Pavement structure and construction method for pavement structure

Abstract

The present invention provides a pavement structure and a method for constructing the same pavement structure that can suppress the infiltration of rainwater and other liquids into the roadbed and drain them to the outside of the pavement, even if the sealing material of the joints of the concrete pavement is damaged. [Solution] A pavement structure 100 comprising a roadbed 110 formed on the road surface, and a concrete slab 120 formed on the roadbed 110 and having a joint 122 opening on its upper surface, further comprising a water guide strip 130 made of nonwoven fabric 132 and disposed within the joint 122, and a sealing member 150 disposed above the water guide strip 130 and closing the opening of the joint 122.

Description

Technical Field

[0001] The present invention relates to a pavement structure and a method for constructing the pavement structure.

Background Art

[0002] Among concrete pavements, for example, ordinary concrete pavements have joints at intervals of about 10 m. The joints are sealed with a sealing member, but during use, the sealing member peels off or scatters and is damaged. When the sealing member is damaged, rainwater or the like penetrates from the joint into the roadbed under the concrete slab, and the pumping action due to traffic load progresses, and the roadbed may become vulnerable and cavities may occur (erosion). When the roadbed support force decreases, the damage to the concrete slab progresses, and there is an increased risk of progressing to damage such as a step occurring in the concrete slab. Therefore, it is important to prevent rainwater or the like from penetrating from the joint into the roadbed.

[0003] Patent Document 1 aims to provide a method for constructing a joint sealing material that can easily restore the joint seal after construction in the construction of a joint sealing material for concrete pavement. A joint sealing material that thermally softens and melts is formed into a rope shape or a rod shape, etc., and an electromagnetic heating element such as an iron wire or an iron net is placed as a core material therein to form a molded body, and this molded body is inserted into the joint groove, and the electromagnetic heating element is heated by an electromagnetic induction device to soften and melt the joint sealing material to seal the joint. A method for constructing a joint sealing material for concrete pavement is disclosed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In concrete pavements, regular maintenance is necessary to keep the joints in good condition to prevent rainwater and other liquids from seeping into the roadbed. However, in practice, proper maintenance can be difficult due to cost and management system limitations. If proper maintenance is not carried out, rainwater and other liquids will seep into the roadbed, weakening it and eventually leading to pavement damage such as unevenness in the concrete slab. Therefore, even if the sealing material is damaged, it is necessary to suppress the infiltration of rainwater into the roadbed.

[0006] This invention has been made in view of these circumstances, and aims to provide a pavement structure and a method for constructing the same pavement structure that can suppress the infiltration of rainwater and the like into the roadbed and drain it to the outside of the pavement, even when the sealing member of the joint of the concrete pavement is damaged. [Means for solving the problem]

[0007] (1) In order to achieve the above objective, the present invention employs the following means. Specifically, the pavement structure of the present invention comprises a base course formed on a subgrade, and a concrete slab formed on the base course and having joints opening on its upper surface, and is characterized by comprising a water guide strip made of nonwoven fabric and disposed within the joint, and a sealing member disposed above the water guide strip and closing the opening of the joint.

[0008] In this way, by providing a water-conducting strip made of nonwoven fabric at the bottom of the sealing member, even if the sealing member of the concrete pavement joint is damaged, the infiltration of rainwater into the roadbed can be suppressed and drained away from the pavement. Furthermore, such a pavement structure can be constructed easily and at low cost.

[0009] (2) Furthermore, the pavement structure of the present invention is characterized in that, in a cross section perpendicular to the long axis direction of the joint, the width of the nonwoven fabric is greater than the width of the joint, and the water guide band includes a portion that protrudes downward. This makes it possible to further suppress the penetration of rainwater into the roadbed even if the sealing member is damaged.

[0010] (3) Furthermore, in the pavement structure of the present invention, the water guide band is characterized in that an impermeable film is formed on its lower surface. This further suppresses the penetration of rainwater into the roadbed even if the sealing member is damaged.

