JP3036375B2 - Method and apparatus for compacting concrete - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for compacting concrete using microwaves.

[0002]

2. Description of the Related Art A rod-shaped vibrator has been generally used as a method for compacting unhardened concrete after casting. The compaction method using this vibrator is to mechanically vibrate a rod inserted from the surface of the concrete into the inside at a vibration frequency of, for example, about 7000 Hz, thereby forcibly bleeding and promoting the densification of the concrete. is there.

[0003]

However, in this vibration compaction method, the compaction effective layer has a depth of 30 to 60 cm.
The required effect cannot be obtained unless the insertion interval is less than 60 cm, and the effective range is narrow. Also, compaction work can be performed efficiently for highly viscous high-fluid concrete. Did not.

Accordingly, the present invention has been made to solve the above-mentioned drawbacks, and it is an object of the present invention to compact uncured concrete over a wide range and to perform compacting work effectively on highly viscous concrete. It is an object of the present invention to provide a method and an apparatus for compacting concrete that can be performed.

Another object of the present invention is to provide a method for compacting concrete and a device suitable for compacting, which can easily develop the early strength of concrete cast simultaneously with compaction. It is.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and has been made in consideration of the above circumstances.
When laying an electromagnetic shield sheet on the casting surface of the board
A rod-shaped waveguide is inserted into the concrete to irradiate the microwave to generate vibrations in free water contained in the concrete and to heat the concrete. The subject of the invention is a method of compacting concrete to be performed.

[0007]

Further compaction apparatus of the concrete of the present invention is placed on a hitting設表surface of the uncured concrete, the rolling plate having a plurality of microwave discharge orifice to the lower surface side, standing from said transfer plate And a waveguide connected to a microwave generator at a tip end thereof for guiding microwaves to the microwave emission port (Claim 2 ).

[0009]

[Action] According to the compaction method of the above-mentioned concrete, conventional
The vibrator can be used in the same form as the rod vibrator described above, and vibrating energy is given to free water in concrete within a microwave radiation range, and compaction is performed by causing forced breathing. The free water and the cement hydrate in the concrete are simultaneously heated by the dielectric loss due to microwaves, and the hydration reaction is accelerated. Con
An electromagnetic shield sheet is laid on the cleat placement surface
Prevents microwave leakage from affecting the human body
be able to.

Further, according to the compaction apparatus of the concrete according to claim 2, it can be compacted at a time concrete over a wide range.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention. A compacting device 1 for compacting uncured concrete C which has been cast therein comprises a hollow rod-shaped main body 1a and a main body 1a. And a mechanical vibrating unit 1b integrated on the upper part of the main body, and the main body 1a is vibrated as a whole by driving the vibrating unit 1b, so that the main body 1a can be easily inserted into the concrete C. At the same time, the dimensions such as the length and diameter are set in consideration of the handleability of workers. In addition, the vibration part 1b does not necessarily need to be provided when it is easy to insert the main body part 1a alone into the concrete C.

The main body 1a is constituted by a waveguide 2. The lower end of the waveguide 2 is a horn-shaped microwave emission port 2a, and the open end face is covered with a lid 2b made of a microwave transmitting material. The upper end is connected to a microwave generator 4 located at a remote position via a high-frequency insulated cable 3, and the generator 4 is driven by a hand switch or the like (not shown) to guide the generated microwave. It is guided through the wave tube 2 and radiates downward from the microwave emission port 2a.

The microwaves have a frequency of 900 to 900, for example.
It can be variably set to 2500 MHz and the output is about 100 to 30 KW, and its radiation range is set to a spread angle according to the spread of the emission port 2a.

When vibration compaction is performed using the compacting apparatus 1 described above, an electromagnetic shielding sheet 5 is previously laid on the concrete C casting surface in order to prevent the microwave from leaking and affecting the human body. Is done. The sheet 5 is made of a rubber sheet or the like with a wire mesh, serves as a curing sheet, and has a cross slit having a hole diameter through which the main body 1a is inserted at each compaction interval. It is used as a guide for the insertion interval.

Therefore, after the concrete C is cast, the compacting device 1 is inserted into the slit after the sheet 5 is laid, and the work is inserted and extracted while radiating the microwaves, and the work of pulling out the concrete C is repeated over the entire area where the concrete C is cast. This ends the compaction work. The radiation range of the microwave per one operation becomes very large in comparison with the diameter of the main body 1a according to the opening angle of the emission port 2a, and accordingly, even if the insertion interval is set to be larger than that of the conventional vibrator, sufficient compaction is performed. The effect can be obtained.

