JP3297007B2 - Surface heating element for asphalt pavement road - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface heating element for asphalt-paved roads installed for preventing snow melting and freezing of roads, sidewalks, parking lots and the like in winter snowfall areas.

[0002]

2. Description of the Related Art Roads in snowfall areas in winter have snowfall and frozen road surfaces, causing traffic congestion and consequently stagnation in logistics economy.

On the other hand, in order to prevent snow accumulation and freezing on the road surface, various measures have been taken in addition to mechanical snow removal. For example, a method of spraying a thawing agent such as calcium chloride, a method of pumping and spraying groundwater, a method of burying a hot water pipe using geothermal heat, and a method of burying an electric heating device using a nichrome wire under a road surface. Method and the like.

[0004] However, the method of spraying the above thawing agent is as follows.
There is a problem of causing deterioration of surrounding structural materials such as concrete. In addition, the above-mentioned method of pumping groundwater may cause land subsidence or water pollution in the surrounding area. Furthermore, the method of burying the above-mentioned hot water pipe has an economic problem. On the other hand, the method of burying an electric heating device is often used because the initial cost is low and the maintenance is maintenance-free, although the running cost is slightly problematic.

[0005] In the above-mentioned heat generating device, a heat generating wire such as a nichrome wire is generally used. However, when the vehicle is buried in the asphalt pavement, a pavement vehicle passes over the pavement, so that it is necessary to provide a protective layer. Since this is an artificial construction, it lowers the workability and raises the cost, and furthermore, the deeper the buried position, the greater the amount of heat generated, resulting in an energy loss. In addition, the heating wire has a disadvantage that the disconnection accident often occurs due to the flow of asphalt and the like, and its influence range is wide.

In recent years, by protecting this electric heating wire with an asphalt-impregnated sheet and using it as a sheet heater,
It is disclosed that the heating wire is prevented from being damaged and a protective layer is not required (JP-A-6-57718).

[0007]

However, in the case of the above-mentioned sheet heater, when the load of the construction vehicle is received through the asphalt aggregate, the strength of the covering material is not sufficient. There is a possibility that damage such as damage, insulation failure, disconnection, etc. may occur.

[0008] Further, the construction portion where the sheet heater is laid has a three-layer structure of the sheet heater, a base asphalt on which the sheet heater is laid, and a surface asphalt covering the sheet heater, and has a shear strength. descend.
For this reason, it is conceivable to provide an adhesive layer on the upper and lower surfaces of the planar heater to enhance the adhesiveness between the three layers and improve the shear strength.

However, when an adhesive layer is provided on the upper surface of the sheet heater in order to adhere to the surface asphalt,
It is necessary to peel off the release paper that protects this adhesive layer during construction. Furthermore, the adhesive layer of the sheet heater may adhere to tires and rollers of a construction vehicle such as a dump truck or asphalt finisher used at the time of construction, and the adhesion between the sheet heater and the surface asphalt may be hindered.

SUMMARY OF THE INVENTION It is an object of the present invention to facilitate construction of a planar heating element for an asphalt pavement road and to suppress disconnection and the like.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a base fabric in which carbon fibers and glass fibers are woven to improve the adhesiveness with synthetic rubber. The carbon fiber is covered with synthetic rubber having a hardness of 60 degrees or more, and two carbon wires are arranged on both sides of the base cloth.

Further, a base cloth made of fibers containing conductive fibers is coated with an elastomer to form a cover, and two conductive wires are arranged on the base cloth, and a gap is formed between the lower surface of the cover and the release paper. An olefin-based primer is applied on the upper surface of the above-mentioned coated body in order to enhance the adhesiveness with rubber asphalt.

[0013] Since an elastomer such as synthetic rubber is used as the covering material, the strength is high, and disconnection of the heating element against a load of a passing vehicle or the like can be suppressed.

When the upper surface of the sheet heating element is treated with the primer, adhesion to the construction vehicle can be prevented, and the adhesion to the surface asphalt can be improved.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

The sheet heating element for an asphalt pavement road (hereinafter referred to as "sheet heating element") 1 according to the present invention.
As shown in FIGS. 1A and 1B, the base cloth 11 and the cover 12
And the conductor 13.

The base fabric 11 is a woven or non-woven fabric using fibers containing conductive fibers. The conductive fibers refer to fibers having conductivity, and include carbon fibers and metal fibers. These conductive fibers generally generate heat when energized, and are therefore used as heating elements. The base fabric may be composed of only the conductive fibers, or may be composed of the heat-generating fibers and reinforcing fibers such as glass fibers, polyamide fibers, and aramid fibers. Since the reinforcing fibers have high strength, the strength of the base fabric is increased, and disconnection and the like can be suppressed.

