JPH0978576A - High-strength structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent high compression yield strength and shear yield strength by preventing the rusting of a reinforcing member. SOLUTION: Multiple reinforcing steel products 1 are arranged at proper intervals. A belt reinforcing bar 5 is spirally arranged in a sheath 6 having irregularities on the peripheral face to surround multiple reinforcing steel products 1. A hardening agent is injection into the sheath 6. The reinforcing steel products 1 and the belt reinforcing bar 5 are buried inside, and concrete 7 is hardened to form a pile A. The reinforcing steel products 1 may be arranged in the sheath 2, and the hardening agent may be injected. Only the belt reinforcing bar 5 inserted into the sheath 6 is buried in porous concrete to form a wale. The belt reinforcing bar 5 is inserted into the sheath 6, and it is kept in no contact with water and is not rusted. Irregularities are formed on the peripheral face of the sheath 6, and the adhesion to the concrete 7 is improved. The concrete 7 is restrained by the belt reinforcing bar 5, and large bend yield strength and shear yield strength are obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure formed by arranging a reinforcing steel material inside a pile, a pillar, a well for ground improvement, etc. and using a cement-based hardening material such as concrete. The present invention relates to a high-strength structure for embedding in the ground. Moreover, the pillars are also applied to pillars installed near the coast or in the sea.

[0002]

2. Description of the Related Art As a pile to be buried in the ground, a precast concrete pile with main bars and ribs arranged inside, or a pile with main bars and ribs drilled in the ground on site to assemble the main bars and ribs. There are various types such as cast-in-place piles that are constructed by filling cement-hardening materials such as concrete in the holes that have been taken down and drilled. In addition, a cylindrical precast water collecting well is used which is buried in the ground and collects surrounding water in an inner space to prevent landslides.

[0003]

The problem with piles and wells buried in these grounds is that the main bars and ribs (band reinforcements) buried inside due to the water contained in the surrounding ground penetrating inward. Is to rust. When concrete cracks or the concrete becomes neutral due to aging, acid rain that has infiltrated the soil easily penetrates into the pile, and the main bars and ribs placed inside the pile are rusted. There was something to do. In particular, the ribs located closest to the outer circumference of the piles are likely to come into contact with water, and small piles have a small fog, so these ribs may rust in a short period of time. In addition, in the well, porous concrete is used as concrete in order to allow water to permeate from the outer periphery to the inner side, but this water sometimes touches the reinforcing bar placed inside to cause rust.

Further, structures near the coast are strongly affected by salt damage, especially when the reinforcing bars are rusted and the volume of the reinforcing bars expands, cracks expand and rust progresses, and further concrete peels off. It is often seen that the function as a structure is lost. In fact, the fact is that even with resin-coated or galvanized steel bars, this salt damage cannot be sufficiently prevented. In addition, the problem of gradually rusting the reinforcing bars due to the use of sea sand as fine aggregate for concrete has recently been greatly highlighted. Moreover, the coating layer such as resin coating such as epoxy directly applied to the reinforcing bar as described above has a thickness of only about 30 microns, and the coating layer is often scratched during transportation to the site or construction. However, it has been reported that water from these scratches touches the reinforcing bar, causing it to rust.

Another problem to be solved by the present invention is
When a bending load is applied to the concrete, the adhesion between the hardening material and the reinforcing bar is easily broken. In the case of a pile or the like, it is conceivable that steel bars are passed through the steel pipe to fill the concrete to form a steel pipe pile, and the concrete is restrained by the restraining force of the steel pipe. Even if the bond between the reinforcing bar and the concrete is broken, the constrained concrete may adhere to the reinforcing bar to obtain a substantial bonding effect. However, when a steel pipe is used, it is necessary to connect the steel pipes by welding according to the length of the pile, which causes troubles such as construction and problems of strength.