The radiated microwaves are reflected by the bedrock or slag E under the concrete C as shown by arrows, and may pass through the surface of the concrete C again. It is desirable to decide in consideration of the reflection angle.

Then, as shown schematically in FIG. 2, the free water w contained in the concrete C is given vibration energy by the microwave radiation, and is sewn in the concrete C while vibrating as shown by the arrow. The ascending breathing is performed in this way, and the concrete is compacted tightly. At the same time, the water in the free water w and the cement hydrate Cw is heated by the dielectric loss, and the temperature rises, whereby the hydration reaction is promoted and the early strength is developed. The compaction and heating effects can also be obtained when the concrete C is a highly viscous concrete such as high-fluidity concrete.

FIG. 3 shows a second embodiment of the present invention, in which parts common to the first embodiment are denoted by common reference numerals, and only different parts will be described using different reference numerals.

The compacting device 10 shown in the figure is a tamper 10a as a rolling plate installed on the surface of concrete C.
And the waveguide 2 which is integrally provided upright from the tamper 10a.

The lower end of the waveguide 2 communicates with a plurality of microwave outlets 2a opened on the lower surface of the tamper 10a, and the upper end is connected to a microwave generator 4 located at a remote position via a high-frequency insulating cable 3. ing.

The compacting device 1 according to this embodiment
According to 0, even when it is difficult to fit the rod-shaped compaction device 1 into the inside of the concrete C, the concrete can be compacted easily and the compaction operation can be performed at once over a wide range.

The compacting devices 1 and 10 can further enhance the compacting effect when used in combination with a conventional vibrator.

[0024]

As described above in detail, in the method for compacting concrete according to the present invention, the inside of unhardened concrete is irradiated with microwaves.
Since the free water contained in the concrete is caused to vibrate, the compaction is performed by giving vibration energy to the free water inside the concrete within the microwave radiation range and forcibly causing breathing. Therefore, compared with the conventional vibration compaction method using a mechanical vibrator, the compactable range per operation can be expanded and the compaction work can be performed efficiently. Also a microphone
The microwave generated by the microwave generator generates a rod-shaped wave
Condensed by spreading along the shape of the launch port along the inside of the tube
The microwave is directed toward the bottom of the REIT
Therefore, compaction work is performed in the same manner as a conventional vibrator.
It can be carried out. In addition, on the concrete casting surface
Since an electromagnetic shield sheet is laid, microwave leakage
The influence on the human body by the leak can be prevented.

Further, the free water and the cement hydrate in the concrete are simultaneously heated by the dielectric loss due to microwaves, and this heating promotes the hydration reaction and develops early strength. Therefore, there is an advantage that the construction period can be shortened, and particularly when applied to cold concrete or the like, the heat preservation curing and the heat supply curing can be saved.

Further, according to the vibration compaction device of the second aspect of the present invention, the microwave generated by the microwave generation device spreads along the rod-shaped waveguide according to the shape of the emission port. Since the microwave is irradiated toward the lower part of the concrete, the compacting operation can be performed by the same handling as the conventional vibrator.

Further, when the configuration of claim 2 is adopted, concrete can be compacted over a wide range at once.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a first embodiment of a compaction apparatus according to the present invention and compaction work using the same.

FIG. 2 is a schematic view of the inside of concrete at the time of compaction.

FIG. 3 is an explanatory view showing a second embodiment of the compaction apparatus and compaction operation using the same according to the present invention.

[Explanation of symbols]

 1,10 Compaction device 1a Main body 2 Waveguide 2a Microwave launch port C Concrete 4 Microwave generator 10a Tamper (compacting plate)

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-133103 (JP, A) JP-A-4-228483 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) E04G 21/06

Claims (2)

(57) [Claims] 1. An electromagnetic shield is placed on the uncured concrete casting surface.
Laying a cold sheet and inserting a rod-shaped waveguide into the concrete to irradiate microwaves to generate vibrations and heat the free water contained in the concrete. How to compact concrete. 2. A rolling plate mounted on an uncured concrete casting surface and provided with a plurality of microwave outlets on a lower surface side, and a standing portion of the rolling plate is provided with a microwave generating end. A concrete compaction device, comprising: a waveguide connected to the device for guiding microwaves to the microwave outlet.