JPH084296A - Method for inoporating high-early-strength additive in placing concrete, etc. - Google Patents

Abstract

PURPOSE:To uniform the mixing by force-feeding a concrete to which high-early- strength additive is injected and added into a force feed pipe, rotating it with the shaft center as the central axis, and sufficiently stirring the high-early- strength additive with concrete. CONSTITUTION:A force feed pipe 2 is connected to a concrete pump 1 to form a device for supplying placing concrete 5 to a required placing position 4 from the discharge port 2a of the force feed pipe 2 through a from 3. An early- strength additive adding nozzle 6 is provided on the force feed pipe 2, an early- strength additive is injected and added to concrete through the nozzle 6, and the resulting concrete is force-fed along the shaft center (a) of a fixed straight pipe part 1b. Further, the concrete carried to the shaft center (a) of the force feed pipe 2 changes the direction toward the side part 10f of an interposed straight pipe 10 to change the course to a circular part 10a, and reversed and sheared in the rotation boundary position. Thus, the early-strength additive can be included into the concrete by sufficient stirring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to the rapid solidification (solidification) of the cast concrete or the like when performing a primary lining work (preceding receiving method, etc.) with concrete or mortar in tunnels and other construction work. ), The present invention relates to a suitable mixing method for providing the concrete with the early-strength admixture so as to be as uniform as possible.

[0002]

2. Description of the Related Art As is well known, when placing concrete or mortar or spraying it, a fast-setting admixture containing a quick-setting agent, a quick-hardening agent, and a hardening rate modifier to the quick-hardening agent is added to the concrete. In this case, in the case of the latter spraying work, the concrete will be sprayed to the required place by compressed air. When sprayed, it mixes well with concrete, etc., and exerts the desired effect as a fast-acting admixture.

However, in the former case of concrete placing work in which concrete is transferred to a required place by a concrete pump by a concrete pump and is supplied by outflow, powder or Since it is only necessary to inject and add the liquid early-strength admixture, it is difficult to mix the early-strength admixture uniformly with concrete, etc. It is also known to add them, but in this case, there arises a problem that hardening of concrete or the like develops in the pressure feeding pipe.

Therefore, although a method of mixing after using the above-mentioned fast-acting admixture and mixing with a stirring blade is also adopted, the stirring blade must be made large in order to obtain a sufficient stirring effect. In this case, however, a problem such as concrete clogging in the pressure feed pipe occurs, and it is not possible to achieve a satisfactory uniform mixed state.

For this reason, a liquid quick-setting agent or the like is further injected into the concrete in the pipe from a nozzle provided on the peripheral wall of the pressure-feeding pipe by a high-pressure pump, or the quick-setting agent or the like is supplied at a low pressure, The present applicant has already proposed a method of accelerating this with a separately attached high-pressure water jet to inject it into concrete or the like in a pipe from the same nozzle as before.

[0006]

According to the above-mentioned method, although the quick-setting admixture can be injected into concrete or the like which is pumped in the pressure-feeding pipe by the pump, the injected quick-setting admixture is not However, not only many things will be squeezed into the pouring place while being pumped as it is, or will wrap around into the part of the sliding surface between the inner wall of the pipe and the concrete that is mortar and has a lot of moisture and weak resistance. ,
In the end, in order to sufficiently mix it, it is necessary to increase the amount of the quick-setting agent or the like added, and as a result, problems such as an increase in cost arise.

In view of the above-mentioned problems of the prior art, the present invention continuously shears and thread-cuts in a pressure-feeding pipe in a state where the concrete or the like to which a fast-setting admixture such as a quick-setting admixture is added is pumped. By so doing, the purpose is to ensure that the early-strength admixture and concrete or the like are sufficiently agitated, and thereby obtain a desired mixed state.

[0008]

Means for Solving the Problems In order to achieve the above object, the present invention provides a concrete or the like in which a fast-acting admixture is injected and added in a pressure-feeding pipe such as concrete, in the middle of the pressure-feeding pipe. A deformed portion, which is arranged so as to be rotatable about the axis as a central axis through a rotation boundary portion and has a flat cross-sectional area which is substantially equal to the pressure feeding path, is provided near the pressure feeding pipe. By rotating in a straight tube that is installed, the concrete and the early-strength admixture are inverted and agitated by shearing continuously in a threaded state in the vicinity of the downstream side of the rotation boundary point by rotating. The present invention is intended to provide a method for mixing an early-strength admixture into a poured concrete or the like, which is characterized by the above.

