JPH11256681A - Execution method of concrete structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the generation of voids due to shrinkage by hydration at the time of curing of concrete in a sealed concrete-filled space. SOLUTION: A cylindrical placing pressure port 5 is installed in the box- shaped structure 1 made of steel consisting of a steel plate, etc., while being communicated with a concrete-filled space on the inside. Uncured concrete C is poured into the concrete-filled space from the placing pressure port 5, the concrete-filled space is filled with concrete C, concrete C is placed up in the placing pressure port 5 in height of 50 cm or more, concrete C in the concrete-filled space is pressed, and concrete C in the concrete-filled space is cured under a pressed state. The formation of an opening between the structure 1 made of steel and concrete C can be inhibited, and the steel-concrete composite structure having high quality is constructed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to construction of a concrete structure by filling concrete in a closed concrete filling space and hardening the concrete in the concrete filling space, such as construction of a steel-concrete composite structure having a sandwich structure. The present invention relates to a method for constructing a concrete structure.

[0002]

2. Description of the Related Art In a sandwich-structured steel-concrete composite structure, unhardened concrete (high-fluidity concrete) is injected into an enclosed space inside a box-shaped steel structure made of a steel plate or the like, and filled. Although it is constructed by hardening concrete in an enclosed space, it is necessary to minimize the gap between the steel structure and the concrete and to integrate the steel structure and the concrete.

[0003]

The method of filling unsealed space inside a steel structure with uncured concrete so as not to form voids is sufficient for concrete to sufficiently fill the closed space in an unhardened state. Even when the concrete hardens, it shrinks when it hardens,
There was a problem that a gap was formed between the steel structure and the concrete inside.

The present invention has been made in view of such a conventional problem,
It is an object of the present invention to provide a concrete structure construction method that can reduce the occurrence of voids due to hydration shrinkage during hardening of concrete when hardening concrete in a closed concrete filling space and constructing a concrete structure. It was done.

[0005]

SUMMARY OF THE INVENTION The features of the present invention for solving the conventional problems as described above and achieving the intended purpose are as follows.
Injecting uncured concrete into a closed concrete filling space, filling the concrete filling space with concrete, and then hardening the concrete in the concrete filling space to construct a concrete structure. Providing a cylindrical pressurized port in communication with the concrete filling space, launching the concrete to a height of 50 cm or more or applying a pressure corresponding to its weight to the pressurized port, Concrete is pressurized, and the concrete in the concrete filling space is hardened in a pressurized state.

[0006] The concrete structure is a steel-concrete composite structure, and the concrete-filled space for concrete is suitable when formed inside a box-shaped steel structure made of a steel plate or the like.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG.

In the figure, reference numeral 1 denotes a steel structure constituting a steel-concrete composite structure having a sandwich structure. The steel structure 1 is formed in a box shape with a steel plate or the like and the inside thereof is filled with concrete. It is a space.

At the center of the upper surface of the steel structure 1, a cylindrical casting pressure port 5 (pressure port) is erected to communicate with the concrete filling space. At the corners, cylindrical exhaust ports 7 are erected to communicate with the concrete filling space.

After the uncured concrete C is filled in the concrete filling space inside the steel structure 1, the concrete C is hardened, so that the steel structure 1 and the concrete C are integrated. A steel-concrete composite structure is constructed.

In order to fill the concrete filling space inside the steel structure 1 with the concrete C, the concrete C (high-fluidity concrete) is injected into the concrete filling space from the casting pressurizing port 5 while the concrete filling space is filled. The inside air is exhausted from the exhaust ports 7, 7, and the concrete filling space is sufficiently filled with the concrete C so as not to form voids.

Further, the concrete C is launched into the casting press opening 5 to a predetermined press height (with extra space), and the weight of the concrete C in the casting press opening 5 makes the inside of the steel structure 1 inside. The concrete C in the concrete filling space is pressurized and hardened while the concrete C in the concrete filling space is pressurized. In addition, the pressurized height of the concrete C in the casting pressurizing port 5 is preferably 50 cm or more, although it depends on the composition of the concrete C and the like.

[0013] As described above, the concrete C in the concrete filling space inside the steel structure 1 is hardened in a pressurized state, and the concrete C in the concrete filling space shrinks during hydration during the hardening. The formation of a gap between the concrete 1 and the inner concrete C is suppressed, and a high-quality steel-concrete composite structure can be constructed.