The present invention has been made in order to solve the above problems, and in particular, corrosion of band rebars does not occur and it is possible to obtain high bending strength and shear strength by restraining the entire structure from the surroundings. It is an object of the present invention to provide a high-strength structure having good adhesion between the reinforcing steel material and the hardened material.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The high-strength structure according to the present invention includes a pile, and can be applied to a precast pile manufactured at a factory or a cast-in-place pile. Plural reinforcing steel materials are appropriately separated and arranged in parallel. As the reinforcing steel material, a normal reinforcing bar may be used, or a single strand or a plurality of bundles of steel twisted wire, twisted bar, deformed PC steel wire, small-diameter deformed PC steel wire, and the like may be used. The strip reinforcing bars passed through the sheath are spirally arranged so as to surround the plurality of reinforcing bars. As the reinforcing bar, a normal reinforcing bar may be used, but a single or plural bundles of steel stranded wire, more reinforcing bar, deformed PC steel wire, small diameter deformed PC steel wire and the like may be used. The sheath has irregularities on the outer circumference, and a synthetic resin or steel sheath can be used. As a steel sheath, a winding sheath made of stainless steel or the like is suitable, and has a strength that does not easily break during handling (handling) such as transportation, loading, and construction at the site, and considering the ease of bending, which will be described later. If
A thickness of about 0.3 mm is suitable. In the case of a synthetic resin sheath such as polyethylene, a sheath having a thickness of about 1 mm is preferable in consideration of handling and strength.

A hardening material is injected into the sheath. A cement paste, a resin-based hardening material, a polymer-based hardening material, or the like can be used as the hardening material injected into the sheath. Fine aggregates such as sea sand are not used for these hardening materials unlike mortar. Therefore, the fact that sea sand does not mix means that
Even if these hardeners are used, there is no risk of salt damage. In the case of a precast structure, the reinforcing steel material and the strip reinforcing bar thus assembled may be put in a formwork and filled with a hardening material such as mortar or concrete to form a pile. In the case of a cast-in-place pile, the reinforcing steel material and the strip reinforcing bar assembled as described above may be suspended in a drilled hole drilled in the ground, and the hardened material may be filled into the drilled hole.

Reinforcing steel material can also be passed through the sheath. Particularly, as reinforcing steel material, stranded steel wire, more rebar, and deformed P
When a C steel wire, a small-diameter deformed PC steel wire, or the like is used, one or more of these are bundled and passed through the sheath.
As the sheath, a deformed synthetic resin sheath having irregularities on the outer periphery or a steel sheath can be used. Putting multiple pieces in the sheath like this is thin as one rebar,
Since the bending work arrangement becomes easy, the bar arrangement is easy. This is particularly advantageous when bending the rebar through the sheath. In addition, by passing it through the sheath, the width becomes wider than that of the stirrups themselves. In other words, there are more parts that restrain the hardened material placed inside the spiral, and the restraining effect is higher,
It is difficult for concrete to break between spiral pitches to escape.

In the case of a water collecting well or a sewer pipe, a sheath reinforcing bar is used, which is filled with a hardening material and formed into a spiral shape. The strip-shaped reinforcing bar is embedded inside and the cement-based hardening material is hardened to form a tubular shape with a space inside. As the sheath and the reinforcing bar, the above-mentioned ones can be adopted. Also in the case of these cylindrical structures, it is possible to manufacture them in a factory or to form them in-situ. In the case of wells, the hardening material is porous concrete with open cells (gap grade concrete)
To use.

As described above, by passing the reinforcing bar through the sheath and filling it with the hardening material, the infiltrated water does not come into contact with the reinforcing bar. By passing the reinforcing steel material through the sheath, the possibility that the reinforcing steel material also rusts is eliminated. Since the entire stiffening material such as piles is constrained from the outer periphery by the spiral band reinforcing bar, the compression strength and bending strength of the stiffening material are improved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the embodiments shown in the drawings. 1 and 2 show a precast concrete pile A, in which 1 is a reinforcing steel material that is passed through a steel sheath 2. A stranded steel wire is used as the reinforcing steel material 1, and as shown in FIG. 3, a plurality of steel stranded wires are inserted into a stainless steel sheath 2 having a spiral convex portion on the outer circumference. In FIG. 3, 3 is a hardening material injection pipe, and the cement paste 4 is injected into the sheath 2 using this pipe 3. A plurality of sheaths 2 passing through the reinforcing steel material 1 are erected in parallel so as to be positioned on the ring at appropriate intervals. A spiral reinforcing bar 5 is arranged so as to surround the plurality of sheaths 2. The pitch of the spiral is about 200 mm for a small diameter pile having a diameter of 400 to 500 mm. As the reinforcing bar 5, a steel twisted wire is also used, and a plurality of steel twisted wires are arranged in the steel sheath 6 together with the hardening material injection pipe 3 as described above. The sheath 6 has a diameter of 30 to 80 m
It is about m, and its width is considerably wider than that of the obi belt 5 itself. The steel sheath 6 has irregularities formed on its peripheral surface, and can be easily spirally bent by expansion and contraction of the irregularities.

