JP7684105B2 - Concrete pavement, precast body, their manufacturing method and non-contact type power supply runway - Google Patents

Description

The present invention relates to concrete pavement and precast bodies used in facilities that supply power to charging objects on the road surface in a non-contact manner, manufacturing methods for these, and non-contact type power supply running roads.

The electric field coupling method, which is one of the methods of wireless power supply, is a method in which electrodes are installed on both the power supply side and the power receiving side, and power is transmitted using the electric field that is generated when the electrodes are brought close to each other. When using the electric field coupling method to supply power to a target to be charged, such as an electric vehicle, without contact via the road surface, the electrode on the power supply side is buried inside the pavement of the road surface. Research is being conducted into structures to improve the power supply efficiency of such facilities for contactless power supply via the road surface.

For example, Patent Document 1 proposes a member made of a material in which an asphalt material or cement-based material is mixed with a substance whose relative dielectric constant or dielectric tangent, or both, are lower than those of general aggregates. Patent Document 2 also proposes cement asphalt emulsion mortar, dense-graded asphalt mixture, and polymer-containing cement concrete as paving materials.

JP 2017-163798 A Patent No. 5374657

To achieve high power supply efficiency with the electric field coupling method, it is important to maximize the effect of electrostatic induction in the electric field that occurs when an AC voltage is applied. Therefore, it is preferable for the pavement to have a high relative dielectric constant. Also, to reduce energy loss in the transmitted power, it is preferable for the pavement to have a low dielectric tangent.

The components described in Patent Document 1 use a pavement containing a material with a lower dielectric constant than general aggregate, which reduces the dielectric constant of the pavement. Patent Document 2 also proposes a concrete pavement material made of cement asphalt emulsion mortar, dense-graded asphalt mixture, or polymer-containing cement, but does not provide any justification or detailed explanation for this.

The present invention was made in consideration of these circumstances, and aims to provide concrete pavement and precast bodies that have a high relative dielectric constant and low dielectric tangent, and that can achieve high power supply efficiency when used for non-contact power supply, as well as manufacturing methods for these and non-contact power supply running paths.

(1) In order to achieve the above object, the concrete pavement of the present invention is a concrete pavement used in a facility for contactlessly supplying power to a charging target on a road surface, and is characterized by comprising aggregate, a hardened cement body that binds the aggregate together, and a polymer that is present in the gaps between the aggregate and the hardened cement body, and having a dielectric loss tangent of less than 0.1.

Polymers have a higher dielectric constant and a lower dielectric tangent than aggregates. Therefore, by including polymers in concrete pavement as described above, the dielectric constant increases and the dielectric tangent decreases. As a result, when power is supplied contactlessly through this concrete pavement, high power supply efficiency can be obtained. In addition, polymers are water repellent, and when used on a road surface, they can prevent moisture from penetrating into the interior. As a result, energy loss during power supply due to moisture penetration can be suppressed, and insulation failure between the power supply electrodes and leakage onto the road surface can be prevented.

(2) The concrete pavement of the present invention is also characterized in that the mass ratio P/C of the unit amount P of the polymer to the unit amount C of cement in the concrete is 5% or more and 25% or less.

As such, because the P/C is 5% or more, the dielectric tangent is reduced, the relative dielectric constant is increased, and waterproof performance is improved. On the other hand, because the P/C is 25% or less, it has sufficient strength to support frequent vehicle traffic.

(3) The concrete pavement of the present invention is also characterized in that the polymer is a styrene-butadiene copolymer. This improves the corrosion resistance of the electrodes.

(4) The concrete pavement of the present invention is a concrete pavement used in a facility for contactlessly supplying power to a charging target on a road surface, and is characterized by comprising aggregate, a hardened cement body that binds the aggregate together, and a rapid-hardening admixture that is present in the gaps between the aggregate and the hardened cement body, and having a dielectric loss tangent of less than 0.1.

Rapid-hardening admixtures have a higher dielectric constant and a lower dielectric tangent than aggregates. Therefore, by including rapid-hardening admixtures in concrete pavement as described above, the dielectric constant increases and the dielectric tangent decreases. As a result, when non-contact power supply is performed through this concrete pavement, high power supply efficiency can be achieved.

(5) The concrete pavement of the present invention is also characterized in that the mass ratio F/B of the unit amount F of the rapid-hardening admixture to the total amount B of the unit amount of cement in the concrete and the unit amount of the rapid-hardening admixture is 10% or more and 50% or less.

