JPS60129304A - Construction of joint such as center joint of asphalt pavement - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] A construction joint in a center joint, etc. of the surface layer or base layer of asphalt pavement that sufficiently connects the construction joint, does not cause cracks, and maintains sufficient watertightness. This relates to the construction method. □”Snow interjoints in asphalt pavement are a problem that is especially difficult in cold regions, and joint cracks often appear after one winter of service, whether new construction or repair work. Even in general areas, As the years of service pass, more or less joint cracks appear.

Furthermore, recently, in order to prevent rutting, sagging, and flow due to traffic loads, flow-resistant pavement has been used, and the quality of asphalt used as a binder has become semi-prone. As a result, construction joints tend to open earlier than in conventional pavement.

When joint cracks occur in pavement, rainwater penetrates into the roadbed and subgrade soil through the cracks, creating a weak bearing capacity that was not considered at the time of design, and causing damage to the pavement. Eventually, the damaged area (initially a tortoise-shell-shaped crack) develops1, leading to the destruction of the pavement.

Therefore, the occurrence of joint cracks is not desirable.

In particular, joint cracks are more likely to occur on roads with two lanes, both up and down, because the joints are located almost near the center line of the road width, and the trajectory of the wheels of vehicles traveling both upward and downward. Another reason was that the two were in the same position.

In addition to center joints, when looking at recent pavements, there are many joints that open up over the years of use and joint cracks appear, and like center joints, cracks must not occur.

Conventional construction joints have been tack coated with asphalt emulsion or cutback asphalt on the cross section of the surface or base layer of existing or previously paved asphalt pavement, which will serve as the construction joint.

However, in reality, joint cranks occur at construction joints, and the establishment of a construction method to prevent this problem is eagerly awaited.

The present invention meets these needs and provides a construction method that prevents joint cracks from occurring at construction joints in the surface layer or base layer of asphalt pavement, particularly at center joints.

The construction method of the present invention is a construction method for construction joints such as center joints that occur when paving a surface layer or base layer that is in contact with the surface layer or base layer of an existing or previously paved asphalt pavement. This article describes a construction method for construction joints in asphalt pavement center joints, etc., which is characterized in that an asphalt-based plate-shaped sealing material is bonded in advance to the cross section of the construction joint of the surface layer or base layer, and then the next surface layer or base layer is paved. It is something to do.

The asphalt plate sealing material used in the present invention is as follows.

Asphalt-impregnated paper, cloth, reticulated cloth, non-woven cloth,
It is a foil or film coated with asphalt on both sides, or an asphalt plate. Asphalt here includes various petroleum asphalts, natural asphalts, asphalt compounds, rubberized asphalt (asphalt modified by adding rubber, powdered rubber, synthetic polymers, etc. to asphalt), and rubberized asphalt-based heating injection. A mold sealant and various fillers were added to these materials. Things, etc. Furthermore, asphalt-based plate sealing materials include petroleum asphalt, natural asphalt, etc., mixed and kneaded with rubber, powdered rubber, synthetic resin, process oil, etc., or pigments (e.g. carbon), Examples include those in which a filler is added and molded into a plate shape, and those in which the above-mentioned core material is inserted into the plate shape.

The thickness of the asphalt-based plate-shaped sealing material is about 2 to 10 mm, and usually about 2 to 5 i+i is sufficient. The width corresponds to the thickness of one paving of the heated Amephalt mixture. It is preferable to apply mineral powder or the like to the surface of the asphalt-based plate-shaped sealing material to prevent the sealing materials from adhering to each other during handling.

The surface of the asphalt-based plate-shaped sealing material may be made pressure-sensitive adhesive, and a release paper or the like may be attached thereon.

Next, the construction method of the present invention will be explained.

FIG. 1 and FIG. 2 are schematic diagrams of a cross-sectional view and a plan view of an asphalt pavement constructed using the construction method of the present invention. In the figure, (1) is the surface asphalt pavement (heated asphalt mixture pavement), (2) is the center joint, and (3) is the asphalt-based plate-shaped sealing material.

