JP4228119B2 - Concrete filling method in concrete filling steel pipe construction method and concrete filling steel pipe used in the method. - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a concrete filling method in a concrete steel pipe construction method, that is, a construction method in which concrete is filled into a steel pipe to form a frame such as a pillar of a structure, and a concrete filling steel pipe used in the method.

  In general, a CFT structure (concrete filling steel pipe structure) has been developed that exhibits properties superior in earthquake resistance and fire resistance compared to RC structure and SRC structure (for example, Non-Patent Document 1). This construction method is a structure type in which concrete is filled in a steel pipe, and axial compression strength, bending strength and deformation performance increase due to the mutual restraining effect between the concrete and the steel pipe. In order to exert this mutual restraining effect, it is necessary to ensure that the concrete is uniformly and solidly filled without gaps and that the necessary strength is developed and that the steel pipe and the concrete are integrated.

  As a concrete filling method in this CFT construction, there are a drop filling method and a press-fitting method. As shown in FIG. 7, the drop filling method is a method in which concrete is driven upward from the bottom of the steel pipe using a tremy pipe 31 or a flexible hose into the steel pipe body 30 from the column head, and the drop height is relatively high. Used when low.

  The press-fitting method is a method in which a concrete inlet 33 is formed in the lower part of the steel pipe 30 as shown in FIG. 8 and concrete is driven up from the bottom of the steel pipe using a concrete pump 33. This press-fit method uses high-fluidity concrete and can be used even when the concrete placement height is high.

By using such a method, the separation of concrete at the time of placing is prevented to maintain the quality of the concrete, and the steel pipe in which the diaphragm is provided at the column-beam joint and the brace joint is filled. At this time, the generation of voids under the diaphragm is prevented.
September 30, 2002 Issued by New City Housing Association, “Technical Standards and Explanation for Steel Tubes for Concrete Filling (CFT)”

  The press-in method in the prior art described above can fill concrete up to a relatively high launch height without separating the concrete. However, since concrete is injected upward from the bottom of the steel pipe, Therefore, when the concrete placement height is relatively low, the dropping method is advantageous.

  However, in the conventional dropping method, the concrete guide pipe is inserted from the upper end of the steel pipe, and the lower end of the concrete pipe is adjusted while the distance from the concrete surface to be placed, that is, the driving height is adjusted to within about 1 m. It is necessary to use a lifting machine to secure the driving height, and when the guide pipe is raised as the filling progresses, the concrete inlet at the upper end also rises. Therefore, it is necessary to input concrete using a concrete bucket, and at least one lifting machine must be occupied for filling concrete. During this period, no other work can be performed by the lifting machine. Therefore, there is a problem that the process is delayed and the cost is increased.

  In view of the problems of the conventional dropping method, the present invention requires that the concrete driving operation does not require the use of a lifting machine and that the work for adjusting the driving height is completely required when casting concrete. The purpose of the present invention is to provide a concrete filling method in a concrete-filled steel pipe construction method in which concrete is filled only by charging concrete from the upper end of the steel pipe, and a steel pipe for concrete filling used in the method.

The feature of the invention described in claim 1 for solving the above-described conventional problems and achieving the intended purpose is that a space in the steel pipe is divided by a partition wall in the steel pipe erected substantially vertically. A vertical concrete guideway formed by partitioning is provided, and a plurality of concrete outlets are formed in the partition wall of the concrete guideway at regular intervals in the vertical direction, and the steel pipe is erected vertically. In this state, concrete is poured from the upper end of the concrete guide path, and the concrete dropped in the concrete guide path is caused to flow into the steel pipe from the concrete outlet, thereby filling the steel pipe with concrete. in concrete filling method in steel construction method, the concrete taxiway, among the edges of the partition wall in which the half-cylindrical of the steel pipe It is to integrally formed along the inner peripheral surface of the steel pipe by welding.

According to a second aspect of the present invention, there is provided a concrete-filled steel pipe used in a concrete-filled steel pipe construction method which is erected in a substantially vertical shape and is filled with concrete and becomes a frame such as a pillar. A concrete-filled steel pipe construction method in which a vertical concrete guideway is integrally formed by partitioning a partition wall, and a plurality of concrete outlets are provided at regular intervals in the partition wall of the concrete guideway. In the concrete-filling steel pipe to be used, the concrete guide path is integrally formed along the inner peripheral surface of the steel pipe by welding both edges of the partition wall having a half-cylindrical shape to the inner surface of the steel pipe. It is in.

