JP2019019544A - Pavement and pavement construction method - Google Patents

Abstract

To provide a pavement and pavement construction method capable of easily filling a cement milk cavity.SOLUTION: A pavement 1 comprises a support base 10 and a semi-flexible pavement 20 formed on the support base 10. The semi-flexible pavement 20 comprises an open-graded asphalt mixture 30 formed by mixing an open-graded mixture being a mix of only a No. 5 crushed stone 31 and a No. 7 crushed stone 32 with a foamed asphalt 33, and a cement milk 40 filled in cavities 34 of the open-graded asphalt mixture 30.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pavement and a construction method for the pavement.

  Conventionally, crushed stone is kneaded with foam door asphalt to form an asphalt mixture, and the asphalt mixture is used for semi-flexible pavement (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2005-68221

  In the related art, since the porosity of the asphalt mixture is small, the cement milk hardly penetrates into the gap, and it is necessary to perform the cement milk filling operation while applying vibration to the asphalt mixture by a plate compactor or the like. For this reason, filling work becomes complicated and early opening of traffic becomes difficult.

  The present invention has been developed from such a viewpoint, and an object of the present invention is to provide a pavement that can easily fill a gap with cement milk and a method for constructing the pavement.

In order to solve the above problems, the present invention includes a support base and a semi-flexible pavement formed on the support base, and the semi-flexible pavement includes only No. 5 crushed stone and No. 7 crushed stone. It is characterized by comprising an open particle size asphalt mixture formed by kneading an open particle size mixture obtained by mixing with foam door asphalt, and cement milk filled in the voids of the open particle size asphalt mixture. To do.
Moreover, in order to solve the said subject, this invention is the construction method of a pavement provided with a support base and a semi-flexible pavement, Comprising: Forming the open particle size mixture formed by mixing only No. 5 crushed stone and No. 7 crushed stone A kneading step of kneading with dophal asphalt to form an open-graded asphalt mixture, a laying step of laying the open-graded asphalt mixture on the support base, and spraying cement milk onto the open-graded asphalt mixture from above And a filling step of filling the voids of the particle size asphalt mixture.

  According to the present invention, by skipping No. 6 crushed stones and mixing only No. 5 crushed stones and No. 7 crushed stones, the gap in particle size increases, so the porosity of the open-graded asphalt mixture increases. This makes it easy for the cement milk to penetrate into the voids, so there is no need to apply vibration to the open-graded asphalt mixture, and the voids can be easily filled simply by spraying the cement milk. Therefore, early traffic opening is possible. In addition, since foam door asphalt that can be cast at a lower temperature than ordinary asphalt is used, it can be transported to a region far from the heated asphalt plant. Since the pavement includes a semi-flexible pavement, durability against traffic loads including large vehicles can be ensured.

  Moreover, it is preferable that the said cement milk contains an early strong cement. In this way, earlier traffic opening is possible.

  According to the pavement and the pavement construction method of the present invention, the cement milk can be easily filled into the gap.

It is sectional drawing which shows the pavement which concerns on embodiment of this invention. It is sectional drawing explaining the construction procedure of the construction method of the pavement which concerns on embodiment of this invention, (a) is a figure which shows a laying process, (b) shows the state which has spread | dispersed cement milk in the filling process. (C) is a figure which shows the state filled with cement milk in the filling process.

Embodiments of the present invention will be described in detail with reference to the drawings. First, the pavement 1 according to the present embodiment will be described.
As shown in FIG. 1, the pavement 1 is a so-called road, and includes a support base 10 and a semi-flexible pavement 20 formed on the support base 10.

  The support base 10 includes a road bed that supports the traffic load in cooperation with the semi-flexible pavement 20. The surface (upper surface) of the support base 10 is flattened by rolling or the like.

  The semi-flexible pavement 20 is a pavement that combines the flexibility of asphalt pavement and the rigidity of concrete pavement. The semi-flexible pavement 20 includes an open-graded asphalt mixture 30 and a cement milk 40. The pavement thickness t of the semi-flexible pavement 20 is formed in the range of 8 to 15 cm, for example.

  The open particle size asphalt mixture 30 is formed by kneading an open particle size mixture obtained by mixing only the No. 5 crushed stone 31 and the No. 7 crushed stone 32 (hereinafter collectively referred to as “crushed stone”) with the foam door bitumen 33. Yes. That is, the open particle size asphalt mixture 30 skips No. 6 crushed stone with a particle size range of 5 to 13 mm, and only No. 5 crushed stone 31 with a particle size range of 13 to 20 mm and No. 7 crushed stone 32 with a particle size range of 2.5 to 5 mm. It is formed by mixing. For this reason, the particle size gap is increased, and the porosity of the open particle size asphalt mixture 30 is increased. For example, the porosity is preferably set in the range of more than 23% and 30% or less (23% <porosity ≦ 30%).

  The surface of each crushed stone is coated with foam door asphalt 33. The crushed stones that are the mother bodies are connected to each other via the foam door asphalt 33 that is the binder. Between the crushed stones, an intricately shaped gap 34 is formed. By using the foam door bitumen 33, the fluidity of the open particle size asphalt mixture 30 can be improved even at a low temperature. The open-graded asphalt mixture 30 is preferably mixed with 80 to 70 parts by weight of No. 5 crushed stone, 5 to 15 parts by weight of No. 7 crushed stone, and 15 parts by weight of fine particles with respect to 100 parts by weight of foam asphalt. With such a blending ratio, durability against traffic load can be ensured while ensuring a high porosity.