[0011] (4) Furthermore, in the pavement structure of the present invention, the water guide strip has an adhesive layer on at least a part of its lower surface, and the water guide strip is bonded to the concrete slab in the joint by the adhesive layer. This ensures that it is securely fixed in a predetermined position at the bottom of the joint, and even if the sealing member is damaged, the penetration of rainwater into the roadbed can be further suppressed.

[0012] (5) The pavement structure of the present invention is further characterized by comprising a backup member disposed between the water guide strip and the sealing member. This makes it possible to reduce the overhang of the sealing member from the road surface during the summer, even when the slab thickness is thick and the joint grooves are deep.

[0013] (6) Furthermore, in the pavement structure of the present invention, the joint is further characterized by comprising a second sealing member positioned below the water guide zone. This makes it possible to further suppress the penetration of rainwater into the roadbed even if the sealing member is damaged.

[0014] (7) Furthermore, the present invention relates to a method for constructing a pavement structure comprising a base course formed on a subgrade and a concrete slab formed on the base course and having joints opening on its upper surface, the method being characterized by comprising the steps of placing a water-conducting strip made of nonwoven fabric in the joint and placing a sealing member above the water-conducting strip to close the opening of the joint.

[0015] This allows for the easy and low-cost construction of a pavement structure that can suppress rainwater infiltration into the roadbed and drain away from the pavement, even if the sealing material in the joints of the concrete pavement is damaged. [Effects of the Invention]

[0016] According to the present invention, even when the seal member at the joint of the concrete pavement is damaged, it is possible to suppress the penetration of rainwater into the roadbed and drain it outside the pavement. In addition, such a pavement structure can be easily constructed at a low cost.

Brief Description of the Drawings

[0017] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of the cross-sectional structure of a pavement structure according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view showing an example of the cross-sectional structure of a non-woven fabric forming a water-permeable zone according to an embodiment of the present invention. [Figure 3] FIG. 3 is a flowchart showing an example of a construction method of a pavement structure according to a first embodiment of the present invention. [Figure 4] FIG. 4 is a schematic cross-sectional view showing an example of the cross-sectional structure of a pavement structure according to a second embodiment of the present invention.

Modes for Carrying Out the Invention

[0018] Embodiments of the present invention will be described with reference to the drawings. For ease of understanding of the description, the same reference numerals are given to the same components in each drawing, and redundant descriptions are omitted. In the configuration diagrams, the sizes of the respective components are conceptually represented and do not necessarily represent actual dimensional ratios.

[0019] [First Embodiment] (Configuration of Pavement Structure) FIG. 1 is a schematic cross-sectional view showing an example of the cross-sectional structure of a pavement structure 100 according to a first embodiment of the present invention. The pavement structure 100 according to the present embodiment includes a roadbed 110, a concrete slab 120, a water-permeable zone 130, and a seal member 150. The backup member 140 is a component provided as needed.

[0020] The roadbed 110 is formed on a roadbed (not shown). The roadbed 110 may be a single layer or may be composed of a lower roadbed 112 and an upper roadbed 114.

[0021] The lower roadbed 112 is formed on the roadbed. The material constituting the lower roadbed 112 may be any material as long as it can ensure a predetermined supporting force and durability. For example, granular roadbed materials such as crusher run and cut gravel, and stabilized roadbed materials such as cement-stabilized treatment materials and lime-stabilized treatment materials can be used. The lower roadbed 112 may consist of two or more layers. The thickness of the lower roadbed 112 varies depending on the material and the required supporting force, but for example, it is preferably 10 cm or more and 80 cm or less.

[0022] The upper roadbed 114 is formed on the lower roadbed 112. The material constituting the upper roadbed 114 may be any material as long as it can ensure a predetermined supporting force and durability. For example, granular roadbed materials such as size-adjusted crushed stone and size-adjusted steel slag, and stabilized roadbed materials such as cement-stabilized treatment materials, lime-stabilized treatment materials, and asphalt-stabilized treatment materials can be used. The thickness of the upper roadbed 114 varies depending on the material and the required supporting force, but for example, it is preferably 8 cm or more and 50 cm or less. An asphalt intermediate layer may be provided between the upper roadbed 114 and the concrete slab 120.

