JPS5869772A - Regeneration of concrete waste products - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for recycling concrete waste material generated during the demolition of concrete buildings.

The construction field is no exception to resource depletion and waste pollution. Therefore, it is being considered to reuse the concrete waste material that is generated when a concrete building is demolished as recycled aggregate instead of throwing it away.

By the way, according to experiments, if a concrete lump is simply broken into small pieces, the actual area ratio representing the shape of crushed stone is 58% or more in the case of coarse aggregate, which exceeds the JASS5 class ■ standard value (55 inches or more). However, the absolute dry specific gravity, which represents the weight of the aggregate, is 1.97 to 2.14, which is far below the standard value of 2.5, and the water absorption rate is 8.3 to 12.1 inches, which is 3.5 inches. 0
% or less has been obtained. Therefore, it is not possible to use a concrete block as an aggregate simply by dividing it into small pieces and adjusting the particle size.

The present invention solves the above-mentioned conventional problems by abrading and removing the cement components attached to the aggregate in concrete waste by mechanical means, and has a high actual area ratio and absolute dry specific gravity. Another object of the present invention is to provide a method for recycling concrete waste material that can obtain aggregate with a low water absorption rate. The present invention will be explained below with reference to the drawings.

FIG. 1 is a conceptual diagram of the present invention.
- The method for recycling waste materials consists of a pretreatment step IA), a classification step IBI, and a sand making step (C).

The pretreatment process (At) adjusts the particle size of concrete waste and removes foreign substances such as iron pieces and earth contained in the concrete waste.In this process, particles generated during the demolition of concrete buildings are The diameter is approximately O
~1ooo 0 concrete lump (waste material) (1) is passed through the first sieving device (Griz IJ- etc.) using a dump truck (2) etc.
3) Transport. In this first sieving device (3), reinforcing bars and the like in the concrete waste material (1) are cut by means such as gas cutting and removed as foreign matter, and the large-diameter concrete waste material is roughly crushed. The concrete waste material having a particle size of approximately 4000 or less that has passed through the sieving device (3) is fed into a second sieving device (4) such as Grizzly. This concrete waste is separated by a second sieving device (4) into particles with a particle size of approximately 1500 or more and particles smaller than this, and the concrete waste with a particle size of 15011II or more is sent to a first crusher (5) such as a crusher. Conc I which passed through the second sieving device (4) with a smaller particle size than
The waste material is fed to a third sieving device (6) such as a screen. The first crusher (1) crushes the given concrete waste into particles with a particle size of 150 u or less and supplies the crushed concrete to a second crusher (7) such as a crusher.

In addition, the third sieving device (6) separates the concrete waste supplied from the second sieving device (4) into those with a particle size of 30 to 150 and those with a particle size of 30 to 150, and those with a particle size of 30 to 150 or smaller.
7), and the latter is removed as sediment. In the process of sending the concrete waste from the first crusher (5) and the third sieving device (6) to the second crusher (7), iron pieces and other foreign substances are removed. In this case, for the removal of shingles.

, usually a magnet is used.

2nd crusher (with force, it can crush the given concrete waste from 0 to
The particles are crushed to a particle size of 40 mm and supplied to a fourth sieving device 181 such as a screen. In the fourth sieving device (8), the given concrete waste is sieved and the particle size δ is
When the concrete waste of ~40 pieces is returned to the second crusher (7), the concrete waste with a particle size of 0 to 25 pieces is put into the intermediate tank (9).

In the classification step IB), the concrete waste material placed in the intermediate tank (9) in the pretreatment step is taken out and classified according to particle size. In other words, this process (in the
The concrete waste of θ~25 degrees stored in the intermediate tank (9) is taken out from the tank (9) and first put into a fifth sieving device O, such as a screen, where the concrete waste is 5~25 degrees of Divide into 0 to 5 dragons. Then, the latter concrete waste with a particle size of 0 to 5 meters is put into a second aging machine (1υ) equipped with a separator, and here it is mixed with concrete waste with a particle size of 0.15 to 51 m and a particle size of O to 0.1.
The concrete waste is divided into 55 m long concrete waste and the latter concrete waste is stored in the fine powder tank (121).

The sand making process fc1 uses the fifth sieve device (1 liter) and the second sieve machine (1 υ) with grain sizes of 5 to 25 W1 and 0.15 to 5
The process involves separating cement components from concrete waste materials from industrial plants and turning it into sand, or recycled aggregate.

First, to explain concrete waste with a particle size of 5 to 250, the concrete waste separated by the fifth sieving device (io) is supplied together with water to the first crusher I! The adhering cement components are separated by the resulting attrition action, and this is drawn and fed to a sixth sieve device α such as a screen.In the sixth sieve device I, the given concrete waste is separated into particles with a particle size of 20~2511II111O~
21Jwx, divided into 5-10■ and 0-5 cranes,
The former champion's concrete waste is stored in a grading tank according to particle size. The concrete waste stored in the grading tank QS is piled up at the desired ratio for each particle size, mixed by the first mixer (111G), and then put into the first product tank Qn or by an appropriate conveyance device decoy. Transport it to the work site, etc.

In the above, the concrete waste material overflowing from the grading tank 0!19 is crushed by a third crusher Ql such as a crusher, and then returned to the sixth sieving device I as it is.