  The cement milk 40 is mainly composed of cement and water, and is filled in the voids 34 of the open-graded asphalt mixture 30. The type of the cement milk 40 is not particularly limited, but in this embodiment, a fast-strength cement excellent in initial strength development is used.

  Next, with reference to FIG. 2 (a)-(c), the construction method of the pavement which concerns on this embodiment is demonstrated.

  The pavement construction method is a method of forming the pavement 1 including the support base 10 and the semi-flexible pavement 20. In the pavement construction method according to the present embodiment, a kneading step, a laying step, and a filling step are performed.

  The kneading step is a step of forming an open particle size asphalt mixture 30 by kneading an open particle size mixture obtained by mixing only No. 5 crushed stone 31 and No. 7 crushed stone 32 with foam door asphalt 33. By using only the No. 5 crushed stone 31 and the No. 7 crushed stone 32, the gaps 34 of the open-graded asphalt mixture 30 are formed large and many. Further, the foam door asphalt 33 serves as a binder to bond the crushed stones, and the gap 34 is maintained. The kneading step may be performed in a heated asphalt plant. A dump truck or the like is used as a transportation means from the heating asphalt plant to the construction site.

  As shown in FIG. 2A, the laying step is such that the open-graded asphalt mixture 30 is laid on the support base 10. In the laying process, the asphalt finisher or the like is placed on the support base 10 while placing the open-graded asphalt mixture 30 and leveled. In addition, the surface of the support base 10 is leveled in advance with a tire roller or the like.

  As shown in FIG. 2B, the filling step is a step of spreading cement milk 40 onto the open-graded asphalt mixture 30 from above and filling the voids 34 of the open-graded asphalt mixture 30. The cement milk 40 is formed by mixing cement and water using a mixer or the like. The cement milk 40 is sprayed on the open-graded asphalt mixture 30 from above using a hose 50 or the like. As shown in FIG. 2C, the sprayed cement milk 40 flows into the gap 34 and is filled. In addition, the cement milk 40 overflowing above the open-graded asphalt mixture 30 may be transferred to another location using a rake or the like as needed, or may be collected using a suction machine or the like. The pavement 1 is formed by the above process.

  According to the present embodiment described above, the gap of the particle size is increased by skipping the No. 6 crushed stone and mixing only the No. 5 crushed stone 31 and the No. 7 crushed stone 32, so that the open particle size asphalt mixture 30 has a high porosity. Become. As a result, the cement milk 40 easily penetrates into the gap 34, so there is no need to apply vibration to the open-graded asphalt mixture 30, and the gap 34 can be easily filled simply by spraying the cement milk 40. Therefore, early traffic opening is possible.

  Moreover, according to this embodiment, since the foam door asphalt 33 that can be placed at a temperature lower than that of normal asphalt is used, it can be transported to an area far from the heating asphalt plant. That is, the foam door bitumen 33 can be placed at a temperature lower by about 30 ° C. than the normal asphalt. Therefore, when the foam door bitumen 33 and the normal asphalt at the time of shipment from the plant have the same temperature, the foam door bitumen 33 33 can be transported farther. Accordingly, when the heated asphalt plant in the affected area is damaged during a disaster and the plant equipment cannot be used, the open-graded asphalt mixture 30 can be transported from a distant heated asphalt plant.

In addition, since the pavement 1 includes the semi-flexible pavement 20, durability against traffic loads including large vehicles can be ensured.
Moreover, according to this embodiment, since the cement milk 40 contains early strong cement, it becomes possible to open traffic earlier.

  Further, according to the present embodiment, since the foam door asphalt 33 is used, it can be shipped at a temperature (for example, about 130 ° C.) lower than the temperature (for example, about 160 ° C.) at the time of normal asphalt shipment. As a result, it is possible to shorten the time required for the temperature to drop to the traffic opening temperature (for example, the temperature of the pavement surface is about 50 ° C.). For this reason, combined with the ease of filling of the cement milk 40 and the initial strength development of the early strong cement, the early traffic opening is improved. Therefore, the road damaged at the time of a disaster can be repaired at an early stage, and an early vehicle such as an emergency vehicle or a support material transportation vehicle can be passed. In addition, by repairing cracks and the like of the road at an early stage, it is possible to prevent the road from collapsing due to intrusion of rainwater or the like. That is, the pavement 1 and the pavement construction method of the present embodiment are suitable for disaster recovery.

The embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention.
In the present embodiment, a roadbed is exemplified as the support base 10, but a roadbed formed on the roadbed may be used. In this case, the semi-flexible pavement 20 is formed on the roadbed.

DESCRIPTION OF SYMBOLS 1 Pavement 10 Support base 20 Semi-flexible pavement 30 Open-graded asphalt mixture 31 No. 5 crushed stone 32 No. 7 crushed stone 33 Foam door bitumen 34 Void 40 Cement milk

Claims (3)

A support base,
A semi-flexible pavement formed on the support base, and
The semi-flexible pavement is
An open particle size asphalt mixture formed by kneading an open particle size mixture obtained by mixing only No. 5 crushed stone and No. 7 crushed stone with foamed asphalt;
Cement milk filled into the voids of the open particle size asphalt mixture;
A pavement characterized by comprising.   The pavement according to claim 1, wherein the cement milk comprises early strong cement. A pavement construction method comprising a support base and a semi-flexible pavement,
A kneading step in which an open particle size mixture obtained by mixing only No. 5 crushed stone and No. 7 crushed stone is kneaded with foam door asphalt to form an open particle size asphalt mixture;
A laying step of laying the open-graded asphalt mixture on the support base;
A filling step in which cement milk is applied to the open-graded asphalt mixture from above to fill the voids of the open-graded asphalt mixture;
A pavement construction method characterized by comprising.

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