Since F/B is 10% or more, the dielectric tangent is reduced and the relative dielectric constant is increased. As a result, high power supply efficiency can be obtained. On the other hand, since F/B is 50% or less, it has sufficient strength to support frequent vehicle traffic.

(6) The concrete pavement of the present invention is also characterized in that the amount of air mixed into the concrete is in the range of 2.0 vol% or more and 8.0 vol% or less of the total. Since the dielectric tangent of air is 0, the dielectric tangent is reduced by including 2.0 vol% or more of air in the concrete pavement. As a result, energy loss can be reduced and high power supply efficiency can be obtained. It is more preferable that the amount of air mixed into the concrete at the fresh concrete stage is 4.0 vol% or more of the total. On the other hand, the relative dielectric constant of air is 1, and by including 8.0 vol% or less of air in the concrete, the relative dielectric constant of the concrete pavement can be maintained high and high strength can be maintained.

(7) The concrete pavement of the present invention is also characterized in that the aggregate contains aggregate with a dielectric tangent of less than 0.1. This reduces energy loss due to the concrete pavement, and allows for high power supply efficiency.

(8) The concrete pavement of the present invention is also characterized in that the aggregate contains aggregate with a relative dielectric constant of 2.0 or more. This allows for high power supply efficiency.

(9) The concrete pavement of the present invention is also characterized in that the aggregate is a ceramic body of an oxide containing one or more elements of Al, Mg, and Si, and contains a sintering aid having a melting point lower than that of the oxide.

When alkali metals such as Na and K are contained as impurities in aggregate, the dielectric tangent increases. By including a sintering aid, alkali metal ions are captured in the pores in the crystal structure during the aggregate firing process, suppressing the movement of ions in the crystals and reducing the dielectric tangent.

(10) Furthermore, the non-contact type power supply runway of the present invention is characterized in that the road surface is formed by the concrete pavement described above in (1) to (9). The wheels of vehicles such as self-driving cars, monorail tracks, and forklifts in factories pass over the same spot many times. If the non-contact type power supply runway is constructed with concrete pavement material as described above, it will have better abrasion resistance than asphalt and can be used for a long time.

(11) The precast body of the present invention is a precast body used in a facility that supplies power to a charging target on a road surface in a non-contact manner, and is characterized in that it comprises aggregate, a hardened cement body that binds the aggregate together, and a polymer that is present in the gaps between the aggregate and the hardened cement body, and has a dielectric tangent of less than 0.1. This allows the concrete pavement to be prepared in advance in a factory and assembled on site, reducing the workload on site.

(12) The precast body of the present invention is a precast body used in a facility that supplies power to a charging target on a road surface in a non-contact manner, and is characterized in that it comprises aggregate, a hardened cement body that binds the aggregate together, and a fast-hardening admixture that is present in the gaps between the aggregate and the hardened cement body, and has a dielectric tangent of less than 0.1. This allows the concrete pavement to be prepared in advance in a factory and assembled on site, reducing the workload on site.

(13) Furthermore, the non-contact type power supply runway of the present invention is characterized in that the road surface is formed from the precast body described in (11) or (12) above. This reduces the workload on site, provides excellent wear resistance, and enables long-term use.

(14) The method for producing concrete pavement of the present invention is used in a facility for contactlessly supplying power to a charging target on a road surface, and includes the steps of: producing concrete by measuring and mixing aggregate, cement, water, and polymer so that the mass ratio P/C of the unit polymer blend amount P to the unit cement amount C is 5% or more and 25% or less; and forming a road surface using the produced concrete. This reduces the dielectric tangent of the concrete pavement, increases its relative dielectric constant, improves its waterproof performance, and provides it with sufficient strength to support frequent vehicle traffic.

(15) The method for producing concrete pavement of the present invention is used for a facility that supplies power to a charging target on a road surface in a non-contact manner, and includes the steps of: producing concrete by measuring and mixing aggregate, cement, water, and a fast-setting admixture such that the mass ratio F/B of the unit amount of fast-setting admixture F to the total amount B of the unit amount of cement and the unit amount of the fast-setting admixture is 10% to 50%, and forming a road surface using the produced concrete. This reduces the dielectric tangent of the concrete pavement and increases its relative dielectric constant. As a result, high power supply efficiency can be obtained, and the pavement can have sufficient strength to support frequent vehicle traffic.

