JPH07166508A - Thawing pavement material - Google Patents

Abstract

PURPOSE:To obtain a thawing pavement material which is water-permeable and improves the heat transfer to efficiently transfer the heat of a heater to the pavement material and effectively thaws out snow and drain the generated water downward through the pavement material. CONSTITUTION:A thawing pavement material is composed of lower and upper pavement layers 3, 8 in which granular aggregates 4, 11 are bound by a binder 5 so as to leave voids 6, 13 among the aggregates 4, 11, and a plane heater 7 between these lower and upper pavement layers 3, 8. Metallic chips 12 having a high thermal conductivity are mixed in the upper pavement layer 8 to efficiently transfer the heat of plane heater 7 to the upper pavement layer 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pavement material in a snowfall area, and more particularly to a snow melting pavement material for melting snow accumulated on the pavement material by heat.

[0002]

2. Description of the Related Art In a snowy area, snowfall is an indispensable work because it not only obstructs traffic but also causes slip accidents of people and vehicles. In the past, snow was removed by snow plows on roadways and snow was manually removed on sidewalks.However, when snowfall recently, water is always sprayed on roadways and sidewalks to melt the snow on the surface of the pavement material, and to remove water and snowmelt. Snow melting roads that drain water to gutters are also being implemented in various places. As snow melting means, water is constantly flown over the pavement material to melt the snow, or heating means such as a hot water pipe is embedded in the pavement material to melt the snow.

[0003]

However, on such a snow-melting road, a water film is formed on the surface of the pavement material, and when the person walks or the vehicle runs, the water is splashed up or the pavement material becomes unsteady. There may be water pools, which may obstruct traffic. In addition, the method of embedding the heating means in the pavement material has a drawback that the pavement material having low heat transfer is located above the pavement material, so that the pavement material is hard to warm and effective use of heat cannot be performed.

Therefore, an object of the present invention is to make the pavement itself water-permeable so that water generated by snow melting is drained downward through the pavement to prevent the formation of water films and water pools. It is an object of the present invention to provide a snow melting pavement material in which the heat transfer is improved and heat is effectively used even if a heating means for snow melting is embedded.

[0005]

The snow melting pavement material of the present invention comprises a pavement material layer in which granular aggregates are fixed so as to have voids between them, and a heating means embedded in the pavement material layer. And a metal material having good thermal conductivity is mixed in the pavement material layer located above the heat generating means in the pavement material layer.

In this case, the pavement layer is made of resin mortar in which coarse aggregate is bound with synthetic resin so as to have voids between the coarse aggregates, and the metal material is smaller than the average diameter of the coarse aggregate. You may comprise. The weight ratio of the metal material to the coarse aggregate is preferably 1/300 to 1/30.

[0007]

Since the metal material having a high thermal conductivity is mixed in the pavement material located above the heating means, the heat generated by the heating means is efficiently transmitted to the upper side of the pavement material to warm the upper pavement material. The snow that falls on the surface of the pavement is melted by the heat. Since the aggregate of the paving material layer is fixed so as to have voids, it is possible to make a porous finish,
Snow can also be melted inside the pavement layer. In addition, the water generated by snow melting is drained downward through the inside of the pavement layer, so a water film may be formed on the surface of the pavement layer, or even if the pavement layer is uneven There is nothing that can be done, and water splashes and water pools can be prevented.

In this case, the pavement material layer is made of resin mortar in which the coarse aggregate is bound with a synthetic resin so as to have voids between the coarse aggregates, whereby the pavement material can be made to have strength. By setting the size of the material to be equal to or less than the average diameter of the coarse aggregate, it is possible to make the mixing of the metal material inconspicuous and to make the finish clean. Furthermore, the heat transfer can be improved by setting the weight ratio of the metal material to the coarse aggregate to 1/300 to 1/30.

