JPH06212797A - Mixing device for additive to forced feed concrete - Google Patents

Abstract

PURPOSE:To enable an additive to be evenly mixed with concrete supplied under pressure through a forced concrete feed tube. CONSTITUTION:An injection nozzle 6 for feeding an additive joins a forced feed tube 3 at a position relatively near the delivery outlet 3a thereof, and an agitation mixing device 10 is coaxially laid with the tube 3 at the downstream side of the nozzle 6. The device 10 is equipped with a rotational tube 11 laid coaxially with the tube 3 and rotatably supported thereon via a bearing, and a drive motor 12 for causing the tube 11 to rotate. In addition, the tube 11 is internally provided with four agitation rods 20 respectively arranged radially and dephased at 90 degrees.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for mixing additive material to a concrete for pressure addition for mixing an additive material such as an admixture to the concrete to be pressure-fed by a concrete pressure-feed pipe.

[0002]

2. Description of the Related Art For example, in a mountain tunnel or the like, when concrete or the like is placed or sprayed in order to form a lining body of concrete or mortar, the strength of the concrete or the like is cured early. In order to develop the above, an admixture such as a quick-setting admixture or a liquid or powder-like fast-strength additive such as a quick-hardening material is added.

At this time, it is necessary to uniformly mix the additive with concrete or the like in order to efficiently bring out the effect thereof. Then, when performing the spraying work, concrete or the like is jetted to a required location by compressed air and collides with the sprayed surface. When mixed appropriately, the desired effect of the additive can be efficiently exhibited.

[0004]

However, for example, in the so-called first receiving method or the like, concrete is fed from a concrete pump using a concrete pumping pipe into the excavation groove, as if a lining body was constructed in advance in front of the face. In the case of placing concrete to be poured, it is necessary to inject and mix the additive material in the middle of the concrete pumping pipe, but in the method of mixing by injecting such additive material, the injected additive is injected at the injection point. The additive is uniformly mixed in the concrete because it is pumped as it is, or it wraps around the sliding surface between the inner wall of the pipe and the concrete to be flown into a place with a large amount of mortar and less resistance. There was a problem that it was difficult.

Further, in order to sufficiently mix, a method of adding the additive at an early stage, stirring and mixing, and then feeding under pressure can be considered. However, for example, when an early-strength additive is used as the additive, a pipe is used. If the path is long, concrete will harden in the pumping pipe, and transportation will be impossible.

The present invention has been made to solve the above problems. The additive material is easily dispersed and mixed in the concrete to be pumped by the concrete pumping tube, and the additive material is uniformly mixed in the middle of the pipeline. It is an object of the present invention to provide an apparatus for mixing additive materials into pumped concrete, which enables easy production of improved concrete.

[0007]

In order to achieve the above-mentioned object, a mixing device for additive material to pressure-fed concrete according to the present invention has one end joined in the middle of a concrete pressure-feed pipe connected to a concrete pressure-feed pump. A pouring nozzle for supplying the additive, a rotary pipe downstream of the pouring nozzle, coaxially and rotatably connected to the concrete pumping pipe, and having a rod projecting on the inner circumference, and the rotary pipe. And a rotation drive means for rotating the.

Here, the concrete is cement,
This is a general term for materials that are mainly composed of water and aggregates and that are hardened by the hydration reaction of cement and water, and also include materials such as mortar.

[0009]

According to the mixing apparatus having the above structure, the concrete in which the additive is injected from the injection nozzle in the pressure feed pipe moves to the downstream side in the pressure feed direction and passes through the rotary pipe. Then, the concrete passing through the inside of the rotary pipe is agitated by the rod projecting on the inner circumference of the rotary pipe,
The rotation of the rotary tube receives a rotational shearing force in a direction perpendicular to the pumping direction to promote mixing with the additive.
Therefore, concrete in which the additive is uniformly mixed is easily formed by these actions.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows the entire configuration of the present invention when applied to a concrete pressure-feeding plant used when constructing a tunnel lining body by a pre-receiving method. One end is connected to a concrete supply tank 1 and a concrete pressure-feeding pump 2. The discharge port 3a of the concrete feed pipe 3 is
The outer periphery of the face 4 is inserted into an excavation groove 4a excavated along the cross-sectional shape of the tunnel, and concrete 5 is supplied and placed in the excavation groove 4a.