(16) The method for producing a precast body of the present invention is used in a facility for contactlessly supplying power to a charging target on a road surface, and is characterized by including the steps of: producing concrete by measuring and mixing aggregate, cement, water and polymer so that the mass ratio P/C of the unit polymer blend amount P to the unit cement amount C is 5% to 25%, and forming a formwork, pouring the produced concrete into the formwork, and steam curing to produce a precast body. This allows a precast body with high power supply efficiency, waterproof performance and strength to be prepared, improving work efficiency at a paving site.

(17) The method for producing a precast body of the present invention is a method for producing a precast body used in a facility that supplies power contactlessly to a charging target on a road surface, and is characterized by including the steps of: measuring and mixing aggregate, cement, water, and a fast-setting admixture so that the mass ratio F/B of the unit blend amount F of the fast-setting admixture to the total amount B of the unit cement amount and the unit blend amount of the fast-setting admixture is 10% to 50%, to produce concrete; and forming a formwork and then pouring the produced concrete into the formwork to produce a precast body. This allows a precast body with high power supply efficiency and strength to be prepared, improving work efficiency at a paving site.

According to the present invention, concrete pavement or precast concrete has a high relative dielectric constant and a low dielectric tangent, and when used for non-contact power supply, high power supply efficiency can be obtained.

1A and 1B are a schematic diagram showing a power supply facility of the present invention and a diagram showing its equivalent circuit, respectively.

The following describes an embodiment of the present invention. The described embodiment is a preferred example, and the present invention is not limited to this.

[Power supply facilities]
1(a) and 1(b) are a schematic diagram of a power supply facility and a diagram showing its equivalent circuit, respectively. As shown in FIG. 1(a), a power supply facility 100 is composed of a power supply device 110 and a concrete pavement 120.

The power supply device 110 is buried in the soil 800 below the concrete pavement 120, and includes a high-frequency power source 111 and a power supply electrode 112. The high-frequency power source 111 applies an AC voltage to the power supply electrode 112 at a predetermined frequency, for example, 13.56 MHz. The power supply electrode 112 is provided on the back side of the concrete pavement 120, and electrostatic induction occurs in the object to be charged by applying an AC voltage via the concrete pavement 120. In this way, it becomes possible to supply power to the object to be charged in a non-contact (wireless) manner.

The object to be charged may be, for example, an electric vehicle that is configured to be rechargeable. The type of vehicle is particularly effective for passenger cars, but is not limited to this and may also be a forklift, construction vehicle, or monorail vehicle. In addition, the object to be charged may also be any device that requires charging, not limited to vehicles.

In the example shown in FIG. 1(a), an electric vehicle 900 is shown as a model to be charged. The electric vehicle 900 has a front tire 910, a wheel 920, a shaft 930, an on-board circuit 940, and a motor 950. When charging, the electric vehicle 900 is driven and stopped so that the front tire 910 is positioned directly above the power supply electrode 112. Then, when a voltage is applied from the power supply side, the wheel 920 functions as a power receiving electrode, and a current flows through the shaft 930, charging the on-board circuit 940. The motor 950 is then driven by the newly charged power.

As shown in FIG. 1(b), when the example of the contactless power supply system shown in FIG. 1(a) is represented by an equivalent circuit, it becomes an RLC series circuit with the concrete pavement 120 as the dielectric. As can be seen from this equivalent circuit, whether the energy of the high frequency power supply 111 can be provided to the on-board circuit 940 with high efficiency depends on the constituent material of the concrete pavement 120.

The concrete pavement 120 is made of concrete pavement material described below, and forms the road surface of the non-contact type power supply runway. As a result, the concrete pavement 120 has a high relative dielectric constant and a low dielectric tangent, and when used for non-contact power supply, high power supply efficiency can be obtained. Non-contact type power supply runway is used, for example, as a road for automobiles, a parking lot, a track such as a monorail, or a floor in a factory where a moving object runs. Autonomous automobiles, monorail vehicles, forklifts in a factory, etc., use the power supply facility 100 for a long period of time by multiple vehicles, so the wheels pass the same place many times. Concrete pavement material has better wear resistance than asphalt, and when used for a non-contact type power supply runway, it can be used for a long period of time.

