JP3429576B2 - Hopper for putting concrete and method for producing concrete product using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hopper for feeding concrete and a method for producing a concrete product in which no bubble mark is formed on the surface of the product using this hopper.

[0002]

2. Description of the Related Art As shown in FIG. 2, for example, when a box culvert made of concrete is manufactured, a vibrating table 2 is used.
While applying vibration to the formwork 1 installed on the table 3 of
Concrete C is thrown into the upper part of the mold 1 from the throwing machine 17, and after vibration compaction, secondary vibration is further applied to remove voids (air bubbles) in the concrete C to improve the appearance of the product. I was doing well.

[0003]

However, in the conventional method as described above, since the flow distance of the concrete C becomes long, the separation of the coarse aggregate progresses, and the form 1 is filled while air is entrained. Therefore, especially the lower surface 1B-1 of the inner formwork 1B
Bubbles are trapped between the surface and the surface C-1 of the concrete C. As a result, there remains a problem that air bubbles remain on the inner surface of the box culvert, resulting in poor appearance and reduced commercial value.

Further, as described above, the concrete C is directly put into the mold 1 from the throwing machine 17, or is put into the mold 1 through the ordinary hopper 10A shown by the one-dot chain line in FIG. However, in the case of the former, there is a problem that concrete is scattered around and deteriorates the working environment, and in the case of the latter, the inclined side wall 10B and the inclined side wall 10B constituting the funnel portion of the hopper 10A are not provided. The connecting portion R with the vertical side wall 10C forming the continuous guide portion at the lower end is formed at the same height position, and the connecting portion R sharply narrows, so that the aggregates overlap and the concrete C goes down. In many cases, there is a case where the concrete C does not flow down, and there is also a problem that the flow rate of the concrete C is slow and inefficient.

[0005]

The present invention has been made to solve the above-mentioned conventional problems, and the gist thereof is to connect a funnel portion into which concrete is poured and a lower end of the funnel portion. In the hopper consisting of the guide part,
On a concrete loading hopper and a vibrating table, the connecting positions of the facing inclined side walls of the funnel section and the facing vertical side walls of the guide section continuous to the lower end of the funnel section are formed at different vertical positions. The hopper is lowered from above the formwork installed in, and the tip is placed near the bottom of the formwork to fill the bottom of the formwork with concrete, and then the hopper is pulled up to the vibration table. A concrete product manufacturing method is characterized by compacting and further pouring concrete into the upper portion of the mold.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in FIGS. 1 is a vertical cross-sectional view of a first step showing one embodiment of the method for producing a concrete product according to the present invention, FIG. 2 is a vertical cross-sectional view of the same second step, and FIG. 3 is a perspective view of a concrete loading hopper. Yes, FIG. 4 is a data table of concrete flow-down time based on the combination of the inclination angle and the step of the funnel of the hopper, and FIG. 5 is a graph drawn based on the data of FIG.

In the figure, reference numeral 1 designates a mold for forming a box culvert whose upper surface is open, which is an outer mold 1A and an inner mold 1B.
The mold 1 is installed on a table 3 of a vibrating table 2 having low vibration and low noise. The table 3 of the vibrating table is composed of a pair of I-shaped steel unit tables 3A and 3A.
Even though B are arranged in parallel with each other, both of the single tables 3A and 3B are provided with a pair of anti-vibration rubbers 6 on the base 5 fixed to the floor 4 at the ends in the longitudinal direction. It is fixed. The left and right unitary tables 3A and 3B are integrally connected at a central portion thereof by a pair of connecting plates 7, and one rotating vibrator 8 is installed at the center of the connecting plates 7. The rotary vibrator 8 rotates the eccentric cam 9 by an electric motor to generate vibration.

A concrete feeding hopper 10 is, as shown in FIGS. 1 and 3, a funnel portion 11 for feeding concrete and a guide portion 12 continuous to the lower end of the funnel portion 11.
It consists of and. The funnel portion 11 has a rectangular shape in a plan view, and the inclined sidewalls 13A and 13B facing each other in the direction orthogonal to the longitudinal direction are inclined so that the interval becomes gradually narrower toward the lower side. The end side walls 14A and 14B facing each other in the direction are set to be parallel to each other. In addition, the guide portion 12 has vertical sidewalls 15 facing each other.
A and 15B are formed in a rectangular cross section, and at the lower end portion of the funnel portion 11, three guide portions 12 hang down at equal intervals along the longitudinal direction thereof.

Next, a process of manufacturing the box culvert M by the method of the present invention will be described below. In addition, as shown in Table 1, the concrete C used in this example is as follows.
Use concrete with high fluidity with a slump value of about 20 cm and less separation of coarse aggregate, so-called high slump separation resistant concrete.

[0010]

[Table 1]

The concrete charging hopper 10 is erected so that it can be moved up and down. First, the concrete charging hopper 10 is lowered, and the tip opening 12A of the guide 12 is moved to the table of the vibrating table 2. It is arranged in the vicinity of the bottom of the mold 1 installed on the surface 3. If necessary, the bar vibrator 16 may be installed in the concrete charging hopper 10.