Taking the construction of the surface layer (1) in asphalt pavement as an example, a tack coat or a prime coat made of a blue-green material such as asphalt emulsion is applied on the base layer or roadbed (4). Conventionally, this tank coat was only carefully applied to construction joints such as center joints.

In the construction method of the present invention, asphalt-based plate-shaped sealing material (
3) is used. For example, when a heated asphalt mixture is spread to a predetermined thickness, a wooden formwork is used, and an asphalt plate-shaped sealing material (3) is nailed to the side of the formwork. This nailing is done lightly at the initial construction length of about 5m, and beyond that it is not necessary to nail it as the paving progresses.
An asphalt plate-shaped sealing material (3) may be inserted between the heated asphalt mixture and the formwork. Heating a,
Asphalt plate sealing material (3
) is melted and pressed and adhered to the vertical surface of the heated asphalt mixture pavement, that is, the surface layer (1). After paving,
When the formwork is removed, the asphalt plate-shaped sealing material (3) is in close contact with the vertical surface of the center joint (2) of the surface layer (1) of the asphalt pavement that has already been paved. Then, when a heated asphalt mixture is spread and rolled next to it, the asphalt-based plate-shaped sealing material (3) melts and adheres to the new pavement, ie, the other surface layer (1), by thermocompression. The center joint (2) is sandwiched between the asphalt plate-shaped sealing material (3) and the left and right pavements.
That is, since the surface layers (1) (1) are completely bonded by thermocompression bonding, the bonding of the center joint (2) is complete and watertight.

In addition, during the above construction, after the heated asphalt mixture is spread and compacted, the asphalt-based plate-shaped sealing material (3) is applied to the construction joint by an appropriate means, and the next heated asphalt mixture paving is carried out. good. In this case, a pressure-sensitive adhesive type asphalt-based sheet sealant (
3) is convenient to use. After paving, as long as the pavement is still warm, the asphalt-based plate sealant (3) can easily adhere to the construction joint surface of the pavement. When joining existing pavement, you can easily use asphalt-based sheet seal material (3) by lightly heating the construction joint with a burner.
can be written down. Then, when a heated asphalt mixture is laid on this, the asphalt-based plate-shaped sealing material (3) melts due to the heat of the heated asphalt mixture and the thermocompression bonding caused by roller rolling, and the asphalt-based plate-shaped sealing material (3) is melted, and the left and right pavements are paved around this as the center. can be completely combined.

' When constructed in this way, the construction joints will not open even if the construction is opened to traffic over time. Center joints do not cause cracks.

The construction method of the present invention completely seals the joint part,
It is possible to make it watertight and connect the left and right pavement bodies. Even after being used for traffic, the shielding effect is maintained, so no glare is observed.

In addition, there is no need to tack construction joints as in the past, making the work easier and reducing the number of workers. Furthermore, since rainwater does not seep through the joint, it has excellent effects such as maintaining the value of the pavement constituent layers for many years.

[Brief explanation of the drawing]

FIGS. 1 and 2 are a cross-sectional view and a plan view schematically showing an asphalt pavement obtained by implementing the construction method of the present invention. The symbols in the figure are explained as follows. (1) is the surface asphalt pavement (heated asphalt mixture pavement) (2) is the center joint (3) is the asphalt plate sealing material (4) is the base layer or roadbed -1 225!1 l

Claims (1)

[Claims] In the construction method for construction joints such as center joints that occur when paving the surface layer or base layer that is in contact with the surface layer or base layer of an existing or previously paved asphalt pavement, disconnection of the construction joint of the existing or previously paved surface layer or base layer □ Revised construction method for construction joints such as center joints of asphalt pavement, which is characterized by paving the next surface layer or base layer after asphalt-based plate-shaped sealing material is bonded to the surface in advance.