JP2001139946A - Method for producing roadbed material using dug soil and roadbed material produced thereby - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve an environmental problem and a problem of shortage in fields for treating wastes by reclaiming dug soil and the concrete lumps, asphalt lumps and construction surplus soil of construction wastes as a roadbed material, while the dug soils of road construction have been scraped in specified waste- treating fields as wastes and while natural fractures and resource exhaustion due to the collection of road materials are serious. SOLUTION: This roadbed material is reclaimed by adding the concrete lumps or asphalt lumps of construction wastes or the mixture of the concrete lumps and the asphalt lumps to dug soil, crushing the mixture, adding quicklime to the crushed product, screening the mixture into granules having granule diameters of 40 to 20 mm, granules having granule diameters of 20 to 2.5 mm and granules having granule diameters of 2.5 mm to 0 mm, and then mixing the granules in a prescribed ratio.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a roadbed material using excavated soil, and a method of manufacturing a roadbed material using excavated soil, wherein a roadbed material is manufactured from excavated soil and concrete or asphalt blocks of construction waste. Roadbed material.

[0002]

2. Description of the Related Art The structure of a conventional general paved road is shown in FIG. In FIG. 4, 1 is on the subgrade, 2 is the roadbed layer, and 3 is the surface layer. The pavement is constructed in the order of a subbase layer 2 and a surface layer 3 on a subgrade 1 constructed by general road earthwork. The subgrade 1 refers to a portion of soil 1 m below the pavement, and is a basis for determining the thickness of the pavement. The strength of the subgrade soil is measured by CBR. Subbase 2
Is a part that plays an important role in distributing the traffic weight and transmitting it to the subgrade. In order to make the configuration of the roadbed mechanically balanced according to the load, the upper subbase
And the lower roadbed 5. The surface layer 3 is often made of a durable heated mixture asphalt to resist friction and shear due to traffic loading at the top of the pavement.

When a pavement road is excavated by construction work such as gas, water supply, sewerage, etc., the excavation is performed from the surface layer 3 to the subgrade 1 part. However, the soil excavated from the paved road contains sand, clay, gravels, concrete, asphalt, etc., and even if it is buried as it is, it cannot be compacted sufficiently and causes land subsidence etc. It cannot be used as backfill material. Construction works such as gas, water, and sewerage need to be promptly and reliably restored to minimize traffic obstacles. For this reason, virgin crushed stone is the main material for roads used in conventional restoration work, and in part, concrete and asphalt lumps on the surface layer 3 are crushed and processed to a specified aggregate. Was re-used as a road, but was excavated by a series of works
And the soil on the subgrade 1 should be discarded unless it is of good quality.
Backfilled with virgin crushed stones
Has been performed conventionally.

[0004]

For this reason, in the case of the conventional method of restoring paved roads, the method of collecting backfill soil mainly from roadbed material, disposal of excavated earth and sand, transportation cost of excavated earth and sand, etc. Various problems are occurring. In other words, the extraction of earth and sand for roadbed materials destroys the natural environment and depletes valuable natural resources, so that natural destruction and resource depletion are serious. In addition, the distance of the sampling site is too long, and the dumping route is empty, which is inefficient. Furthermore, in conventional reuse of construction waste alone, the rate of use as roadbed material is low, and unused waste is discarded as industrial waste at designated waste disposal sites. The dumping of sediment has become inefficient and uneconomical due to the fact that it is becoming distant and the dump return path is empty. An object of the present invention is to recycle the excavated soil and construction waste concrete lumps, asphalt lumps, and construction slag as roadbed materials to dramatically increase the recycling rate, and as a secondary effect, designated waste as a secondary effect. It is to solve the problem of shortage of treatment plant.

[0005]