Next, when concrete C is injected from the injection machine 17 into the funnel portion 11 of the concrete injection hopper 10, the concrete C is formed from the funnel portion 11 through the guide portion 12 and the outer mold 1A and the inner mold 1B. First, it is stored at the bottom of the mold 1 to be formed. When the storage amount of the concrete C increases, the concrete C flows toward the space portion between the upper surface 1A-1 of the outer mold 1A and the lower surface 1B-1 of the inner mold 1B to completely fill the space portion. , And fill the left and right spaces from the bottom to the top gradually.

When about half the height of the left and right spaces is filled with concrete C, the concrete input hopper 10 is raised and the guide portion 12 is moved to the formwork 1.
Pull out to outside. In addition, at the time of concrete injection, it is adjusted so that the upper part of the funnel portion 11 of the concrete injection hopper 10 is always filled with concrete C so that the flow of concrete C into the mold 1 is not interrupted.

After that, when the rotary vibrator 8 is driven at a low frequency and a low frequency, the table 3 mainly performs horizontal rotary vibration to compact the concrete C in the formwork 1. Then, by the same method as the conventional method shown in FIG. 2, concrete C is injected from the injection machine 17 to the upper part of the form 1, but no secondary vibration is applied at this time.

Here, both inclined side walls 13A and 13B in the funnel portion 11 of the concrete charging hopper 10 are described.
And the height difference (step B) between the connecting positions R ₁ and R ₂ between the vertical side walls 15A and 15B in the guide portion 12 that is continuous with the funnel portion 11 is greatly related to the flowing time of the concrete C, The experimental data are shown in FIGS. 4 and 5. From this experimental data, the inclined side wall 13 in the funnel part 11
The magnitude of the inclination angle of A and 13B has little effect on the concrete flowing time (70 ° is slightly shorter than the case of 50 °), but the step B is 0 mm and 80 mm when the concrete flows down. It became clear that it had a great impact on time.

[0016]

As described above, the concrete hopper according to the present invention is a hopper comprising a funnel part for pouring concrete and a guide part connected to the lower end of the funnel part. Since the connection position between the side wall and the vertical side wall of the guide portion that is continuous with the lower end of the side wall is formed in different positions in the vertical direction, concrete flows down smoothly and quickly, significantly shortening the filling time. be able to.

Further, in the method for manufacturing a concrete product according to the present invention, as described above, the concrete feeding hopper is lowered from above the mold installed on the vibrating table, and the tip of the hopper is placed inside the mold. When the bottom of the mold is filled with concrete through the concrete charging hopper, the concrete charging hopper is pulled up and compacted with the vibration table, and the mold is further closed. Since the concrete is poured into the upper part of the concrete, the flow distance of the concrete when the concrete is poured becomes as short as possible.

Therefore, the concrete is filled into the mold without progressing the separation of the coarse aggregate and without entraining air, and large bubbles are formed especially in the lower part of the inner mold where air bubbles are easily trapped. Since it is completely filled without any bubbles, it is possible to obtain a product having a good appearance with no air bubbles on the surface of the product. Also, in this case, since it is not necessary to apply secondary vibration when using concrete with high slump separation resistance, it can be said that the work process can be omitted and the problems of noise and vibration can be solved. There are various effects.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a first step showing a method for manufacturing a concrete product according to the present invention.

FIG. 2 is a vertical sectional view of the second step.

FIG. 3 is a perspective view of a concrete input hopper.

FIG. 4 is a data table of concrete flow-down time according to a combination of a tilt angle and a step of the funnel portion of the hopper.

FIG. 5 is a graph drawn based on the data of FIG.

[Explanation of symbols]

1 Formwork 1A Outer formwork 1B Inner formwork 2 Shaking table 3 Table 8 Rotary vibrator 10 Concrete hopper 11 Funnel part 12 Guide parts 13A, 13B Inclined side walls 15A, 15B Vertical side wall 17 Inserting machine R ₁ Connecting position R ₂ Connecting position B Step B

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Claims (2)

(57) [Claims] 1. A hopper comprising a funnel portion for pouring concrete and a guide portion connected to a lower end of the funnel portion, wherein inclined sidewalls of the funnel portion and vertical sidewalls of the guide portion continuous to the lower end of the funnel portion are opposed to each other. The hopper for concrete throwing, characterized in that the connecting positions of are formed in different positions in the vertical direction. 2. A concrete loading hopper according to claim 1 is lowered from above a formwork installed on a vibrating table, and the tip of the hopper is disposed in the vicinity of the bottom part of the formwork, so that concrete is supplied to the formwork. A method for producing a concrete product, which comprises filling the bottom portion, pulling up the hopper, compacting it with the vibrating table, and further pouring concrete up to the upper portion of the mold.