An injection nozzle 6 for adding an additive such as an early-strength admixture merges with the pressure-feeding pipe 3 relatively near the discharge port 3a side and communicates with the inside of the pressure-feeding pipe 3. There is. The injection nozzle 6 is connected to a fast-strength admixture supply tank 8 and a metering pump 9 through a hose 7, and supplies the admixture in an amount corresponding to the amount of concrete transported through the pressure feed pipe 3 into the pressure feed pipe 3.

At the tip of the injection nozzle 6, that is, on the downstream side,
In the middle of the pressure feeding pipe 3, a stirring and mixing device 10 that constitutes the mixing device 50 together with the injection nozzle 6 is arranged coaxially with the pressure feeding pipe 3.

The stirring / mixing device 10 is provided with a rotary pipe 11 coaxial with the pressure feed pipe 3 and rotatably supported by the pressure feed pipe 3, and a drive motor 12 for rotating the rotary pipe 11. Further, as shown in more detail in FIG. 2, both ends of the rotary pipe 11 are rotatably connected to the connecting ends of the pressure feed pipe 3 via watertight rotary joint portions 14. Further, a pedestal 17 is provided at one end of the rotation stopping fixed bracket 16 of the pressure feed pipe 3, and the drive motor 12 is mounted on the pedestal 17.
Is fixed.

The drive motor 12 is connected to a gear 18, which is flange-connected on the rotation side of the rotary joint portion 14, to the pinion 1.
9, and the rotary tube 11 is rotationally driven according to the rotation direction of the drive motor 12.

Inside the rotary tube 11, as shown in FIG. 3, four stirring rods 20 are respectively arranged at intervals in the axial direction of the tube and are shifted in phase by 90 ° in the circumferential direction toward the center. It is projected.

The stirring rods 20 rotate with the rotation of the rotary pipe 11 to stir the concrete fed through the pressure feed pipe 3, and the pressure feed pipe 3 through the injection nozzle 6.
The rapid-strength admixture, which has been quantitatively injected, is uniformly mixed and dispersed inside the concrete by this stirring action. Further, the rotary tube 11 gives a large rotational shearing force to the concrete passing through the inside of the rotary tube 11 at the rotary connection portion along the plane perpendicular to the pumping direction by the rotary drive,
This further enhances the stirring effect. Then, the concrete that has passed through the rotary pipe 11 is in a state where the early-strength admixture is uniformly dispersed, and in this state, the concrete is filled and placed in the excavation groove 3a. As a result, the filled pouring concrete 5 is rapidly hardened by the action of the early-strength admixture, and the strength can be exhibited early.

Here, the rotation speed of the rotary tube 11 is preferably about 80 to 160 rotations per minute. 8
At 0 revolutions or less, the stirring efficiency is poor and the stirring effect is reduced,
Even if the number of rotations exceeding 160 is given, the stirring effect is not extended, and the apparatus is unnecessarily increased in size.

Further, the projecting length of the stirring rod 20 projecting inside the rotary tube 11 is ⅓ of the tube diameter of the rotary tube 11.
It is preferably 1/2. When the protruding length is shorter than 1/3 of the pipe diameter, the stirring efficiency is poor and a portion where the additive is not mixed is generated in the central portion of the concrete flow. Concrete tends to become blocked.

Next, in order to confirm the mixing effect in the above apparatus, the relationship between the rotation speed of the rotary tube 11 and the mixing effect and the relationship between the protruding amount of the stirring rod 20 and the mixing effect were investigated. The following results were obtained.

Relationship between the number of revolutions and the mixing effect: The squeeze type pump was used as the concrete pump with the pumping pipe 3 and the rotating pipe 11 having a diameter of 100 mm and the stirring rod 20.
The amount of protrusion is fixed to 1/4 (25 mm) of the diameter of the rotary tube 11 and the number of rotations is 40, 80, 120, 160, respectively.
200 (revolutions / minute), samples obtained at each number of revolutions were sampled in a mold for compressive strength test, demolded after 5 minutes, and then visually observed and the curing state was investigated. The results shown in Table 1 were obtained. Was obtained.

The examination of the curing state was carried out by a wash-out test with tap water, and it was determined that the early-strength admixture was not sufficiently mixed in the washed-out portion.

[0022]

[Table 1] From Table 1, it was confirmed that the stirring effect is high when the number of rotations is about 80 to 160 rotations, the stirring effect decreases when the rotation speed is 80 rotations or less, and the effect does not extend even when the rotation speed exceeds 160 rotations.