SUMMARY OF THE INVENTION The present invention relates to an excavated soil 70%.
To 75%, add 20% to 25% of concrete lump or asphalt lump or mixture of concrete lump and asphalt lump of construction waste, pulverize, add 5% or less quicklime, and sieve. Is 40mm ~
The roadbed material is reclaimed by dividing it into three types, one having a diameter of 20 mm, one having a particle diameter of 20 mm to 2.5 mm, and one having a particle diameter of 2.5 mm to 0 mm, and mixing them at a predetermined ratio. It is something to do. According to the present invention, the excavated soil as waste is improved to the same quality as the backfill material (crushed stone, mountain gravel, sand, etc.) of the conventional roadbed material, and can be reused, so that resources are effectively used and environmental destruction is prevented. Can be done.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a diagram showing a construction of a roadbed material production plant for producing a roadbed material by a method of manufacturing a roadbed material using excavated soil according to the present invention. In FIG. 1, reference numeral 10 denotes a raw material hopper. The raw material hopper 10 is charged with excavated soil, concrete lump of construction waste, and asphalt lump. 11 is a grizzly feeder. The grizzly feeder 11 sifts the excavated soil of the raw material hopper 10, the concrete lump of construction waste, and the asphalt lump while transporting the lump having a predetermined size or more and the following lump. 12 is a primary crusher. The primary crusher 12 crushes excavated soil having a predetermined size or more and a concrete lump and as-a-alut lump of construction waste sent out from the grizzly feeder 11.

Reference numeral 13 denotes a magnetic separator. The magnetic separator 13 includes excavated soil having a certain size or less sent out from the grizzly feeder 11, concrete lumps of construction waste, and the like crushed by the primary crusher 12, and magnetic metals such as iron pieces therein. Is removed. Reference numeral 14 denotes a quicklime silo for storing quicklime. A screw feeder 15 feeds quicklime from the quicklime silo 15. The screw feeder 15 adjusts the amount of quicklime fed from the quicklime silo 15 by changing its rotation speed. 16
Is a flight bear for adding quicklime fed from the screw feeder 15 to excavated soil from which metals such as iron pieces are sent out from the magnetic separator 13 and crushed material such as concrete lump of construction waste.

Reference numeral 17 denotes a vibrating sieve. The vibrating sieving machine 17 is configured to mix a mixture of quick lime sent from the flight bear 16, excavated soil from which iron and other metals such as iron pieces sent from the magnetic separator 13 have been removed, and a crushed material such as a concrete lump of construction waste with a particle size of 40 mm or less. Sift into the above and above. 18 is a secondary crusher. Secondary crusher 18
Has a particle size of 40 sieved by the vibrating sifter 17.
Excavated soil and concrete lump or the like of construction waste having a diameter of not less than 1 mm are crushed again to a particle diameter of not more than 40 mm. 19 is a secondary crusher 1
8 is a conveyor for returning the crushed material of No. 8 to the vibrating sieve 17. A dust collector 20 collects dust generated around the vibrating sieve 17 and prevents the dust from scattering around. Reference numeral 21 denotes a screw feeder that sends dust collected by the dust collector 20 to the conveyor 19 and adds the dust to the vibrating sieve 17.

Reference numeral 30 denotes an intermediate raw material hopper. The intermediate raw material hopper 30 holds, as an intermediate raw material for the roadbed material, a mixture of excavated soil sieved by the vibrating sieve 17 and a pulverized material such as a concrete lump of construction waste or the like having a particle size of 40 mm or less. 31 is a vibrating screen machine. The vibrating screen machine 31 is a vibrating screen machine having a screen sieve having a mesh of 20 mm in an upper stage and a screen sieve having a mesh of 2.5 mm in a lower stage. Reference numeral 32 denotes a first intermediate hopper that holds the intermediate raw material remaining in the 20 mm mesh screen of the vibrating screen machine 31. Reference numeral 33 denotes a second intermediate hopper that holds the intermediate material remaining in the 2.5 mm mesh screen of the vibrating screen machine 31. Reference numeral 34 denotes a third intermediate hopper that holds intermediate raw materials that have passed through a 2.5 mm mesh mesh screen of the vibrating screen machine 31. Reference numeral 35 denotes a first feeder that feeds out the intermediate raw material held in the first intermediate hopper 32. Reference numeral 36 denotes a second feeder for sending out the intermediate raw material held in the second intermediate hopper 33. 37 is a third feeder for sending out the intermediate raw material held in the third intermediate hopper 34. 38 is a first feeder 35
This is a mixer for mixing the intermediate raw materials sent out from the second feeder 36 and the third feeder 37 into a roadbed material. 39 is a manufactured roadbed material.

The operation of the roadbed material production plant configured as described above will be described as follows. Raw material hopper 1
0, concrete which becomes aggregate for 70-75% of the excavated soil after removing large foreign matters such as excavated soil, concrete lumps of construction waste and pipe pieces mixed in asphalt lumps. Lump and asphalt lump are introduced at a ratio of 20 to 25%. The ratio of excavated soil to concrete mass and asphalt mass is adjusted according to the characteristics of excavated soil. The ratio of the aggregate concrete asphalt mass and the asphalt mass is arbitrary, and it is not always necessary to add both, and only one of them can be used. Excavated soil from the raw material hopper 10 and concrete lump and asphalt lump of construction waste are sieved by a grizzly feeder 11 into those having a certain size or more and those having a certain size or less. Magnetic metals are removed.