The reinforcing steel material 1 and the strip reinforcing bar 5 which have passed through the sheaths 2 and 6 are put in a formwork, and concrete 7 is cast to form piles A made of precast concrete. The spiral strip reinforcing bar 5 functions to restrain the concrete 7 from the surroundings, and restrains the entire pile A even if the concrete 7 and the sheath 2 of the reinforcing steel material 1 are disconnected from each other due to a bending load. It functions so as to maintain a substantial adhesive effect and prevent the bending and shear strengths from decreasing. In some cases, a wire mesh such as expanded metal, which is rust-proofed with zinc plating or synthetic resin, is wound around the reinforcing bar 5 so as to surround the entire pile A, and then the concrete 7 is placed.
Even if the pile A is cracked, the concrete 7 between the pitches of the strip reinforcing bars 5 does not easily collapse, and the restraining effect is further enhanced.

FIG. 4 shows the construction state of the pile A that is cast in-situ. As described above, the reinforcing steel material 1 and the band reinforcing bar 5 which are passed through the sheath 2 integrally assembled are excavated in the ground. It is hung on the drilled hole 8. The drill hole 8 is filled with muddy water 9. At this time, the cement paste 4 has not been injected into the sheaths 2 and 6, and the lower ends of the sheaths 2 and 6 are sealed. A clearance is provided between the lower end of each sheath 2 and the bottom of the drilled hole 7, and the lower end of each sheath 2 is drilled 8
Each sheath 2 is kept vertical in the drilled hole 8 without touching the bottom of the. In this state, the cement paste 4 is injected into each of the sheaths 2 and 6 using the hardening material injection pipe 3. Since the cement paste 4 is restrained by the sheath 2, the gap between the sheaths 2 and 6 and the reinforcing steel material 1 is filled, and the reinforcing steel material 1, the sheaths 2 and 2, and the hardening material 4 effectively function as one reinforcing member. .

Inside the drilled hole 8 is an inner grout pipe 1
0 is used to inject concrete 11 to replace muddy water 9. Since the peripheral surfaces of the sheaths 2 and 6 have irregularities, the adhesion to the replaced concrete 11 is good. The sheaths 2 and 6 have a diameter larger than that of the steel strand itself, and since irregularities are formed on the peripheral surface, the effect of mud water 9 is small, and the irregularities on the peripheral surface and the hardened concrete 11 are attached so as to mesh with each other. And substantially functions like bonding. In addition, after winding wire mesh such as expanded metal, which is rust-proofed with zinc plating or synthetic resin, around the periphery of the spiral strip reinforcing bar 5, the reinforcing steel material 1 and the strip reinforcing bar 5 are drilled 8
It may be dropped inside. In addition to preventing the concrete 11 from collapsing between the pitches of the reinforcing bars 5, the hardened material inside and outside the wire netting is connected, and the adhesion to the ground around the pile A is also good.

FIG. 5 and FIG. 6 show an example in which the well B for preventing landslides is used, and the strip reinforcing bar 5 passed through the sheath 6 is arranged in the form. Porous concrete 12 is poured into the mold to form a cylindrical well B in which the reinforcing bar 5 is embedded. Well B has a diameter of 300
It is 0 to 5000 mm, the wall thickness is 300 to 700 mm, and the sheath 6 has a diameter of 35 to 80 mm. The well B is lowered into the drilled hole 13 drilled in the ground, a plurality of the wells B are stacked, and the anchor 14 fixed to the ground forms a continuous body structure. Water contained in the surrounding ground enters inside through the bubbles of the porous concrete 12 and is pumped up to lower the groundwater to prevent landslides. Even if water passes through the air bubbles of the porous concrete 12, the strip reinforcing bar 5 embedded inside is passed through the sheath 5 and does not come into contact with water and does not rust. Further, the spiral bar reinforcing bar 5 has a stronger integrity as a whole than the case where a plurality of ring-shaped ribs are used, and the strength of the whole becomes high. The strip reinforcing bar 5 passed through such a sheath 6 can also be used for other precast products or cast-in-place sewer pipes.

