JP2000225612A - Compounding method of fine aggregate and kneading water and continuous kneading method of concrete - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the compounding ratio between aggregate and water constant and realize a continuous kneading, in which the variation in quality is small by a method wherein the fine aggregate and the kneading water are put in a container so as to compact the fine aggregate by giving vibration or the like to the container in order to finally take out a compacted mixture from the bottom of the container. SOLUTION: A controlling part 7 controls water quantities and the openings of gates 9 so as to make the mixing ratio of fine aggregate and water equal to the predetermined volume ratio and, at the same time, drives a vibrator 8 in order to vibrate a mixing hopper 1 so as to vibratingly compact the fine aggregate. By opening the gates 9, a fine aggregate- water mixture having a certain compounding ratio is fed in a screw mixer 6. At the same time, the balance water, a cement and coarse aggregate are successively fed by a constant quantity. By rotatingly driving the mixer 6, a concrete is continuously kneaded at the constant ratio and successively delivered through a discharging port to a belt conveyor 19. Thus, the compounding ratio of the fine aggregate and the kneading water can be made constant. By continuously kneading the balance water, the cement and the coarse aggregate with the metered above mixture in accordance with the compounding planning, a concrete, the variation in quality of which is small, is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compounding method in which the mixing ratio of fine aggregate and kneading water can be kept constant, and that concrete can be continuously kneaded by using this mixing ratio. It relates to a continuous kneading method.

[0002]

2. Description of the Related Art As a method for producing concrete, there are a kneading method using a batch mixer and a continuous mixer. Of these, the batch type can be manufactured at a relatively accurate mixing ratio with respect to the concrete mixing design, but the batch type is unsuitable when it is necessary to continuously supply concrete at the casting site. On the other hand, the continuous type is suitable for continuous supply at the casting site, but it is said that quality fluctuation is large.

[0003] The reason for this is that, in the case of a batch type, each of materials such as water, cement, fine aggregate, coarse aggregate and the like is measured and charged into a mixer, whereas a continuous mixer uses a belt for continuous supply. This is because the supply amount of each material is adjusted according to the traveling speed of the conveyor, and the fluctuation width thereof is large.

[0004] In any of the methods, the surface water amount of the fine aggregate has been a bottleneck in accurately measuring the water amount. That is, the aggregate contains water, and water other than the amount of water absorbed in the aggregate is referred to as the surface water amount. Coarse aggregates have low water retention, so the surface water content is almost no problem,
In the case of fine aggregate, since the particle size is small, the amount of surface water has a large effect on the water-cement ratio, and as a result, the concrete strength.

[0005]

In order to solve the above problems, in a continuous mixer system, the surface water content of fine aggregate is measured in advance, and the supply amount of fine aggregate containing surface water per hour is calibrated. Then, water, cement, and coarse aggregate are also supplied in a similar manner, and the supply amount per hour is determined, and the feed rate from each belt conveyor and the supply speed from the nozzle are adjusted in accordance with the mixing plan.

However, in practice, the surface water amount of fine aggregate varies greatly from lot to lot depending on the place where fine aggregate is deposited, the presence or absence of rain, and the like. For this reason, even if the surface water content is measured in advance, it is not always specified by the measured value, and this is a major factor of the fluctuation of the water-cement ratio.

When the fine aggregate is packed in a container in a saturated water state, the container is in a water-tight state at the bottom of the container, and the mixing ratio of water to the fine aggregate in the surface dry state is almost constant at all times. I found it to be.

[0008] The present invention has been made based on the above viewpoints, and an object of the present invention is to make the mixing ratio of fine aggregate and mixing water constant based on the above principle. It is intended to provide a blending method.

[0009] Another object of the present invention is to continuously mix and knead residual water, cement and coarse aggregate with the fine aggregate-water mixture measured by the above blending method in accordance with the blending plan. It is intended to provide a method for continuously kneading concrete with less amount.

[0010]

Means for Solving the Problems To achieve the above objects, the method of the present invention for mixing fine water with kneading water is provided by mixing the fine kneading water with kneading water into a container and vibrating the container. The method is characterized in that the fine aggregate is compacted by a method such as above, and a mixture of the compacted fine aggregate and water is taken out from the bottom of the container. According to the above method, the fine aggregate is water-tight at the bottom of the container, and the mixing ratio of the fine aggregate-water mixture becomes constant regardless of the storage condition of the fine aggregate, so that accurate measurement can be performed. .

In the present invention, the mixing ratio of the fine aggregate to be mixed and the mixing water is 80 to 50% by volume of the fine aggregate.
When the amount of water is 20 to 50% by volume, the mixing ratio of the fine aggregate-water mixture can be accurately and constant.

Further, in the continuous kneading method of the present invention, water is mixed with the fine aggregate in a predetermined mixing ratio into the container, the container is compacted by a method such as vibration, and the container is compacted from the bottom of the container. The hardened fine aggregate-water mixture is drawn out into the screw mixer at a constant speed, and then the remaining water, cement and coarse aggregate are mixed into the screw mixer while being sequentially added at a mixing ratio according to a predetermined mixing design. Features. Therefore,
According to the above-described kneading method, since the mixing ratio of the supplied fine aggregate-water mixture is constant, the variation factor is extremely small, and concrete of constant quality can be continuously produced.