The excavated soil having a certain size or more and the concrete lump and asphalt lump of construction waste sent out from the grizzly feeder 11 are pulverized through a primary crusher 12 and then passed through a magnetic separator 13 to be crushed therein. Magnetic metals such as iron pieces are removed. The excavated soil from which irons and other metals have been removed and the crushed material such as concrete lumps sent from the magnetic separation machine 13 are added with quicklime as a stabilizing material sent out from the flight bearer 16 to the vibration sieving machine 17. Sent to. The amount of quicklime added to pulverized material such as excavated soil and construction waste concrete mass is about 3% of excavated soil and construction waste concrete mass.
The amount of quicklime added is adjusted according to the characteristics of the excavated soil,
In the case of high quality excavated soil, it is small, and in the case of poor quality, it is generally adjusted with a mixing ratio of 5% or less. The mixing ratio of quick lime is adjusted by changing the amount of quick lime sent out from the silo 15 by changing the rotation speed of the screw feeder 15.

A mixture of calcined lime, excavated soil from which metals such as iron chips have been removed, and pulverized materials such as concrete lumps of construction waste are sieved by a vibrating sifter 17 having a mesh of 40 mm. Used as an intermediate material for roadbed materials. Also, the excavated soil having a particle size of 40 mm or more sieved by the vibrating sifter 17 and the concrete lump and the like of construction waste are pulverized again to reduce the particle size to 40 mm or less and used as an intermediate material of a roadbed material. The vibrating sieve 17 generates dust around the excavated soil and pulverized materials such as concrete lump of construction waste, so that dust is generated around the vibrating sieve 17 and collected by the dust collector 20 to prevent the dust from scattering around. In addition, since the dust duct collected by the dust collector 20 is returned to the vibrating sieve 17 so as to be used as an improved soil for road construction, not only is dust pollution prevented from occurring but also the dust is collected. The dust duct has an advantage that it can be used for road construction as a roadbed material.

The mixture of the excavated soil sieved by the vibrating sifter 17 and the pulverized material such as concrete lumps of construction waste having a particle size of 40 mm or less is used as the intermediate material hopper 30.
Vibrating screen machine 31 held as an intermediate material for roadbed material
Is added to Vibrating screen 31 is 20m above
holding a mesh screen of 2.5 m
Has two types of sieves, ie, a mesh sieve having a mesh size of 40 mm and 20 mm.
The intermediate raw material of 20 to 2.5 mm particles remains in the mesh screen of 5 mm mesh, and the intermediate raw material of 2.5 to 0 mm particles passes through the mesh screen of 2.5 mm mesh. The intermediate raw material of 40 to 20 mm particles remaining in the 20 mm mesh screen of the vibrating screen machine 31 is held in the first intermediate hopper 35 and remains in the 2.5 mm mesh screen of the vibrating screen machine 31. 20 ~
The intermediate material of 2.5 mm particles is supplied to the second intermediate hopper 33.
The intermediate raw material of 2.5 to 0 mm particles that has passed through the 2.5 mm mesh screen of the vibrating screen machine 31 is held by the third intermediate hopper 34.

The intermediate raw material held in the first intermediate hopper 32 is fed by a first feeder 35, the intermediate raw material held in the second intermediate hopper 33 is fed by a second feeder 36, and the third intermediate hopper 34 Is added to the mixer 38 by the third feeder 37 and mixed, and the roadbed material 39 is manufactured. The intermediate raw material held in the first intermediate hopper 32 and the second intermediate hopper 3
The mixing ratio of the intermediate raw material held in 3 and the intermediate raw material held in the third intermediate hopper 34 adjusts the speeds of the first feeder 35, the second feeder 36, and the third feeder 37, respectively. It is adjusted by This mixing ratio should be within the particle size distribution specified by the following guidelines for asphalt paved roads specified by the Japan Road Association, and the desirable quality (upper subgrade) of aggregate used for lime stabilization specified in the Road Earthwork Construction Guidelines. Is controlled.