[0017]

The present invention has the above-mentioned structure and can obtain the following effects. Since the strips are passed through the sheath, the water that has penetrated into the concrete does not touch the strips and does not get rusted, which makes it possible to maintain extremely long durability. The diameter of the sheath with the reinforcing bar is about 30 to 80 mm, and the width is wider than that of ordinary reinforcing bar. Therefore, the bearing width for constraining against the concrete inside the spiral is wider, so the constraint effect is more effective. Demonstrate. Since the reinforcing bar is passed through the sheath, it is not necessary to increase the cover thickness and wall thickness, and the durability of small diameter piles can be improved. By passing the reinforcing steel material through the sheath as well, rusting is similarly prevented, and extremely long durability can be maintained. Since the hardening material is injected into the sheath, the reinforcing steel material or the band reinforcing bar and the sheath integrally function as an effective reinforcing member. Since the sheath restrains the hardened material injected inside, it is difficult for the sheath to adhere to the reinforcing steel material or the band reinforcing bar, and the substantially high adhesive effect is maintained, and the sheath functions extremely effectively as an integrated reinforcing member. Since the sheath has a diameter larger than that of reinforcing bars and steel strands, and irregularities are formed on the peripheral surface, it is difficult for muddy water to adhere, and even if it adheres, the effect of this is that the sheath itself has large irregularities. It is possible to obtain a high bending resistance by being attached so as to mesh with the hardening material. The spiral rebar restrains the hardened material to increase the compressive strength and shear strength of the hardened material, and to substantially maintain the effect of adhesion between the hardened material and the reinforcing member, the bending strength and shear strength of the structure It does not reduce the yield strength. Since the spiral rebar is arranged so as to be continuously stretched, regardless of the length of the structure, a procedure such as welding is unnecessary, and the manufacturing and the construction are remarkably easy.

[Brief description of drawings]

FIG. 1 is a partially cutaway explanatory view in which the present invention is applied to a pile.

FIG. 2 is a cross-sectional view of a pile.

FIG. 3 is a cross-sectional view of a reinforcing steel material or a band reinforcing bar arranged in a sheath.

FIG. 4 is a cross-sectional view of constructing a cast-in-place pile.

FIG. 6 is a cross-sectional view of a well.

FIG. 7 is an explanatory diagram of water collection using wells.

[Explanation of symbols]

 A pile B well 1 Reinforced steel material 2 Sheath 3 Hardened material injection pipe 4 Cement paste 5 Strip reinforcing bar 6 Sheath 7 Concrete 8 Drilling hole 9 Mud water 10 Inner grout pipe 11 Concrete 12 Porous concrete 13 Drilling hole 14 Anchor

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[Procedure amendment]

[Submission date] December 26, 1995

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[Brief description of drawings]

FIG. 1 is a partially cutaway explanatory view in which the present invention is applied to a pile.

FIG. 2 is a cross-sectional view of a pile.

FIG. 3 is a cross-sectional view of a reinforcing steel material or a band reinforcing bar arranged in a sheath.

FIG. 4 is a cross-sectional view of constructing a cast-in-place pile.

FIG. 5 is a cross-sectional view of a well.

FIG. 6 is an illustration of water collection using wells.

[Explanation of symbols] A pile B well 1 Reinforced steel material 2 Sheath 3 Hardened material injection pipe 4 Cement paste 5 Strip reinforcement 6 Sheath 7 Concrete 8 Drilling 9 Mud 10 Inner grout pipe 11 Concrete 12 Porous concrete 13 Drilling 14 Anchor

Claims (3)

[Claims] 1. A plurality of reinforcing steel materials are arranged at appropriate intervals,
A reinforcing bar is inserted into a sheath having irregularities on the peripheral surface so as to surround the reinforcing steel materials in a spiral shape and filled with a hardening material. A high-strength structure that is embedded in the interior and cured by curing a curing material. 2. A plurality of reinforcing steel materials passed through a steel sheath having irregularities on the circumferential surface are arranged at appropriate intervals, and a reinforcing steel strip is passed through the sheath so as to surround the plurality of reinforcing steel materials. A high-strength structure formed by filling a hardening material in the form of a spiral, embedding a reinforcing steel material and a band reinforcing bar in these sheaths, and hardening the hardening material. 3. A reinforcing bar is passed through a sheath having irregularities on its peripheral surface and filled with a hardening material in a spiral shape. The reinforcing bar is embedded inside and the hardening material is hardened to form a tubular shape. High strength structure.