[0009]

EXAMPLE An example of a snow melting pavement material according to the present invention will be described below with reference to the drawings. On the base layer 1, an underlayer composed of crushed stone, soil, concrete, asphalt concrete or the like as in the conventional pavement. 2 is provided, and a water-permeable lower pavement material layer 3 is provided on the base layer 2 with a predetermined thickness. This lower pavement material layer 3 is
It is composed of sand, pebbles, or crushed rock, and has a grain size of 0.8-1.
Composed of resin mortar, resin concrete, coarse-grained asphalt concrete, or open-grained asphalt concrete in which 0 mm of coarse aggregate 4 is fixed with binder 5 such as polyurethane resin or epoxy resin so as to have voids 6 between these coarse aggregates 4. Has been done. The void 6 is formed so that a part thereof is connected to the adjacent void 6. On the lower pavement material layer 3, for example, strip-shaped surface heating elements 7 composed of sheet heating elements that generate heat when energized as seen in Japanese Patent Laid-Open No. 3-25881 are arranged at appropriate intervals and have a heating surface. Are provided with the above on. These surface heating elements 7 are arranged so as to extend in the width direction of the road, sidewalk, or promenade. A water-permeable upper pavement material layer 8 is provided on these surface heating elements 7 similarly to the lower pavement material layer 3, and the upper surface of the upper pavement material layer 8 is smoothed to form a road surface 9. . The upper pavement material layer 8 is composed of coarse aggregate 11 such as natural stone or ceramic balls having a particle size of 0.8 to 10 mm, and metal cutting waste such as iron, copper, stainless steel, or aluminum having good thermal conductivity. It is composed of a resin mortar in which a mixture of certain metal pieces 12 is fixed by a binder 5 so as to have voids 13 between the coarse aggregates 11. As the metal piece 12, a fine piece having a length shorter than the average particle diameter of the coarse aggregate 11 is used. The metal piece 12 is exaggerated in the drawings. The layer thickness of the upper pavement material layer 8 is smaller than the layer thickness of the lower pavement material layer 3.

In the snow melting pavement material thus constructed, the surface heating element 7 generates heat by energizing the surface heating element 7 during snowfall, and the heat is evenly distributed to the upper pavement material layer 8 including the metal pieces 12. It can be heated to a temperature higher than that of the lower pavement material layer 3 having a low heat transfer coefficient. As a result, the snow that has fallen on the road surface 9 of the upper pavement material layer 8 is melted into water and flows through the voids 6 to the lower pavement material layer 3. Since the voids 6 are also formed in the lower paving material layer 3, the water further descends and flows to the surface of the underlayer 2. If the base layer 2 is made water-permeable, water can be absorbed by the base layer 1,
When the underlayer 2 is made water impermeable, a side groove or the like may be provided on a side portion of the underlayer 2 so that water flowing on the surface of the underlayer 2 is drained. In any case, since water does not stop near the surface heating element 7, the risk of electric leakage can be eliminated. Since the lower pavement material layer 3 is also warmed to some extent by the surface heating element 7, the molten water is melted by the lower pavement material layer 3
It does not freeze inside. Further, the surface heating element 7 is inexpensive, and the construction can be performed by disposing the surface heating element 7 on the lower pavement material layer 3 at a predetermined interval and connecting each surface heating element 7 to a power source. Furthermore, since the amount of heat can be adjusted by adjusting the power supply voltage, it is possible to perform control that immediately responds to environmental changes such as fluctuations in the outside air temperature and wind strength.

Although the metal piece 12 is conspicuous in the coarse aggregate 11 and is not aesthetically pleasing, the metal piece 12 is formed into a fine piece having a length shorter than the average particle size of the coarse aggregate 11. The mixture of is not noticeable. Furthermore, if the length of the metal piece 12 is increased, the metal piece 12 may rise up and be exposed like a whiskers on the surface when performing the metal trowel finishing at the time of construction, but prevent this. You can also

Further, when the wide surface heating element 7 is used, the surface heating element 7 may be provided with through holes at appropriate intervals, and the drainage may be performed downward through these through holes. Further, in the above-mentioned embodiment, the surface heating element is used as the heating means, but a hot water pipe may be stretched around.

