JP4090944B2 - Concrete stripping prevention method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for preventing concrete pieces from peeling off.
[0002]
[Prior art]
Concrete structures are easily cracked, and water, air, or various chemical substances infiltrate into these cracks, causing deterioration of concrete due to corrosion of reinforcing bars or neutralization of concrete. Along with such deterioration, the concrete piece may fall off and a large accident may occur. Therefore, for example, Japanese Patent Application Laid-Open No. 2001-311288 has been filed.
In underground structures, groundwater leaks together with ejecta from fragile locations, causing wastewater treatment problems, so the following measures are taken.
(1) After the cracked part is V-shaped or U-shaped, stop with a water-stopper and repair with mortar.
(2) A steel plate ridge is attached to the leaking crack, and a pipe is attached to the ridge for drainage.
(3) Suspended along the leaked cracks, pipes are buried in concrete and drained.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-311288 (FIG. 1)
[0004]
[Problems to be solved by the invention]
However, the method (1) has a long construction period, and dust is generated when the concrete is suspended, and there is a problem in the adhesive strength between the new concrete and the existing concrete. In addition, the method (2) requires labor and space for mounting the steel plate, and also requires rust prevention of the steel plate after mounting, and the projections of the drain pipe and anchor bolt narrow the space after construction. . Furthermore, the method (3) has a problem that the deterioration proceeds deep inside the concrete structure.
[0005]
The present invention has been made in view of these problems. The purpose of the present invention is to surely prevent the concrete piece from peeling off, and to eliminate the anchor bolt protrusion and to suppress the concrete deterioration factor from the outside. It is to provide a prevention method.
[0006]
The concrete piece peeling prevention method of the present invention for solving the above problems is to inject a water-stopping agent into the deep part of the crack in the concrete structure from the injection hole and repair the periphery of the crack to make it a smooth surface. Then, an adhesive is applied to the smooth surface, a fiber sheet is pasted on the location where the adhesive is applied, an adhesive is applied from above the fiber sheet, and the fiber sheet is sandwiched with these adhesives. An anchor insertion hole is made in a concrete structure from the sandwich-like fiber sheet surface by this adhesive , and a part of the fiber anchor is inserted and bonded to the anchor insertion hole. It is characterized by being affixed radially on the upper surface of the sheet. The smooth surface includes affixing a fiber sheet provided with an insertion hole in advance. The fiber sheet includes that the basis weight is 40 g / m ^{2 to} 1000 g / m ² and the tensile strength is 30 N / mm or more. The fiber anchor includes that the single fiber fineness is 0.5 dtex to 100 dtex and the tensile strength is 5 cN / dtex or more.
[0007]
Since the water is stopped without sealing the surface of the concrete structure and without sealing, the effect can be easily confirmed.
Since the fiber sheet is affixed to the surface of the concrete structure, the deterioration factor of the concrete from the outside can be suppressed, and small delamination caused by explosion due to rust of the reinforcing bar can be prevented.
Also, by sticking a fiber sheet provided with an insertion hole in advance on the smooth surface, without waiting for the adhesive to harden, an anchor insertion hole is opened from the insertion hole to the concrete structure to insert the fiber anchor. Since work can be performed, workability is improved.
In addition, the fiber anchor can be pressed by finely tearing and anchoring the fiber anchors on the upper surface of the fiber sheet, and when the concrete piece is peeled off, the load is held together with the fiber sheet. Can also prevent the peeling of large concrete.
Moreover, it is possible to prevent the concrete from peeling off without requiring a large-scale machine.
Moreover, even if it is not a skilled worker, it is possible to perform a uniform construction.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a concrete piece peeling prevention method in a concrete structure according to the present invention will be described with reference to the drawings.
[0009]
The concrete structure 1 in this embodiment is intended for a concrete tunnel such as a subway. However, this is not limited to tunnels such as subways, but can also be applied to other concrete structures such as concrete viaducts and reinforced concrete structures.