  In the present invention, a vertical concrete guideway formed by partitioning a space in a steel pipe with a partition is integrally provided in the steel pipe, and a plurality of partition walls of the concrete guideway are provided at regular intervals in the vertical direction. By using the steel pipe formed with the concrete outlet, the concrete dropped from the concrete guide path is poured by putting concrete from the upper end of the concrete guide path with the steel pipe standing vertically. The concrete flows out from the concrete outlet near the top surface of the installed concrete into the steel pipe, and the concrete is sequentially launched upward from the bottom, and the lower end height of the induction pipe needs to be adjusted as before. Instead, it is necessary only to put concrete into the guideway opening at the upper end of the steel pipe. Nkurito filling is made.

  Further, the concrete guideway is formed by welding both edges of a partition wall having a half-cylindrical shape on the inner surface of the steel pipe, or a hollow cylindrical guideway pipe is inserted into the steel pipe, and the guideway pipe and By constructing the steel pipe by integrating it with the connecting means, the guide path can be easily formed.

  Furthermore, the concrete filling state in the steel pipe can be made more uniform by forming the concrete outlets with alternately different horizontal orientations spaced apart in the vertical direction.

  Next, embodiments of the present invention will be described based on examples shown in the drawings. 1 to 4 show an example of a steel pipe for filling concrete used in the concrete filling method according to the present invention.

  This steel pipe is mainly composed of a cylindrical steel pipe main body 1 constituting the outer shell of the pillar of the structure, and the steel pipe main body 1 is provided with thick portions 2 for reinforcement on the inner surface of the beam connecting portion at regular intervals. Yes. A concrete guide path 3 is integrally provided along the inner surface of the steel pipe body 1. The concrete guide path 3 is integrally formed along the inner peripheral surface of the steel pipe main body by welding a semicylindrical partition wall 4 having a vertically divided half cylinder to the inner surface of the steel pipe main body 1. It is formed. The partition wall 4 has a semi-cylindrical diameter that is about ¼ to の of the diameter of the steel pipe body 1 and is installed over the entire length of the steel pipe body 1.

  The partition wall 4 is formed with a plurality of concrete outlets 5a to 5f at regular intervals in the longitudinal direction. The concrete outlets 5 a to 5 f are formed so that the diameter thereof is approximately the same as the diameter of the semi-cylinder of the partition wall 4. This size is determined in consideration of the fluidity of the concrete used when placing concrete, which will be described later, so that the top surface height of the concrete guide path 3 and the steel pipe body 1 outside thereof are approximately the same. To decide.

  When using the steel pipe constructed as described above, as shown in FIG. 3, the steel pipe main body 1 is erected and the necessary beams 6 are connected, and then the concrete is opened at the upper end of the steel pipe main body 1 as in the prior art. Concrete is poured into the guide path 3. When injecting concrete, a funnel-like hopper 7 is used at the opening as necessary, and the concrete is injected from a hose 8 from a concrete pump.

  The injected concrete falls in the concrete guiding path 3 and flows out into the steel pipe body 1 from the outlet 5 at the lower end. Further, by pouring concrete, the upper surface of the concrete placed in the steel pipe body 1 becomes higher than the outflow port 5, but flows out from the outflow port 5 buried by the weight of the concrete that is sequentially dropped into the steel pipe body 1, It is placed upward from a position lower than the concrete upper surface.

  In this way, the concrete upper surface sequentially rises, and when the next outlet height is reached, the concrete outflow from the outlet starts and the concrete is filled upward as described above.

  In addition, according to the experiment, the concrete guide path 3 is connected to the steel pipe main body 1 having a diameter of 800 mm and a length of 5000 mm as shown in FIG. Formed over the top end, six concrete outlets 5a to 5f with an opening diameter of 300 mm are formed at intervals of 800 mm from the lower end of the partition wall 4, and the materials shown in Table 1 are used. When the concrete kneaded in was cast at a casting speed of 1 m / min, the concrete top surface of the concrete guide path 3 and the steel pipe main body 1 were filled with substantially the same height.