The conducting wire 13 is used to supply electricity to the base cloth 11 and is connected to a power supply (not shown). This conductor 13
Are connected to the conductive fibers of the base cloth 11, an electric current flows through the base cloth 11 between the two conductive wires 13, and the base cloth 11 generates heat. For this reason, it is particularly preferable to arrange the two conductive wires 13 along both sides of the base cloth 11 as shown in FIG.

As an example of the base cloth 11 made of the conductive fiber and the reinforcing fiber, as shown in FIG. 1B, the warp (or weft) of the base cloth 11 made of the reinforcing fiber such as the glass fiber 21 is used. Among them, a warp (or weft) at predetermined intervals is made of conductive fiber such as carbon fiber 22, and both ends of the conductive fiber such as carbon fiber 22 are arranged on conductive wire 13. With this structure, all the conductive fibers can be energized, and the base fabric 11 itself is reinforced with reinforcing fibers. For this reason, the heat generation efficiency can be improved, and breakage of the base cloth 11 can be prevented.

The base cloth 11 may be directly covered with a coating described later, but may be subjected to a treatment for improving the adhesiveness with synthetic rubber in order to improve the adhesion with the coating described later. . Examples of this treatment include RFL treatment, epoxy treatment, latex treatment, and the like. The RFL treatment refers to a treatment of impregnating the base cloth 11 with a mixture obtained by adding a rubber latex to an initial condensate of resorcinol and formaldehyde.

The cover 12 covers the base cloth 11 and is made of an elastomer such as synthetic rubber. Since the coating 12 is required to have insulation properties, heat resistance, pressure resistance and the like, among the elastomers, ethylene-propylene rubber (EPDM), chloroprene rubber (CR), butyl rubber (IIR) and the like are particularly preferable.

The hardness of the elastomer is preferably 60 degrees or more, more preferably 60 degrees to 73 degrees. If the hardness is less than 60 degrees, there is a possibility of promoting the rut formed on the paved asphalt. Although it may be more than 73 degrees, it is more preferable to be 73 degrees or less, since a decrease in the adhesiveness between the coated base cloth 11 and the asphalt on the upper and lower surfaces thereof is suppressed, and the flow of the asphalt is more easily suppressed. .

Further, the cover 12 transmits the heat generated in the base cloth 11 to the outside quickly and efficiently.
It is preferable that the base cloth 11 is covered in a spread state.
It is preferable to adopt a shape having smooth upper and lower surfaces according to the shape of. By forming the smooth upper and lower surfaces, it becomes easy to spread on asphalt.

An adhesive layer 15 can be provided on the lower surface of the cover 12. At this time, the adhesive layer 15 is protected by the release paper 14. The adhesive layer 15 is for improving the adhesiveness to asphalt (hereinafter, referred to as “base asphalt”) on which the sheet heating element 1 is laid. Therefore, it is preferable that the adhesive used for the adhesive layer 15 has a high adhesiveness to the base layer asphalt, and an example of such an adhesive is a butyl rubber-based adhesive.

A primer 16 can be applied to the upper surface of the cover 12. On the upper surface of the planar heating element 1, a rubber asphalt sheet or a rubber asphalt-based emulsion is
Asphalt (hereinafter, referred to as “surface layer asphalt”) covering the planar heating element 1 is laminated. The above-mentioned rubber asphalt sheet or rubber asphalt-based emulsion has good adhesiveness to asphalt and is easily bonded to surface asphalt. In addition, since the upper surface of the cover 12 of the sheet heating element 1 is surface-treated by applying the primer 16, the adhesion between the sheet heating element 1 and asphalt, particularly rubber asphalt, is enhanced.

As the primer 16, it is preferable to use an olefin-based primer in order to enhance the adhesiveness with asphalt, particularly rubber asphalt. A specific example of this is Primer 459X manufactured by Lord Far East, Inc.
The coating of the primer 16 on the coating 12 can be performed by a general coating method.

Next, a method of laying the sheet heating element 1 according to the present invention on a road or the like will be described.

First, a base layer asphalt is cast, and a sheet heating element 1 is laid thereon. At this time, the sheet heating element 1 can be adhered to the base asphalt by laying the release paper 14 while peeling it off.

Next, a rubber asphalt-based emulsion is sprayed or applied on the upper surface of the sheet heating element 1. When the rubber asphalt-based emulsion is used, the upper surface of the sheet heating element 1 is treated with the primer 16, so that the upper surface of the sheet heating element 1 has improved adhesion with the rubber asphalt emulsion. The rubber asphalt emulsion is well bonded to the sheet heating element 1.

Finally, surface asphalt is cast. At this time, the rubber asphalt emulsion is bonded to the surface asphalt. Therefore, each layer of the base asphalt, the planar heating element 1, the rubber asphalt-based emulsion and the surface asphalt is bonded to each other, and integrated as a whole.

