JP2000319853A - Method for placing joint of concrete and form for use in placing joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for placing joint of concrete, which does not generate a cold joint in a jointed-concrete surface, and to provide a form for use in placing joint. SOLUTION: A joint placing form 1 has its entire surface unevenly formed and has projections 3 which each have a through hole 4 formed therein. The joint placing form 1 is laid on a jointed-concrete surface before hardening of concrete, to thereby form depressions and projections. After the water content in the placed concrete is taken in from the through holes 4 into the depressions 2, the joint placing form 1 is removed, and next concrete is placed on the uneven surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of joining concrete and a joining form thereof.

[0002]

2. Description of the Related Art When placing concrete such as a dam, a thick slab, or a large beam,
In order to reduce the number of times of concrete transfer, concrete quality control is being carried out by taking measures against mass concrete according to the amount of concrete poured. In addition, construction management at the joint of concrete is important, but such management is complicated and costly.

[0003]

Unless such construction management is carried out sufficiently, there is a problem that a cold joint or the like is generated at the joint surface of concrete and the quality of structural concrete is deteriorated.

[0004] The present invention has been made in view of the above-described problems, and an object of the present invention is to achieve the construction of a concrete placement amount that does not require mass control measures,
It is an object of the present invention to provide a concrete jointing method and a joint formwork that do not generate a cold joint or the like on a concrete joint surface.

[0005]

According to a first aspect of the present invention, there is provided a splicing formwork in which the entire surface is formed in a concavo-convex shape and a through-hole is provided in a convex portion. After laying on the joint surface of the cast-in-place concrete before hardening to form irregularities, the excess water of the cast-in concrete is taken into the recess from the through-hole, and then the next concrete is placed on the irregularities with the joint form removed. Is characterized by being cast.

According to the first aspect of the present invention, when the joint form is installed on the joint surface of the cast concrete, air between the concrete and the concrete and the joint form can be removed.
Excess water, latency, and the like can be discharged from the through hole and taken into the recess. In addition, since the unevenness can be formed on the joint surface of the cast concrete, the bonding area of the joint surface of the concrete is increased, and the integrity with the next cast concrete can be strengthened, and the horizontal load can be reduced. Shear resistance increases.

According to a second aspect of the present invention, in the first aspect, the joint formwork is laid so that a reinforcing bar projecting from the existing concrete surface is inserted into the through hole.

According to the second aspect of the present invention, since the reinforcing bar projecting from the existing concrete surface can be inserted into the through hole, the method of laying the joint form can be freely selected without limitation. Can be.

According to a third aspect of the present invention, in the first aspect, the joint formwork is laid between reinforcing bars protruding from an existing concrete surface.

According to the third aspect of the present invention, the joint form can be laid between the reinforcing bars protruding from the existing concrete surface, so that the method of laying the joint form can be freely laid without limitation. You can choose the method.

A fourth aspect of the present invention is characterized in that, in any of the first to third aspects, the joint form laid on the joint surface of the cast concrete is pressed downward.

According to the fourth aspect of the present invention, when the joint form is pressed downward, air can be released from the cast concrete through the through hole, and excess water can be easily taken into the recess through the through hole.

The invention of claim 5 is the first, second, or fourth invention.
In any one of the above, the joint formwork is characterized in that adjacent ones are closely laid.

According to the fifth aspect of the present invention, when the joint form is closely laid on the joint surface of concrete, irregularities are formed on the joint surface of concrete without interruption.

According to a sixth aspect of the present invention, in any one of the first to fourth aspects, the joint formwork is laid at appropriate intervals.

According to the sixth aspect of the present invention, the irregularities can be formed at any positions on the joint surface of the concrete.

The invention according to claim 7 is characterized in that the entire surface is formed in an uneven shape, and a through hole is provided in the convex portion.

According to the seventh aspect of the present invention, it is possible to form irregularities on the joint surface of concrete, and it is possible to easily remove surplus water and latencies from the joint surface of concrete.