In the above description, the intermediate raw material sieved by the vibrating sieve 17 is supplied to the intermediate raw material hopper 3.
Although an example in which the mixture is temporarily held at 0 has been described, when there is no need to adjust the production amount or the like, the vibration sieve 17 and the intermediate raw material hopper 30 are omitted, and the pulverized mixed material is directly By adding to the vibrating screen machine 31,
It is also possible to simplify the configuration of the roadbed material production plant by sieving three types of intermediate raw materials having different particle diameters. The components of the roadbed material produced by the roadbed material production plant of the present invention are as follows. Concrete mass pulverized material 0% -30% Asphalt mass pulverized material 0% -30% Construction surplus soil 70% -75% Stabilized quicklime less than 5%

Since lime as a stabilizing material is added to the roadbed material produced by the roadbed material production plant of the present invention, * quicklime and water react by the hydration reaction to reduce the heat of hydration reaction. The water content evaporates, and the water content of the improved soil decreases. * By the pozzolanic reaction, lime reacts with alumina and silicon in the earth and sand to form compounds such as calcium aluminate and calcium silicate, and unites the earth and sand. * By the carbonation reaction, part of the lime reacts with carbon dioxide gas,
It becomes calcium carbonate and increases the strength of the soil. * By ion exchange reaction, fine clay particles are aggregated to make the soil easy to compact. Therefore, the characteristics as a roadbed material are greatly improved.

FIGS. 2 and 3 show data obtained by measuring various characteristics of the roadbed material produced by the roadbed material production plant of the present invention.
Shown in The data in FIGS. 2 and 3 are the sample of the roadbed material, N
o. It shows values of 0-40. The value of this data is based on the asphalt-paved road outline specified by the Japan Road Association and the desirable quality (upper subgrade) of aggregate used for lime stabilization specified in the road earthwork construction guidelines. Percentage of passing through eyes (%) 100 Percentage of passing through 2.37.5 mm sieves (%) 95-100 Percentage of passing through 3.19 mm sieves (%) 50-100 4.2.36 mm sieves 5. Percentage of passing through eye (%) 20-60 5.75 μm Percentage of passing through sieve (%) 2-20 It sufficiently satisfies the uniaxial compressive strength of 7 kgt / cm ² (10 days).

Further, since the roadbed material produced by the roadbed material production plant of the present invention has a uniform grain size, it has characteristics of easy rolling, easy compaction, and excellent mechanical strength. By using this, reduction of material cost and construction cost can be realized. As a result, the roadbed material produced by the roadbed material production plant of the present invention was obtained from the measurement data of FIG. 2 on September 7, 1999 by Hamamatsu Civil Engineering Office, Hamamatsu No. 1032-1. It was approved for use as a lower roadbed material for the Shizuoka Prefectural Government's government office construction work, as it satisfies the quality plan of the "Asphalt Pavement Guidelines". The soil quality of the excavated soil used in the roadbed material manufacturing plant in which the method for manufacturing the roadbed material using the excavated soil of the present invention is applicable. It is a plant. In addition, due to the effect of quicklime as a soil improving agent, a roadbed material having a strength higher than that of conventional purchased soil (mountain sand) can be obtained. By using the roadbed material produced by the plant that has implemented the method for manufacturing the roadbed material using the excavated soil of the present invention for road renovation work and the like, it becomes unnecessary to collect the soil for backfilling the roadbed, so that natural destruction occurs. Not only is pollution prevented, pollution is prevented because the need to dispose of excavated soil is eliminated.

[0019]

As is apparent from the above description, the method of manufacturing a roadbed material using the excavated soil according to the present invention and the roadbed material manufactured by the method can reduce 70% to 75% of the excavated soil and reduce the amount of construction waste. Concrete mass or asphalt mass or mixture of concrete mass and asphalt mass of 20% to 25% is added and pulverized, to which 5% or less quicklime is added and sieved. 1. Those having a particle size of 20 mm to 2.5 mm, and those having a particle size of 2.
The roadbed material usable for road construction is reclaimed by sieving into three types of 5 mm to 0 mm and mixing them at a predetermined ratio. According to the present invention, the excavated soil causing environmental destruction is improved to the same quality as conventional backfill materials for roadbed materials such as crushed stone, mountain gravel and sand, so that the soil can be recycled. It is effectively used and contributes to preventing natural destruction and resource depletion by collecting aggregates, and has the effect of compensating for serious shortage of waste disposal sites. In addition to this, since the cost of transporting excavated earth and sand is saved, various problems that have occurred with the current road renovation can be simultaneously solved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a roadbed material production plant in which a method of manufacturing a roadbed material using excavated soil according to the present invention is performed.