[0013]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows a concrete continuous kneading plant to which the method of the present invention is applied. In the figure, this plant comprises a fine aggregate-water mixing hopper 1, a fine aggregate storage hopper 2, a water tank 3, a cement hopper 4, a coarse aggregate hopper 5, each hopper 2, 4, 5, and a lower part of the water tank 3. It is roughly composed of a screw mixer 6 which is obliquely raised so that the downstream side is at an upper position, and a control unit 7 which is connected to each of these facilities and controls them collectively.

The lower outlet of the mixing hopper 1 is provided with a mixer 6
And a vibrator 8 for compaction is provided on the side thereof, and a gate 9 for discharge adjustment is provided at the discharge port, all of which are driven and opened and closed by the control of the control unit 7. Control is exercised.

The fine aggregate storage hopper 2 is located above the mixing hopper 1, and has a gate 9 for discharge adjustment at the lower end discharge port, and a load sensor 10 on the upper side surface. These are all connected to the control unit 7. The control unit 7 adjusts the gate 9 based on the detection value of the load sensor 10 and performs control so that a fixed amount of fine aggregate is put into the mixing hopper 1.

The water tank 3 has two pipes for supplying water into the mixing hopper 1 and also supplying water into the mixer 6, and is connected to a control unit 7 for each of the pipe systems. A flow sensor 11 and a flow control valve 12 are provided.

The discharge ports of the cement hopper 4 and the coarse aggregate hopper 5 are respectively connected to the mixer 6, and similarly to the above, discharge control gates 14 and 15 respectively connected to the control unit 7, and a load sensor. 16 and 17 are provided.

The screw mixer 6 is rotationally driven by a motor 18 driven and controlled by the control unit 7 to knead the materials supplied therein and to continuously mix the concrete through a discharge port provided at the upper portion thereof. The composition is discharged, and the discharged material is successively conveyed through a plurality of belt conveyors 19 to a casting site.

In the above, the control unit 7 determines that the mixing ratio of fine aggregate and water to the mixing hopper 1 is 80:20 to 50:
The amount of water and the opening of the gate 9 are adjusted so as to be 50 (volume ratio), and at the same time, the vibrator 8 is driven to vibrate the mixing hopper 1 to vibrate and compact the fine aggregate.

Then, the gate 9 is opened and the fixed ratio of fine aggregate-water mixture is sequentially supplied into the mixer 6 while the remaining water, cement and coarse aggregate are sequentially mixed according to the mixing plan. The concrete is kneaded at a constant rate by supplying the fixed amount at a constant rate and rotating the mixer 6, and the belt conveyer 19 is discharged through the discharge port.
Will be delivered sequentially.

In the above embodiment, the method for mixing fine aggregate and water of the present invention is applied to a method for continuously kneading concrete. This is because it is suitable for sequentially taking out the compacted aggregate from the bottom of the hopper. However,
Even in a production method using a batch plant, there is a variation due to the amount of surface water of fine aggregate, so the method of the present invention can be applied to production using a batch plant.

[0023]

As is apparent from the above description, in the present invention, the mixing ratio of fine aggregate and mixing water can be made constant. Further, in the present invention, it is possible to obtain concrete with less quality fluctuation by continuously mixing remaining water, cement, and coarse aggregate with the fine aggregate-water mixture measured by the above mixing method according to the mixing plan. Can be done.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a concrete continuous kneading plant to which the method of the present invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mixing hopper (container) 2 Fine aggregate hopper 3 Water tank 4 Cement hopper 5 Fine aggregate hopper 6 Screw conveyor 7 Control part

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Norihiko Miura 4-640 Shimoseito, Kiyose-shi, Tokyo F-term in Obayashi Corporation Technical Research Institute Co., Ltd. 4G056 AA06 CB02 CB15 CB31 CB34 CC09 CC11 CC31 CC37 CC39

Claims (3)

[Claims] 1. Mixing water with fine aggregate in a container,
A method of blending fine aggregate with water, wherein the fine aggregate is compacted by, for example, vibrating a container, and a mixture of the compacted fine aggregate and water is taken out from the bottom of the container. 2. The composition according to claim 1, wherein the mixing ratio of the fine aggregate and the mixing water to be supplied is 20 to 50% by volume of water to 80 to 55% by volume of the fine aggregate. How to mix water with kneaded fine aggregate. 3. Mixing water with fine aggregate in a container,
The fine aggregate is compacted by vibrating the container, etc., and a mixture of the compacted fine aggregate and water is drawn out from the bottom of the container into the screw mixer at a constant speed, and then the remaining water and cement are mixed into the screw mixer. And a method of continuously kneading concrete, wherein kneading is performed while sequentially adding coarse aggregate at a mixing ratio according to a predetermined mixing design.