The invention of claim 8 is characterized in that, in claim 7, the uneven portion is formed in a tapered shape.

According to the eighth aspect of the present invention, the uneven portion of the joint form is easily cut into the cast concrete, so that the uneven surface can be easily formed on the joint surface of the concrete.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a concrete splicing method and a formwork thereof according to the present invention will be described below in detail with reference to the drawings. First, a joint formwork (hereinafter, referred to as a formwork) will be described, and then a concrete jointing method will be described. (1) and (2) of FIG. 1 show a plan view and a side view of the mold of the first embodiment.

The mold 1 of the first embodiment is a single metal plate having an entire surface formed in an uneven shape, and a hexagonal pyramid recess 2 is formed adjacent to the metal plate 1 to form the uneven portions 2, 3. A through hole 4 is opened in the convex portion 3. The through-hole 4 is for discharging air and excess water between the concrete and the concrete and the joint formwork, and is provided at the center of three adjacent concave portions 2. Therefore, in FIG. 2, water flows into the concave portion 2a from the through hole 4a and into the concave portion 2b from the through hole 4b, and water flows into all the concave portions 2. On the other hand, the outside is bent vertically so that water can flow into the odd concave portion 2c around the mold 1 (see FIG. 3). The mold 1 is not limited to a metal plate, but may be integrally formed of a hard synthetic resin.

FIG. 4 shows a mold 5 of the second embodiment, which has the same structure as the mold 1 of the first embodiment, except that the tip of the concave portion 2 has a wedge shape.

FIG. 5 shows a mold 6 of the third embodiment, which has the same configuration as the mold 1 of the first embodiment, except that the concave portion 2 is a quadrangular pyramid.

FIG. 6 shows a mold 7 of the fourth embodiment, which has the same configuration as the mold 1 of the first embodiment except that a through hole 4 is provided at the top of a hexagonal pyramid.

FIG. 7 shows a case in which a long form 8 made of a synthetic resin is wound into a roll. The mold 8 is stretched when used, and wound into a roll after use. The form 8 has a feature that it can be easily handled, stored, and transported.

The planar shape of the concave portions in the above-mentioned molds 1, 5, 6, 7, 8 is not limited to a hexagon and a quadrangle, but may be a triangle, a pentagon, an octagon, a circle, or the like. The number of the through holes 4 is not limited to the above, and a required number of through holes 4 may be provided at an arbitrary position.

Next, a method of joining concrete using the formwork of FIG. 1 will be described with reference to FIG. This is a joint method when building a thick slab that requires a large amount of concrete.

First, the form 1 manufactured in the factory is carried into the site. Next, as shown in (1), a plurality of molds 1 are
It is laid in close contact with the jointing surface 9a of the cast concrete. At this time, the mold 1 is sunk into the concrete by its own weight. If the digging is small, an operator or the like is put on the mold 1 and pushes it. When the formwork 1 is inserted into the concrete 9, irregularities 9 b are formed on the joint surface 9 a of the concrete, air in the concrete 9 is removed from the through hole 4, and surplus water 10 is also removed from the through hole 4 into the recess 2. And the rainwater after the concrete is cast can be stored in the recess 2.

When the mold 1 is removed from the concrete joining surface 9a after a predetermined time has elapsed, as shown in (2), the concrete joining surface 9a has irregularities 9b.
Are formed, and the bonding area is increased by the unevenness 9b. In addition, the surplus water 10 accumulated in the concave portion 2 of the mold 1 is discarded.

Then, as shown in (3), the next concrete 11 is cast on the unevenness 9b, and the joint surface 12 is formed.
A plurality of molds 1 are laid in the same manner as described above. By repeating such a process in sequence, concrete splicing that can enhance the integrity of the concrete splicing surface 9a can be performed.

Although the above-mentioned slab is not provided with vertical bars, when constructing a slab having vertical bars,
The formwork can be laid so that the vertical streaks are inserted into the through holes. When the vertical bars are not inserted into the through-holes, the formwork is laid so that the reinforcing bar is located at an adjacent portion of the formwork adjacent to each other (not shown).

