JPH08120929A - Method and device for compacting concrete - Google Patents

Abstract

PURPOSE: To apply this method and device for the concrete at a high viscosity by widening the effective range of compaction, and to easily realize the early strength of the placed concrete. CONSTITUTION: A compacting device 1 is formed of a hollow tubular main body 1a forming a waveguide 2 and a micro wave emitting port 2a provided in the lower end opening of the waveguide 2, and the upper side of the waveguide 2 is connected to a microwave generating device 4, which is provided at a separate position, through a high frequency insulated cable 3. In the case of performing the compacting work with the compacting device 1, after placing the concrete C, the compacting device 1 is inserted into the concrete C, and the microwave is emitted, and while the work for inserting and pulling this compacting device 1 is repeated for compaction.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art As a method for compacting uncured concrete after pouring, a bar-shaped vibrator has been generally used. This compaction method using a vibrator is a method of mechanically vibrating a rod-shaped body inserted inside from the surface of concrete at a vibration frequency of, for example, about 7,000 Hz, forcibly bleeding and promoting solidification of concrete. is there.

[0003]

However, in this vibration compaction method, the depth of the compaction effective layer is 30 to 60 cm.
If the insertion interval is not less than 60 cm, the desired effect cannot be obtained and the effective range is narrow, and compaction work can be performed efficiently on highly viscous high fluidity concrete. There wasn't.

Therefore, the present invention is to solve the above-mentioned drawbacks, and it is possible to compact uncured concrete over a wide range, and to perform compaction work effectively even on highly viscous concrete. It is an object of the present invention to provide a concrete compaction method and device capable of performing the above-mentioned concrete compaction.

Another object of the present invention is to provide a concrete compaction method and a device suitable for this compaction, which can easily express the early strength of the concrete poured simultaneously with the compaction. Is.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above-mentioned object, and it is possible to irradiate the interior or the surface of uncured concrete with microwaves to thereby obtain the freedom of inclusion in the concrete. A method for compacting concrete is characterized in that water is vibrated and heated, and the gist thereof is (claim 1).

The concrete compacting device of the present invention is a rod-shaped waveguide which can be inserted into uncured concrete and has one end connected to the microwave generator, and the other of the waveguides. And a microwave emission port provided at the end of (1) (claim 2).

Still another concrete compacting device of the present invention is mounted on a casting surface of uncured concrete.
A compaction plate provided with a plurality of microwave emission ports on the lower surface side, and a waveguide for guiding microwaves to the microwave emission port, which is erected from the compression plate and has its tip end connected to a microwave generator. And a pipe (claim 3).

[0009]

According to the above concrete compaction method, vibration energy is applied to free water in the concrete within the radiation range of microwaves to cause forced breathing, thereby performing compaction. The free water and the cement hydrate inside the concrete are simultaneously heated by the dielectric loss due to microwaves, and the hydration reaction is accelerated.

According to the concrete compacting device of claim 2, the concrete compacting device can be used in the same form as the conventional rod-shaped vibrator, and when the structure of claim 3 is adopted, concrete can be compacted over a wide range at once. You can

[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 cast uncured concrete C comprises a hollow rod-shaped main body 1a and a main body 1a. And an integrated mechanical vibration unit 1b on the upper part of the structure, and by virtue of the driving of the vibration unit 1b, the main body unit 1a is vibrated as a whole so that the main body unit 1a can be easily inserted into the concrete C. At the same time, the dimensions such as the length and the diameter are set in consideration of the handling property of workers. The vibrating portion 1b is not necessarily provided if the main body portion 1a alone can be easily inserted into the concrete C.

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

The microwave has a frequency of 900 to, for example.
It can be variably set to 2500 MHz and an output of about 100 to 30 KW, and its radiation range is set to a spread angle corresponding to the spread of the launch port 2a.