[0010]
First, as shown in FIG. 1, an injection hole 4 reaching the deep part of the crack 3 from the surface of the concrete 2 is opened, and a water-stopping agent 6 is injected into the deep part of the crack 3 from the injection plug 5 from here.
[0011]
Next, after removing and removing said injection | pouring plug 5, the protrusion in the surface of the concrete 2 and the ejection thing accompanying the water leakage from a crack are scraped off, and it wash | cleans with a brush etc., and the base material adjustment by sandpaper is carried out.
[0012]
Next, as shown in FIG. 2, the dents and peeled portions on the surface of the concrete 2 that has been subjected to the base preparation are repaired with a mortar and smoothed. Then, a primer such as an epoxy resin, a polyester resin, or a methacrylic resin is applied to the surface of the smoothed concrete 2, an adhesive 7 is applied to a location where the primer is applied, and a location where the adhesive 7 is applied, As shown in FIG. 3, the fiber sheet 9 provided with the insertion hole 8 is affixed.
[0013]
Then, when an adhesive 10 such as an epoxy resin, a polyester resin, or a methacrylic resin is applied from above the fiber sheet 9 and fixed to the surface of the concrete 2, the fiber sheet 9 becomes a sandwich with the adhesives 7 and 10.
[0014]
The type of fiber constituting the fiber sheet 9 is not particularly limited, and may be organic synthetic fiber, natural fiber, semi-synthetic fiber, artificial fiber, inorganic fiber, or a combination of two or more of these. good.
[0015]
Examples of the synthetic fibers include polyester fibers (including wholly aromatic polyester fibers), polyamide fibers (including aromatic fiber polyamides), polyolefin fibers, polyvinyl alcohol fibers, acrylic fibers, and the like. Examples of synthetic fibers and artificial fibers include viscose fibers, acetate fibers, and cupra fibers. Natural fibers include hemp, cotton, wool and the like, and inorganic fibers include glass fiber and carbon fiber.
[0016]
Among these fibers, synthetic fibers are preferable from the viewpoint of mechanical properties, handleability, heat resistance, light weight, and the like, and polyvinyl alcohol fibers are preferable in terms of weather resistance, chemical resistance (particularly alkali resistance), and the like. It is more preferable that
[0017]
The shape of the fibers constituting the fiber sheet is not particularly limited, and examples thereof include monofilament yarns, multifilament yarns, and spun yarns.
[0018]
The tensile strength of the fiber sheet is preferably 30 N / mm or more. When the tensile strength is less than 30 N / mm, the concrete piece peeling prevention function is insufficient. As also the basis weight of the fiber sheet is ^{preferably 40g / m 2 ~1000g / m 2} , more preferably the basis weight is ^{100g / m 2 ~500g / m 2} . When the basis weight is less than 40 g / m ² , the number of fibers constituting the fiber sheet is reduced, and it becomes difficult to set the tensile strength to 30 N / mm or more.
[0019]
On the other hand, if the basis weight exceeds 1000 g / m ² , the tensile strength increases and the concrete piece peeling prevention function increases, but the weight of the fiber sheet becomes heavy, and the pasting becomes dense and hard, making the pasting work difficult. .
[0020]
Examples of the fiber sheet include woven fabrics, knitted fabrics, and non-woven fabrics, as well as sheet-like products obtained by aligning or crossing a plurality of fibers and bonding the fibers. Of these, considering the strength of the fiber sheet, a woven fabric is preferable. When the fiber sheet is used as a woven fabric, the woven fabric can be a basic fabric such as plain weave, twill weave, satin weave, leno weave or imitation weave.
[0021]
In addition, as described above, it is preferable to use polyvinyl alcohol fiber as the fiber sheet. However, the fiber sheet includes fibers other than polyvinyl alcohol fiber as long as the strength as a sheet and the adhesion to a concrete structure are not lowered. It may be. That is, another fiber may be used as a part of the structure as the fiber constituting the fiber sheet. For example, in the case of a woven fabric, one using another fiber as a part of warp or weft may be used.
