JP3775147B2 - Placing high fluidity concrete - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for placing high-fluidity concrete used to construct a wall body such as an LNG tank, a breakwater, or a floor slab.
[0002]
[Prior art]
In the construction of concrete structures, when concrete is placed on long walls such as LNG tanks, liquid breakwaters, and floor slabs with a large placement area, a concrete pumping pipe is installed. Generally, a method is provided in which gate valves are provided at a plurality of locations and the concrete placement locations are sequentially moved. This method has the advantage that it can be compacted within a limited range of the places to be placed, and the material separation by flow is small for concrete with a relatively hard slump area.
[0003]
[Problems to be solved by the invention]
However, concrete wide floor like long walls and pouring area of the above-mentioned wall length, in the case of pouring the high fluidity concrete in particular, there is a technical problem UNA by are shown in below. That is, due to the high fluidity of the concrete itself, the concrete flows widely from the placement site, so it is necessary to frequently open and close the gate valve to limit the flow distance and suppress material separation. Cost.
[0004]
Also, in the method where concrete is poured from multiple gates at the same time by branching the pipe, the piping distance becomes longer and the piping equipment becomes larger, and the number of outlets increases as the number of outlets increases. There is a problem such as small.
[0005]
The present invention solves the above problems, and its purpose is to be able to place high-fluidity concrete that does not require compaction work in a layered state in a homogeneous state, so that the piping equipment does not become large-scale, efficiency A method for placing a typical high fluidity concrete is provided.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a main pipe in which high-fluidity concrete is pumped from the base end and the tip is always opened so that the concrete is always placed from the tip, and the main A plurality of branch pipes that are branched with respect to the pipe and whose leading ends are opened at appropriate positions where high-fluidity concrete should be placed together with the leading ends of the main pipes, and connecting portions of the respective branch pipes to the main pipes; A method of placing high-fluidity concrete by a pumping device provided with an adjusting means for adjusting the pumping amount of the high-fluidity concrete to the branch pipe, wherein all of the plurality of branch pipes are grouped in advance. For the plurality of branch pipes belonging to the same group, the amount of high-fluidity concrete discharged is constant and the high-fluidity concrete is simultaneously discharged from the plurality of branch pipes. It is characterized in that to control the pumping quantity of the high-flow concrete into the branch pipes by the adjusting means. Note that the fact that the front end of the main pipe is open means that there is no adjustment means such as a valve at the front end of the main pipe, and that such adjustment means is open.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a perspective view of an embodiment in which the method for placing high-fluidity concrete according to the present invention is used to construct an LNG tank wall.
[0008]
In the figure, an LNG tank 1 includes an arc-shaped bottom plate 3 (for example, a height of 2100 mm) and a tank wall body 5 that also has an arc shape on the upper portion of the bottom plate 3 and extends in the height direction. The height of 1500 mm) and two lot parts 5B (for example, height of 4370 mm) are stacked in five layers, and then the sixth layer of concrete is placed. A slide mold 7 that slides in the height direction is disposed inside and outside the tank wall 5 (the inner mold is not shown), and slides in synchronization with the slide mold 7 on the outer side of the slide mold 7. A slide scaffold 9 is arranged. In this embodiment, for example, the tank wall thickness, that is, the distance between the slide molds 7 is 800 mm. Although only a part is shown, a large number of reinforcing bars 11 are arranged between the slide molds 7 while being connected upward.
[0009]
A pilaster section frame scaffold 13 extending in the vertical direction is provided at a predetermined position in the circumferential direction of the LNG tank 1, and a vertical pipe 15 (for example, 6 inches in diameter) as a main pipe is piped in the framework scaffold 13. As the LNG tank wall 5 is constructed, the vertical pipe 15 and the frame scaffold 13 are successively connected upward. The lowermost end of the vertical pipe 15 is located on the ground, and a valve 17 (pin valve and gate valve) and a concrete pumping total amount check device 19 are provided in this portion. Ready-mixed concrete is put into the lowermost end of the vertical pipe 15 from the ready-mixed car 21, and the concrete is pumped upward in the vertical pipe 15 by the pump truck 23.
[0010]
A branch pipe 25 for bifurcating the horizontal pipe in the horizontal direction is connected to the upper part of the vertical pipe 15, and a left horizontal pipe 29 and a right horizontal pipe 31 are connected to the branch pipe 25 via a reducer 27. (For example, both are 5 inches in diameter). For example, the reducer 27 reduces the diameter of the branch pipe 25 having a diameter of 6 inches to 5 inches.