In the above-described embodiment, the case where the concrete C in the concrete filling space inside the steel structure 1 is pressurized by launching the concrete C into the casting press opening 5 has been described. As shown in FIG. 2, a pressure corresponding to the weight of the concrete having a height of 50 cm or more may be applied by placing a weight 8 on the concrete C of the casting pressure port 5 or the like.

Further, in the above-described embodiment, the case of constructing a steel-concrete composite structure having a sandwich structure has been described. However, the present invention can also be applied to a concrete-filled steel tubular column of an inner diaphragm type as shown in FIG. .

That is, when filling the inside of the steel pipe 11 with concrete, the concrete is lifted up to a predetermined pressing height above the diaphragm 13, and the concrete below the diaphragm 13 is pressed by its weight, and By curing the lower concrete in a pressurized state, the gap between the diaphragm 13 and the concrete can be reduced.

In this case, a portion below the diaphragm 13 inside the steel pipe 11 corresponds to a concrete filling space, and a portion above the diaphragm 13 inside the steel pipe 11 corresponds to a pressure port.

[0018]

EXAMPLE Using a cylindrical box-shaped formwork, the concrete of 14 types of composition shown in FIG.
0, 500, 1000 mm) and a concrete pressure-hardening test.

As shown in FIG. 4, the form body has a cylindrical box shape (inner diameter 250 mm × height 100 mm) having a large-diameter cylinder 21 made of acrylic, a bottom plate 22 and an upper plate 23 made of steel.
0 mm), and the casting pressure port 25 has a cylindrical shape (inner diameter 250 mm × height 3 mm) with a small-diameter cylinder made of acrylic.
00, 550, 1050 mm (changes depending on the pressing height)
And fixed to the upper plate 23 of the form body by communicating with the inside of the form body through a communication hole provided in the center of the upper plate 23.

A release material was applied to the inner surface of the form body to reduce friction with concrete. this is,
In order to properly evaluate the effect of concrete pressing, a release material was applied to eliminate the effect of formwork friction.In actual structures, the dimensions were larger than in the examples, and the friction of formwork was reduced. The effects are limited to local ones and can be ignored.

Then, concrete C is filled into the formwork body from the casting pressure port 25, and the concrete C is further poured into the casting pressure port 25 to a predetermined pressure height. As shown in FIG. 5, the large-diameter cylinder 21 of the mold body was removed, and the gap G between the lower surface of the upper plate 23 and the upper surface of the concrete C was measured with a gap gauge.

As shown in FIGS. 7 to 11, the test results show that the larger the pressing height of any concrete,
The gap between concrete and concrete C is reduced, and the pressure height is 0.5m
In the case of (1), the gap was greatly reduced, and in the case of the pressurized height of 1 m, almost no gap was observed. The gap amount in FIGS. 7 to 11 is an average of measured values in the circumferential direction (16 locations) of the form body.

FIG. 6 shows the test results at a pressing height of 0 mm.
As shown in the figure, when concrete C is cast to a height of 1000 mm and cured on a cylindrical box-shaped (inner diameter 250 mm) form body composed of an acrylic large-diameter cylinder 21 and a steel bottom plate 22, The amount of settlement of the upper surface of the concrete C.

Using a rectangular parallelepiped box-shaped formwork, a concrete pressure-hardening test was carried out on the concretes of the eight types shown in FIG. 22 while changing the pressing height (250, 500, 1000 mm).

As shown in FIGS. 12 and 13,
.., A bottom plate 32 and a top plate 33 can be disassembled into a rectangular parallelepiped box (200 mm deep x 2000 m wide)
m × 1000 mm in height), the casting pressure port 35 and the exhaust port 37 are each made of an acrylic cylinder and have a cylindrical shape (inner diameter 80 mm × height 300, 550, 1050 mm).
(Changed according to the pressing height), the inner diameter is 50 mm), and the upper body 33 of the form body is communicated with the inside of the form body through communication holes provided near both side ends of the upper plate 33. Fixed. Note that the upper plate 33 of the form body is H
It was fixed in a form reinforced by mold steel and angle steel. In addition, a release material was applied to the inner surface of the formwork body to reduce friction with concrete.

Then, concrete C is filled into the formwork body from the casting pressure port 35, and the concrete C is further poured into the casting pressure port 35 to a predetermined pressure height, as shown in FIG. After the concrete C has hardened, the side plate 31,
31 were removed, and the gap G between the lower surface of the upper plate 33 and the upper surface of the concrete C was measured at a plurality of locations in the width direction (20 locations at 10 cm intervals) using a gap gauge.