Explaining a concrete experimental example, 60 Kg of pebbles having a grain size of 0.8 to 10.0 mm as coarse aggregates 4 and 11 and 10 K of epoxy resin as a binder are used.
g into a 50 liter mortar mixer, and the resin mortar mixed for 2 to 3 minutes is used as the lower pavement material layer 4 in a vertical direction of 90.
cm, 90 cm wide and 1.0 cm thick,
On top of that, an organic PCT with a width of 15 cm, which is commercially available from Dainippon Ink and Chemicals, Inc. under the product name "Dielek"
The heating elements are arranged at intervals of 20 cm, and 60 kg of pebbles and 10 kg of epoxy resin are further laid on the resin mortar, and fibrous aluminum as the metal piece 12 is cut to a length of 1.0 to 2.0 mm. Experimental Example 1 in which 1.4 kg of waste was mixed to form the upper pavement material layer 8, Experimental Example 2 in which 0.2 kg of similar cutting waste was mixed to form the upper pavement material layer 8 and such cutting waste 3 types of conventional snow-melting pavement materials in which the upper pavement material layer 8 is formed without mixing the above, and 250 seconds after placing a temperature sensor on each upper pavement material layer 8,
The change in surface temperature after 500 seconds, 750 seconds and 1000 seconds was measured. The results are shown in Table 1. The thickness of each upper pavement material layer 8 was 0.8 cm, the room temperature in the laboratory was 21 ° C., the humidity was 42%, and the surface temperature of each upper pavement material layer 8 before the experiment was 21 ° C. .

[0014]

[Table 1] From this table, in Experimental Examples 1 and 2, the temperature increased to 25 ° C. and 23.7 ° C. after 250 seconds and increased to 32.2 ° C. and 30.3 ° C. after 1000 seconds, that is, after about 17 minutes. On the other hand, in the conventional example, 250 seconds later is 2
After 1000 seconds at 3.2 ° C., the temperature increased only to 29.3 ° C. From this experiment, it can be seen that the thermal conductivity can be improved by mixing the metal pieces in a weight ratio of 1/300 or more with respect to the coarse aggregate, and a snow melting pavement material with good thermal conductivity can be provided.

Although 10 liters of water was sprayed, the water was drained downward through the pavement material within 10 seconds, and no water film was formed on the surface of the pavement material.

[0016]

As described above, the snow melting pavement material of the present invention is
A pavement having a pavement material layer in which granular aggregates are fixed so as to have voids between them and a heat generating means embedded in the pavement material layer, and which is located above the heat generating means in the pavement material layer. Since the material layer is mixed with a metal material with good thermal conductivity, the heat generated by the heating means is efficiently transferred to the upper part of the paving material, and the upper paving material can be warmed and fell on the surface of the paving material. The heat can melt snow. Since the aggregate of the pavement layer is fixed so as to have voids, it can be made into a porous finish, snow can be melted even inside the pavement layer, and the water generated by the snow melting can generate water in the pavement layer. Since water is drained downward through the inside of the pavement layer, there is no formation of a water film on the surface of the pavement layer, and there is no water pool even if the pavement layer is uneven, and water splashes and water pools occur. Can be prevented.

In this case, as described in claim 2, the paving material layer is composed of resin mortar in which coarse aggregate is bound with synthetic resin so as to have voids between the coarse aggregates, and the metal material is coarse aggregate. By configuring the pavement material to have a size equal to or less than the average diameter, the mixing of the metal material becomes less noticeable by setting the size of the metal material to be equal to or less than the average diameter of the coarse aggregate, and The surface can be finished smooth.

Further, as described in claim 3, the heat transfer can be improved by setting the weight ratio of the metal material to the coarse aggregate to be 1/300 to 1/30.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view schematically showing a part of an embodiment of the snow melting pavement material of the present invention.

[Explanation of symbols]

 2 Underlayer 3 Lower pavement material layer 4,11 Coarse aggregate 5 Binder 6,13 Void 7 Surface heating element 8 Upper pavement material layer 12 Metal piece

Claims (3)

[Claims] 1. A pavement material layer in which granular aggregates are fixed so as to have voids between them, and a heat generating means embedded in the pavement material layer, wherein the pavement material layer includes: A snow melting pavement material, wherein a metal material having a high thermal conductivity is mixed in the pavement material layer located above the heat generating means. 2. The paving material layer is a resin mortar in which coarse aggregate is bound with a synthetic resin so as to have voids between the coarse aggregates, and the metal material has a size equal to or smaller than an average diameter of the coarse aggregate. The snow melting pavement material according to claim 1, wherein the snow melting pavement material is 3. The snow melting pavement material according to claim 1, wherein the weight ratio of the metal material to the coarse aggregate is 1/300 to 1/30.