JPH0585682B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD This invention relates to a method for recycling asphalt pavement waste. In recent years, with the quantitative increase and qualitative changes in traffic, social demands on roads have tended to become more sophisticated and diversified.In particular, it is important to carry out appropriate maintenance and repair at the appropriate time to prevent damage to asphalt-paved roads. It has become an extremely important issue to ensure that roads are properly maintained and provide high-quality roads at all times. A large amount of asphalt pavement waste is generated due to the maintenance and repair of asphalt pavement, including replacement, but until now most of this waste has been disposed of in landfills and the like. In recent years, from the viewpoints of energy conservation, resource conservation, and prevention of overexploitation, there is a strong desire to develop an appropriate recycling method for these asphalt pavement waste materials. Conventional technology In the conventional asphalt recycling method, asphalt pavement waste is mechanically crushed at room temperature, or placed in a container and heated in the air to melt and pulverize the asphalt. It has been reused with an aggregate usage rate of 30% or less. Problems to be Solved by the Invention In conventional methods of recycling asphalt pavement waste, the asphalt waste is mechanically crushed at room temperature and in the air, or placed in a container and heated in the air to soften or soften the asphalt. Because the recycled aggregate is melted and pulverized and reused with a usage rate of less than 30%, mechanical and thermal energy consumption is high, and recycling takes a relatively long time, resulting in high costs. There were drawbacks such as unprofitability. Means for Solving the Problems The present invention has been made in view of the above, and
In order to reduce mechanical and thermal energy consumption, improve the quality of recycled materials, and improve workability, asphalt pavement waste is disintegrated in hot water at a temperature of about 30 to 85 degrees Celsius above the softening point of asphalt. The purpose of the present invention is to provide a method for recycling asphalt pavement waste material, in which asphalt pavement waste material is loosened by applying a relatively weak external force such as stirring or shaking to the waste material along with warm water while soaking the waste material for a sufficient period of time. . The method for recycling asphalt pavement waste of the present invention involves stirring, shaking, etc. with hot water while immersing the asphalt pavement waste in hot water at a temperature of about 30 to 85°C above the softening point of asphalt for a sufficient time to disintegrate the waste. The method is characterized in that it consists of a step of applying a relatively weak external force to the waste material to loosen the waste material. In addition, the method for recycling asphalt pavement waste of the present invention involves immersing asphalt pavement waste in hot water of approximately 30 to 85°C for a sufficient period of time, stirring with hot water or applying a simple impact to break up the waste. The asphalt-covered aggregate whose surface is covered with asphalt and separated into each original aggregate particle unit is separated by particle size using a classifier, and the separated asphalt-covered aggregate is divided according to the purpose. It is characterized by being reformulated and reused as a raw material for asphalt pavement. Function By immersing asphalt pavement waste in hot water of about 30 to 85 degrees Celsius, the surface is covered with asphalt and the asphalt coating is separated into individual aggregate particles, which can be easily broken down with bare hands. Can be made into aggregate. By this hot water treatment and applying relatively weak external forces such as stirring and shaking,
Asphalt pavement waste is separated into individual particles, but in this case, asphalt is separated while adhering to the periphery of the sand grains. The surface of the asphalt particles attached around the sand grains is coated with water or the temperature decreases, so that asphalt particles attached to other sand particles do not stick or adhere to each other, and loosening of asphalt pavement waste is promoted. Ru. The asphalt pavement waste is returned to aggregate units by a relatively weak external force such as stirring or shaking in warm water, and is then sent to a classification device by a conveyor.
Here, asphalt-coated (or attached) aggregate and crushed stone (or gravel) are classified and stored according to particle size. Depending on the application, such as simple pavement or heavy traffic road use, each asphalt pavement grade is used according to the respective particle size composition. EXAMPLE An embodiment of the method for recycling asphalt pavement waste according to the present invention will be described below. FIG. 1 is a schematic explanatory diagram of a series of asphalt pavement waste recycling devices used in the present invention.
Asphalt pavement waste material generated from replacement etc. 1
The asphalt pavement waste is first charged into a hot water tank 2 maintained at a temperature of about 30 to 85°C above the softening point of asphalt, and immersed for a predetermined period of time (at least until the center of the asphalt pavement waste reaches the temperature of the hot water). . By immersing it in this warm water, the asphalt pavement waste becomes ready to be loosened with bare hands. For example, by stirring the asphalt pavement waste material 1 with hot water using a stirrer 3, the waste material is easily crushed and separated into gravel or crushed stone under the asphalt pavement and sand grains to which asphalt is attached. The surface of the asphalt attached around the sand grains is coated with water or the temperature is lowered, so that adhesion or adhesion between the asphalt attached to adjacent sand grains does not occur. The hot water tank 2 can be heated using various types, such as installing a separate boiler to circulate hot water, using a long hot water tank to continuously transfer asphalt pavement waste, or heating from the bottom of the tank. It can be made into an aquarium. The following example examines the relationship between the disintegration (aggregate separation) of asphalt pavement waste and hot water. The water used in this example was
Warm wastewater from an incinerator is charged into a hot water layer, and its temperature is adjusted to 30℃, 40℃, 50℃, and 60℃.
°C, 70°C and 80°C. The heated wastewater flowed extremely slowly in the hot water tank. The dimensions of asphalt pavement waste are small lumps of about 20 mm and 50 mm.
There were three types: medium-sized lumps and large lumps of 50 x 300 x 300 mm. The results are shown in the table below.

[Table] Collapse
In this way, the asphalt pavement waste, which has been loosened by stirring in the hot water tank 2 at about 30 to 85°C and returned to its original aggregate particle units, is then transferred to the classification device 5 by an appropriate conveyance device 4. sent to. The asphalt pavement waste material, which has been decomposed into crushed stone, asphalt-adhered sand, sand, etc., and transferred to the classification device 5, is separated by particle size using a sieve. In some cases, only crushed stone is separated from other constituent components. The classified asphalt-adhered sand, sand, and crushed stone are stored separately by particle size. In this way, asphalt pavement waste material that has been separated and recycled according to particle size can be used as asphalt pavement material after being dehydrated and heated at a predetermined mixing ratio using normal methods, but these processes are not well known. Since there is, I will omit it. In this case, it is not particularly necessary to add new asphalt, but it may be desirable to add a small amount depending on the purpose. Effects of the invention In the present invention, asphalt pavement waste material is
It is agitated with hot water of 30 to 85 degrees Celsius, and the ingredients are separated and regenerated by particle size using a classifier, resulting in low mechanical and thermal energy consumption.
Moreover, 100% of asphalt pavement waste can be easily recycled.

[Brief explanation of the drawing]

FIG. 1 is a schematic illustration of a series of devices used in the present invention.

Claims (1)

[Scope of Claims] 1 Asphalt pavement waste is immersed in hot water at a temperature of 30 to 85°C above the softening point of asphalt for a sufficient time to disintegrate the waste, while applying a relatively weak external force such as stirring or shaking with the hot water. In addition to the waste material,
A method for recycling asphalt pavement waste material, comprising a step of breaking up the waste material. 2. While soaking asphalt pavement waste material in hot water of 30 to 85°C for a sufficient time to disintegrate the waste material,
A relatively weak external force such as stirring or shaking with hot water is applied to the waste material to break up the waste material, and asphalt-covered bone whose surface is covered with asphalt and is separated into each original aggregate particle unit is obtained by breaking the waste material. A method for recycling asphalt pavement waste material, which comprises separating the material by particle size using a classifier, remixing the separated asphalt-coated aggregate according to the purpose, and reusing it as a raw material for asphalt pavement. .