If moisture penetrates into the road surface, the dielectric tangent of the concrete pavement material increases, resulting in greater energy loss. It also becomes difficult to ensure insulation between the electrodes on the power supply side and between people and other equipment on the road surface. Therefore, it is preferable to prevent moisture from penetrating into the road surface.

[Concrete pavement composition]
The concrete pavement 120 includes concrete pavement materials including aggregate, hardened cement body, and at least one of a polymer and a rapid hardening admixture. The aggregate is not limited to general aggregate (a collection of mineral particles) consisting of gravel or sand, but may be a collection of ceramic particles. The hardened cement body is cement hardened by a hydration reaction, and bonds the aggregates together. A polymer is a compound formed by polymerizing multiple monomers into a chain or network, and exists in the gaps between the aggregate and the hardened cement body.

As described above, the inclusion of a polymer or a fast-setting admixture, which has a higher dielectric constant and a lower dielectric tangent than aggregate, increases the dielectric constant of the entire concrete pavement 120 and decreases the dielectric tangent. As a result, when non-contact power supply is performed through the concrete pavement 120, high power supply efficiency can be achieved. In addition, it is preferable that both a polymer and a fast-setting admixture are included, in which case higher power supply efficiency can be obtained. In addition, the polymer is water-repellent, and the polymer fills the voids inside the concrete, suppressing the formation of continuous air layers, and when used on a road surface, it is possible to prevent moisture from entering the inside. As a result, energy loss during power supply due to moisture intrusion can be suppressed, and insulation failure between the power supply electrodes and leakage onto the road surface can be prevented. Note that the polymer can be effective in preventing moisture intrusion if it is included to an extent that can be detected by infrared spectroscopy (FT-IR).

The polymers that can be used include styrene-butadiene copolymers (latex), polyacrylic acid ester copolymers, ethylene-vinyl acetate copolymers, vinyl acetate copolymers, polychloroprene, etc. Of these, styrene-butadiene copolymers (latex) are most preferred from the viewpoint of corrosion resistance to electrodes.

Latex is water repellent (waterproof) and can prevent moisture from penetrating into the road surface. When moisture penetrates into the concrete pavement 120, the dielectric tangent increases, resulting in large energy loss when AC voltage is applied. By using latex, energy loss associated with an increase in the dielectric tangent due to moisture penetration can be suppressed, and poor insulation between the power supply electrodes 112 and leakage current onto the road surface can be prevented.

The polymer content is preferably controlled such that the mass ratio P/C of the unit amount of polymer (polymer addition amount) P to the unit amount of cement (cement addition amount) C at the fresh concrete stage is 5% or more and 25% or less. Since P/C is 5% or more, the dielectric tangent can be lowered, the relative dielectric constant can be increased, and waterproof performance can be improved. On the other hand, since P/C is 25% or less, it can support frequent vehicle traffic with sufficient strength. The lower limit of P/C is more preferably 10% or more, and the upper limit is more preferably 20% or less. It is preferable that the mass ratio of the polymer addition amount P is a constant sum of the amount of polymer-containing admixture and the amount of water. This makes it possible to suppress the decrease in strength due to an increase in the amount of polymer addition.

The above range is for the fresh concrete stage, when the concrete is manufactured, but when converted into the volumetric percentage of polymer in the hardened cement in the concrete pavement 120, it corresponds to approximately 15% to 50%. It is common in the industry to manage and express the percentages of various materials in the concrete mix (water, cement, aggregate, water reducer, and other chemicals) by weight at the fresh concrete stage. This type of expression is often used because the final composition of concrete is difficult to specify, as it is highly dependent on the external environment, changes over time in the hydration reaction of the cement, the water absorption rate of the aggregate, etc.

Examples of fast-setting admixtures include those containing one or more of the following as the main component: calcium aluminates, sodium aluminate, alums including calcined alum, activated alumina, aluminum hydroxide, aluminum sulfate, calcium nitrite, calcium nitrate, and the like. Particularly preferred fast-setting admixtures are those containing calcium aluminates as the main component. The fast-setting admixture is preferably in powder form.

It is preferable that the content of the rapid-hardening admixture is controlled so that the mass ratio F/B of the unit amount of rapid-hardening admixture F to the total amount B of the unit amount of cement C at the fresh concrete stage and the unit amount of rapid-hardening admixture (amount of rapid-hardening admixture added) F is controlled to be 10% or more and 50% or less. Since F/B is 10% or more, the dielectric tangent can be lowered, the relative dielectric constant can be increased, and the power supply efficiency can be improved. On the other hand, since F/B is 50% or less, sufficient strength can be provided to support frequent vehicle passage. The lower limit of F/B is more preferably 15% or more, and the upper limit is more preferably 35% or less.

