JP2860610B2 - Joint construction method and static crushing agent injection jig on concrete pavement. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

This invention relates to concrete pavement,
More particularly, the present invention relates to a method of applying a joint joint in a roller compacted concrete pavement, and a jig for injecting a static crushing agent for joint formation used for performing the method.

[0002]

2. Description of the Related Art For example, there is a so-called compacted concrete pavement in which super-hardened concrete is spread with a finisher without using a formwork, and the spread concrete is compacted with a vibrating roller or a tire roller, and compacted. In the so-called pavement method, when jointing joints are constructed, conventionally, they are constructed by the following means. First, since a formwork is not used, concrete is laid on the joint at a predetermined joint position, that is, beyond the joint line. Specifically, 10
It protrudes about 15cm longer and is paved. Then, after the concrete has hardened, as shown in FIG. 5A, a cut groove 20 is formed along a predetermined joint position by using a concrete cutter or the like. Then, using the cut groove 20, the concrete at the protruding portion was scraped off to form a joint so as to have a substantially vertical cross section using a breaker or an electric pick or the like. FIG. 5 (b) shows the joint formed by removing and shaping. Then, when the filing operation is finally completed, a cement paste is applied to the cross section 21 as shown in FIG. 5 (C), and then new concrete 22 is spread as shown in FIG. 5 (D). Then, the spread concrete 22 is rolled flat as shown in FIG. 5 (e), and new concrete pavement is added to the already-constructed concrete pavement for construction.

[0003]

Since the conventional joint joint construction is performed according to the procedure described above, there are the following problems. (1) A large amount of labor and time is required for removing the seam, that is, the concrete portion which is excessively paved so as to have a vertical cross section at the joint joint. Particularly in the case of compacted concrete pavement that is paved without using a formwork, it is important to form the joint part into a vertical section in order to ensure the quality of the joint part of the pavement. The advantages of the concrete pavement method, such as the economics and shortening of the construction period, which do not require a formwork, are reduced. (2) Although a tool such as a breaker is used, since the main body of the filing operation is manually, the efficiency and speed of the operation are hindered. The present invention solves such problems in the conventional joint joint construction, and saves labor, increases efficiency and speeds up work, and provides a new joint joint construction method and a method for implementing this construction method. It has been developed to provide a jig for injecting a static crushing agent for butt joint construction used for a joint.
Particularly, the present invention is characterized by using a static crushing agent used for crushing and demolition of concrete structures and the like. Utilizing the expansion pressure generated during the hydration reaction of minerals as is well known,
Static crushing techniques for crushing and dismantling brittle objects such as concrete structures are known. For example, calcium oxide (C
aO) at a high temperature (about 1500 ° C)
Moreover, it is fired for a long time to make a clinker-like powder,
This is mixed with water to form a so-called static crushing agent, which is injected and filled into a structure to be crushed, and the structure is crushed by the expansion pressure due to the hydration reaction. Looking at the implementation response, drilling multiple holes in a concrete structure in an urban area, injecting a static crushing agent into the holes and curing it, inducing cracks in the line connecting the holes and crushing In order to remove the convex part of the concrete slab, a plurality of continuous kerfs are provided on the surface, and a static crushing agent is injected into every other kerf and hardened. There is a method in which a crack is continuously and horizontally induced between the base and the bottom to remove the projection. An object of the present invention is to form an abutting joint having a vertical section efficiently and quickly by using the static crushing technique. That is, a method is employed in which a crack is formed vertically along the cut groove in the depth direction and the molding is performed.

[0004]

First, as a means for forming an abutting joint using the static crushing agent, the present invention is to form a joint having a vertical cross section by the following procedure. is there. That is, in the compacted concrete pavement construction without using a formwork, concrete is first laid so as to protrude outside a planned joint joint line. Then, after the paved concrete has hardened, a cut groove is provided along the scheduled joint joint line. Next, the static crushing agent is injected into the kerf, and a crack extending vertically downward is generated in the kerf by the expansion pressure of the static crushing agent. This is because joints are formed. In particular, at this time, the kerf is a numerator of the remaining thickness obtained by subtracting the depth of the kerf from the thickness of the concrete pavement, and the length from the bottom of the kerf to the edge of the concrete in the horizontal direction. Is set as a denominator, and the ratio is set to 1.65 or less, and the width of the kerf is set to 10 mm or less.

