JP2005240305A - LOW mu ROAD PAVEMENT STRUCTURE - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive low μ road pavement structure which has a road surface having a low-range slide resistance value, and can hold the set slide resistance value to an almost constant value even if conditions including the traveling speed of a vehicle are varied. <P>SOLUTION: The low μ road pavement structure 10 is formed of basic asphalt concrete 13 containing coarse aggregate 11 and asphalt mortar 12, and a surface finish layer 15 made of low μ road asphalt mastic 14 containing filler bitumen 16 and μ value adjusting aggregate 17, and adheringly formed on the surface of the basic asphalt concrete 13. The low μ road pavement structure is regulated so as to have a surface slide resistance value (μ value) in a range of 0.10 to 0.30. By the low μ road pavement structure, the μ value adjusting aggregate 17 mixed in the low μ road asphalt mastic 14 is made of artificial lightweight aggregate having specific gravity in a range of 90 to 110 % of the specific gravity of filler bitumen with a particle size of 5 mm or less, and makes up 10 to 45 vol% of the low μ road asphalt mastic 14. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is, for example, a low μ road pavement structure adjusted to have a low surface slip resistance (μ value), which is used as a part of a road surface for vehicle test driving or a road surface of a driving school. About.

  Asphalt concrete paved surfaces are slippery not only when driving at low speeds but also when driving at high speeds, so that vehicles such as cars can run stably without slipping, depending on changes in weather, temperature, etc. In general, the resistance value (μ value) is designed to be about 0.4 to 0.8, for example.

  On the other hand, for example, in a test course for testing a braking system of an automobile on a slippery road surface, a test course for testing a braking characteristic, and a technique for acquiring a technique for driving on a slippery road surface in a driving school, etc. For example, a so-called low μ road pavement may be required in which the μ value is set to a low value of about 0.15 ± 0.05 to 0.25 ± 0.05.

  According to the prior art, as a low μ road pavement for such a test course, one using a basalt tile is generally known (see, for example, Non-Patent Document 1 and Patent Document 1). The basalt tile is, for example, a tile having a size of about 200 to 250 mm × 200 to 250 mm obtained by dissolving basalt from Czechoslovakia, pouring it into a mold as it is, for example, and placing it on a roadbed. For example, a road surface having a slip resistance value (μ value) of about 0.15 to 0.25 in a wet state in which water is sprinkled is arranged by being arranged side by side on the formed concrete foundation. is there.

  In addition, according to the conventional low μ road pavement using basalt tiles, the basalt tiles are laid on the ground concrete through the mortar, the joint mortar is injected to finish the joints, and then the surface of the tiles are floor polished. The slip resistance value (μ value) can be set to an appropriate size within the above-mentioned range depending on the degree of polishing when polishing with a polishing apparatus such as The set slip resistance value (μ value) can be kept substantially constant.

  Furthermore, as another technique related to low μ road pavement, the asphalt surface is polished to expose the coarse aggregate of the asphalt mixture, the exposed portion of the coarse aggregate is rounded, and the surface of the coarse aggregate surface Low μ road pavement with reduced roughness (for example, see Patent Document 2), crushed stone, sand, stone powder and asphalt are mixed in a prescribed composition to obtain a mother asphalt mixture, and the mother asphalt mixture is transported to the pavement site Then, pavement process that spreads and compresses, and a process that injects cement milk for penetration mixed with normal Portland cement, water and additives in a predetermined composition into the mother asphalt mixture, and after a predetermined curing, diamond and grindstone are added. A low μ road construction method (for example, see Patent Document 3) comprising a step of obtaining a predetermined μ value by polishing a pavement surface using the method is disclosed.