[0022]
Next, as shown in FIG. 4, an anchor insertion hole 12 deeper than the structural reinforcing bar 11 is formed in the concrete structure 1 from the fiber sheet insertion hole 8, and an epoxy resin, a polyester resin, a methacrylic resin, or the like is formed there. The adhesive 13 is injected.
[0023]
Also, when using a fiber sheet that is not provided with the insertion holes 8 in advance, the fiber sheet is sandwiched as described above, and then anchors are inserted into the concrete structure 1 from above the fiber sheet coated with adhesive. A hole 12 is opened, and the same adhesive 13 as above is injected therein.
[0024]
Next, as shown in FIG. 5, the double-folded fiber anchor 15 hooked on the fixing ring 14 is inserted into the adhesive 13 and jumps out from the remaining portion of the fiber anchor 15, that is, the anchor insertion hole 12. 6 is torn finely in the vertical direction and is adhered radially to the upper surface of the fiber sheet 9 with the adhesive 10 to form a peeling prevention structure as shown in FIG.
[0025]
Therefore, the fiber sheet 9 affixed to the surface of the concrete 2 is held and fixed by the fiber anchor 15 inserted on the back side of the structural reinforcing bar 11, and the covering concrete 16 is prevented from peeling off.
[0026]
The type of fiber constituting the fiber anchor 15 is not particularly limited, and may be organic synthetic fiber, natural fiber, semi-synthetic fiber, artificial fiber, inorganic fiber, or a combination of two or more of these. .
[0027]
Examples of the synthetic fibers include polyester fibers (including wholly aromatic polyester fibers), polyamide fibers (including aromatic fiber polyamides), polyolefin fibers, polyvinyl alcohol fibers, and acrylic fibers.
[0028]
Semisynthetic fibers and artificial fibers include viscose fibers, acetate fibers, and cupra fibers.
[0029]
Furthermore, natural fibers include hemp, cotton, wool and the like, and inorganic fibers include glass fiber and carbon fiber.
[0030]
Among these fibers, it is preferably made of a synthetic fiber from the viewpoints of mechanical properties, handleability, heat resistance, lightness, etc., and polyvinyl from the viewpoint of good weather resistance, chemical resistance (particularly alkali resistance), and the like. More preferably, it is an alcohol fiber.
[0031]
The shape of the fiber constituting the fiber anchor is not particularly limited, and examples thereof include monofilament yarn, multifilament yarn, and spun yarn.
[0032]
Examples of the shape of the fiber anchor 15 include those in which the above-mentioned fibers are aligned in the longitudinal direction or rope-like stringed, and the portion to be inserted into the concrete structure 1 and the fiber bundle are finely divided into radial shapes. It consists of parts that can be spread out.
[0033]
In order to improve the workability at the time of insertion, the portion to be inserted into the concrete structure 1 is made of an epoxy resin, polyester resin, chloride, or the like, in which the fibers are aligned in the longitudinal direction or roped. It is preferable to harden by applying or impregnating an adhesive such as vinyl resin, phenol resin, or acrylic resin.
On the other hand, the portion that can be radially expanded should be used without being hardened with an adhesive like the portion to be inserted into the concrete structure 1 in consideration of the workability of tearing it finely and attaching it radially to the upper surface of the fiber sheet. The surface of the fiber is preferable even if an adhesive is applied.
[0034]
Moreover, it is preferable that the single fiber fineness of the fiber which comprises the fiber anchor 15 shall be 0.5 dtex-100 dtex, and 1.5 dtex-50 dtex are especially preferable. When the single fiber fineness is less than 0.5 dtex, the diameter of the single fiber becomes small, and the portion that can be radially expanded becomes easy to get entangled with each other, making it difficult to spread uniformly and weakening the reinforcing effect. Cheap. Moreover, when the single fiber fineness exceeds 100 dtex, the diameter of the single fiber becomes large, and when the portion to be inserted into the concrete structure 1 is hardened with an adhesive, it becomes difficult for the adhesive to adhere and impregnate.