Further, as a means for efficiently injecting the static crushing agent into a kerf provided along a joint joint line, the following dedicated static crushing agent injection jig has been developed. It is in. That is, the following dedicated injection jig is constituted by a divergent injection pipe main body, a connection nozzle, a ski-shaped guide plate, and two thin plate-shaped leakage prevention plates. First, the injection pipe main body has a supply pipe of a liquid static crushing agent at an upper end portion, and has an elongated linear opening at a lower end surface thereof, and the connection nozzle is provided at the upper end of the injection pipe main body. The guide plate is connected to and fixed to a linear opening in the lower end surface, and the guide plate is integrally fixed to the injection pipe main body via the connection nozzle, and communicates with the connection nozzle in the longitudinal direction of the guide plate. An elongated opening is provided, and the two leak-prevention plates are parallel to each other along both longitudinal edges of the elongated opening in the guide plate, and a lower edge thereof is suspended below the bottom surface of the guide plate. That is, it is configured to be fixed in such a state.

[0006]

According to the present invention, a method for constructing a joint joint is as follows.
As described above, concrete is laid so as to protrude outside the planned joint line, and when hardened, a cut groove is provided along the planned joint line, and a static crushing agent is injected into the cut groove. Because of this, due to the inflation pressure of the static crushing agent, the concrete at the protruding portion is cut off with a substantially vertical cross section at the cut groove, that is, at the joint line. That is, this kerf is the remaining thickness obtained by subtracting the depth of the kerf from the thickness of the concrete pavement, and the denominator is the length from the bottom of this kerf to the edge of the concrete in the horizontal direction. 1.65 ratio
Since the width is set to 10 mm or less and the width of the kerf is set to 10 mm or less, joints are formed with a substantially vertical fracture surface within a crack angle θ3 to 5 ° as shown in an experimental example described later. Further, since a dedicated injection jig is provided as a means for injecting the static crushing agent into the kerf, the injection operation can be performed extremely efficiently. That is, since the leakage prevention plate is hung down on the lower surface of the guide plate in the injection jig, the drip-prevention plate is set by inserting it into the cut groove, and the guide plate is slid along the cut groove. Hopefully, the static crushing agent is injected into the kerfs. As a result, joints having a substantially vertical cross section are efficiently formed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Further, the present invention will be specifically described based on embodiments shown in the drawings. First, FIG. 1A is a perspective view showing a configuration in which a part of a jig T for injecting a static crushing agent is cut away, and FIG. 1B is a vertical sectional front view taken along line YY of FIG. It is. As shown, the jig T includes an injection pipe main body 1, a connection nozzle 2, a guide plate 3, and two thin plate-shaped leak prevention plates 4 and 4. In this embodiment, the injection pipe main body 1 is formed of a molded product made of a synthetic resin material, the upper end portion has a substantially circular shape, the lower end portion has a flared shape, and is narrowed down as shown in FIG. It was a slim shape. Therefore, the lower end of the injection tube main body 1 is shown in FIG.
Although not shown in (a), an elongated opening is formed in the longitudinal direction, that is, in the left-right direction in FIG. 1 (a). The reference numeral 1a shown in FIG. 1B is formed in the opening in the front-rear direction toward the paper surface. As shown in FIG. 1B, the connection nozzle 2 includes a flange portion 1b provided at a lower end portion of the injection pipe main body 1 shown in FIG.
The connection nozzle 2 is bonded and fixed by polymerizing the flange portion 2b of the connection nozzle 2 itself. The nozzle hole 2 a of the connection nozzle 2 is configured to communicate with the opening 1 a at the lower end of the injection pipe main body 1. Next, the guide plate 3 is made of a ski plate as shown in FIG. 1A and is integrally fixed to the lower surface of the connection nozzle 2. That is, as shown in FIG. 1B, the connection nozzle 2 is fixed using a flange portion 2c provided at a lower end of the connection nozzle 2, and is integrated with the injection pipe main body 1. A communication hole 3a corresponding to the nozzle hole 2a of the connection nozzle 2 is formed in the guide plate 3, and the opening 1 of the injection pipe main body 1 is formed through the communication hole 3a.
When the static crushing agent is connected to the injection pipe body 1 and supplied to the injection pipe main body 1, the static crushing agent flows down through the opening 1a, the nozzle hole 2a, and the communication hole 3a. Finally 2
The thin plate-like leakage prevention plates 4 and 4 are formed of thin metal plates, and are arranged in parallel with both longitudinal edges of a communication hole 3a formed in the guide plate 3 as shown in FIG. The lower end edges 4a and 4a are fixed so as to hang down from the bottom surface of the guide plate 3. That is, the guide plate 3 is fixed so as to project downward from the bottom surface. Note that reference numeral 5 shown in FIG.
Is a supply pipe for the static crushing agent connected to the upper end of the injection pipe main body 1, and 5a is a connection flange thereof. The configuration of the injection jig T for the static crushing agent has been described above.