[0023] The concrete slab 120 is formed on the roadbed 110. The concrete slab 120 has joints 122 that open to the upper surface. The joints 122 may communicate with drainage facilities provided outside the pavement structure 100. Since FIG. 1 shows a shrinkage joint as an example, there are cracks generated by the shrinkage of the concrete slab 120 under the joints 122, but there may be joint plates under the joints 122.

[0024] The materials constituting the concrete slab 120 are selected to possess the required performance and quality, such as durability, workability, and safety. For example, Portland cement, blast furnace cement, silica cement, fly ash cement, and eco-cement can be used. Water, fine aggregate, coarse aggregate, and other admixtures are also selected from the perspective of the performance and quality of the concrete slab 120. The thickness of the concrete slab 120 varies depending on the traffic conditions, base conditions, and environmental conditions of the road on which the pavement structure 100 will be used, but is preferably between 15 cm and 30 cm.

[0025] The structure of the present invention can be applied to various types of joints 122, such as transverse contraction joints, transverse expansion joints, longitudinal warp joints, and longitudinal expansion joints, applied to concrete slabs 120 of ordinary concrete pavement, continuous reinforced concrete pavement, or compacted concrete pavement.

[0026] The water guide strip 130 is placed within the joint 122. The water guide strip 130 is formed of nonwoven fabric 132. This allows water that has entered to be captured by the water guide strip 130 and drained outside the pavement, even if a gap occurs between the sealing member 150 and the concrete slab 120, or if the sealing member 150 is lost. Furthermore, a drainage structure within the joint 122 can be formed at low cost. As a result, damage to the roadbed 110 and damage to the entire pavement structure 100 can be suppressed. The thickness of the nonwoven fabric 132 is preferably 1 mm to 15 mm. If the joint 122 communicates with drainage equipment provided on the outside of the pavement structure 100, it is preferable to install the water guide strip 130 up to the drainage equipment.

[0027] In a cross-section perpendicular to the long axis direction of the joint 122 of the pavement structure 100, the width of the nonwoven fabric 132 forming the water guide zone 130 is greater than the width of the joint 122, and the water guide zone 130 preferably includes a downwardly convex portion. This allows water that has penetrated into the interior of the joint 122 to be received not only on the surface and interior of the nonwoven fabric 132 but also in the space above the downwardly convex portion. It is even more preferable that the water guide zone 130 is in the shape of a downwardly convex arc or U.

[0028] Figure 2 is a schematic cross-sectional view showing an example of the cross-sectional structure of a nonwoven fabric 132 forming a water guide band 130 according to an embodiment of the present invention. Figure 2 shows a cross-section perpendicular to the longitudinal direction of the nonwoven fabric 132. As shown in Figure 2, it is preferable that an impermeable film 134 is formed on the lower surface of the water guide band 130. This makes it difficult for water to penetrate below the water guide band 130, and even if the sealing member 150 is damaged, the penetration of rainwater and the like into the roadbed 110 can be further suppressed. The impermeable film 134 can be made of polyester, polyethylene, or the like. The impermeable film 134 may be formed on a portion of the width of the nonwoven fabric 132. Alternatively, the impermeable film 134 may be formed on the upper surface of the nonwoven fabric 132.

[0029] The water guide strip 130 preferably has an adhesive layer 136 on at least a portion of its lower surface, and is bonded to the concrete slab 120 in the joint 122 by the adhesive layer 136. This ensures that the water guide strip 130 is securely fixed in a predetermined position at the bottom of the joint, making it difficult for water to penetrate below the water guide strip 130, and further suppressing the penetration of rainwater and the like into the roadbed 110 even if the sealing member 150 is damaged. The surface of the concrete slab 120 to which the water guide strip 130 is bonded may be the side surface or the bottom surface of the joint 122. The adhesive layer 136 can be formed from asphalt, rubber-asphalt compound, organic adhesive, etc.