The test results are as shown in FIGS.
In general, the larger the pressure height, the more
5. The gap G between the upper plate 33 and the concrete C was reduced closer to the exhaust port 37. The gap amounts in FIGS. 14 to 21 are the average of the measured values on the left and right of the form body.

[0028]

As described above, in the concrete structure construction method according to the present invention, a cylindrical pressure port is provided in communication with a closed concrete filling space, and unhardened concrete is injected into the concrete filling space. Then, the concrete is filled in the concrete filling space, and the concrete in the concrete filling space is pressurized by launching the concrete to a height of 50 cm or more or applying a pressure corresponding to the weight of the concrete to the pressurizing port. By hardening the concrete in the space in a pressurized state, it is possible to suppress the occurrence of voids in the concrete filling space due to hydration shrinkage during hardening of the concrete.

When the concrete structure is a steel-concrete composite structure and the concrete filling space for concrete is formed inside a box-shaped steel structure made of a steel plate or the like, the steel structure is The formation of a gap between the concrete and the concrete can be suppressed, and a high-quality steel-concrete composite structure can be constructed.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of an embodiment of a concrete structure construction method according to the present invention.

FIG. 2 is a schematic view showing another example of the embodiment of the concrete structure construction method according to the present invention.

FIG. 3 is a perspective view showing a concrete-filled steel pipe column to which the concrete structure construction method according to the present invention can be applied.

FIG. 4 is a longitudinal sectional view showing a concrete pressure hardening test device using a cylindrical box-shaped formwork.

5 is a longitudinal sectional view showing a state where a large cylinder (mold side surface) in FIG. 4 is removed.

FIG. 6 is a longitudinal sectional view showing a concrete non-pressure hardening test device using a cylindrical formwork.

FIG. 7 is a graph showing test results obtained by the test apparatus of FIG.

8 is a graph showing test results obtained by the test device shown in FIG.

FIG. 9 is a graph showing test results obtained by the test apparatus of FIG.

FIG. 10 is a graph showing test results obtained by the test apparatus shown in FIG.

FIG. 11 is a graph showing test results obtained by the test apparatus shown in FIG.

FIG. 12 is a longitudinal sectional view showing a concrete pressure hardening test apparatus using a rectangular box-shaped formwork.

FIG. 13 is a perspective view showing a state where a side plate (mold side surface) in FIG. 12 is removed.

FIG. 14 is a graph showing test results obtained by the test apparatus of FIG.

FIG. 15 is a graph showing test results obtained by the test apparatus of FIG.

FIG. 16 is a graph showing test results obtained by the test apparatus of FIG.

FIG. 17 is a graph showing test results obtained by the test apparatus of FIG.

FIG. 18 is a graph showing test results obtained by the test apparatus shown in FIG.

FIG. 19 is a graph showing test results obtained by the test apparatus of FIG.

FIG. 20 is a graph showing test results obtained by the test apparatus of FIG.

FIG. 21 is a graph showing test results obtained by the test apparatus shown in FIG.

FIG. 22 is a table showing the composition of concrete subjected to a concrete pressure hardening test by the test apparatus of FIGS.

[Explanation of symbols]

 C Concrete G Gap 1 Steel structure 5 Casting pressurizing port (pressurizing port) 7 Exhaust port 9 Weight 11 Steel pipe 12, 13 Diaphragm 21 Large diameter cylinder (form body) 22 Bottom plate 23 Top plate 25 Pressure port 31 Side plate (form body) 32 Bottom plate 33 Top plate 35 Casting pressure port 37 Exhaust port

Claims (2)

[Claims] 1. A concrete for constructing a concrete structure by injecting unhardened concrete into a closed concrete filling space, filling the concrete filling space with concrete, and then curing the concrete in the concrete filling space. In the method for constructing a structure, a tubular pressure port is provided in communication with the concrete filling space, and the concrete is launched into the pressure port at a height of 50 cm or more or a pressure corresponding to the weight thereof is applied, A concrete structure construction method, wherein concrete in a concrete filling space is pressurized and the concrete in the concrete filling space is hardened in a pressurized state. 2. The concrete structure according to claim 1, wherein the concrete structure is a steel-concrete composite structure, and the concrete filling space is formed inside a box-shaped steel structure made of a steel plate or the like. Object construction method.