JP3120070B2 - How to build a thin concrete overlay - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a thin concrete overlay which is a method for repairing asphalt pavement.

[0002]

2. Description of the Related Art Asphalt pavement overlay repairing methods include overlay by asphalt and thin overlay by fiber reinforced concrete.

[0003] However, in overlaying with asphalt, rutting due to plastic flow is likely to occur at high temperatures in summer, and cracks are generated due to brittleness of asphalt at low temperatures in winter.

On the other hand, due to the thin-layer overlay by fiber reinforced concrete is concrete - requires joint for shrinkage due to bets curing drying shrinkage, run for the joint
Passenger cars may generate noise and driving comfort may be impaired.
Was. In addition, this joint reduces the strength of concrete.
Or cause edge defects in partial since it becomes, there is an inconvenience such as causing corner cracking.

[0005] Further, in the case of the fiber-reinforced concrete , unlike ordinary concrete, cracks are liable to be formed at places other than joints . In addition, even if the cracks occur at the intended joints , the concrete may break down at a relatively early stage due to the development of the cracks . In such a case, the crack width or the crack width guided to the joint is mostly over 1 mm, and in some cases, 10 m.
m.

[0006] Therefore, to consider the cause of the fiber-reinforced concrete in accordance with, is due to the normal concrete, et al or the tensile strength of concrete is small, cause cracks that were scheduled at the bottom of the joint, of the concrete cracks split
This progress stops at the joint, the stress and displacement due to concrete shrinkage are not transmitted to the adjacent concrete slabs, and since the weakened concrete slabs are reinforced with slip bars, Adjacent to traffic loads acting vertically on concrete slabs
To have a joint original function that transfers the load to the concrete edition. However, in fiber reinforced concrete, even if joints are provided at planned locations, fibers are connected at the lower part of the joints , transmitting not only traffic load but also stress and displacement due to concrete shrinkage to the adjacent concrete slab, It does not have the joint function inherent to ordinary concrete .

[0007]

The present invention To solve the above problems, division of the present invention
The problem is the problem in the thin layer overlay method using the fiber-reinforced concrete described above, that is, even if the joint is provided in the concrete due to the presence of the fiber, the function as a joint for shrinkage is not exhibited, and cracks occur in places other than the joint , even if the crack occurs in the joint was planned, Hibiwari
It is intended to solve problems such as the structural failure of concrete at a relatively early stage due to the development of the gap.

[0008]

Means for Solving the Problems As a result of intensive studies on the above problems, the present inventors have found that when overlaying a thin layer of fiber reinforced concrete on the upper surface of a damaged asphalt pavement, the existing It has been found that the above problem can be solved by providing a restraint plate having a predetermined installation interval and a predetermined height in the width direction of the asphalt pavement and casting fiber-reinforced concrete there.

That is, the present invention has been found by the present inventors.
The above research results are used.

[0010] In order to achieve the above object, the invention according to claim 1 is provided.
Ming's method of building a thin concrete overlay is
Fiber-reinforced concrete on top of damaged asphalt pavement
When overlaying a REIT in a thin layer,
5% to 50% of the thickness of the fiber reinforced concrete slab
The restraining plate having the width of the existing asphalt pavement
In the direction of extension of the existing asphalt pavement
Provide at intervals of 0.5m to 3m, where fiber reinforced concrete
It is characterized by casting a sheet.

[0011] In order to achieve the above object, the invention according to claim 2 is provided.
The construction method of Ming's thin concrete overlay is
In the invention of claim 1, the existing asphalt pavement
The constraining plate to be provided may be bonded using an adhesive or cut
A method of providing a groove and fitting it into the kerf or nailing
It is characterized in that it is performed by any of the methods.

[0012]

DETAILED DESCRIPTION OF THE INVENTION The damage of the resulting existing asphalt pavement, but refers to those made from the existing asphalt pavement caused breakage undergo cracking and plastic flow, the extent and design height after repair of the damage Can be used as it is, or a part of it can be cut and used.

[0013] Installation of the constraining plate, by performing a method of bonding using an adhesive constraining plate, and a method of fitting the constraining plate is provided with grooves cut into the existing asphalt pavement, by a method in which nailing the constraining plate Can be. By the way, in these installation methods , it is preferable to use a cutting groove method in which a cutter groove is desirably formed on an existing asphalt pavement surface, and a restraint plate is fitted therein.

Further, it is necessary to provide the restraint plates at intervals of 0.5 m to 3 m in the extension direction (longitudinal direction) of the pavement. If the distance exceeds 3 m, the concrete shrinks or cracks in places other than where the restraint plate is installed, or the crack width is undesirably developed to 1 mm or more. The interval is 0.5
If it is less than m, there is no problem as described above, but it is only uneconomical to provide an unnecessary number of restraint plates.

Here, the installation height of the restraint plate from the asphalt pavement surface must be 5% to 50% of the thickness of the fiber reinforced concrete slab to be overlaid . If it is less than 5%, there is a risk that cracks cannot be induced at a predetermined location, and if it exceeds 50%, the function of transmitting a load to an adjacent concrete slab is reduced. Preferably, it is 15% to 35%.

Further, the installation length of the constraining plate, but to a constraining plate consisting of 1-sheet 50% to 100% of the width length of the existing asphalt pavement is desired, the constraining plate suitably formed of a plurality other than this It can also be installed at intervals.

[0017] The cross-sectional shape of the constraining plate, linear, triangular, trapezoidal, be those consisting of rectangular, etc.
The material of the restraint plate can be made of metal, plastic, wood, concrete or the like.

Here, in order to prevent adhesion between the restraining plate and the fiber reinforced concrete, it is desirable to apply a release agent or the like to the surface of the restraining plate in advance.

