JPH0584787B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a concrete manufacturing apparatus for adding a powder quick-setting agent to concrete in shotcrete.

<Prior Art> When spraying concrete onto the walls inside a tunnel, an quick-setting agent is sometimes added to harden the concrete in a short time.

By adding this quick-setting agent, it is possible to prevent concrete from sagging or peeling due to its own weight, and since it hardens early, it can quickly exert its supporting effect inside the tunnel.

There are liquid and powder forms of this quick-setting agent, but the liquid type adds more moisture to the concrete.

Accurate control of the supply amount is essential for this purpose, but the current method uses a combination of gears and supplies by applying pressure to the tank itself, making accurate control difficult.

As a result, the slump of the concrete increases before the desired rapid hardening begins, and although it is a quick setting agent to prevent sagging and peeling, it makes the concrete flow easily, resulting in peeling. .

Therefore, during construction, it is extremely important to control the amount and timing of addition of the quick-setting agent, which has a large effect on the product.

In addition, methods using powdered quick-setting agents use a combination of gears or means to apply pressure to the entire tank, which results in incomplete blockage and prevents backflow of concrete injection pressure. It is difficult to prevent it completely.

For this reason, the supply pressure of the powder quick-setting agent can only be set to a level that is the same as or slightly higher than the pressure of the conveyed concrete, making it difficult to adjust the pressure, making concrete clogging accidents more likely to occur, and mixing efficiency is poor.

<Object of the Invention> The present invention has been made to improve the above-mentioned drawbacks, and an object of the present invention is to provide a concrete manufacturing apparatus as described below.

<B> A device that can supply an accurate amount of powder quick-setting agent.<B> A device that prevents pressure from flowing back to the powder quick-setting agent side even when spraying at high pressure.<C> Accurate slump. <Structure of the present invention> An apparatus capable of spraying concrete with sufficient strength and ease of construction. Next, embodiments of the present invention will be described.

<A> Concrete pumping mechanism The method of the present invention is carried out using an apparatus as shown in FIG.

That is, in FIG. 1, 1 is a spray machine,
For example, a commercially known concrete pump or screwcrete may be used.

Concrete is pumped from this sprayer 1 through a pressure pipe 2, and is discharged from a nozzle 3 at the tip.

A jet pipe 6 is positioned near the nozzle 3 of this pressure pipe 2.

The quick-setting agent supply pipe 4 is connected to the jet pipe 6.

<B> Quick-setting agent supply mechanism The quick-setting agent supply pipe 4 is connected to an addition device 5 to be described later, and supplies high-pressure air and quick-setting agent S mixed by the addition device 5 through a jet pipe 6. Supplied to pressure pipe 2.

<C> Addition Device An embodiment of the addition device 5 and its attachment to the quick-setting agent supply pipe 4 will be described with reference to FIG. 2.

In this addition device 5, a stirring blade 52 is provided in a hopper 51 for addition which has an input port opened at the upper end and a discharge port opened at the lower end.
Configure so that it can be mixed.

In particular, a delivery screw 53 is positioned at the delivery portion of the addition hopper 51, that is, at the joint between the hopper 51 and the quick-setting agent supply pipe 4.

At this time, the inner diameter of the cylinder of this carrying-out section and the outer diameter of the blades of the carrying-out screw 53 are configured to be approximately equal.

The rapid setting agent S in the hopper 51 can be forced into the supply pipe 4 by the rotation of the delivery screw.

Further, an electromagnetic pipe 54 is provided at the joint between the hopper 51 of the addition device and the quick-setting agent supply pipe 4, and the valve 54 is configured to be able to be opened and closed by a signal to be described later in the event of a blockage accident or the like.

<D> Quick-setting agent supply pipe The following device is provided at the connection between the quick-setting agent supply pipe 4 and the addition hopper 51.

That is, on the upstream side there is a check valve 55 and a dehumidifier 5.
6 is provided, and a spiral stirring blade 57 is provided downstream thereof.