Furthermore, unlike the technology related to low μ road pavement, as a technique for strengthening the surface of drainage asphalt pavement while maintaining its drainage performance, filling with a mixture of aggregate and resin with a predetermined particle size and particle size A road paving method (see, for example, Patent Document 4) and a road paving material (see, for example, Patent Document 5) in which a material is laid on the surface of a drainage asphalt pavement are disclosed.
"Car Research", Vol. 9, No. 11 (November 1987), pp. 449-453, "Completion of comprehensive test road, slippery test road and skid pad repair work", Shoji Uejima, et al. 2 Name Utility Model Registration No. 3067774 Japanese Utility Model Publication No. 3-96331 Japanese Patent Laid-Open No. 10-121404 Japanese Patent Laid-Open No. 11-293614 JP 2001-11812 A

  However, according to the low μ road pavement using conventional basalt tiles, it takes a lot of work to lay the basalt tiles one by one, and basalt tiles are limited to Czechoslovakia. Since it is a product, it is difficult to obtain, and since it is an expensive product, the construction cost increases. In addition, the conventional technique related to the low μ road pavement requires polishing the surface of the pavement where both are laid, which makes the work complicated.

  On the other hand, as an alternative to these conventional low-μ road pavements, it is conceivable to develop pavements in which resin that reduces slip resistance is applied to the pavement surface of concrete and other tile products that replace basalt tiles. In the former, it is difficult to ensure durability, and in the latter, it is difficult to sufficiently improve the workability and construction cost.

  Moreover, even if it is going to obtain the pavement in which the micro value of the surface became a low value by applying the technique of patent documents 4 and patent documents 5, these paving methods and paving materials are the surface of drainage asphalt pavement. Since the slip resistance value (μ value) of the surface is increased by the laid filler, the μ value is, for example, 0.15 ± 0.05-0. It is difficult to form a low μ road pavement of about 25 ± 0.05.

  The present invention has been made paying attention to such a conventional problem, and can be provided with a road surface set to have a slip resistance value (μ value) in a low range, and the traveling speed of the vehicle, etc. It is an object of the present invention to provide a low-μ road pavement structure that can keep the set slip resistance value (μ value) substantially constant even if the above conditions change, and that can be easily and inexpensively constructed.

  The present invention is a matrix asphalt concrete made of aggregate, filler, and asphalt, and a low μ made of paving binder, filler, and μ value adjusting aggregate formed by being laid and adhered to the surface of the matrix asphalt concrete. A low-μ road pavement structure comprising a surface treatment layer made of asphalt mastic for roads and adjusted to have a surface slip resistance (μ value) of 0.10 to 0.30, wherein the base asphalt concrete The aggregate of the particle size range for the gap asphalt mixture has a rough surface, and the μ value adjusting aggregate to be mixed with the low μ road asphalt mastic is composed of grains. 90 to the specific gravity of filler bitumen, which is an aggregate having a diameter of 5 mm or less, which is a mixture of the paving binder and the filler. The object is achieved by providing a low μ road pavement structure comprising 10% to 45% by volume of the low μ road asphalt mastic comprising an artificial lightweight aggregate having a specific gravity of 10%. It is a thing.

  And according to the low μ road pavement structure of the present invention, the pavement binder of the low μ road asphalt mastic is preferably a special asphalt.

  Moreover, according to the low μ road pavement structure of the present invention, it is preferable that the asphalt of the base asphalt concrete is a modified asphalt that improves durability.

  Furthermore, according to the low μ road pavement structure of the present invention, the special asphalt is preferably an asphalt made of a mixture of petroleum asphalt and one or more of resin, rubber and natural asphalt.

  Furthermore, according to the low μ road pavement structure of the present invention, the artificial lightweight aggregate used as the μ value adjusting aggregate is preferably a porous ceramic.

  Here, in the above description, the slip resistance value (μ value) is from page 288 to page 293 of “Paving Test Method Handbook (provisional test method)” (October 1996, issued by the Japan Road Association). Is measured as a dynamic friction coefficient of the road surface by a slip resistance measuring device using a rotary disk according to “4-1-1T SL rotational slip resistance measuring method”. Value. That is, the rotational slip resistance measuring instrument used in this measuring method is composed of a disk that rotates in a structure in which the road surface and the tire rubber piece are in contact, a device that measures a frictional force that acts on the tire rubber piece during rotation, and a recording device. Thus, for example, a dynamic friction tester (DF tester) can be used as a portable device of such a measuring instrument.