As with the polymer content, the above range is for the fresh concrete stage, at the time of concrete production, but when converted into the volume fraction of the fast-hardening admixture in the hardened cement body of the concrete pavement 120, it corresponds to approximately 1.3% to 10%.

The amount of air mixed at the fresh concrete stage is preferably in the range of 2.0 vol% to 8.0 vol% of the total. Since the dielectric tangent of air is 0, the dielectric tangent is reduced by including 2.0 vol% or more of air in the concrete. As a result, energy loss can be reduced and high power supply efficiency can be obtained. On the other hand, the relative dielectric constant of air is 1, and by including 8.0 vol% or less of air in the concrete, the relative dielectric constant of the concrete pavement 120 can be kept high and high strength can be maintained. The lower limit of the amount of air mixed is more preferably 4.0 vol% or more, and the upper limit is more preferably 6.0% or less. The amount of air mixed at the fresh concrete stage can be adjusted by using a chemical admixture for concrete called an AE agent or AE water reducing agent, and can be measured by a fresh concrete air amount measuring device.

It is preferable that the dielectric tangent of at least some of the aggregate is less than 0.1. In this case, the aggregate has a lower dielectric tangent than aggregates made of general natural materials. This reduces energy loss through the concrete pavement 120, and allows for high power supply efficiency. It is also preferable that the relative dielectric constant of at least some of the aggregate is 2.0 or more. In this case, the aggregate has a higher relative dielectric constant than general aggregates. This allows for high power supply efficiency. It is even more preferable that the average dielectric tangent or relative dielectric constant of the aggregate as a whole is within a predetermined range. It is even more preferable that the dielectric tangent or relative dielectric constant of all the aggregates is within a predetermined range.

The amount of aggregate with a dielectric tangent of less than 0.1 added may be adjusted appropriately so that the dielectric tangent of the concrete pavement is less than 0.1. For example, natural crushed sand can be used as fine aggregate, and aggregate with a dielectric tangent of less than 0.1 can be used as coarse aggregate. The proportion of aggregate with a dielectric tangent of less than 0.1 in the total aggregate is preferably 50% or more.

The aggregate may be a ceramic body of an oxide containing one or more of the elements Al, Mg, and Si, and may contain a sintering aid with a melting point lower than that of the oxide. In this case, if the aggregate contains alkali metals such as Na and K as impurities, the dielectric tangent increases, but by containing a sintering aid, alkali metal ions are captured in vacancies in the crystal structure during the firing process of the aggregate, and the dielectric tangent can be reduced by suppressing the movement of ions in the crystal.

Examples of constituent materials of such aggregates include alumina ( _Al2O3 ), magnesia ( _MgO ), _silica ( _SiO2 ), mullite ( _3Al2O3.2SiO2 ), forsterite ( _2MgO.SiO2 ), steatite ( _MgO.SiO2 ), _spinel ( _MgO.Al2O3 ) and _{cordierite ( 2MgO.2Al2O3.5SiO2} ) _.

The sintering aid will be explained using alumina as an example. When _SiO2 and MgO are added to alumina as sintering aids in a total amount of 0.2 wt% to 1.0 wt%, with a weight ratio ( _SiO2 /MgO) of 2 to 4, a cordierite phase with a lower melting point than alumina is precipitated at the grain boundaries during the sintering process. During the formation of this cordierite, alkali metal ions are captured in the vacancies in the crystal structure, suppressing ion migration in the crystal, thereby reducing the dielectric loss tangent.

[Method of manufacturing concrete pavement]
A method for manufacturing the concrete pavement 120 configured as above will be described. First, a predetermined amount of aggregate, cement, water and polymer are weighed and mixed in a mixer (specific examples of each mix will be described later). At that time, it is preferable that the mass ratio P/C of the polymer additive amount P to the cement additive amount C is 5% or more and 25% or less, and the mass ratio F/B of the rapid hardening admixture additive amount F to the total amount B of the cement additive amount C and the rapid hardening admixture additive amount F is 10% or more and 50% or less. At this time, it is more preferable that P/C is 10% or more and 20% or less, and F/B is 15% or more and 35% or less. The concrete obtained in this way is poured, compacted, and the surface is finished to manufacture the concrete pavement 120.

