b) is a 4fil group sectional view, and FIGS. 6 and 7 are conventional steel pipe concrete. (a) is a side cross-sectional view, and (b) is a side view of the joint portion of the pillars. In the figure (lυ is a steel pipe concrete column, Oz is its inner protrusion, 03 is the factory-cast concrete of the column, α4) is the bottom surface of the factory-cast concrete of the upper column, (15) is the reinforcing bar, (+
6) is the concrete at the joint, (17) is the concrete injection hole, and (18) is the air vent hole. Agent Patent Attorney Tadashi Sato Figure 7 (Q) (b)

Claims (1)

[Claims] When joining steel pipes and concrete columns, square steel tubes with internal protrusions filled with concrete are used for the columns, the lower surface of the factory-cast concrete of the upper column is sloped, and air vent holes are drilled in the steel tube at the upper end of the slope. After installing multiple deformed reinforcing bars in the column longitudinal direction at the column joints and connecting the steel pipes of the upper and lower columns with high-tensile bolts through battens, concrete is filled into the steel pipes at the joints. A method for joining a steel pipe concrete column, characterized in that the joint is configured by