The concrete joining using the formwork 8 of FIG. 6 is performed in the same manner as described above. The formwork 8 can be easily carried into the site, laid on the joint surface of concrete, and removed from the joint surface of concrete, and storage management can be easily performed.

[0034]

When the joint form is installed in the cast concrete, air can be vented from the through-hole and surplus water and latence can be taken into the recess from the through-hole.

Since irregularities can be formed on the joint surface of the cast concrete, the integration with the next cast concrete can be enhanced.

Since the bonding area of the joint surface of concrete can be increased, the shear resistance against a horizontal load increases.

Since the concave and convex portions of the form can easily penetrate into the concrete, the concave and convex portions can be easily formed on the joint surface of the concrete.

Depending on the interval and the number of reinforcing bars protruding from the existing concrete surface, a method of laying the connecting formwork, such as using a joint formwork having a small area or passing a reinforcing bar through a through hole of the jointing formwork, is used. Free laying method can be selected without restriction.

When the joint form is pressed downward, it is easy to bleed air from the cast concrete through the through hole and to take in excess water into the recess.

By laying a plurality of joint form frames in close contact, unevenness can be formed on the joint surface of concrete without interruption, and wet curing can be performed.

The irregularities can be formed at any positions on the joint surface of the concrete.

The irregularities can be formed on the joint surface of concrete, and excess water and the like can be easily removed from the joint surface of concrete. In addition, the use of a mold to which a heat insulating material is attached enables heat insulating curing in winter.

[Brief description of the drawings]

FIG. 1A is a plan view of a mold according to a first embodiment,
(2) is the same front view.

FIG. 2 (1) is an enlarged plan view of a main part of a mold, and FIG. 2 (2) is a perspective view of a concave portion in a state where the mold of (1) is inverted.

3A is a sectional view taken along line AA of FIG. 2, and FIG.
It is a B sectional view.

FIG. 4A is a plan view of a mold according to the second embodiment,
(2) is a perspective view of the concave portion in a state where the mold of (1) is inverted.

FIG. 5A is a plan view of a mold according to a third embodiment,
(2) is a perspective view of the concave portion in a state where the mold of (1) is inverted.

FIG. 6A is a plan view of a mold according to a fourth embodiment,
(2) is a sectional view of (1).

FIG. 7 is a side view of a mold according to a fifth embodiment.

FIGS. 8A to 8C are cross-sectional views illustrating a method of joining concrete.

[Explanation of symbols]

 1, 5, 6, 7, 8 Formwork 2 Concave part 3 Convex part 4 Through hole 9 Concrete 9a Concrete joining surface 9b Irregularity 10 Water 11 Next concrete 12 Next concrete joining surface 13 Concrete

Claims (8)

[Claims] 1. A jointing formwork having an entire surface formed in an uneven shape and having a through hole formed in a convex portion is laid on a jointing surface of cast-in-place concrete before hardening to form unevenness. A method for splicing concrete, comprising the steps of: introducing surplus water from the concrete into a recess from a through hole; and pouring the next concrete onto the unevenness from which the splicing form has been removed. 2. The method according to claim 1, wherein the joint formwork is laid so that a reinforcing bar projecting from an existing concrete surface is inserted into a through hole. 3. The method according to claim 1, wherein the joint form is laid between reinforcing bars protruding from an existing concrete surface. 4. The method for joining concrete according to claim 1, wherein the joining formwork laid on the joining surface of the cast concrete is pressed downward. 5. The splicing formwork according to claim 1, wherein adjacent ones are closely laid.
5. The method for splicing concrete according to any one of 4. 6. The method for splicing concrete according to claim 1, wherein the splicing forms are laid at appropriate intervals. 7. A joint formwork characterized in that the entire surface is formed in an uneven shape and a through hole is provided in a convex portion. 8. The spliced formwork according to claim 7, wherein the uneven portion is formed in a tapered shape.