  The present invention will be described in detail below. The low μ road pavement structure of the present invention, as described above, is a base asphalt concrete composed of aggregate, filler, and asphalt, and a paving binder, filler, formed by being laid and adhered to the surface of the base asphalt concrete, And a surface treatment layer made of asphalt mastic for low μ road composed of aggregate for μ value adjustment, and the low μ adjusted so that the slip resistance value (μ value) of the surface becomes 0.10 to 0.30. It is a road pavement structure, and the base asphalt concrete is mixed with the low-μ asphalt mastic for low-μ road as the surface of the base asphalt concrete is mixed with an aggregate having a particle size range for a gap asphalt mixture. The μ value adjusting aggregate is an aggregate having a particle size of 5 mm or less, and is a mixture of the paving binder and the filler. It consists Lightweight Aggregate with 90-110% of the specific gravity of Rabichuumen, the contained 10 to 45% by volume of the low μ road asphalt mastic.

  The base asphalt concrete forming the lower layer portion of the low μ road pavement structure of the present invention is composed of aggregate, filler, asphalt, and other additives added and mixed as necessary, and gap asphalt By mixing the aggregate in the particle size range for the mixture, the paved surface of the base asphalt concrete is made rough. When the pavement surface of the base asphalt concrete is a rough surface, it is possible to ensure strong adhesion to the surface treatment layer laid on the surface.

  Here, the aggregate of the particle size range for the gap asphalt mixture constituting the base asphalt concrete is, for example, a pavement surface such as an aggregate of a particle size range mixed in a fine particle size gap asphalt mixture or a fine particle size gap asphalt mixture. Aggregates whose grain sizes are adjusted so as to have a rough surface can be used.

  In addition, the filler that constitutes the base asphalt concrete has a particle size of 0.074mm or less and is mixed with asphalt and aggregate to improve the durability, temperature sensitivity, consistency, etc. of the asphalt, and the entire asphalt mixture For example, limestone stone powder (stone powder), cement, fly ash, or the like can be used.

  Further, asphalt constituting the base asphalt concrete is a residue after refining petroleum and taking out volatile components, and exhibits a function as a binder for connecting aggregate particles in asphalt pavement. As such asphalt, that is, a binder, various modified asphalts that improve the durability of asphalt concrete such as Ciroflex (manufactured by Obayashi Road Co., Ltd.) can be used in addition to various straight asphalts that are generally used. it can.

  On the other hand, the surface treatment layer forming the upper layer portion of the low μ road pavement structure according to the present invention is a low asphalt mastic for low μ road, which is a slurry material made of a binder for paving, filler, and μ value adjusting aggregate. The μ value adjusting aggregate formed by laying and adhering to the concrete surface and mixed with the low μ road asphalt mastic is an aggregate having a particle size of 5 mm or less, and is composed of a paving binder and a filler. It consists of an artificial lightweight aggregate having a specific gravity of 90 to 110%, preferably 95 to 105% of the specific gravity of the filler bitumen as a mixture, and is contained in the low μ road asphalt mastic in an amount of 10 to 45% by volume.

  Here, as the paving binder constituting the asphalt mastic for low μ road, various known binders known as paving binders such as asphalt emulsion and resin can be used in addition to heated asphalt. In consideration of durability and workability of the surface treatment layer, special asphalt is preferably used. As such special asphalt, for example, asphalt formed by mixing petroleum asphalt and any one or more of resin, rubber or natural asphalt can be used. In addition, as the resin asphalt in which a resin is added and mixed, for example, epoxy asphalt in which an epoxy resin is added and mixed, urethane asphalt in which urethane is added and mixed, and the like, among these resin asphalts, epoxy asphalt is used. It is particularly preferred. By using epoxy asphalt, it is possible to construct a thin surface treatment layer having flow resistance and appropriate toughness. According to the present invention, as the pavement binder, an asphalt emulsion can be used alone, or a resin such as an epoxy resin or a urethane resin can be used alone.

  In addition, the filler constituting low-μ road asphalt mastic mainly has a particle size of 0.074 mm or less, and improves the durability, temperature sensitivity, consistency, etc. of the paving binder, and low-μ road asphalt mastic. It exhibits the function of improving the overall stability. For example, stone powder, cement, fly ash or the like can be used.