[0009]

[Function] Concrete, etc., in which a quick-setting admixture such as a quick-setting admixture for accelerating the setting and hardening in the pumping pipe is added, is pumped along the axial center of the pumping pipe. , Is rotatable about the above-mentioned center axis and is fed under pressure into an interposed straight pipe formed in a deformed shape such as a flattened shape having a cross-sectional area approximately equal to that of the pressure feed pipe.

By the pressure feeding from the pressure feeding pipe to the inside of the interposed straight pipe as described above, the concrete or the like is rotated at the rotation boundary between the fixed feeding pipe and the rotating straight pipe by rotating the deformed portion. In the vicinity of the downstream side, the shearing force is continuously applied, and in reality, the concrete or the like is moved by the pressure feeding, so that the state of spiral inversion and shearing occurs. Since the spiral reversal and shearing are determined by the ratio of the pumping speed of concrete or the like and the rotating speed of the interposed straight pipe, the lead angle of the spiral can be brought close to the effective mixing angle in advance. desirable.

When the bonded state of concrete or the like is disturbed by the shearing of concrete or the like as described above, the ground portion of the concrete or the like becomes a considerably large scale, and this turbulence has a high strength. In addition to effectively mixing the admixture with concrete, the admixture is also promoted in the form of being peeled off by the pumping movement of the concrete, which promotes the mixing of the fast-setting admixture into the concrete. It becomes a mixed state in which it is uniformly dispersed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for carrying out the method according to the present invention will be described below with reference to the case where the apparatus for pouring concrete shown in FIG. 1 is used. In the figure, 1 is a pump for concrete and 2 is a pump for concrete. Shows a pressure feed pipe of concrete or the like that is connected to the casting pipe 2. The casting concrete 5 is supplied from the discharge port 2a of the pressure feed pipe 2 through the form 3 to the required placement place 4.

The pressure-feeding pipe 2 is provided with a fast-strength admixture addition nozzle 6 relatively close to the discharge port 2a side. A metering pump 9 for pressure-feeding a fast-setting admixture such as a quick-setting admixture through a drug supply hose 8 is connected.

Then, the above-mentioned early-strength admixture additive nozzle 6
On the downstream side of the pressure feed pipe 2, between the fixed straight pipe portions 2b and 2c of the pressure feed pipe 2, it is rotatable about the axis a of the fast-acting admixture additive nozzle 6 as the central axis b, and Two
With a cross-sectional area substantially the same as that of FIG. 1B, it is deformed into an elliptical cross-section or the like so as to have a flat shape as illustrated in FIG. 1B, and thereby the interposed straight pipe 10 having the deformed portion 10a is interposed. Has been done. That is, the deformed end portions 10b and 10c of the deformed portion 10a are formed in the vicinity of the rotation boundary portion R where the pressure feeding pipe 2 and the interposed straight pipe 10 are continuously provided, and thus the deformed end portions 10b and 10c of FIG. As shown in (B), the interposed straight pipe 1
The upper and lower arc-shaped portions 10e of the cylindrical base portion 10d of 0 are thinned toward the upper and lower side portions 10f of the interposed straight pipe 10, and the left and right arc-shaped portions 10g of the cylindrical base portion 10d are the interposed straight pipes 10d.
The deformed end portions 10b are set by increasing the diameter toward the arc-shaped portions 10h on the left and right sides of.

Further, in the apparatus shown in FIG. 1, both fixed straight pipe portions 2b and 2c have the frame 1 on the same axis a, as the main portion is clearly shown in FIG.
1, fixed rotary pipe members 2 and 12 fixed to both ends of the interposed straight pipe 10 are liquid-tightly sealed at respective opposite ends of the fixed straight pipe portions 2b and 2c through seals 13 and 13. It is fitted so that it can rotate freely.