The concrete manufactured in this way, with a dielectric loss tangent of less than 0.1, is used between a power supply electrode that supplies power contactlessly and a vehicle or the like to be powered. The dielectric loss tangent of concrete pavement only needs to be less than 0.1 while in service, but it is preferable for it to become less than 0.1 within 28 days after manufacture, and more preferably within 7 days after manufacture.

It is preferable that the concrete pavement 120 be manufactured by pouring the mixed raw materials on-site. This allows the concrete pavement 120 to be flexibly formed according to the conditions at the site.

The concrete pavement 120 may be formed in advance as precast concrete (precast body) in a factory and laid down for a non-contact power supply runway. The precast body and the power supply side electrode component may be integrated in advance in the factory, transported, and constructed on-site. This allows the concrete pavement to be prepared in advance in the factory and assembled on-site, reducing on-site work time.

When making precast concrete, it is preferable to include a step of steam curing the concrete produced in the same manner as the concrete pavement described above after it has been poured into a formwork, or after it has been poured into a formwork and removed from the formwork. By carrying out steam curing, a denser hardened body is formed, preventing the infiltration of moisture into the interior, and the water added is reliably reduced by forming hydrates, thereby reliably reducing the dielectric tangent. Steam curing may be carried out by a known method, for example, at a temperature of 50 to 80°C for 2 to 12 hours. If the material contains a fast-hardening admixture, the steam curing step may be omitted.

[experiment]
An experiment was conducted on the concrete pavement as described above. Test specimens of 500 x 500 x 50 mm simulating road surfaces were prepared using various concrete pavement materials. The material age was set to 28 days. Table 1 shows an example of the materials used in the experiment and their mix ratios. Using the examples shown in Table 1 as a reference, the aggregates and polymers were replaced with other types. The amount of polymer added was set to a constant total value of the amount of polymer-containing admixture L and the amount of water W, as shown in Table 2 (symbols are the same as in Table 1).

Six types of aggregate were used: general aggregate, steatite, alumina, mullite, forsterite, and special aggregate. The general aggregate is gravel containing silica ( _SiO2 ) as the main component and _Al2O3 and MgO as secondary components. The special aggregate was made by adding 0.4 wt% _SiO2 and 0.2 wt% MgO as sintering aids to alumina and heat treating the mixture at 1600°C. The dielectric properties of the aggregate were measured using an impedance analyzer. Table ₃ shows the relative dielectric constant and dielectric loss tangent of the aggregates used in the experiment.

The polymers used were styrene butadiene copolymer (SBR), polyacrylic ester copolymer (PAE), and ethylene vinyl acetate copolymer (EVA). The polymers were added at 5-25% by weight to the cement, which corresponds to 14-45% by volume.

Facet (registered trademark, manufactured by Pacific Materials Corporation) was used as the fast-setting admixture. The fast-setting admixture was added at a weight ratio of 15-35% of the total weight of the cement and fast-setting admixture. This corresponds to a volume ratio of 16-37%. The amount of air mixed at the fresh concrete stage was measured using a fresh concrete air content measuring device in accordance with JIS A 1115, and was adjusted to be 2.0-8.0 vol%.

As comparative examples, test specimens were similarly prepared for ordinary concrete and ordinary asphalt that did not contain polymer. The dielectric properties of each test specimen were measured using an impedance analyzer. Table 4 shows the manufacturing conditions and measurement results of the test specimens.

From the obtained results, a power supply efficiency simulation was performed using electromagnetic field analysis software. In addition, two copper electrodes measuring 250 x 200 x 1 mm were attached at the center of the back surface of the test specimen, spaced 50 mm apart, and water was sprayed onto the surface of the test specimen while an AC voltage was applied to the electrodes. The resistance between the electrodes at that time was measured with a tester to confirm the presence or absence of insulation failure. Resistance obtained in the insulation test was expressed as ◯ if it was 10 MΩ or more, △ if it was 1 to 10 MΩ, and × if it was less than 1 MΩ. The compressive strength of each type of test specimen was also measured. Table 5 shows the simulation results and test results.

In all of the examples, the power supply efficiency was 80% or more. In addition, no insulation failure was observed. The compressive strength of the examples was 35 MPa or more, which satisfied the values required for concrete pavement. Note that concrete pavement is required to have a bending strength of 4.5 MPa or more and a compressive strength of 35 MPa or more.