  And according to the present invention, as a μ value adjusting aggregate constituting a low μ road asphalt mastic, a filler having a particle size of 5 mm or less, which is a mixture of a paving binder and a filler, is used. An artificial lightweight aggregate having a specific gravity of 90 to 110%, preferably 95 to 105% of the specific gravity of the men is used. That is, generally used aggregate usually has a specific gravity of about 2.60 to 2.70, and has a specific gravity of about 140 to 160% of filler bitumen, whereas the present invention. The artificial lightweight aggregate has a specific gravity of about 1.55 to 1.90, for example, and is 90 to 110% of the specific gravity of the filler bitumen.

  Here, examples of the artificial lightweight aggregate having such a specific gravity include porous ceramics, molten slag, natural lightweight aggregates, etc., and have the advantage of being excellent in homogeneity, durability, and the like. Therefore, it is preferable to use a porous ceramic. In addition, by setting the specific gravity of the artificial lightweight aggregate in the above-mentioned range, for example, in a mixture plant, filler bitumen and μ value adjusting aggregate are mixed to form a low μ road asphalt mastic. For example, after moving to a goose cooker car and transporting it to the construction site while cooking, and laying it on the construction site, the aggregate for μ value adjustment is used in the filler bitumen until the predetermined curing period elapses. It is possible to easily and reliably maintain a substantially uniformly dispersed state without causing material separation due to precipitation or levitation. Thus, by mixing the aggregate for μ value adjustment of a predetermined blending amount from the state where the surface treatment layer with only the filler bitumen which is a mixture of a binder for paving and a filler can hardly exhibit slip resistance, Setting adjustment for obtaining a low μ road pavement in which the slip resistance value (μ value) is 0.10 to 0.30 can be performed with accuracy within an error range of ± 0.05, for example. In addition, even when conditions such as vehicle speed and temperature change, it is easy to create a low-μ road pavement that keeps the set surface slip resistance (μ value) within a range of ± 0.05. It becomes possible to form.

  That is, according to the present invention, the specific gravity of the aggregate for adjusting the μ value by the artificial lightweight aggregate is substantially equal to the specific gravity of the filler bitumen, so that during mixing, construction, and curing of asphalt mastic for low μ roads Since the fine-value-adjusting aggregate retains good uniform dispersibility in the filler bitumen, the texture due to unevenness on the pavement surface is determined by the amount of the fine-value-adjusting aggregate. Therefore, it becomes possible to easily obtain a low μ road pavement having a desired low μ value.

  According to the present invention, the artificial lightweight aggregate having the above-described specific gravity is mixed with 10 to 45% by volume in the low μ road asphalt mastic. Setting to obtain a low μ road pavement with a surface slip resistance (μ value) of 0.10 to 0.30 by mixing 10 to 45% by volume of artificial lightweight aggregate with low μ road asphalt mastic. Adjustment can be easily performed.

  The remaining part of the asphalt mastic for low μ roads, excluding the blended amount of artificial lightweight aggregate, is mainly the blended part of filler bitumen that combines paving binder and filler. The specific gravity varies depending on the ratio of the amount of the paving binder and filler. Here, the specific gravity of the filler bitumen increases as the blending amount of the filler in the filler bitumen increases. And the artificial lightweight aggregate is provided with the specific gravity of the above-mentioned ratio with respect to the specific gravity of the filler bitumen whose compounding quantity was adjusted in this way.

  In addition, the operation of laying and attaching the low μ road asphalt mastic, which is a slurry material having the above-described configuration, to the rough surface of the base asphalt concrete, for example, the low μ road asphalt mastic conveyed by a goose cooker car, for example, asphalt It can be easily performed by laying using a mastic finisher.

  According to the low μ road pavement structure of the present invention, it is possible to provide a road surface set to have a slip resistance value (μ value) in a low range of 0.10 to 0.30, and the traveling speed of the vehicle, etc. The slip resistance value (μ value) set can be kept substantially constant even when the above conditions change, and can be easily and inexpensively constructed.

  A preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. The low μ road pavement structure 10 of this embodiment shown in FIG. 1 is used to test a brake system of an automobile on a slippery road surface, a test course for testing braking characteristics, a slippery road surface in an automobile driving school, or the like. To form a so-called low-μ road pavement that is a slippery pavement that is set so that the μ value becomes a low value such as 0.10 to 0.30 in a test course for acquiring techniques for traveling It has been adopted.