<E> Signal system Each of the above devices is connected by a signal system.

That is, the control panel 7 is configured so that the following signals are input.

1 Concrete flow rate 2 Operation signal of the check valve 55 3 Operation signal of the spraying machine 4 Storage amount in the hopper 51 And by inputting each signal to the corresponding device, mutually linked operation is possible.

<Operation of the present invention> Next, the operation of the device of the present invention will be explained.

<A> Mixing and discharging the quick-setting agent S The quick-setting agent S is put into the hopper 51 for mixing the quick-setting agent and mixed by the stirring blade 52.

When the electromagnetic valve 54 is open, the quick-setting agent S thus mixed is forced into the quick-setting agent supply pipe 4 by the delivery screw 53.

Compressed air is supplied to the quick-setting agent supply pipe 4 from a compressor 8 provided upstream thereof, but the discharge path of the hopper 51 is blocked by a discharge screw 53.

Therefore, regardless of the magnitude of the pressure upstream of the hopper 51, the quick setting agent S is forced into the compressed air.

In this case, depending on the pitch and rotational speed of the delivery screw 53, it is possible to supply an accurate amount of the powder quick setting agent S to the pipe 4 while making delicate adjustments.

Moreover, the unloading path of the hopper 51 is the unloading screw 5.
Since the outer diameter is approximately equal to the outer diameter of No. 3, the discharge path is completely blocked by the powder quick-setting agent S filled inside, and the pressure on the nozzle side does not flow back.

The powder quick-setting agent S thus extruded is fed to the stirring blade 57 of the stirring section inside the quick-setting agent supply pipe 4.
It moves inside the pipe 4 while being stirred by the.

<B> Pressure feeding of concrete The concrete sent out by the sprayer 1 passes through the pressure pipe 2 and reaches the jet pipe 6.

<C> Mixing of concrete The quick-setting agent S sufficiently mixed as described above is
It is combined with the pumped concrete in the jet pipe 6 and mixed.

Then, the spraying work can be performed by ejecting it to the outside from the nozzle 3 at the tip.

<Effects of the Present Invention> Since the present invention is as described above, the following effects can be expected.

<B> There is almost no change in slump.

Since it is a method of supplying a powder quick-setting agent, it has almost no effect on changes in the concrete mix compared to a method of supplying a liquid quick-setting agent.

Therefore, the slump does not change during spraying, and concrete can be sprayed as designed.

<B> Accurate composition adjustment is possible.

A screw is used in the part that pushes the powder quick-setting agent out of the hopper.

This has made it possible to supply a precise amount of powder quick-setting agent with delicate adjustments, making it possible to spray concrete with guaranteed quality.

<C> Prevention of backflow.

By configuring the supply part of the powder quick-setting agent with a screw, it has become possible to always maintain a closed state.

Therefore, there is no need to worry about pressure backflow, so the supply pressure of the powder quick setting agent can be set independently of the discharge pressure from the nozzle, and mixing can always be carried out in the best condition.

<d> The quick-setting agent is not directly mixed into the concrete, but is first supplied into a compressed air path using a screw, and then transported to the concrete via the compressed air path.

In this way, when supplying powder to the air passage,
Since there is no resistance, any amount can be delivered accurately at any speed.

<E> It is characterized by using compressed air to transport the powder quick-setting agent to the concrete.

Therefore, there is almost no resistance during transfer, and any amount can be transferred at any speed.

[Brief explanation of the drawing]

FIG. 1: An explanatory diagram of one embodiment of the concrete manufacturing apparatus of the present invention, FIG. 2: An explanatory diagram of an addition device used in the apparatus.

Claims (1)

[Scope of Claims] 1. In a concrete manufacturing apparatus that adds a powder quick-setting agent to concrete that has not yet hardened, the powder quick-setting agent is pushed out through a screw into a compressed air path and transported by compressed air, This shotcrete manufacturing equipment is configured to mix this powdered quick-setting agent into pumped concrete.