JP2704826B2 - Construction method of asphalt road with buried heating pipe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an asphalt road construction method in which a heating plastic pipe for preventing snow melting and freezing is embedded.

[0002]

2. Description of the Related Art When constructing an asphalt road on which a plastic pipe for heating used to prevent snow and freezing is laid on a roadbed, first, a wire mesh is laid on the roadbed, and a plastic pipe is placed on the wire mesh. After piping and fixing,
Coarse-grained asphalt concrete is supplied on a roadbed, and asphalt concrete is spread and leveled so as to embed a plastic pipe, and is compacted to form a lower layer of asphalt concrete.

Next, a method is known in which dense or fine asphalt concrete is supplied and spread on the lower layer of asphalt concrete, and then the upper layer of asphalt concrete is compacted (Japanese Patent Laid-Open No. Hei 4 (1994)).
-289301). Here, the particle size is 2.5
mm, expressed as a percentage (%) that passed through a sieve.
35, the fine particle size is 35 to 50, and the fine particle size is 50 to 80.

[0004]

The asphalt road formed by the above method is inferior in heat conductivity because the lower layer of asphalt concrete on the roadbed is a coarse-grained layer having a large number of voids. It was found that there was a problem that it could not function sufficiently. Therefore, an object of the present invention is to embed a heating pipe which is improved so as not to cause defects such as deformation in the embedded plastic pipe and to improve the thermal conductivity of the asphalt concrete layer formed on the roadbed. It is an object of the present invention to provide an asphalt road construction method.

[0005]

In order to achieve the above object, a method of constructing an asphalt road having a heating pipe embedded therein, which is a feature of the present invention, comprises laying a wire mesh on a roadbed, and heating the wire mesh on the wire mesh. After the plastic pipe is fixed by piping, dense or fine asphalt concrete is supplied onto the roadbed so as to embed the plastic pipe, and the lower layer of asphalt concrete formed by spreading and spreading the asphalt concrete is 1 to 5 tons. After preliminarily pressing under the load of
Crushing is performed under a normal load of 10 to 20 tons, then dense or fine asphalt concrete is supplied and spread on the lower layer of asphalt concrete, and the upper layer of asphalt concrete is spread under a normal load of 10 to 20 tons. It is pressed below.

[0006] The reason why the preliminary compaction load of the lower layer of asphalt concrete is set to 1 to 5 tons is that if it exceeds 5 tons, the plastic pipe for heating becomes significantly deformed and the resistance to flowing water increases. There are problems such as a problem that the heating medium does not flow and a deterioration in physical properties of the pipe. Also, if it is less than 1 ton, there is no effect of compaction.

[0007]

First, pebbles, sand, etc. are spread over the ground that has been leveled, compacted, and asphalt concrete (hereinafter simply referred to as ascon in this section) is poured on the ground to form a 4 m wide roadbed. . Then, as shown in FIG. 1, a grid-like welded wire mesh (diameter 3.2 mm, interval 150 m
m) 2 is laid, and a plastic pipe (in this example, a pipe made of crosslinked polyethylene having an inner diameter of 13 mm and an inner thickness of 2 mm) 3 is fixed in a meandering state at intervals of 150 mm.

Next, as shown in FIG. 2, densely-grained (or fine-grained) ascon heated to about 150 ° C. is supplied onto the roadbed 1 and spread so that the plastic pipes 3 are embedded to form the ascon lower layer 4. Form. After the ascon lower layer 4 is rolled with a rolling load of 1 to 5 tons by a suitable rolling machine (primary pre-rolling process), it is rolled with a macadam roller and / or a tire roller at a rolling load of 10 to 20 tons. Rolling (primary rolling process).

After the above-mentioned ascon lower layer 4 is sufficiently cooled, dense assorted (or fine-grain) ascon heated to 180 ° C. by an asphalt finisher is supplied onto the ascon lower layer 4 as shown in FIG. ,after,
The ascon upper layer 5 is rolled with a macadam roller and / or a tire roller with a rolling load of 10 to 20 tons (secondary rolling step), and the pavement is completed to form a road (thickness of the ascon lower layer 4 is 40 mm). , Thickness of Ascon upper layer 5 30m
m).

In this construction method, in order to protect the plastic pipe 3 in the primary pressing step, the supplied ascon is preferably spread by hand using a scoop or the like. If there is no fear of damaging 3, the ascon may be supplied using a suitable spreading machine. Further, when this construction method is carried out, a cooling medium (for example, tap water at 20 ° C.) is flowed through the plastic pipe 3 before ascon is supplied to suppress deformation of the plastic pipe, and the inside of the pipe is reduced to 0 °. 0.05-5 kg / cm ^2, preferably 0.5-3
It is preferable to keep the pressurized state of kg / cm ² .

The deformation of the plastic pipe according to the embodiment of the method of the present invention in which the lower layer of the ascon is formed of a coarse particle and the deformation of the plastic pipe according to the embodiment of the present invention in which the lower layer of the ascon is formed of a fine particle are measured by flatness (%). The result
The difference is 3.1 in the comparative example and 3.0 in the example, and there is almost no difference. After completion of the road, hot water of 30 ° C. was passed at a flow rate of 9.2 liters / minute, and the surface temperature of the road surface after 3 hours (outside air temperature was −2 ° C.) was 2.9 in the comparative example. ℃,
In Example, the temperature was 3.7 ° C., and it was found that the method of the present invention can improve the thermal conductivity of the ascon layer.

[0012]

The present invention is as described above, and the asphalt concrete driving operation is performed in two stages of a lower layer and an upper layer, and a preliminary piling is performed on the lower layer by minimizing the compaction load. Since the pressure is applied, the plastic pipes can be prevented from being unduly deteriorated in physical properties and deformed, and there is no fear that the use of the heating pipe after the completion of the road will be hindered. In addition, as the asphalt concrete is driven, dense or fine-grained asphalt concrete is used at any construction stage, so the thermal conductivity of the asphalt concrete layer formed on the roadbed is improved, and the heating function is sufficiently improved. Providing asphalt roads that can be used.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an initial stage of the method of the present invention in which a plastic pipe is fixed on a roadbed.

FIG. 2 is a sectional view showing an intermediate stage of the method of the present invention.

FIG. 3 is a sectional view showing the final stage of the method of the present invention.

[Explanation of symbols]

 1 is roadbed 2 is wire mesh 3 is plastic pipe 4 is asphalt concrete lower layer 5 is asphalt concrete upper layer

Claims (1)

(57) [Claims] 1. A wire net is laid on a roadbed, and a heating plastic pipe is laid on the wire net and fixed. Then, asphalt concrete of fine or fine grain size is laid on the roadbed so as to embed the plastic pipe. After the lower layer of asphalt concrete formed by spreading and flattening this was preliminarily pressed under a load of 1 to 5 tons,
Rolling under the normal load of ton, then supplying dense or fine-grained asphalt concrete on the lower layer of asphalt concrete and laying it down, then rolling the upper layer of asphalt concrete under the normal load of 10 to 20 tons. A method for constructing an asphalt road in which a heating pipe is buried.