[0030] In cases where the slab thickness is high and the joint grooves are deep, a backup member 140 may be placed above the water guide strip 130 to reduce the overhang of the sealing member 150 from the road surface during the summer. The backup member 140 can be made of foamed polyethylene, foamed urethane, or the like. The cross-sectional shape of the backup member 140 can be any shape that allows for separation between the water guide strip 130 and the sealing member 150 and reduces the depth of the sealing member 150.

[0031] The sealing member 150 is positioned above the water guide band 130 or the backup member 140 and closes the opening of the joint 122. The sealing member 150 can be formed from common materials used in concrete pavements. For example, it can be formed from a heat-applied injection joint material in which a modifier (polymer) such as rubber is mixed into bituminous material to increase its elasticity.

[0032] [Construction methods for pavement structures] An example of a construction method for the pavement structure 100 will be described. Figure 3 is a flowchart showing an example of a construction method for a pavement structure according to the first embodiment of the present invention. First, a water guide strip 130 formed from a nonwoven fabric 132 is placed in the joint 122 of the concrete slab 120 (step S1). If the width of the nonwoven fabric 132 is greater than the width of the joint 122, it is preferable to arrange the water guide strip 130 so as to include a portion that protrudes downward in a cross section perpendicular to the long axis direction of the joint 122, and it is more preferable to arrange it in an arc shape or a U shape. Also, if the water guide strip 130 has an adhesive layer 136, it is preferable to adhere the water guide strip 130 to the concrete slab 120 in the joint 122. Furthermore, it is preferable to arrange the water guide strip 130 after the concrete slab 120 has been sufficiently cured.

[0033] Next, a sealing member 150 is placed on top of the water guide strip 130 positioned in step S1 to close the opening of the joint 122 (step S2). A step of placing a backup member 140 on top of the water guide strip 130 as needed may be included between step S1 and step S2. In this way, the water guide strip 130 can be easily formed inside the joint 122 of the concrete slab 120. Even if a gap occurs between the sealing member 150 and the concrete slab 120, or if the sealing member 150 is lost, the penetration of rainwater and other water into the roadbed 110 through the joint 122 can be suppressed, and the water can be drained outside the pavement structure 100. As a result, damage to the roadbed 110 and damage to the entire pavement structure 100 can be suppressed.

[0034] [Second Embodiment] (Composition of the pavement structure) Figure 4 is a schematic cross-sectional view showing an example of the cross-sectional structure of a pavement structure 100 according to a second embodiment of the present invention. The pavement structure 100 according to this embodiment comprises a base course 110, a concrete slab 120, a water guide belt 130, a sealing member 150, and a second sealing member 152. In the second embodiment as well, the backup member 140 is a component that is provided as needed. The base course 110, concrete slab 120, water guide belt 130, backup member 140, and sealing member 150 are the same as in the first embodiment, so their description is omitted.

[0035] The second sealing member 152 is positioned below the water guide band 130. This further suppresses the penetration of rainwater into the roadbed 110 even if the sealing member 150 is damaged. The second sealing member 152 can be made of the same material as the sealing member 150.

[0036] Since the second sealing member 152 is spaced apart from the sealing member 150 and installed at a deeper position than the sealing member 150, even if maintenance is not performed until the sealing member 150 is damaged, the second sealing member 152 is more likely to remain undamaged. Therefore, even if more rainwater enters than the drainage channel 130 can handle when the sealing member 150 is damaged, the second sealing member 152 can further suppress the infiltration of rainwater into the roadbed 110.

[0037] A second backup member 142 may be provided between the water guide belt 130 and the second sealing member 152. The second backup member 142 can be made of the same material as the backup member 140.