In addition, the concrete waste material with a particle size of 0.15 to 5 cm obtained by the second aging machine 0υ is mixed with the concrete waste material with a particle size of 0 to 5 cm separated by the 6th sieving device 04 and water. The waste is passed through a sand machine (7), and the adhering cement components are separated by the abrasive action that occurs between the conc IJ waste materials as described above, and the separated cement components are supplied to a seventh sieving device (21) such as a screen. In the seventh sieving device Q1), the given concrete waste is sieved with particle sizes of 2.5 to 5 m and 1.2 to 2.511.
1, and θ ~ 1.2 m, and store the former two in a powder-filtering tank according to particle size, and store the latter with a particle size of 0 to 1.2 m.
．． Supply 2M of concrete waste to the separator.

The separator (c) separates the waste material with a particle size of 0.15 to 1.2M from the given concrete waste material and transfers it to the grading tank (2z
while eliminating other concrete waste or slurry. The concrete waste stored in the grading tank 02 above is taken out at the desired ratio for each particle size, and
After the mixture is mixed in the second mixer CL, it is placed in the second product tank (to) or transported to a work site using an appropriate transport device. In this case as well, the concrete waste that overflows from the granulation tank is removed by a fourth crusher such as a crusher@
It is sent to the sieve, crushed, and returned to the seventh sieve device Qυ.

Incidentally, dust generated from parts such as the sieving device and the crusher is collected by a dust collector (to) and placed in the fine powder tank Vt. Also,
The slurry produced in the sixth sieving device I is the concrete waste material with a grain size of 0 to 5 m, which is passed through the second sand making machine
Exclude when sending to. Although each particle size (IllI) of the concrete waste mentioned above is shown in parentheses in FIG. 1, this is just an example.

Figures 2 and 3 show an example of a sand making machine with 0 boiling point and ■.
The sand making machine consists of a horizontal rotary drum with many wear-resistant materials protruding from its inner circumferential surface, and an inner cylindrical rotor 0υ with a large number of wear-resistant materials protruding from its outer circumferential surface offset from its center. , while rotating the rotating drum (to) and the inner cylinder rotor Gυ in opposite directions, the concrete waste and water are transferred to the rotating drum (to).
inside the rotating drum (to) and the inner cylinder rotor (3D
Concrete waste is forcibly fed into the wedge-shaped part formed on the outer surface of the concrete IJ to destroy it, and the cement components adhering to the surface can be removed by working with water. . Although the sand maker having the above structure is suitable for wet processing of concrete waste, other structures may be used.

Next, an example of the fine aggregate treatment process will be explained.

The classified mortar portion and the mortar portion obtained in the coarse aggregate processing step are introduced from (a). This material is thrown off at high speed in the direction of (b) by the rotation of the rotor (to). Then, the sand collides with an impact plate located on the outside of the rotor, and the cement components attached around the sand are separated by impact crushing. ((ha)～ni)). The fine powder (cement, stone powder) (e) generated at this time is taken out of the machine by a suction duct (e) and collected. Also,
In the process of (a) to (a) to (a), a considerable amount of the cement components attached to the sand are removed, but in order to satisfy the specified aggregate quality (specific gravity, water absorption, etc.) This process is repeated an appropriate number of times, and the fine powder (e) is also sucked in at the same time, and the tamper is finally opened to obtain fine aggregate (9).

By the way, there are two types of adhesion forms of cement components: physical adhesion and chemical adhesion.The former is relatively easy to separate due to impact etc. during crushing, but the latter chemical adhesion cannot be separated by impact. Have difficulty. However, mechanical abrasion, as in the case of the sand machine mentioned above, allows the cement components to be separated relatively easily and effortlessly, and the original aggregate is not broken, making it possible to cut corners and build up the cement. rate can be increased.

As explained above, in the present invention, concrete waste is crushed into appropriate pieces, the particle size is adjusted to an appropriate value, foreign matter is removed from the waste, and the waste is classified, and finally, sand is produced. Since the cement component is separated by applying it to the material, the water absorption rate of the recycled aggregate caused by the adhesion of the cement component can be greatly reduced, and the absolute dry specific gravity of the recycled aggregate can be increased. In addition, since the cement components are separated by abrasion, chemically adhered materials can be easily separated from the correct number, and the corners can be rounded without damaging the aggregate to increase its actual area ratio, making it a good recycled aggregate. be able to.

[Brief explanation of the drawing]

The drawings are explanatory drawings showing an example of the method for recycling concrete waste according to the present invention. Fig. 1 is a conceptual diagram of the present invention, Fig. 2 is a schematic side view showing an example of a sand machine, and Fig. 3 is a schematic front view of the same. , 4th
The figure is a diagram of the fine aggregate processing process.

Claims (1)

[Claims] A pre-treatment step in which the concrete waste is crushed with a crusher, and the concrete waste is sieved to adjust the particle size to an appropriate value, and foreign substances such as iron pieces and soil contained in the concrete waste are removed; There is a classification process in which the concrete waste obtained in this pre-treatment process is passed through a sieving device to separate it by particle size, and the concrete waste separated in this classification process is passed through a sand machine into each particle size to produce cement)
1. A method for recycling concrete waste, comprising a sand-making process in which the components are separated by abrasion.