  In addition, the low μ road pavement structure 10 of the present embodiment has a road surface slip resistance value (μ) set in the range of 0.10 to 0.30 even if the traveling conditions such as the vehicle traveling speed and temperature change. Value) is employed to form a low μ road pavement that can be kept substantially constant within a range of variation of ± 0.05.

  The low μ road pavement structure 10 of the present embodiment is formed of a coarse aggregate 11 and an asphalt mortar 12 made of fine aggregate, filler, and asphalt, and has a thickness (T1) of about 40 mm, for example. An asphalt concrete 13 and a surface treatment layer 15 having a thickness (T2) of about 5 mm, for example, formed by laying and attaching a low μ road asphalt mastic 14 as a slurry material on the surface of the base asphalt concrete 13 And the surface slip resistance value (μ value) is adjusted to be 0.10 to 0.30.

  According to the low μ road pavement structure 10 of the present embodiment, the asphalt mortar 12 that is a constituent material of the base asphalt concrete 13 forming the lower layer portion thereof is fine aggregate, stone powder as a filler, and asphalt as a binder. In the base asphalt concrete 13, it hardens so as to fill the gaps between the coarse aggregates 11. The asphalt mortar 12 can be appropriately mixed with other additives as necessary.

  Moreover, according to this embodiment, the coarse aggregate 11 which is a constituent material of the base asphalt concrete 13 and the fine aggregate contained in the asphalt mortar 12 are aggregates having a particle size range for a dense particle size gap asphalt mixture, for example. Therefore, the surface of the base asphalt concrete 13 to which the low-μ road asphalt mastic 14 is laid and adhered forms a rough surface. Further, it is considered that the surface treatment layer 15 made of the low μ road asphalt mastic 14 is less likely to be peeled off or twisted.

  Furthermore, according to this embodiment, modified asphalt such as Ciroflex (manufactured by Obayashi Road Co., Ltd.) or the like is used as the asphalt that is a constituent material of the parent asphalt concrete 13. Durability can be improved.

  On the other hand, the low μ road asphalt mastic 14 that covers the surface of the base asphalt concrete 13 is a filler bitumen that forms a main body portion of the low μ road asphalt mastic 14 made of special asphalt as a pavement binder and stone powder as a filler. 16 and a μ-value adjusting aggregate 17 which is an artificial light-weight aggregate having a particle size of 5 mm or less mixed in the filler bitumen 16. The μ-value adjusting aggregate 17 is a filler bitumen. It has a specific gravity of 90 to 110% of the specific gravity of the men 16, and is blended in the low μ road asphalt mastic 14 at a ratio of 10 to 45% by volume. Further, the low μ road asphalt mastic 14 is laid and adhered to the surface of the base asphalt concrete 13 so as to form a surface treatment layer 15 that is an upper layer portion of the low μ road pavement structure 10.

  Here, according to the present embodiment, epoxy asphalt is preferably used as the special asphalt that is a constituent material of the low μ road asphalt mastic 14, thereby improving the durability and workability of the surface treatment layer 15. The filler bitumen 16 which is effectively improved and mixed with stone powder has a specific gravity of about 1.60 to 1.85, for example.

  Moreover, according to this embodiment, the specific gravity of 90 to 110% of the specific gravity of the filler bitumen 16 is used as the μ value adjusting aggregate 17 having a particle size of 5 mm or less, which is a constituent material of the low μ road asphalt mastic 14. Therefore, the μ value adjusting aggregate (artificial lightweight aggregate) 17 has a specific gravity of about 1.55 to 1.90, for example. According to the present embodiment, for example, porous ceramic is preferably used as the artificial lightweight aggregate 17 having such a specific gravity.

  The low μ road pavement structure 10 of the present embodiment having the above-described configuration can be easily provided according to a method substantially similar to the existing pavement method. That is, the base asphalt concrete 13 can be easily formed by spreading and rolling the asphalt concrete 13 with a predetermined thickness on the roadbed surface.