[0035]
Further, the fiber anchor 15 has an effect that the load can be held together with the fiber sheet by pressing the fiber sheet by finely tearing and sticking the radially expandable portion to the upper surface of the fiber sheet. In order to achieve sufficient performance, it is preferable that the tensile strength of the single fiber is 5 cN / dtex or more, and more preferably 7 cN / dtex. For the same reason as described above, the number of single fibers is preferably 1000 or more.
[0036]
Further, the strength of the fiber sheet in the present invention is measured at a sample width of 30 mm, a gripping interval of 20 cm, and a tensile speed of 20 cm / min using a constant speed extension type tensile tester according to JIS L-1096A method. The strength of the fiber was measured using a constant speed extension type tensile tester according to JIS L-1013 at a gripping interval of 50 cm and a tensile speed of 50 cm / min.
[0037]
In addition, the method of preventing peeling of concrete fragments of concrete viaducts and reinforced concrete structures is also performed in the same manner as described above, and the same effect is obtained.
[0038]
【The invention's effect】
Since the water is stopped without sealing the surface of the concrete structure and without sealing, the effect can be easily confirmed.
[0039]
Since the fiber sheet is affixed to the surface of the concrete structure, the deterioration factor of the concrete from the outside can be suppressed, and small delamination caused by explosion due to rust of the reinforcing bar can be prevented.
[0040]
By tearing the fiber anchor finely and sticking it radially on the top surface of the fiber sheet, it is possible to prevent large concrete from peeling off.
[0041]
The concrete can be prevented from peeling off without requiring a large-scale machine.
[0042]
Even if you are not a skilled worker, you can perform homogeneous construction.
[Brief description of the drawings]
FIG. 1 (1) is a sectional view in which an injection hole is formed in a crack of a concrete structure, and (2) is a top view of (1).
FIG. 2 (1) is a sectional view in which a mortar is filled in a crack of a concrete structure, and (2) is a top view of (1).
FIGS. 3A and 3B are cross-sectional views in which an anchor insertion hole is formed around a crack in a concrete structure, FIG. 3B is an enlarged cross-sectional view of the main part, and FIG.
4A is a cross-sectional view of a fiber anchor inserted into an anchor insertion hole, and FIG. 4B is a top view of FIG.
FIGS. 5A and 5B are cross-sectional views of inserting a fiber anchor into an anchor insertion hole.
FIG. 6 is a cross-sectional view in which a fiber anchor is inserted into the anchor insertion hole.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Concrete structure 2 Concrete 3 Crack 4 Injection hole 5 Injection plug 6 Water stop agent 7, 10, 13 Adhesive 8 Insertion hole 9 Fiber sheet 11 Structural reinforcement 12 Anchor insertion hole 14 Fixing ring 15 Fiber anchor 16 Covered concrete

Claims (4)

A portion where the waterproofing agent is injected from the injection hole into the deep part of the crack in the concrete structure, and the periphery of the crack is repaired to be a smooth surface, and then an adhesive is applied to the smooth surface, and the adhesive is applied. A fiber sheet is affixed to the fiber sheet, adhesive is applied from above the fiber sheet, and the fiber sheet is sandwiched with these adhesives. An anchor insertion hole is formed in the concrete structure from the surface of the fiber sheet sandwiched by the adhesive. A method for preventing delamination of a concrete piece, comprising: opening and bonding a part of a fiber anchor into the anchor insertion hole and then tearing the remaining part of the fiber anchor finely and adhering them radially to the upper surface of the fiber sheet .   The method for preventing a concrete piece from peeling off according to claim 1, wherein a fiber sheet having an insertion hole is pasted on the smooth surface in advance. Fiber sheet spalling prevention method of the concrete element according to claim 1 or 2, wherein the basis weight is the ^{40g / m 2 ~1000g / m 2} , a tensile strength of 30 N / mm or more.   The fiber anchor has a single fiber fineness of 0.5 to 100 dtex and a tensile strength of 5 cN / dtex or more, and the method for preventing the concrete piece from peeling off according to any one of claims 1 to 3.

Images