JPS58110706A - Regeneration of asphalt paving waste material - 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 the replacement and repair of existing asphalt reinforcement, and also to the recycling of asphalt pavement waste generated when equipment buried under the existing asphalt reinforcement is removed. .

A general method for recycling conventional asphalt pavement waste H is to first crush large chunks of waste excavated from road construction, etc. using a crushing means, and then to form asphalt coatings on the surface of the aggregate (units of aggregate particles). The crushing methods include a mechanical crushing method in which rough-split waste material is crushed and crushed using a primary rasher and a show crusher, and a secondary crusher using an impact crusher, etc.; There is a thermal crushing method in which the waste material is immersed in steam to soften the asphalt contained in the waste material (1), and then the material (1) is mechanically agitated to break the bonds. The crushed waste particles generated by the crushing means are sieved and classified by particle size, e.g.
13% to 13%, 5% to 13%, 5% to 25%, 25% to below L1 Storage in storage hopper L1 Depending on the type of asphalt mixture to be manufactured, take out the waste material from the storage hopper as appropriate 1 Rotatably It is supplied to a drum mixer, which is a heating device that is pivotably supported, and a scraper 1- disposed inside the drum mixer.
The waste is moved down while being scraped up by feathers, and hot air is sent in the same direction as the direction of movement of the waste to heat and regenerate the waste. In addition, if necessary, the heated waste material discharged from the drum mixer is supplied to the after mixer to replenish the asphalt that is missing, and a softening agent that rejuvenates aged asphalt is added and mixed homogeneously for regeneration.

However, when the waste material is crushed using the above-mentioned crushing method, a large amount of fine particles of the waste material are generated, and thus, various problems are caused when the waste material is supplied to the tram mixer.

Figure 1 is a passage rate curve showing the particle size distribution of crushed waste particles when waste is crushed using a show crusher, an impact crusher, and a thermal crushing method.
% or less fine particles is approximately 15% by weight in the show crusher,
The impact crusher yields approximately 30 M·χ′, and the thermal crushing method yields approximately 107 Ij·Da. Since the surface area of such fine particles, especially # particles, is larger than that of piled waste, a relatively large amount of asphalt adheres to the surface. When the asphalt content deteriorates due to
When the components contained in the smoke burn and the smoke from the chimney turns yellow on a clear day, when the water vapor disappears, it produces white trailing smoke called blue smoke. This flue gas has a bad odor from burning asphalt, and there is a concern that it may cause odor pollution.
°It is also thought to contain harmful substances. For this reason, either lower the heat sent to the drum mixer Q to prevent the asphalt from overheating, or spray water with a relatively large specific heat to the waste material C. Countermeasures have been taken to increase the amount by 1 and supply it to the drum mixer fK. If the L or L1 hot air temperature is lowered, the desired production capacity will not be reached, and if the waste wood is moistened, the presence of water on its surface causes more heat M of the hot air to be consumed in evaporation of water, resulting in heat loss. .

The present invention aims to improve these drawbacks, and the present inventor discovered that when the fine particles of crushed waste particles are heated and stirred, the asphalt that covers the waste particles softens and the particles of waste particles become sticky. Focusing on the fact that the particles become larger when they combine (hereinafter referred to as "grain enlargement"), we have created asphalt that coats the waste particles by heating and stirring only the finer particles of the crushed waste particles before feeding the waste to the tram mixer. The waste material particles are softened and the waste material particles are adhesively bonded to increase the particle size and heat capacity is increased.The waste material fine particles are supplied to a tram mixer together with the waste material coarse particles at a desired blending ratio, and hot air is passed through the drum mixer. The waste material is heated and regenerated using the following method.

In addition, the present invention uses petroleum fractionated oil (Shell Petroleum,
In order to increase the grain-enhancing effect, we focused on increasing the grain-enhancing effect by adding products such as Mobil Oil, etc. 1. Before feeding the waste material to the drum mixer, only the fine particles of the crushed waste material were heated and stirred with the addition of an appropriate softening agent. The asphalt that covers the waste particles is softened and the waste particles are adhesively bonded to increase the particle size and heat capacity, and the fine particles are mixed with the coarse particles of the waste at a desired blending ratio. The waste material is heated and regenerated by heat K supplied to the tram mixer and passed through the drum mixer.