FIG. 2 is a front view showing an end of a concrete pavement for performing joint construction according to the present invention. That is,
The end of the concrete pavement that has been protruded outside the joint line 10 scheduled in advance is shown. L is the protruding length, and 11 is a cut groove provided along the planned joint line 10. Therefore, as shown in FIG.
The depth of the kerf 11 is a, the width is b, the thickness of the pavement is t, and the remaining thickness obtained by subtracting the depth a of the kerf 11 from the thickness t of the pavement is set as c. The occurrence of the crack angle θ was confirmed by experiments. This is because the chemical composition of the static crushing agent injected into the kerf 11, that is, cracks caused by the expansion pressure generated by the hydration reaction of the static crusher is induced vertically below the kerf 11, and the joint due to the rupture becomes This is because it is necessary to have a so-called vertical cross section. Incidentally, in the examples, the amount of water of a static crushing agent (trade name: calmite) mainly composed of calcium oxide (CaO), which is generally widely used, that is, the mixed water amount to the static crushing agent is 25 to 30%, and The operating environment temperature was set to 20 to 30 ° C., and the swelling pressure generated in that case was about 200 kg / cm ^2. Therefore, a fracture test was performed on the premise of the above conditions. As a result, it was understood that the fracture occurred at a crack angle as shown in Table 1.

[0009]

[Table 1]

From Table 1 based on this experiment, in order to obtain a vertical fracture surface, in order to make the crack angle θ smaller, the depth a of the kerf 11 into which the static crushing agent is injected is made larger than the pavement thickness t. It was found from this experimental result that c / L is most preferably 1.65 or less in relation to the remaining thickness c deducted and the length L of the protruding portion to be broken and removed. . That is, as shown in Table 1, the crack angle θ is 3 to 5 ° when c / L is 1.65 to 1.40 in reverse. However, in Experimental Example 4 in which 1.85 was set, the crack angle θ was remarkably large at 40 °. This is c
/ L is 1.65 or less based on experimental results. Further, it was estimated from the experimental results through Table 1 that the width b of the kerf 11 should be 10 mm or less. Furthermore, even if the kerf 11 is relatively shallow, about 2.5 cm,
It has also been found that a substantially vertical break is possible. FIG.
Is the case where the pavement thickness t = 25 cm, the protruding length L = 10 cm, the kerf depth a = 8.5 cm, the kerf width b = 0.4 cm, and the fracture treatment is performed by injecting a static crushing agent. FIG. As indicated by the dotted lines, substantially vertical cracks are induced, and joints having a desired vertical fracture surface are formed.