[0019] For the placement of fiber reinforced concrete ,
In order to improve the adhesion to the asphalt pavement surface, cement milk, epoxy resin, or the like can be previously applied to the casting surface.

By the way, fiber reinforced concrete used herein, the steel fiber reinforced concrete reinforced with steel fibers, plastic fiber reinforced concrete reinforced with plastic fibers, carbon fibers reinforced concrete reinforced with carbon fibers, also iron insert the wire netting Various materials such as mesh concrete and geotextile reinforced concrete for arranging geotextile can be used.

The pavement thickness of the fiber-reinforced concrete is usually about 5 cm to 15 cm.

[0022]

Next, embodiments of the present invention will be described in more detail with reference to tables and drawings. FIG. 1 is a sectional view showing an existing asphalt pavement configuration before repair. In this pavement structure, an existing asphalt pavement 1 is applied on a subgrade 3 and a subbase layer 2 to a thickness of 25 cm.

FIG. 2 is a longitudinal sectional view after a part of the existing asphalt pavement 1 of FIG. 1 is partially cut and provided with a restraint plate 5 and overlaid with a thin fiber reinforced concrete 4 thereon.

The method of constructing the overlay using the thin layer fiber reinforced concrete 4 is as follows. The upper surface of the existing asphalt pavement 1 is cut by 10 cm using a cutting machine, the cut surface is cleaned, and the diamond cutter is used to cut the upper surface of the asphalt pavement 1 to a width of 5 mm in the width direction of the road. After the kerf 6 was provided, the restraint plate 5 was inserted into the kerf 6, and three types of thin-layer fiber reinforced concrete 4 shown in Table 1 were cast with a thickness of 10 cm. here,
The fiber content of the various fiber reinforced concretes was based on standard ones.

[0025]

[Table 1]

FIG. 3 shows how the restraint plate 5 is installed on the existing asphalt pavement 1 after partial cutting.

As shown in FIG. 3, the constraint plate 5 has a length b of 3 m, a thickness t of 5 mm, and a height h of 50 mm and 65 m.
m was used.

The spacing L of the restraint plates 5 in FIGS. 2 and 3 is set at three levels of 1 m, 3 m and 5 m. The installation height x of the restraint plate 5 from the asphalt cutting surface was two levels of 15 mm and 35 mm, and three levels of which 25 mm was partially added. Of these, the installation height x from the asphalt cutting surface is 35 mm
The one having a height h of the restraint plate 5 of 65 mm was used. Here, for comparison, a case in which a joint having a width of 6 mm and a depth of 35 mm is cut at intervals of 10 m with a cutter is also listed. Then, a crack occurrence site and a crack width after 6 months from the construction were observed. Table 2 shows the results.

[0029]

[Table 2]

As shown in Table 2, when the installation interval L of the restraint plates 5 is within 3 m, controlled cracks occur at the places where the restraint plates 5 are installed, regardless of the installation height x of the restraint plates 5. ,
It can be seen that the width is 0.5 mm or less. On the other hand, in the cases of Comparative Examples 1 and 3, no cracks occurred except at the crack induction portions, but the width of the cracks reached 3 mm or more in a wide area.
In the case of Comparative Example 2, it can be seen that cracks were generated in places other than the places where the cracks were induced, and the width of the cracks was 2 mm or more.

Table 3 shows the results of measuring the crack width and the load generated on the lower surface of the bending specimen (10 × 10 × 40 cm) using the various fiber-reinforced concretes at the time of a three-point load bending test. Show. From this, it can be seen that the fiber reinforced concrete has a sufficient load transmitting ability without a decrease in strength (bending load) if the crack width is about 0.5 mm.

[0032]

[Table 3]

[0033]

According to the present invention , a restraint plate is provided on an existing asphalt pavement surface so that it can enter a fiber reinforced concrete slab, and does not transmit a displacement due to shrinkage of the fiber reinforced concrete to an adjacent concrete slab. Therefore, controlled cracks are surely generated in the upper part of the restraint plate, and the spacing between the restraint plates is 3 m.
In addition to being able to be made crack width occurring at the top of the restraint plate is fine like 0.5mm or less since it was limited less, since the fibers in concrete to enhance the tensile strength of concrete, concrete Does not cause early structural destruction .

Further, from the above, since the joint for the like conventional shrinkage due invention is not in the upper surface, generation of noise associated with conventional joint, driving comfort is impaired
It or edge defects or due to strength reduction at a portion of joints, does not cause corner cracking.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an existing asphalt pavement configuration.

FIG. 2 is a longitudinal sectional view after overlaying with thin fiber reinforced concrete.

FIG. 3 is a perspective view of a restraint plate installation state after partially cutting an existing asphalt layer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Existing asphalt pavement 2 Subbase layer 3 Subgrade 4 Thin-fiber reinforced concrete 5 Restraint plate 6 Cut groove for fixing restraint plate L Installation interval of restraint plate x Height of restraint plate b Length of restraint plate t Constraint plate thickness H Height of restraint plate

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) E01C 23/00 E01C 7/35 E04G 23/02

Claims (2)

(57) [Claims] 1. A upon overlaying corruption resulting existing asphalt pavement top to fiber reinforced concrete in a thin layer, 5% of the fiber reinforced concrete panel thickness overlaying
The restraining plate having a height of about 50% to 50%
In the width direction of the pavement and the existing asphalt
A method for constructing a thin-layer concrete overlay , comprising: providing a fiber-reinforced concrete at intervals of 0.5 m to 3 m in a pavement extension direction . 2. A restraint plate provided on an existing asphalt pavement ,
A method of bonding using an adhesive , or providing a cut groove to form the cut
The method for constructing a thin concrete overlay according to claim 1, wherein the method is performed by either a method of fitting into a groove or a method of nailing.