JP2750381B2 - Treatment method of waste ready-mixed concrete - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating excess waste ready-mixed concrete remaining in a ready-mixed concrete factory or a mixer truck and discarded together with washing water.

[0002]

2. Description of the Related Art Fresh concrete discharged when washing the inside of a drum of a concrete mixer truck is conventionally led to a coarse aggregate recovery device such as a trommel or a tilted slat to separate and collect coarse aggregate such as gravel. Subsequently, it is guided to a fine aggregate recovery device such as a classifier to separate and collect fine aggregates such as sand, and then guided to a stirring tank to collect supernatant water, and sludge water settled in the stirring tank is subjected to high pressure. Dewatering by pumping to filter press by pump, cake (cake)
It is to be processed as.

[0003]

As described above, the filter cake discharged from the filter press is composed of fine particles of cement hydrate, and if it is dumped into the sea or the ground as it is, it is easily dispersed. Conventionally, an appropriate processing method has not been established, which may cause environmental destruction.

[0004]

DISCLOSURE OF THE INVENTION A method for treating waste ready-mixed concrete according to the present invention is to solve the above-mentioned problem, and is a method for treating waste ready-mixed concrete discharged together with washing water from a ready-mixed concrete factory or a mixer truck. A small-quantity treatment step performed when the amount of the waste ready-mixed concrete is small, and a large-scale treatment step performed when a large amount of the ready-mixed concrete is generated. After separating and collecting the aggregate and the fine aggregate, respectively, the aggregate and the fine aggregate are led to a stirring tank, and the sludge water settled in the stirring tank is dehydrated by a filter press and stored as filter cake. In the treatment step, the filter cake generated in the small-amount treatment step and the waste ready-mixed concrete are kneaded by a mixer, and then dried and solidified to form a concrete. It is intended to form the over door products.

[0005]

In a large-scale treatment step performed when a large amount of waste ready-mixed concrete is produced, the cake formed in the small-scale treatment step is kneaded with the waste ready-mixed concrete and is naturally processed by being formed into a concrete product. Eliminating the need for disposal as filter cake eliminates the risk of environmental pollution.

[0006]

Next, an embodiment of the present invention will be described with reference to FIG. First, the small amount processing step will be described. This small-quantity treatment step is employed when the amount of waste ready-mixed concrete remaining in the drum of the mixer truck returned from the civil engineering construction site or the like is substantially zero or small. In this case, as shown in FIG. 2, the mixer truck 1 is carried into a car wash, and washing water 2 is poured into the drum to wash residual ready-mixed concrete and the like adhering to the inside of the drum. The drainage is guided to a trommel classifier 4 through a chute 3 to separate coarse aggregates such as gravel, and sludge water containing fine aggregates is dropped into a sludge tank 5.
At the gravel yard 7. Sludge water is in the sludge tank 5
It is conveyed to a screw conveyor type classifier 9 by a sand pump 8 provided therein, and fine aggregate such as sand is separated and collected in a sand yard 10.

The sludge water containing the remaining cement hydrate from which the fine aggregate has been separated in the sludge tank 5 is led to a stirring tank 11 having stirring blades 12. The sludge water settled in the stirring tank 11 is supplied to the receiver tank 1 by the pump 13.
4, and is further pumped to a filter press 16 by a high-pressure pump 15 and dewatered to form a filter cake (dewatered cake) 17.
The filtered water discharged from the filter press 16 is stored in the supernatant water tank 19 and reused as the washing water 2 for the mixer truck 1 or for other uses. Therefore, in this small-volume treatment step, the amount of the cake 17 remains in the cake storage 18 gradually.

On the other hand, the mass treatment process is carried out when there is a large amount of excess ready-mixed concrete in the drum of a mixer truck returned from a civil engineering construction site or the like and needs to be discarded. As shown in FIG. 3, the mixer truck 1 is carried into a waste disposal site. Reference numeral 20 denotes a mixer in which several stirring rods and a mixing screw are provided in the vessel.
Is conveyed by a conveyor 26 or the like, and the waste ready-mixed concrete 21 existing in the drum of the mixer truck 1 is removed.
Is charged into the mixer 20 together with the filter cake 17 and kneaded.
Then, the moisture in the waste ready-mixed concrete 21 is absorbed by the filter cake 17 and discharged from the discharge port 22 to the conveyer 24 in the form of a solid body 23 having appropriate hardness. The massive solid material 23 is then hardened by natural drying to form a massive concrete product 2 several centimeters to several tens centimeters in diameter.
It becomes 5. This concrete product 25 is effectively used as an internal material for relatively low strength parts such as embankments and road foundations.

The mixing ratio between the filter cake 17 and the waste ready-mixed concrete 21 is determined in consideration of the mechanical strength and the like required for the concrete product 25. In order to increase the strength, a new cement or blast furnace is required. Slag, quicklime, slaked lime, fly ash, etc. may be added.

In the above embodiment, the concrete product 2
Although the size, shape, and the like of 5 are not specified, a concrete product having a desired shape can be formed by filling the massive solid material 23 into a mold having an appropriate shape.

In this way, the filter cake 17 produced in the ready-mixed concrete factory is consumed for producing concrete products as appropriate, so that the filter cake 17 is directly discarded as troublesome industrial waste outside the factory. This eliminates the need and eliminates the costs associated with disposal and the risk of environmental pollution. The present invention can be applied not only to the treatment of waste ready-mixed concrete discharged from a mixer truck as shown in the embodiment but also to the treatment of excess ready-mixed concrete discharged from a ready-mixed concrete factory itself.

[0012]

As described above, according to the method for treating waste ready-mixed concrete of the present invention, coarse aggregates and fine aggregates are recovered from waste ready-mixed concrete by a small-volume processing step that is continuously performed. Are collected and effectively reused, respectively, and the filter cake is stored, and the filter cake and the waste ready-mixed concrete are kneaded by a mixer in a large-scale processing step performed when a large amount of waste ready-mixed concrete is occasionally generated. Then, since the concrete product is formed by drying and solidifying, the filter cake can be effectively used, which has a beneficial effect such as eliminating the risk of environmental pollution.

[Brief description of the drawings]

FIG. 1 is a process diagram of a method for treating waste ready-mixed concrete according to the present invention.

FIG. 2 is a schematic diagram of a small amount processing step.

FIG. 3 is a schematic diagram of a mass processing step.

[Explanation of symbols]

 Reference Signs List 1 mixer truck 2 washing water 4 trommel classifier 5 sludge tank 7 gravel storage 9 classifier 10 sand storage 11 stirring tank 15 high-pressure pump 16 filter press 17 filter cake 18 cake storage 20 mixer 21 waste ready-mixed concrete 23 massive solids 25 concrete Product

Claims (1)

(57) [Claims] 1. A method for treating waste ready-mixed concrete discharged together with washing water from a ready-mixed concrete factory or a mixer truck, comprising: a small-quantity treatment step performed when the amount of the waste ready-mixed concrete is small; It consists of a mass processing step to be carried out when concrete occurs,
In the small-volume treatment process, coarse aggregate and fine aggregate are separated and collected from the waste ready-mixed concrete, respectively, guided to a stirring tank, and the sludge water settled in the stirring tank is dewatered by a filter press and stored as filter cake. On the other hand, the large-scale treatment step is to knead the filter cake generated in the small-scale treatment step and the waste ready-mixed concrete with a mixer, and then dry and solidify to form a concrete product. A method for treating waste ready-mixed concrete, characterized by the following.