JPH07127008A - Construction method for crack induction part in continuous concrete pavement - Google Patents

Abstract

PURPOSE:To control crack width and space in continuous concrete pavement so as to make the load transmission of a crack part efficient. CONSTITUTION:PC linear material 11 is disposed in the longitudinal direction of a continuous concrete pavement plate 10. A hollow pipe 12 is disposed in the width direction at a required crack part, and concrete is placed. After a crack 14 is generated, grout 13 such as cement milk is filled in the hollow pipe 12.

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 crack inducing portion in a jointless continuous concrete pavement.

[0002]

2. Description of the Related Art Conventionally, continuous concrete pavement (CRC pavement) using RC plates has been developed. As shown in FIG. 4, the reinforcing bars 2 are continuously arranged from the surface of the concrete paving slab 1 to a depth of about 1/3 of the plate thickness in a longitudinal direction, and a construction section of 3 to 4 km is provided with expansion joints. This is a method of continuous construction without provision, and in this paving method, a large number of fine cracks (cracks) 3 oriented in the width direction are generated in the concrete slab 1 by preventing contraction in the longitudinal direction during drying of concrete by reinforcing bars. Then, the same action as the conventional expansion joint between the concrete slabs is applied to absorb the expansion and contraction of the concrete slab 1 due to the temperature change.

In recent years, instead of the conventional reinforcing bar, a continuous PC steel material is embedded below the center of the plate thickness, and the PC steel material is made to act in the tensile direction with respect to a vertical load to reduce the plate thickness. Continuous concrete pavement (CPCC pavement) has been developed.

In these continuous concrete pavements, the load transmission after the cracks have occurred is such that the reinforcing bar 2 penetrates the cross section.
And the effect of engaging the aggregates 4 on the cracked surface.

[0005]

The distance and width of cracks induced in such conventional continuous concrete pavement are selected based on an experimental theory by selecting the amount of reinforcing bars (ratio of sectional area of reinforcing bars to sectional area of concrete plate). Since it is indirectly controlled by doing so, the induced crack spacing and width do not always occur at the desired spacing, and lack of certainty.As a result, the crack spacing and width vary, and the crack width is excessive. There is a problem that harmful cracks occur.

Further, in particular, CPC using a conventional PC steel material
In the case of C pavement, the concrete slab thickness is small, and the effect of meshing the aggregate on the cracked surface cannot be expected so much, so that there is a problem in that the load transmission capacity is reduced. In order to solve this, it is conceivable to construct a structure in which steel materials such as slip bars and tie bars are straddled between concrete slabs as is used for the expansion joints of conventional concrete pavements with expansion joints. In this case, there are many cracks that are induced, which is uneconomical and poor in workability.

In view of such a conventional problem, the present invention solves the uncertainty of the control of the crack interval and the width in the conventional jointless continuous concrete pavement, and at the same time, particularly in the CPCC pavement where the concrete slab is thin. It is an object of the present invention to provide a method for constructing a crack inducing portion of continuous concrete pavement in which load transfer in the crack portion can be efficiently performed and which can be economically constructed.

[0008]

SUMMARY OF THE INVENTION To solve the above-mentioned conventional problems and to achieve the intended purpose, the gist of the present invention is to provide reinforcement in a continuous concrete pavement plate in the longitudinal direction. During the construction of a continuous concrete pavement in which a material is embedded and cracks in the width direction are generated by shrinkage of concrete, cracks are induced by the cross-section defect of the concrete paving slab at the desired position where the cracking is desired. After placing an empty tube in the width direction of the pavement plate, placing concrete, and after the cracks are generated by drying shrinkage of the concrete, the hollow tube is filled with grout that is solidified with time. The construction method of the crack inducing part in continuous concrete pavement.

[0009]

In the method of constructing a crack inducing portion of the present invention, when concrete is solidified in a state where the hollow pipe is embedded in the width direction of the concrete plate in which the reinforcing material is embedded in the longitudinal direction, the crack caused by the drying shrinkage is It tends to occur in the hollow pipe embedding portion where the cross-section defect of concrete has occurred, in the direction of the hollow pipe, and as a result, cracks concentrate on the hollow pipe embedding portion. The size of the crack can be set in advance by the shrinkage rate of concrete and the embedding interval of hollow tubes.

After inducing cracks in this way,
When a hollow tube is filled with grout that solidifies with time, such as cement milk, the solidification of the grout serves as a vertical load transfer material, and the load transfer between longitudinal concrete plates partitioned by induced cracks is achieved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an example of the embodiment of the present invention will be described with reference to FIGS.

This example shows continuous concrete pavement by CPCC pavement. In the figure, 10 is a concrete pavement plate, and 11 is embedded in the longitudinal direction at a height of about 1/3 from the bottom of the plate thickness. It is a PC linear material. Further, in the concrete paving slab 10, hollow tubes 12 are embedded at positions on the PC linear members 11 in the width direction at predetermined intervals,
Solidified grout 13 is packed in it.

In constructing this paving slab, the PC linear material 11 is embedded in a predetermined position, and the hollow pipes 12 are arranged at predetermined intervals in the width direction so as to intersect the PC linear material 11 and then concrete is poured. The concrete paving plate 10 is molded.
Then, the concrete hardens, and cracks occur due to shrinkage during drying and the shrinkage-preventing action of the PC linear material 11. Because it is in a missing state,
The cracks 14 in the width direction are concentrated and induced in the upper and lower portions of the hollow tube 12.

After the crack is thus induced,
The hollow tube 12 is filled with grout 13 such as cement milk that is solidified with time. When the grout 13 is solidified, it becomes a hard rod shape, and the hard grout 13 is embedded between the cracked surfaces to serve as a vertical load transfer material and exert a load transfer capability.

The PC linear material used in this example is PC
A steel rod, a PC steel wire, a PC steel stranded wire, and a corrosion-resistant FRP tension material can be used as a reinforcing material.

The hollow tube 12 can be made of various materials regardless of whether it is made of synthetic resin or metal. In addition to FIG. 1, FIG.
Various cross-sectional shapes such as an ellipse, a quadrangle, and a rhombus can be used as shown in (c). In the hollow tube, rebar, PC
It is also possible to reinforce in the width direction by inserting a steel rod or the like.

[0017]

As described above, in the method for constructing the crack inducing portion of the continuous concrete pavement of the present invention, by embedding the hollow pipe in the width direction, it is possible to concentrate the cracks at the disposition position. Therefore, the crack-inducing interval and width can be generated as expected, and since the grout is filled and solidified in the hollow tube, it serves as a load transfer material in the vertical direction of the joint. Therefore, a high load transmission force can be economically obtained.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of an embodiment of the present invention.

FIG. 2 is a plan view showing the arrangement of the above hollow tube and PC steel rod.

3A to 3C are cross-sectional views showing different embodiments of the present invention.

FIG. 4 is a sectional view of a conventional example.

[Explanation of symbols]

 10 Concrete pavement plate 11 PC linear material 12 Hollow tube 13 Grout 14 Crack

Claims (1)

[Claims] 1. When constructing a continuous concrete pavement in which a reinforcing material is embedded in a continuous concrete pavement plate in the longitudinal direction, and cracks generated in the width direction due to shrinkage of concrete are dispersed and generated, After placing a hollow tube in which cracking is induced by a section loss of the concrete paving slab toward the width direction of the paving slab at a desired position where cracking is desired, concrete is poured, and the concrete is dried and contracted to shrink the concrete. A method for constructing a crack inducing portion in a continuous concrete pavement, which comprises filling the hollow pipe with grout that solidifies with time after the crack has occurred.