The flange portions 14, 14 fixed to the outer periphery of the fixed straight pipe portions 2b, 2c near the ends thereof are
The rotary shaft bearing members 12, 12 are rotatably fitted with a bearing 15 interposed therebetween, and the fixed straight pipe portions 2b, 2c are fixed to the outer surface of the flange portion 14 via a seal 16.
Rotating members 17, 17 which are externally mounted so as to be freely rotatable, and the rotating shaft bearing members 12, 12 are fixed by bolts 18 ... As a result, the fixed straight pipe portion 2
b, 2c, the interposed straight pipe 10, the rotary shaft bearing member 1
2, 12 and the rotating members 17, 17 can rotate together.

Further, among the rotating members 17, 17,
On one of them, a gear 19 is provided, which has a drive gear 20b fixed to a motor shaft 20a of a motor 20 as a drive source.
By interlocking with each other, the interposed straight pipe 10 is rotated by the motor 20 with the same axis as the pressure feed pipe 2.

In the case of the above apparatus, the fast-setting admixture such as a quick-setting admixture is added from the fast-setting admixture additive nozzle 6 to the concrete for pouring at this time in the fixed straight pipe portion 2b of the pressure feeding pipe 2. The concrete in which the agent is injected and added, and the early-hardening admixture is injected and added, after being pumped along the axis a of the fixed straight tube portion 2b, enters the interposing straight tube 10 at the above-mentioned axis. It is sent eccentrically from the heart a.

That is, the above-mentioned straight pipe 10 is used for the gear 1
While being rotated by the motor 20 via 9,
Since the fixed straight pipe portions 2b, 2c are rotated about the axis a of the fixed straight pipe portions 2b, 2c, in the case illustrated in FIG. 1B, the concrete flowing along the axis a of the pressure feed pipe 2 is used. Is deflected toward the side portion 10f of the interposed straight pipe 10 and its course is changed toward the arcuate portion 10h. As a result, the fixed straight pipe portions 2b and 2c and the interposed straight pipe 10 are separated from each other. The concrete is sheared in the vicinity of the downstream side of the rotation boundary point R.

In reality, since the concrete is moved by pressure feeding, it is spirally inverted at the rotating boundary point R and continuously sheared (threaded), and is compacted by pressure feeding. Moreover, the concrete is disturbed, and this disturbance promotes the mixing of the concrete and the quick-setting admixture.

[0021]

EFFECTS OF THE INVENTION The present invention can be carried out as described above. Therefore, a concrete having a fast-strength admixture injected and added into a pressure-feeding pipe and pressure-fed along the axial center of the pressure-feeding pipe. The mortar and the mortar eccentrically detour from the axis of the rotary straight line downstream of the rotary boundary, and in this state the straight pipe rotates around the axial center of the pressure-feeding pipe. The concrete and the like are sheared after the rotating boundary point between the mounting pipe and the pressure-feeding pipe, and the concrete and the like are pressure-fed in a spiral reversal, in a shearing state, and by this being continuously performed, The concrete, etc. that has been pumped is disturbed, and this effectively acts on the mixing, so that the concrete, the quick-setting agent, the quick-hardening agent, and the quick-strength admixture obtained by adding the hardening rate modifier to the quick-hardening agent. Be satisfied One mixing is carried out promptly in pumping process such as concrete.

[Brief description of drawings]

FIG. 1 (A) is a use state explanatory view showing one device for pouring concrete which can be used for carrying out the method for mixing a fast-strength admixture with pouring concrete according to the present invention,
(B) is a vertical cross-sectional side view taken along the line BB of (A).

FIG. 2 is an enlarged side view of a main part of the apparatus shown in FIG.

[Explanation of symbols]

 2 Pressure feed pipe 10 Straight pipe 10a Deformed portion a Shaft center b Center axis R Rotation boundary point

Claims (1)

[Claims] 1. A concrete or the like in which a fast-acting admixture is injected and added in a pressure-feeding pipe of concrete or the like is located midway in the pressure-feeding pipe and is rotatable about its axis as a central axis through a rotation boundary portion. The deformed portion which is arranged in such a manner as to be flat and has a cross-sectional area substantially equal to that of the pressure feeding path is rotated in the straight pipe directly adjacent to the pressure feeding pipe, In the vicinity of the downstream side of the rotating boundary, continuous shearing is performed in a threaded state to invert and stir the concrete and the early-strength admixture. Method of mixing strong admixture.