Comparing Example 3 and Example 12, in which the amount of polymer added and the amount of mixed air are almost the same, Example 12, in which a fast-hardening admixture was added, had a lower dielectric tangent than Example 3, and a higher power supply efficiency was obtained. In addition, Example 12 also had a higher compressive strength. According to this comparison, the dielectric tangent is further reduced by further adding a fast-hardening admixture in addition to the polymer. And when non-contact power supply is performed through a concrete pavement to which a fast-hardening admixture has been further added, a high power supply efficiency can be obtained.

The compressive strength of Example 5, where the P/C was 25%, was 38 MPa, and the compressive strength of Example 13, where the air content was 8.0 vol%, was 36 MPa. This compressive strength is close to the standard lower limit required for concrete pavement. Therefore, it is not preferable for the air content of the concrete pavement to exceed 8.0 vol%, or for the P/C at the fresh concrete stage to exceed 25%. As shown in the table, in the comparative example, the power supply efficiency was very low, and it was found that poor insulation occurred.

Reference Signs List 100 Power supply facility 110 Power supply device 111 High frequency power source 112 Power supply electrode 120 Concrete pavement 800 Soil 900 Electric vehicle 910 Front tire 920 Wheel 930 Shaft 940 Vehicle circuit 950 Motor

Claims (11)