Relationship between the amount of protrusion of the stirring rod 20 and the mixing effect: From the result of the above, the rotation speed is fixed to the optimum number, and the stirring rod 2
When the same amount of inspection was conducted by changing the protruding amount of 0 to 1/3, 1/2, 3/4 of the tube diameter, the results shown in Table 2 were obtained.

[0024]

[Table 2] From Table 2, the amount of protrusion of the stirring rod 20 is 1/3 to 1 of the pipe diameter.
It was confirmed that / 2 had a good stirring efficiency, and that when it exceeded 1/2, the concrete was clogged inside the pressure feed pipe.

That is, in order to obtain a sufficient mixing effect in the above apparatus, the rotation speed of the rotary tube 11 is 80 to 160 rotations per minute, and the protruding amount of the stirring rod 20 is set to the rotary tube 1.
It is desirable that the diameter is 1/3 to 1/2 of the diameter of the pipe 1.

[0026]

As described above in detail with reference to the embodiments, according to the mixing apparatus for the additive material to the concrete for pumping according to the present invention, it is provided on the inner circumference of the concrete pumping pipe so as to be coaxially and rotatably connected thereto. Since the rotating pipe having a rod for rotating and the rotating drive means for rotating the rotating pipe are provided, the concrete passing through the rotating pipe is agitated by the rod, and the rotating shear rotates in a direction perpendicular to the concrete pumping direction. By generating force and promoting mixing with the additive by these, concrete in which the additive is uniformly mixed can be easily obtained.

[Brief description of drawings]

FIG. 1 is an overall explanatory view showing an embodiment to which a mixing device of the present invention is applied.

FIG. 2 is a cross-sectional view of essential parts of a stirring and mixing device in the same pressure-feeding pipe.

3 is a cross-sectional view taken along the line AA of FIG.

[Explanation of symbols]

2 Concrete pressure feed pump 3 Concrete pressure feed pipe 6 Admixture injection nozzle 10 Stirring mixer 11 Rotating pipe 12 Drive motor 18,19 Power transmission mechanism (18 gear, 19 pinion) 20 Stirring rod 50 Mixing device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (71) Applicant 000219875 Tokyu Corporation 1-16-14 Shibuya, Shibuya-ku, Tokyo (71) Applicant 000231198 Japan Land Development Co., Ltd. 4-9-9 Akasaka, Minato-ku, Tokyo (71) Applicant 000140982 2-5-8 Kitaoaoyama, Minato-ku, Tokyo (71) Applicant 000005924 Mitsui Miike Manufacturing Co., Ltd. 2-1-1 Nihombashi Muromachi, Chuo-ku, Tokyo (71) Applicant 000003296 Electric Chemical Industry Co., Ltd. 1-4-1 Yurakucho, Chiyoda-ku, Tokyo (72) Inventor Koji Adachi 284-2 Obuchi, Fuji City, Shizuoka Prefecture Japan Construction Mechanization Association Construction Mechanization Research Institute (72) Inventor Hiroyuki Matsushima Tokyo Metropolitan Government 2-3, Kandajimachi, Chiyoda-ku Stock company Obayashi Corporation Tokyo head office (72) Inventor Hideki Takeuchi Koraku 2-, Bunkyo-ku, Tokyo -8 In Goyo Construction Co., Ltd. (72) Inventor Reie Iwasaki 1-19-40 Edakita, Midori-ku, Yokohama-shi, Kanagawa Prefecture (72) Inventor Fumio Kamoshida 4-9-9 Akasaka, Minato-ku, Tokyo Japan Land Development Co., Ltd. (72) Inventor Hiroshi Taniguchi 2-5-8 Kita-Aoyama, Minato-ku, Tokyo In-house Co., Ltd. (72) Inventor Jun Tsurumoto 2-1-1 Nihonbashi Muromachi, Chuo-ku, Tokyo Mitsui Miike Manufacturing Co., Ltd. (72) Inventor Tetsuo Otsuka 2209 Ome, Ome-cho, Nishikubiki-gun, Niigata Prefecture Ome Plant of Denki Kagaku Kogyo Co., Ltd.

Claims (1)

[Claims] 1. A pouring nozzle that joins a pipeline of a concrete pumping pipe connected at one end to a concrete pumping pipe to supply an additive material, and a downstream side of the pouring nozzle, which is coaxial with the concrete pumping pipe. And a rotatably connected rotary tube having a rod projecting from the inner circumference, and a rotary drive means for rotating the rotary tube. .