Figure 1 is a passage rate curve showing the particle size distribution obtained by sample measurement of crushed waste particles when waste materials are crushed using a show crusher, an impact crusher, or a thermal crushing method.
According to this, the impact crusher generates about 30% by weight of fine particles of waste material with a particle size of 25% or less. The fine particles of this waste material are heated and stirred in a test chamber until the temperature of the waste material reaches 6".
The second sample was obtained by measuring the particle 1+ distribution of waste particles each time by increasing the temperature stepwise from C, go℃ + 00'c to 120'c.
It is a diagram. In other words, when waste material is heated to about 60°C or higher, the asphalt coating the surface of the waste material particles softens and increases its adhesive strength, causing the waste material particle quanta to adhesively bond and become relatively large in particle size, which lowers the temperature of the waste material. It is recognized that the grain enlarging effect increases as the temperature increases.

Figure 3 shows a commercially available oil-fractionated tomesode (product of Shell Oil, Mobil Oil, etc.), which is added as a softening agent to rejuvenate asphalt that has aged due to aging during road construction, to the waste material at a rate of 1.5% by weight. Heat the waste material at 60℃ while adding
It is a passage rate curve showing the particle size distribution of waste material particles when the temperature is raised to 0°C. Since the softener restores the properties of aged asphalt to zero, it is recognized that the addition of the softener has a remarkable effect of enlarging the waste material particles.

Softeners are usually recycled waste discharged from drum mixers1),
' Since it is added at about 0.5% by weight to CC, the softening agent is 1+t commensurate with the weight of fine particles in the recycled waste material.
What is necessary is to add it to the fine particles of the waste material to be enlarged. If a softener is added during granulation, the granulation effect can be enhanced even at the same heating temperature, and furthermore, the softener can be added earlier than when added to the 111 waste material after being discharged from a drum mixer, as is the case in the past. can promote the recovery of the properties of aged asphalt.

The fine particles of the waste material are supplied to the drum mixer together with the coarse particles of the waste material at a desired blending ratio, and the waste material is blown by the hot air C passing through the drum mixer.
It is regenerated by heating to around 60°C.

As described above, in the present invention, only the fine particles of crushed waste particles are heated and agitated to increase the particles, and this is supplied to the tram mixer together with the coarse particles of the waste material at a desired blending ratio, so the KL is heated in the drum mixer. By increasing the heat capacity by enlarging the fine particles of waste material that were easy to burn, especially the fine particles, it is possible to minimize the asphalt content due to overheating. It becomes less.

Further, by adding a softening agent when only the fine particles of the crushed waste particles are heated and stirred in advance, the effect of enlarging the waste particles can be further enhanced.

[Brief explanation of the drawing]

In the figure, Fig. 1 is a graph showing the distribution of crushed waste particles in particle 1 of the crushing method L of waste tote 21, and Fig. 2 is a graph showing the particle size of the waste particles when fine particles of the crushed waste particles are heated and stirred. Figure 3 is a graph showing the particle size distribution of waste particles when the fine particles of crushed waste particles are heated and stirred while adding a softener.Patent applicant Nikko Co., Ltd.-3 ' Fig. 1, 5. Uttsssn! (proboscis) Fig. 2

Claims (2)

[Claims] (1) Only the fine particles of crushed waste particles generated by crushing asphalt pavement waste are heated and stirred in advance to soften the asphalt covering the waste particles and adhesively bond the waste particle particles to increase the heat capacity. Feed the fine particles of waste material to the drum mixer L1 together with the coarse particles of waste material at a desired mixing ratio
A method for recycling asphalt pavement waste material, characterized in that the waste material is heated and recycled by passing it through a drum mixer. (2) Only the fine particles of crushed waste particles generated by crushing asphalt pavement waste are heated and stirred while adding an appropriate amount of softener to soften the asphalt covering each waste particle and adhesively bond the waste particle quantum. 1. A method for recycling asphalt pavement waste material, characterized in that: 1. the fine particles of the waste material are supplied to a drum mixer together with the coarse particles of the waste material at a desired mixing ratio; 1. the waste material is heated and regenerated by hot air passing through the drum mixer. .