  Further, the surface treatment layer 16 is, for example, a mixture plant of low-μ road asphalt mastic 14 formed by mixing with a predetermined composition in a mixture plant, transferred to the goose cooker car 18 and transported to the construction site while cooking, As shown in FIG. 2, the transported low μ road asphalt mastic 14 is spread and smoothed by pouring between the aggregates on the surface of the base asphalt concrete 13 using, for example, an appropriately modified asphalt mastic finisher 19. By finishing, it is easily laid and formed. If the surface temperature of the base asphalt concrete 13 is lowered prior to the leveling work of the asphalt mastic 14 for the low μ road, the heating work with a heater is appropriately performed.

  And according to the low μ road pavement structure 10 of the present embodiment formed as described above, the low μ road asphalt mastic 14 constituting the surface treatment layer 16 is 5 mm or less in the filler bitumen 16. Since the filler for bitumen 16 is mixed with 10 to 45% by volume of an aggregate for adjusting μ value of an artificial lightweight aggregate having a particle size and a specific gravity of 90 to 110% of the specific gravity of the filler bitumen. The surface of the road surface formed by the surface treatment layer 16 formed only by laying and attaching the low μ road asphalt mastic 14 on the surface of the base asphalt concrete 13 by the action of the μ value adjusting aggregate dispersed substantially uniformly therein. The slip resistance value (μ value) can be easily set and adjusted to be in the low range of 0.10 to 0.30 without requiring polishing work on the paved surface. It becomes possible. In addition, low μ road pavement that keeps the set slip resistance value (μ value) of the surface approximately constant within a range of ± 0.05, even if conditions such as vehicle speed and temperature change. It becomes possible to form easily.

  The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the configurations described in each claim. For example, asphalt that is a constituent material of the base asphalt concrete does not necessarily need to be modified asphalt that improves durability, and other various asphalts can be used. Further, the paving binder, which is a constituent material of the low μ road asphalt mastic, does not necessarily need to be special asphalt or epoxy asphalt. Furthermore, the artificial lightweight aggregate need not necessarily be a porous ceramic.

  Hereinafter, although the low μ road pavement structure of the present invention will be described in more detail with reference to Examples and Reference Examples, the present invention is not limited thereto.

[Example 1]
As an aggregate for adjusting the μ value included in the asphalt mastic for low μ roads, it has substantially the same configuration as the low μ road pavement structure 10 of the above embodiment. Quality ceramics: Using the brand name “Pamiston A-1” (manufactured by Mishu Kosan Co., Ltd.) as the pavement structure of Example 1, according to the following measurement method, each mixing rate of artificial lightweight aggregates ( (10, 15, 20, 25, 30, 35, 40, 45 (%)) at each measurement speed 40, 60, 80 km / h, and tracking the effect of temperature on the slip resistance did. The specific gravity of the artificial lightweight aggregate was 1.745, and the specific gravity of the filler bitumen was 1.679 to 1.827. Therefore, the ratio of the specific gravity of the artificial lightweight aggregate to the specific gravity of the filler bitumen was 95.5 to 103.9%.

[Reference Examples 1 and 2]
As an aggregate included in the asphalt mastic for low μ road having substantially the same configuration as the low μ road pavement structure 10 of the above embodiment, a reference example using natural coarse sand having the properties and particle sizes shown in Table 1 1 pavement structure. Further, as the aggregate contained in the asphalt mastic for low μ road, the pavement structure of Reference Example 2 was used which uses the gravel with the properties and particle sizes shown in Table 1. In the same manner as the pavement structure of Example 1, according to the following measurement method, the measurement speed at each mixing rate (10, 15, 20, 25, 30, 35, 40, 45 (%)) of the artificial lightweight aggregate The slip resistance values at 40, 60, and 80 km / h were measured, respectively. The specific gravity of natural coarse sand was 2.601, and the specific gravity of jade gravel was 2.653. The specific gravity of the filler bitumen was 1.679 to 1.827. Therefore, the ratio of the specific gravity of the natural coarse sand to the specific gravity of the filler bitumen is 142.4 to 154.9%, and the ratio of the specific gravity of the gravel to the specific gravity of the filler bitumen is 145.2 to 158.0%. It was.