A concrete pavement used in a facility for wirelessly supplying power to a charging target on a road surface,
Aggregate;
a hardened cement body that bonds the aggregates together;
a polymer present in the gaps between the aggregate and the hardened cement body;
the polymer is either a styrene butadiene copolymer, a polyacrylic acid ester copolymer, or an ethylene vinyl acetate copolymer;
The mass ratio P/C of the unit blend amount P of the polymer to the unit cement amount C of the concrete is 5% or more and 25% or less,
The air content of the concrete is in the range of 2.0 vol.% to 8.0 vol.% of the total,
The aggregate contains an aggregate having a dielectric tangent of less than 0.1 and a relative dielectric constant of 2.0 or more,
A concrete pavement characterized in that it has a dielectric tangent of less than 0.1. A concrete pavement used in a facility for wirelessly supplying power to a charging target on a road surface,
Aggregate;
a hardened cement body that bonds the aggregates together;
and a rapid hardening admixture present in the gaps between the aggregate and the hardened cement body,
The fast-hardening admixture is a substance mainly composed of calcium aluminates,
The mass ratio F/B of the unit blend amount F of the rapid-hardening admixture to the total amount B of the unit cement amount of concrete and the unit blend amount of the rapid-hardening admixture is 10% or more and 50% or less,
The air content of the concrete is in the range of 2.0 vol.% to 8.0 vol.% of the total,
The aggregate contains an aggregate having a dielectric tangent of less than 0.1 and a relative dielectric constant of 2.0 or more,
A concrete pavement characterized in that it has a dielectric tangent of less than 0.1. 3. A concrete pavement as described in claim 1 or claim 2, characterized in that the aggregate is a ceramic body of an oxide containing one or more of the elements Al, Mg and Si , and contains a sintering aid having a melting point lower than that of the oxide. A non-contact type power supply travelway, the road surface of which is formed by the concrete pavement according to any one of claims 1 to 3 . A precast body used in a facility that supplies power to a charging target on a road surface in a non-contact manner,
Aggregate;
a hardened cement body that bonds the aggregates together;
a polymer present in the gaps between the aggregate and the hardened cement body;
the polymer is either a styrene butadiene copolymer, a polyacrylic acid ester copolymer, or an ethylene vinyl acetate copolymer;
The mass ratio P/C of the unit blend amount P of the polymer to the unit cement amount C of the concrete is 5% or more and 25% or less,
The air content of the concrete is in the range of 2.0 vol.% to 8.0 vol.% of the total,
The aggregate contains an aggregate having a dielectric tangent of less than 0.1 and a relative dielectric constant of 2.0 or more,
A precast body having a dielectric tangent of less than 0.1. A precast body used in a facility that supplies power to a charging target on a road surface in a non-contact manner,
Aggregate;
a hardened cement body that bonds the aggregates together;
and a rapid hardening admixture present in the gaps between the aggregate and the hardened cement body,
The fast-hardening admixture is a substance mainly composed of calcium aluminates,
The mass ratio F/B of the unit blend amount F of the rapid-hardening admixture to the total amount B of the unit cement amount of concrete and the unit blend amount of the rapid-hardening admixture is 10% or more and 50% or less,
The air content of the concrete is in the range of 2.0 vol.% to 8.0 vol.% of the total,
The aggregate contains an aggregate having a dielectric tangent of less than 0.1 and a relative dielectric constant of 2.0 or more,
A precast body having a dielectric tangent of less than 0.1. A non-contact type power supply runway, the road surface of which is formed from the precast body according to claim 5 or 6 . A method for manufacturing a concrete pavement used in a facility for contactlessly supplying power to a charging target on a road surface, comprising:
A process of producing concrete by weighing and mixing aggregate, cement, water and a polymer so that a mass ratio P/C of a unit polymer blend amount P to a unit cement amount C is 5% to 25%;
forming a road surface using the produced concrete ;
the polymer is either a styrene butadiene copolymer, a polyacrylic acid ester copolymer, or an ethylene vinyl acetate copolymer;
The mass ratio P/C of the unit blend amount P of the polymer to the unit cement amount C of the concrete is 5% or more and 25% or less,
The air content of the concrete is in the range of 2.0 vol.% to 8.0 vol.% of the total,
2. A method for producing a concrete pavement , comprising the steps of: (a) forming a concrete pavement using a concrete material having a dielectric tangent of less than 0.1 and a relative dielectric constant of 2.0 or more ; A method for manufacturing a concrete pavement used in a facility for contactlessly supplying power to a charging target on a road surface, comprising:
A process of measuring and mixing aggregate, cement, water and a rapid-hardening admixture so that a mass ratio F/B of a unit blend amount F of the rapid-hardening admixture to a total amount B of a unit cement amount and a unit blend amount of the rapid-hardening admixture is 10% or more and 50% or less to produce concrete;
forming a road surface using the produced concrete ;
The fast-hardening admixture is a substance mainly composed of calcium aluminates,
The mass ratio F/B of the unit blend amount F of the rapid-hardening admixture to the total amount B of the unit cement amount of concrete and the unit blend amount of the rapid-hardening admixture is 10% or more and 50% or less,
The air content of the concrete is in the range of 2.0 vol.% to 8.0 vol.% of the total,
2. A method for producing a concrete pavement , comprising the steps of: (a) forming a concrete pavement using a concrete material having a dielectric tangent of less than 0.1 and a relative dielectric constant of 2.0 or more ; A method for manufacturing a precast body used in a facility for contactlessly supplying power to a charging target on a road surface, comprising:
A process of producing concrete by weighing and mixing aggregate, cement, water and a polymer so that a mass ratio P/C of a unit polymer blend amount P to a unit cement amount C is 5% to 25%;
and forming a formwork, pouring the produced concrete into the formwork, and steam curing the concrete to produce a precast body .
the polymer is either a styrene butadiene copolymer, a polyacrylic acid ester copolymer, or an ethylene vinyl acetate copolymer;
The mass ratio P/C of the unit blend amount P of the polymer to the unit cement amount C of the concrete is 5% or more and 25% or less,
The air content of the concrete is in the range of 2.0 vol.% to 8.0 vol.% of the total,
A method for manufacturing a precast body, characterized in that the aggregate contains aggregate having a dielectric tangent of less than 0.1 and a relative dielectric constant of 2.0 or more . A method for manufacturing a precast body used in a facility for contactlessly supplying power to a charging target on a road surface, comprising:
A process of measuring and mixing aggregate, cement, water and a rapid-hardening admixture so that a mass ratio F/B of a unit blend amount F of the rapid-hardening admixture to a total amount B of a unit cement amount and a unit blend amount of the rapid-hardening admixture is 10% or more and 50% or less to produce concrete;
and forming a formwork and then pouring the generated concrete into the formwork to generate a precast body .
The fast-hardening admixture is a substance mainly composed of calcium aluminates,
The mass ratio F/B of the unit blend amount F of the rapid-hardening admixture to the total amount B of the unit cement amount of concrete and the unit blend amount of the rapid-hardening admixture is 10% or more and 50% or less,
The air content of the concrete is in the range of 2.0 vol.% to 8.0 vol.% of the total,
A method for manufacturing a precast body, characterized in that the aggregate contains aggregate having a dielectric tangent of less than 0.1 and a relative dielectric constant of 2.0 or more .