[0011]
The left and right horizontal pipes 29 and 31 are piped along the curvature of the slide mold 7 on the outside of the slide mold 7, that is, along the curvature of the LNG tank 1 to be constructed. The one end of the flexible hose 35 is connected to the tip of the flexible hose 35 via a reducer 33. The other end of the flexible hose 35 is suspended in the slide mold 7 and the concrete is discharged from the lowermost end thereof. The vertical pipe 15, the left and right horizontal pipes 29 and 31, the flexible hose 35, and the like constitute a “main pipe” according to the present invention.
[0012]
In the middle of the left and right horizontal tubes 29, 31, T-tubes 37 (at the branch portion, for example, the diameter of the tube is 5 inches) at positions where the tip of the left horizontal tube 29 and the tip of the right horizontal tube 31 are divided into approximately five equal parts. 1 to 4 inches), and each T-shaped pipe 37 is connected to one end of a plurality of branch pipes 39 each consisting of a short horizontal pipe directed to a concrete placing portion between the slide molds 7.
[0013]
An opening / closing valve 41 is provided between each T-shaped pipe 37 and the branch pipe 39, and the opening / closing thereof is controlled together with the valve 17 provided at the lowermost end of the vertical pipe 15 by a control means (not shown). For example, in the left horizontal pipe 29, the control means opens and closes the two open / close valves 41 simultaneously, or alternately opens / closes the concrete so that the concrete opens from the lowest end of the flexible hose 35 that opens the valve 41. It will be discharged according to. The control of the concrete discharge by the control means is performed so that, for example, the concrete discharge amount is constant for all branch pipes 39 or a plurality of branch pipes 39 belonging to a group grouped in advance among all the branch pipes 39. Alternatively, the flow distance of the placed concrete can be controlled.
[0014]
According to the present embodiment, the tip of the main pipe composed of the vertical pipe 15, the left and right horizontal pipes 29, 31, the flexible hose 35, etc. is always open, and concrete is always cast from the flexible hose 35. The concrete always flows in the pipe, and as a result, the residual concrete in the main pipe does not solidify and block the main pipe. This also facilitates the flow and discharge of the concrete from the short horizontal 39 pipe, and as a result, it is possible to prevent a decrease in the fluidity and blockage of the concrete in all of the main pipe and the branch pipe 39.
[0015]
As described above, the concrete is constantly flowed in the main pipe, and the open / close valve 41 provided in the branch pipe 39 is opened / closed by appropriate control of the control means, so that the flow distance is controlled and the homogenous state is appropriately set. A pumped material such as concrete can be pumped in layers in an amount (layer height). Therefore, high-fluidity concrete that does not require compaction work can be cast in layers in a homogeneous state.
[0016]
In the above-described embodiment, the left and right horizontal pipes 29 and 31 and the branch pipe 39 are piped symmetrically about the vertical pipe 15, but may be piped asymmetrically. Moreover, in the said embodiment, although the branch pipe 39 was piped at equal intervals, it does not need to be equal intervals.
[0018]
【The invention's effect】
As is clear from the above description , according to the present invention , high-fluidity concrete that does not require compaction work can be cast in a layered state in a homogeneous state, and the piping facility does not become a large-scale, efficient high-fluidity A method for placing concrete can be provided.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an example in which the present invention is applied to concrete placement of an LNG tank wall.
[Explanation of symbols]
1 LNG tank 3 Bottom plate 5 Tank wall 7 Slide mold 9 Slide scaffold 13 Frame scaffold 15 Vertical pipe (main pipe)
29 Left horizontal pipe 31 Right horizontal pipe 35 Flexible hose 39 Branch pipe 41 Open / close valve

Claims (1)

High-fluidity concrete is pumped from the base end and the main pipe is always open so that the concrete is always placed from the front, and the main pipe is branched from the main pipe to the main pipe, and the tip is A plurality of branch pipes opened at appropriate positions along with the tip of the main pipe to be placed at appropriate positions, and a high-fluidity concrete pumped to the branch pipe provided at a connection portion of each branch pipe with the main pipe A method of placing high-fluidity concrete by a pressure feeding device provided with an adjusting means for adjusting the amount,
For all of the plurality of branch pipes or a plurality of the branch pipes belonging to the group grouped in advance, the high fluid concrete is discharged from the plurality of branch pipes at the same time so that the discharge amount of the high fluid concrete is constant. As described above, a method for placing high-fluidity concrete, wherein the amount of high-fluidity concrete fed to each branch pipe is controlled by the adjusting means.

Images