The above-mentioned rubber asphalt sheet can be used instead of the above-mentioned rubber asphalt emulsion. In this case, the temperature at the time of casting the surface asphalt is 1
Since the temperature is 50 to 180 ° C., the rubber asphalt sheet is softened at this time. For this reason, the upper surface of the planar heating element 1 treated with the primer 16 and the rubber asphalt sheet, and the rubber asphalt sheet and the surface asphalt are joined. Therefore, each layer of the base asphalt, the planar heating element 1, the rubber asphalt sheet, and the surface asphalt is bonded to each other, and integrated as a whole.

The above-mentioned rubber asphalt emulsion is used for a case where the traffic volume is relatively small or for roads where heavy vehicles are hardly passed, and the above-mentioned rubber asphalt sheet is used for a main road such as a national road. This is because the rubber asphalt sheet has better adhesiveness.

[0033]

EXAMPLES (Example 1) Withstand pressure test of planar heating element As shown in FIG. 1 (b), a base fabric 1 in which glass fibers 21 and carbon fibers 22 were woven was covered with EPDM. This E
A butyl rubber-based pressure-sensitive adhesive was applied to the lower surface of the cover 12 made of PDM, and protected with a release paper 14. Further, a primer 459X (manufactured by Lord Far East, Inc.) is applied to the upper surface of the coating 12 and
Dried for minutes.

The obtained sheet heating element is exposed and installed on an approach road of a truck scale, and the material is carried in for 10 tons.
Passing through 100 n trucks. Then, the electrical performance (insulation property, heat generation performance) of each sheet heating element was measured. As a result, performance deterioration hardly occurred.

Example 2 Field Test The sheet heating element manufactured in Example 1 was laid on a base asphalt having a thickness of 4 cm, and a rubber asphalt sheet was laid thereon. Then, a surface asphalt having a thickness of 4 cm was laid.

Next, 200,000 running tests were conducted using an experimental facility capable of applying a wheel load of 10 tf corresponding to the rear wheel load corresponding to the road bridge instruction book T-25. As a result, the sheet heating element did not promote rut digging, and further, the formation of the rut did not damage the sheet heating element laid underneath. Also, no asphalt flow was observed with respect to the shearing force in the brake zone.

[0037]

According to the sheet heating element of the present invention, the strength of the base cloth and the cover is combined, and when the surface asphalt is paved after the sheet heating element is laid, the construction vehicle directly travels on the sheet heating element. However, it does not cause disconnection or insulation damage. For this reason, there is no need to provide a curing layer such as a protective layer, and the construction speed is remarkably improved as compared with the conventional construction of a heating wire.

As for the bonding property between the asphalt and the sheet heating element, the surface of the sheet heating element was chemically treated with a primer, so that the adhesion to asphalt, especially rubber asphalt was improved, and the flow of surface asphalt was improved. Adverse effects on asphalt pavement, such as promoting rut digging and damaging the planar heating element due to rut formation, can be prevented.

Furthermore, since the surface of the sheet heating element is chemically treated with the primer, even when the construction vehicle runs directly on the sheet heating element during surface asphalt pavement after the sheet heating element is laid, the construction vehicle is not affected. Construction becomes easy without the sheet heating element adhering to the tire or the roll.

[Brief description of the drawings]

FIG. 1 (a) is a front sectional view showing an example of a planar heating element for an asphalt pavement road according to the present invention. FIG. 1 (b) is a partially cutaway plan view of FIG. 1 (a).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Planar heating element 11 Base cloth 12 Coating body 13 Conductive wire 14 Release paper 15 Adhesive layer 16 Primer 21 Glass fiber 22 Carbon fiber

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kiyoshi Yanagimoto 868-2, Fukuma, Yoshinaga-cho, Waki-gun, Okayama Prefecture Inside Tigers Polymer Co., Ltd. Okayama Plant (72) Motohiro Nishii 868, Fukuma, Yoshinaga-cho, Wake-gun, Okayama Prefecture No. 2 Inside Tigers Polymer Co., Ltd. Okayama Plant (56) References JP-A-7-1114975 (JP, A) JP-A-6-180004 (JP, A) JP-A 64-31835 (JP, U) Kaihei 7-27091 (JP, U) Jiko 48-38263 (JP, Y1) (58) Fields investigated (Int. Cl. ⁷ , DB name) E01C 11/26 H05B 3/36

Claims (1)

(57) [Claims] Claims: 1. A treatment for improving the adhesiveness with synthetic rubber on a base fabric woven of carbon fibers and glass fibers,
This base cloth is coated with a synthetic rubber having a hardness of 60 degrees or more, and two conductors are arranged on both sides of the base cloth, and the carbon fibers are heated by energizing the conductors to produce a surface for asphalt pavement. Heating element.