In addition, the concrete section after hardening was almost uniformly distributed in both fine and coarse aggregates. In addition, the opening diameter 300 mm of the concrete outlet mentioned above is the size formed in what developed the semicylindrical partition 4 in flat form.

  In the above-described embodiment, the concrete guide path is provided along the inner surface of the steel pipe body 1, but in addition, the concrete guide path 11 is provided in the central portion of the steel pipe body 10 as shown in FIGS. 5 and 6. In this case, the tubular body 12 which becomes the concrete guide path 11 is used, and this is fixed and integrated to the inner surface of the steel pipe body 10 with a radial connecting member 13 at regular intervals.

  Concrete outlets 14 are formed in the pipe body 11 at regular intervals. The concrete outlets 14 are arranged in two rows on the side surfaces symmetrical to each other of the pipe body 11, and on each side so that the outlets on the other side face are positioned between the upper and lower concrete outlets on one side face. It is provided in a staggered arrangement. Thus, the concrete filling state in the steel pipe main body 10 is homogenized by changing the direction of the upper and lower concrete outlets.

  In the use of this steel pipe, the concrete is filled into the steel pipe by pouring concrete from the upper end of the concrete guide path 11 in the same manner as in the above-described example.

In each of the above-described embodiments, a case where a concrete guide path using a cylindrical steel pipe body, a semi-cylindrical wall, or a cylindrical partition wall is provided is shown. A concrete guiding path using a semi-cylindrical or cylindrical partition may be provided.
Further, in the above-described embodiment, the concrete guide path is formed by welding both edges of the semi-cylindrical partition wall to the steel pipe main body, but the other concrete guide path is formed with a half-tubular partition wall on the inner surface of the steel pipe. You may form by welding both the edges.

It is a top view which shows an example of the steel pipe for concrete filling used for the concrete filling steel pipe construction method concerning this invention. It is the sectional view on the AA line in FIG. It is a longitudinal cross-sectional view which shows a use condition same as the above. It is a perspective view which shows the steel pipe used for experiment of this invention method, and a partition. It is a top view which shows the other example of the steel pipe for concrete filling used for the concrete filling steel pipe construction method which concerns on this invention. FIG. 6 is a sectional view taken along line BB in FIG. It is sectional drawing which shows an example of the conventional concrete filling construction method. It is sectional drawing which shows the other example of the conventional concrete filling construction method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steel pipe main body 2 Thick part 3 Concrete guide path 4 Partition walls 5a-5f Concrete outlet 6 Beam 7 Hopper 8 Hose 10 Steel pipe main body 11 Concrete guide path 12 Tubing body 13 Connecting material 14 Concrete outlet

Claims (2)

In the steel pipe erected substantially vertically, a vertical concrete guide path formed by partitioning the space in the steel pipe with a partition wall is provided, and the partition wall of the concrete guide path is spaced at regular intervals in the vertical direction. A plurality of concrete outlets are formed, and concrete is poured from the upper end of the concrete guide path in a state where the steel pipes are erected vertically, and the concrete dropped from the concrete guide path is discharged from the concrete outlet. In a concrete filling method in a concrete-filled steel pipe construction method in which concrete is filled in the steel pipe by allowing it to flow into the steel pipe,
Concrete in the concrete-filled steel pipe construction method, wherein the concrete guide path is integrally formed along the inner peripheral surface of the steel pipe by welding both edges of the partition wall having a half-cylindrical shape to the inner surface of the steel pipe Filling method. A concrete-filled steel pipe that is used in a concrete-filled steel pipe construction method that is erected in a substantially vertical shape and is filled with concrete inside to form a column or other structure, and that guides the concrete in the vertical direction by partitioning the interior space with a partition wall In the concrete-filled steel pipe used for the concrete-filled steel pipe construction method in which the road is integrally formed and the partition wall of the concrete guide path is provided with a plurality of concrete outlets at regular intervals in the vertical direction,
The concrete guiding path is formed integrally with the inner peripheral surface of the steel pipe by welding both edges of the partition wall having a half-cylindrical shape to the inner surface of the steel pipe, and is filled with concrete. Steel pipe for filling concrete used for