FIG. 4 shows an operation of injecting a static crushing agent in which water is added to the kerf 11 shown in FIG. 2 by using the injection jig T shown in FIGS. 1 (a) and 1 (b). It is a work procedure diagram showing a state of. As shown in the figure, in this embodiment, a horn-like base 12 is provided, a tank 13 for containing a static crushing agent is mounted on the base 12, and the tank 13 and the injection jig T are connected by a hose 14. . That is, the static crushing agent is supplied to the injection jig T using the head difference and injected into the cut groove 11. As described above, the injection jig T has the divergent injection pipe main body 1 and the ski-shaped guide plate 3, and the lower surface of the guide plate 3, in particular, is formed of two thin metal plates. Since the prevention plates 4 and 4 are provided, the head pressure due to the head difference acts, and the injection of the static crushing agent into the kerf 11 is reliably ensured. as a result,
Efficient joint joint construction is possible.

[0012]

As described above, as described through the embodiments,
The present invention uses a static crushing agent that generates an expansion pressure due to a hydration reaction, and injects it into a kerf provided in a line where a joint is to be formed using a special injection jig, so that an appropriate Since the joint is formed, the following effects can be exhibited as compared with the conventional joint construction. (1) No filing work is required. As a result, labor and time, such as labor and time for the joint joint construction, are released, and the pavement work cost can be significantly reduced by not only shortening the pavement work period but also labor saving. (2) By setting the depth and width of the kerfs and the length of the concrete pavement portion to be protruded and paved in advance according to the chemical composition of the static crushing agent used, That is, joint construction with a vertical cross section that is optimal as a joint joint can be performed. As a result, pavement construction by economic design becomes possible.

[0013]

[Brief description of the drawings]

The drawings show an embodiment of a method for constructing a joint joint in compacted concrete pavement according to the present invention and a jig for injecting a static crushing agent used for implementing the method.

FIG. 1A is a perspective view showing a part of a static crushing agent injecting jig according to the present invention. (B) is a vertical sectional front view taken along the line YY in (A).

FIG. 2 is an end elevational view of a concrete pavement where an abutment joint is to be formed.

FIG. 3 is a front view showing an end of a concrete pavement in which a static crushing agent is injected to induce cracks and form an abutting joint having a vertical fracture surface.

FIG. 4 is a front view showing an operation state of injecting a static crushing agent into a joint construction part using an injection jig.

FIG. 5 is a flowchart showing a work procedure of a conventional joint construction.

[Description of Signs] T Static crushing agent injection jig 1 Injection pipe main body 2 Connection nozzle 3 Guide plate 4 Leak prevention plate 5 Supply pipe 10 Scheduled joint line 11 Cut groove 12 Mount 13 Tank 14 Hose

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) E01C 11/04 B02C 19/18 E21C 37/00

Claims (3)

(57) [Claims] 1. A concrete pavement in which concrete is laid so as to protrude from a predetermined joint line, and after hardening, a cut groove is provided along the joint line, and the joint is cut using the cut groove. In place of construction, a method for constructing joints in concrete pavement, characterized by injecting a static crushing agent that generates an expansion pressure by a hydration reaction into a kerf and forming a joint having a substantially vertical cross section by the expansion pressure. . 2. The kerf is a numerator of a remaining thickness obtained by subtracting a kerf depth from a plate thickness of a concrete pavement,
The length from the bottom of the kerf to the edge of the concrete in the horizontal direction is defined as a denominator, and the ratio is 1.65.
The method of claim 1, wherein the width of the kerf is 10 mm or less. 3. A jig for injecting a liquid static crushing agent into the kerf, comprising: a divergent injection pipe main body, a connection nozzle, a ski-shaped guide plate, and two plate shapes. The injection pipe main body has a supply pipe of a liquid static crushing agent at an upper end portion, and has an elongated linear opening at a lower end surface, and the connection nozzle is The guide plate is fixedly connected to the injection pipe body via the connection nozzle, and is connected to the connection nozzle in the longitudinal direction of the guide plate. The two leak prevention plates are fixed in a state where the two leak prevention plates are parallel to each other along both longitudinal edges of the elongated openings in the guide plate, and the lower end edge is suspended from the bottom surface of the guide plate. Static crushing characterized by having a configuration of Agent injection jig.