FIG. 2 shows data obtained by measuring various characteristics of a roadbed material produced by the roadbed material production plant of the present invention.

FIG. 3 shows data obtained by measuring various characteristics of a roadbed material produced by the roadbed material production plant of the present invention.

FIG. 4 is a diagram showing the structure of a conventional general paved road.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Raw material hopper, 11 ... Grizzly feeder, 12 ... Primary crusher, 13 ... Magnetic separator, 14 ... Quicklime silo for storing quicklime, 15 ... Quicklime from silo 15 Screw feeder to be sent out, 16: Flight bear added to the crushed material sent out from screw feeder 15, 17: Vibrating sieve, 18: Secondary crusher, 19: crushed material of secondary crusher 18 Vibrating sieve machine 17
Conveyor returning to 20; dust collector; 21: screw feeder for adding the duct collected by dust collector 20 to vibrating sieve 17; 30: intermediate raw material hopper; 31: vibrating sieve machine; 32 ... first intermediate hopper, 33 ... second intermediate hopper, 34 ... third intermediate hopper, 35 ... first feeder, 36 ... second feeder, 37. ..Third feeder, 38 ... mixer, 39 ... manufactured roadbed material, 1 ... on roadbed, 2 ... roadbed layer, 3 ... surface layer, 4 ... upper roadbed , 5 ... lower roadbed,

Claims (5)

[Claims] 1. A pulverized concrete mass of 0% to 30%, a pulverized asphalt mass of 0% to 30%, having a particle size of 40 mm or less.
A roadbed material having a mixture ratio of 30%, excavated soil 70% to 75%, and quicklime 5% or less. 2. A crushed concrete lump having a particle size of 40 mm or less, 0% to 30%, and an asphalt lump crushed material having a particle size of 0% to 30%.
30%, excavated soil 70% to 75%, a material consisting of a mixture of quicklime of 5% or less, the particle size of which is 40mm to 20mm
A roadbed material which is sieved into three types, a material having a particle size of 20 mm to 2.5 mm, and a material having a particle size of 2.5 mm to 0 mm, and mixed at a predetermined ratio. 3. An excavated soil of 70% to 75% to which 20% to 25% of a concrete lump or asphalt lump or a mixture of a concrete lump and an asphalt lump of construction waste is added and pulverized, and the lime is reduced to 5% or less. And the mixture is sieved to a particle size of 40 mm or less.
~ 2.5mm and the particle size is 2.5mm ~ 0mm
Roadbed material that is sieved into three types and mixed at a predetermined ratio. 4. A means for adding a concrete lump or asphalt lump of construction waste or a mixture of concrete lump and asphalt lump to excavated soil, a concrete lump or asphalt lump of construction waste or a mixture of concrete lump and asphalt lump to said excavated soil. Means for pulverizing the excavated soil, means for adding quicklime to a concrete lump of construction waste or asphalt lump or a mixture of concrete lump and asphalt lump to the excavated soil, construction waste to the excavated soil to which the quicklime is added Concrete mass or asphalt mass or a mixture of concrete mass and asphalt mass having a particle size of 40 mm to 20 mm, a particle size of 20 mm to 2.5 mm, and a particle size of 2.5 mm to 0 mm Means for sieving into three types, the above three types Means for obtaining a road base course material sieved mixture was mixed at a predetermined ratio, and a method of producing a road base course material than more become excavated soil. 5. A means for adding a concrete lump or asphalt lump or a mixture of concrete lump and asphalt lump of construction waste to 70% to 75% of excavated soil, concrete lump of construction waste or Means for crushing asphalt lumps or a mixture of concrete lumps and asphalt lumps; 5% of said excavated soil is crushed to concrete lumps of construction waste or asphalt lumps or a mixture of concrete lumps and asphalt lumps;
The following means for adding quicklime, the means for obtaining a mixed material having a particle size of 40 mm or less by sieving concrete lump or asphalt lump or a mixture of concrete lump and asphalt lump of construction waste to the excavated soil to which quicklime is added. The mixed material obtained is further reduced to a particle size of 40.
mm to 20 mm, and the particle size is 20 mm to 2.5
mm, and means for sieving into three types of particles having a particle size of 2.5 mm to 0 mm, means for mixing the mixed material sieved into the three types at a predetermined ratio to obtain a roadbed material. A method of manufacturing a roadbed material from excavated soil consisting of: