JPS63122809A - Asphalt forcible cooling method in asphalt paving - 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 (Industrial Application Field) The present invention provides an asphalt forcible system that can forcibly cool the asphalt heat in a short time during asphalt pavement work, thereby shortening the construction period. It concerns cooling methods.

(Prior art) As shown in Figure 3, asphalt pavement is usually made by laying basic gravel on top of the subgrade A to form the lower subgrade B, and then placing fine-grained finishing gravel on top of it. After laying an upper base course C consisting of, a base layer made of coarse-grained asphalt is paved on top of the upper base course C, and a surface layer E made of dense-grained asphalt is further paved on the base layer.

The asphalt used for such paving work is at a high temperature of 150 to 160 degrees Celsius when it arrives at the site, and even when it is paved and compacted, the surface is around 90 degrees Celsius and the inside is around 140 degrees Celsius. maintains a high temperature. For this reason, in this type of pavement work,
After the base layer has been paved and compaction completed, the base layer asphalt must be cooled once before forming the surface layer E.

However, as a means of cooling this base layer asphalt,
Conventionally, the reality is that we have relied on a natural cooling method in which stiffness is left undisturbed for about two hours a day and night.

When such natural cooling methods are used, the construction period becomes longer, which not only lengthens the period during which traffic is unavailable and causes noise and vibration, but also tends to increase construction costs. Also, because it is left alone day and night, the surface of the base layer may become uneven due to external causes.

Furthermore, in the case of so-called spot paving that is carried out in conjunction with repair or replacement work for buried pipes F such as gas pipes or water pipes (for example, when paving only the areas that are not shaded in Figure 3), ), a level difference corresponding to the thickness of the surface layer E is created with respect to the road surface G, which poses a danger when driving a vehicle during the daytime during the cooling period, and also causes traffic congestion.

(Purpose) In view of these points, the present invention forcibly cools the heat of asphalt in a short time, shortens the construction period of the four types of asphalt pavement construction, and thereby improves the efficiency of the natural cooling method described above. The object of the present invention is to provide a method for forced cooling of asphalt in asphalt pavement, which solves various problems and can obtain the same level of pavement condition as with natural cooling.

(Structure) In order to achieve the above object, the present invention sprays water on the asphalt surface after the completion of compaction of the asphalt layer, and disperses the water on the asphalt surface by blowing air at the same time or immediately after this watering. It is also characterized in that it forcibly cools the asphalt by removing latent heat.

(Examples) Hereinafter, the present invention will be described in detail based on illustrated examples.

FIG. 1 shows a cross-sectional view of a road on which so-called 75-type pavement work was performed using a method according to an embodiment of the present invention.

First, the lower base course 1 has a thickness of 300 mm, and the upper base base 2 has a thickness of 300 mm.
are each formed to a thickness of 100n+m, and on top of this, first 100m1 of coarse-grained asphalt is applied! The base layer 3 with a thickness of 300 mm is formed by repeating the same operation three times. Since the base layer 3 is in a high temperature state as described above, a cooling device S shown in FIG. 2 is installed on this surface to forcibly cool it down.

This device S includes a hanging plate 5 which also serves as a rear agitating plate for the cargo platform 4.
The vehicle M is movable up and down toward the road surface and functions as a lid, and a water storage tank 6 is mounted in front of the cargo platform 4, and a blower 7 is mounted in the middle part. The capacity of the water storage tank 6 and the displacement of the blower 7 are appropriately selected depending on the loaded weight of the vehicle M and the like.

The suspension plate 5 is designed to be held horizontally with respect to the road surface at a predetermined interval when lowered, and a plurality of water sprinklers 8 or water pipes 8 are provided on the lower surface of the suspension plate 5 along the width direction of the vehicle M. The book is fixed. This sprinkler pipe 8 is connected to the water storage tank 6 and the pipe line 9.
There is a refrigerator 10 in the middle of the pipe 9.
The water that has been cooled is discharged downward from a nozzle (not shown) of the sprinkler pipe 8, that is, toward the road surface.

Further, a cylindrical air retention chamber 11 is attached to the suspension plate 5 at the rear of the water sprinkler pipe 8 along the width direction of the vehicle M.

This air retention chamber 11 has an air discharge port on the lower surface,
Further, a baffle plate 12 is attached along this discharge port so as to be inclined rearward.

The air retention chamber 11 is connected to a relay hose 13 via a flange pipe.
One end of the relay hose 13 communicates with the other end of the air blower 7.
It is connected to the. The relay hose 13 connects the air retention chamber 1
It is desirable to attach a plurality of pieces along the longitudinal direction of the piece.