When vibration compaction is performed using the compaction device 1 as described above, an electromagnetic shield sheet 5 is laid in advance on the placing surface of the concrete C in order to prevent the influence of microwave leakage on the human body. To be done. This sheet 5 is made of a rubber sheet containing a wire mesh, etc., and also serves as a curing sheet, and a cross slit having a hole diameter through which the main body portion 1a is inserted is opened at each compaction interval. It is used as a guide for the insertion interval.

Therefore, the work of placing concrete C, inserting the compacting device 1 after laying the sheet 5 into the slit, inserting while radiating microwaves, and pulling out is repeated over the entire region where the concrete C is placed. This completes the compaction work. The microwave radiation range per operation is much wider than the diameter of the main body 1a according to the opening angle of the discharge port 2a, and accordingly, the fitting interval is larger than that of the conventional vibrator, and the compaction is sufficient. The effect can be obtained.

The radiated microwave may be reflected by the bedrock or slag E in the lower layer of the concrete C as shown by the arrow, and may penetrate through the placing surface of the concrete C again. It is desirable to decide in consideration of the reflection angle.

As shown schematically in FIG. 2, the free water w contained in the concrete C is given vibration energy by the radiation of microwaves, and sew in the concrete C while vibrating as shown by the arrow. In this way, it is forced to breathe while rising, which causes the concrete to be compactly compacted. At the same time, the free water w and the water in the cement hydrate Cw are heated by the dielectric loss and the temperature rises, which accelerates the hydration reaction and develops early strength. Even when the concrete C is a highly viscous concrete such as high-fluidity concrete, the compaction and heating effects can be obtained.

FIG. 3 shows a second embodiment of the present invention. Parts common to those of the first embodiment will be designated by common reference numerals, and different portions will be described by 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 is communicated with a plurality of microwave emission ports 2a opened on the lower surface of the tamper 10a, and the upper end thereof is connected via a high frequency insulating cable 3 to a microwave generator 4 at a remote position. ing.

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

The compaction devices 1 and 10 can further enhance the compaction effect by being used together with a conventional vibrator.

[0024]

As described in detail above, in the concrete compaction method according to the present invention, the uncured concrete is irradiated with microwaves to be contained in the concrete. Since it causes the free water to vibrate, it gives vibration energy to the free water inside the concrete within the microwave radiation range.
Compaction is performed by causing forced breathing, so compared to the conventional vibration compaction method that uses a mechanical vibrator, the compactable range per operation is expanded and efficient compaction work is performed. It can be performed.

Further, the free water and the cement hydrate inside the concrete are simultaneously heated by the loss of the dielectric 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 concrete in the cold, labor-saving curing and heat-supply curing can save labor.

According to the vibration compaction device of the second aspect of the present invention, the microwave generated by the microwave generator propagates through the inside of the rod-shaped waveguide and spreads according to the shape of the emission port. Since the microwave is radiated toward the bottom of the concrete, the compaction work can be performed by the same handling as a conventional vibrator.

When the structure of claim 3 is adopted, the concrete can be compacted over a wide range at once.

[Brief description of drawings]

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

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

FIG. 3 is an explanatory diagram showing a second embodiment of the compaction device according to the present invention and compaction work using the compaction device.

[Explanation of symbols]

 1,10 Compaction device 1a Main body 2 Waveguide 2a Microwave outlet C Concrete 4 Microwave generator 10a Tamper (rolling plate)

Claims (3)

[Claims] 1. A method for compacting concrete, characterized in that by irradiating the inside or the surface of uncured concrete with microwaves, free water contained in the concrete is vibrated and heated. 2. A rod-shaped waveguide which can be inserted into uncured concrete and has one end connected to a microwave generator, and microwave emission provided at the other end of the waveguide. A concrete compactor characterized by comprising a mouth. 3. A rolling compaction plate having a plurality of microwave emission ports on the lower surface side, which is placed on the casting surface of uncured concrete, and which is erected from the compaction rolling plate and has a tip end that generates microwaves. A compaction device for concrete, comprising: a waveguide connected to the device to guide microwaves to the microwave emission port.