[0038] [Examples] (Example 1) Concrete pavement was constructed on a 3m x 3m subgrade formed of crushed stone. After the concrete hardened, a dummy joint measuring 3m in length and 10mm in width was formed on the top surface using a cutter. After 14 days of curing, the side of the concrete slab was inspected, and cracks due to concrete shrinkage were observed from the bottom of the dummy joint down to the subgrade.

[0039] A water-conducting strip made of nonwoven fabric was placed on the bottom surface of the joint and bonded to the concrete slab. The water-conducting strip used a tape-like member having an impermeable film and adhesive layer on a portion of the underside of the nonwoven fabric. Next, a backup member with an elliptical cross-section made of expanded polystyrene was placed on top of the water-conducting strip. Then, a sealing member made of a heat-applied injection joint material was injected on top of the backup member to close the opening of the joint, thereby creating the pavement structure of Example 1.

[0040] After the sealing material hardened, a precipitation test was conducted on the surface of the pavement structure of Example 1 at a rainfall intensity of 10 mm / h for 1 hour. Subsequently, the amount of moisture inside the cracks in the concrete slab was checked, and no change in moisture content was observed before and after the precipitation test. This confirmed that when the sealing material functions sufficiently, moisture does not penetrate into the concrete slab.

[0041] (Example 2) The pavement structure of Example 1 was modified by removing the sealing members and backup members to obtain the pavement structure of Example 2. The pavement structure of Example 2 is intended to be in a condition equivalent to a pavement structure that has not been maintained for several years after construction, and in which the sealing members have been damaged and lost.

[0042] A precipitation test was conducted on the surface of the pavement structure in Example 2 at a rainfall intensity of 5 mm / h for 1 hour. Afterwards, the amount of moisture inside the cracks in the concrete slab was checked, and no change in moisture content was observed before and after the precipitation test. This confirmed that, due to the presence of a water-conducting zone, even if the sealing member is lost, moisture will not penetrate into the concrete slab with rainfall of about 5 mm / h.

[0043] The present invention is not limited to the embodiments described above, and it goes without saying that it extends to various modifications and equivalents that fall within the spirit and scope of the present invention. Furthermore, the structure, shape, number, position, size, etc., of the components shown in each drawing are for illustrative purposes only and may be modified as appropriate. [Explanation of symbols]

[0044] 100 Pavement Structures 110 Roadbed 112 Lower subgrade 114 Upper subgrade 120 Concrete slab 122 Joint 130 Water conduit 132 Nonwoven fabric 134 Impermeable film 136 Adhesive layer 140 Backup components 142 Second backup member 150 sealing member 152 Second sealing member

Claims

1. A pavement structure comprising a roadbed formed on the subgrade, and a concrete slab formed on the roadbed and having joints opening on its upper surface, A water-conducting strip, formed of nonwoven fabric, is placed within the aforementioned joint, A pavement structure characterized by comprising a sealing member disposed above the water diversion zone and closing the opening of the joint.

2. In a cross-section perpendicular to the longitudinal axis of the joint, the width of the nonwoven fabric is greater than the width of the joint. The pavement structure according to claim 1, characterized in that the water diversion zone includes a portion that protrudes downward.

3. The pavement structure according to claim 1 or 2, characterized in that an impermeable film is formed on the lower surface of the water diversion zone.

4. The water guide strip has an adhesive layer on at least a portion of its lower surface, The pavement structure according to claim 1 or 2, characterized in that the water-conducting strip is bonded to the concrete slab in the joint by the adhesive layer.

5. The pavement structure according to claim 1 or 2, further comprising a backup member disposed between the water guide belt and the sealing member.

6. The pavement structure according to claim 1 or 2, characterized in that the joint further comprises a second sealing member disposed below the water guide zone.

7. A method for constructing a pavement structure comprising a roadbed formed on a subgrade and a concrete slab formed on the roadbed and having joints opening on its upper surface, The steps include placing a water-conducting strip made of nonwoven fabric within the aforementioned joint, A method for constructing a pavement structure, comprising the step of placing a sealing member on the upper side of the water guide belt to close the opening of the joint.

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