In the figure, reference numeral 14 indicates a generator similarly mounted on the loading platform 4 of the vehicle M, and 15 indicates a compressor for the blower.

After lowering the suspension plate 5, the device S that has entered the base layer 3 opens a valve (not shown) installed in the middle of the cooling water pipe 9 and turns the operation switch of the blower 7 ON/OFF to slowly move the vehicle M. It travels from one end of the base layer surface to the other end at the same speed.

As the vehicle M travels, cooling water is ejected from the nozzle of the water sprinkler pipe 8 to lower the temperature of the asphalt of the base layer 3. At this time, some of the cooling water sprayed onto the hot asphalt becomes steam and diffuses, taking away the heat of vaporization. Isn't there a separate limit on the temperature of the cooling water? In this example, it is 2°C.
is set to .

Simultaneously with the jetting of the cooling water, air is jetted at a predetermined pressure toward the asphalt surface from the air discharge port of the air retention chamber 11. Since the air outlet is provided at the rear of the water sprinkler pipe 8, the air disperses the cooling water on the asphalt surface, promotes water vaporization of the cooling water, and evenly cools the asphalt surface by removing latent heat. . Further, this air flow is urged in the traveling direction of the vehicle M by a baffle plate 12 provided at the rear end of the air discharge port, and efficiently collides with the cooling water.

By repeatedly running this device S on the asphalt surface several times, the high-temperature asphalt forming the base layer 3 is rapidly cooled. Therefore, after completing the launch of base layer 3,
Asphalt as the surface layer 16 can be laid without much time. In the case of 75 type, this surface layer 16
is set to a thickness of 50 mm. And this surface layer 16
By running this device S, the asphalt surface is forcibly cooled down in a short time by the action of water and wind. In this way, the asphalt pavement work, which conventionally took two days and nights, was completed in one night.

In FIG. 1, reference numeral 17 indicates a concrete curb, and 18 indicates a road shoulder made of asphalt.

By the way, when using this device at night when the temperature is 25℃,
The experimental results for spot paving with an area of 2 are shown below.

In addition, the water storage N! used in this experimental example! 4 is 1.5
t, and the amount of air sent by the blower 7 is! 50111'/min.

From this experimental example, it can be seen that after the base layer 3 and the surface layer 16 are laid, the asphalt surface is rapidly cooled by using this apparatus.

In this experiment, a road that was closed at P, M, 21.00 could be opened the next day, at A, M, 5.0 (l).
A, M, 4.05i4, surface treatment or finishing compaction added). Furthermore, the density after paving the road and the results of the Marshall stability test were also good and no different from the conventional ones (surface temperature 45°C to 50°C, softening point 51.5°C).

In the above embodiment, a water storage tank and a blower are mounted on one vehicle as the cooling device S, and cooling water and air are injected onto the asphalt surface from this single device. However, the present invention is not limited to this embodiment, and the water storage tank and the blower are mounted on different devices, and the device equipped with the water spraying means is first run on the asphalt surface, and then the air injection means is immediately applied. A similar effect can be achieved by dispersing water by running the installed device.

(Effects) As described above, according to the present invention, since water is first sprayed on the asphalt surface after completion of rolling to cool it, the temperature of the asphalt can be lowered in a short time. Moreover,
Since air is sent towards the asphalt surface immediately after water is sprayed, the water on the asphalt surface can be dispersed appropriately and the asphalt can be cooled evenly, and the asphalt can be rapidly cooled by removing latent heat. It is possible to do this. Therefore, after forming one layer made of asphalt, another layer made of asphalt etc. can be immediately paved on top of it without waiting for natural cooling time.
The paving work can be shortened, and various inconveniences associated with this type of work, which takes two days and nights, such as spot paving, can be eliminated.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a paved road constructed using an embodiment of the present invention, Fig. 2 is an explanatory diagram of a forced cooling device used in the present invention, and Fig. 3 is a cross-sectional view of a road showing spot paving work. It is a diagram. In the figure, 8.1 is the lower roadbed, C92 is the upper roadbed, D, 3
is the base layer, S is the strong IIJ cooling system, M is the vehicle, 4 is the loading platform,
5 is a hanging board, 6 is a water storage tank, 7 is a blower, 8 is a water pipe,
11 is an air retention chamber, 12 is a baffle plate, 3 is a relay hose, F, and 16 are surface layers, respectively.

Claims (1)

[Claims] After the compaction of the asphalt layer is completed, water is sprinkled on the asphalt surface, and air is blown at the same time or immediately after this watering to disperse the water on the asphalt surface and to forcibly cool the asphalt by removing latent heat. Characteristic forced cooling method of asphalt in asphalt pavement.