[Measurement of slip resistance at measurement speeds of 40, 60, and 80 km / h]
Example 1 in which a surface treatment layer was formed by laying asphalt mastic for low μ road, in which the mixing ratio of μ value adjusting aggregate or aggregate was changed in the range of 10 to 45% by volume on the base asphalt concrete Samples were sampled from the pavement structures of Example 1 and Reference Example 2, and slip resistance values (μ values) at measurement speeds of 40, 60, and 80 km / h were measured using the above-described DF tester. The measurement temperature was room temperature. The measurement results are shown in FIGS.

  From the measurement results shown in FIGS. 3A to 3C, according to the pavement structure of Example 1 according to the present invention, the slip resistance value (μ value) of the surface is a low range of 0.10 to 0.30. Adjusting the slip resistance value (μ value) to an arbitrary value within an error range of ± 0.05 by changing the mixing ratio of the μ value adjustment aggregate for the low μ road pavement that became the value It turns out that it can be easily obtained. Further, it is found that even if the traveling speed of the vehicle changes, the set slip resistance value (μ value) is kept substantially constant within a variation range of ± 0.05.

[Effect of temperature on slip resistance value]
Regarding the pavement structure of Example 1 using the artificial lightweight aggregate as the μ value adjusting aggregate contained in the low μ road asphalt mastic, the change in the slip resistance value (μ value) when the temperature is changed is described above. DF tester. Assuming that μ value = 0.3, the blending amount of the artificial lightweight aggregate was 45% by volume and the blending amount of the epoxy asphalt was 40% by volume. Moreover, the change of the slip resistance value (micro value) in travel speed 40, 60, and 80 km / h was measured. The measurement results are shown in FIG.

  From the measurement results shown in FIG. 4, according to the pavement structure of Example 1 according to the present invention, even if the temperature changes, the set slip resistance value (μ value) is substantially within the range of ± 0.05. It turns out that it remains constant. It is also found that there is almost no influence of temperature at a speed of 40 km / h.

It is a schematic sectional drawing explaining the structure of the low micro road pavement structure which concerns on one Embodiment of this invention. It is explanatory drawing which shows the construction example of the low micro road pavement structure which concerns on one Embodiment of this invention. (A)-(c) is a chart which shows the measurement result of the slip resistance value in measurement speed 40, 60, and 80 km / h. It is a chart which shows the measurement result of the slip resistance value at the time of changing temperature.

Explanation of symbols

10 Low μ road pavement structure 11 Coarse aggregate 12 Asphalt mortar 13 Base asphalt concrete 14 Low μ road asphalt mastic 15 Surface treatment layer 16 Filler bitumen 17 μ value adjusting aggregate 18 Goose cooker car 19 Asphalt mastic finisher

Claims (5)

Asphalt mastic for low-μ roads composed of a base asphalt concrete made of aggregate, filler, and asphalt, and a pavement binder, filler, and μ-value adjusting aggregate formed on the surface of the base asphalt concrete. Is a low μ road pavement structure that is adjusted to have a surface slip resistance value (μ value) of 0.10 to 0.30,
The matrix asphalt concrete has a rough surface by blending aggregates in the particle size range for gap asphalt mixture,
In addition, the μ value adjusting aggregate mixed with the low μ road asphalt mastic is an aggregate having a particle size of 5 mm or less, and is a filler bitumen that is a mixture of the paving binder and the filler. A low μ road pavement structure comprising an artificial lightweight aggregate having a specific gravity of 90 to 110% of the specific gravity, and contained in the low μ road asphalt mastic in an amount of 10 to 45% by volume.   2. The low μ road pavement structure according to claim 1, wherein the pavement binder of the low μ road asphalt mastic is a special asphalt. ,   The low μ road pavement structure according to claim 1 or 2, wherein the asphalt of the base asphalt concrete is a modified asphalt that improves durability.   The low μ road pavement structure according to claim 2 or 3, wherein the special asphalt is an asphalt made of a mixture of petroleum asphalt and one or more of resin, rubber, and natural asphalt. The low μ road pavement structure according to claim 1, wherein the artificial lightweight aggregate used as the μ value adjusting aggregate is a porous ceramic.

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