KR101453072B1 - Composite Fibre Panel and Flexural, Shear and Seismic Reinforcing Methods for Concrete Structures by using Composite Fibre Panel - Google Patents

Abstract

The present invention relates to a composite fiber board to enhance flexure, seismic performance of a concrete structure or enhancing all flexure, shear and seismic performance of a concrete structure; and a reinforcing method to enhance flexure, seismic performance or reinforcing flexure, shear, and reinforcing and enhancing seismic performance of a concrete structure using the same. More specifically, the said invention relates to a composite fiber board and a reinforcing method to enhance flexure, shear, and seismic performance wherein a reinforcement sheet prevents a unidirectional crack of a fiber board when a composite fiber board is perforated by a low-cost composite fiber board including a unidirectional fiber board having carbon fiber yarns arranged in one direction and accounting for 80-90 wt% in total weight; and a reinforcing sheet bonded to one or both of an upper side and a lower side of the unidirectional fiber board by an adhesive and accounting for 10-20 wt% in total weight is introduced such that the reinforcing sheet prevents cracking phenomenon of the unidirectional fiber board when the composite fiber board is perforated, such that degradation of reinforcing performance to enhance flexure tension or flexure tension and a shear crack does not occur, and additional performance reinforcing a shear crack exhibits when a shear crack is reinforced through various shapes of anchoring plates and nuts.

Description

TECHNICAL FIELD [0001] The present invention relates to a composite fiber panel and a reinforced concrete structure using the same,

The present invention relates to a composite fiber board for simultaneously reinforcing bending, bending and shear reinforcement of a concrete structure, and a method of reinforcing a bending, shearing and seismic performance of a concrete structure using the same.

Generally, reinforced concrete structure methods include the attachment method and the cross-sectional extension method.

Here, the adhesion method includes a steel plate attachment method, a fiber sheet reinforcement method, and a fiberboard reinforcement method.

The steel plate attaching method is a method of reinforcing by using a steel plate. The weight of the steel plate is large, and heavy equipment is required at the time of construction.

In addition, there is concern about corrosion of the steel sheet itself, and there is a problem of interfacial delamination due to lack of air permeability due to sealing phenomenon.

In addition, the fiber sheet reinforcing method has a problem in that it is difficult to construct the fiber sheet in comparison with the reinforcing performance, and the quality is influenced by the skill of the operator.

In addition, the front surface construction lacks air permeability and is difficult to maintain.

The fibrous plate reinforcement method has excellent material properties, but has a limitation in adhesion performance, such as early peeling at the end, due to the dependence of the adhesion performance with the structure to be reinforced only on the epoxy adhesive.

Korean Patent No. 10-0614916 (2006.08.16.), "Building reinforcing beam with an insert part formed thereon" has been proposed as a conventional technique for the fiberboard reinforcing method.

The above-mentioned patent discloses a structure in which an upper sheet is formed on the upper side of the reinforcing portion and a lower sheet is formed on the lower side, and an inserting portion is formed at both ends of the concrete structure to be inserted into the groove, consist of.

Such a patent has an insertion part at both ends so as to prevent the phenomenon that the reinforcing beam is peeled off, thereby preventing the both ends of the concrete structure from peeling off.

(Patent Document 1) KR10-0614916 B1 Building reinforcing beam formed with inserting portion

However, such a registered patent is rarely used in actual construction due to the complexity of the structure.

Particularly, in the case of the above-mentioned registered patent, it is used for the purpose of reinforcing the deteriorated concrete structure. In the case of forming the grooves into which the insertion portion can be inserted as described above, the physical deterioration is further promoted, There was a problem.

In order to solve the above-mentioned problems, the composite fiber board of the present invention and the concrete structure using the composite fiber board are used to reinforce the bending, shearing and seismic performance of the composite fiber board. The present invention aims to provide a method of reinforcing a reinforced concrete structure, which is capable of performing a single reinforcement for flexural tensile or a composite reinforcement for flexural tensile and shear crack without deteriorating the reinforcing performance.

Another object of the present invention is to improve the tensile ability by dying carbon on the surface when the reinforcing sheet is formed of a polyester nonwoven fabric.

It is a further object of the present invention to provide a method and apparatus for locating reinforcement bars embedded in a concrete structure during a composite reinforcement due to flexural tensile and shear cracks to prevent deterioration occurring at the time of reinforcement, So as to form an additional shear reinforcement capability.

The present invention has a structure in which a reinforcing sheet of a nonwoven fabric or a woven fabric is bonded to one or both sides of the unidirectional fiberboard, thereby preventing the unidirectional fiberboard from being cracked at the time of perforation of the composite fiberboard, And thus the construction cost can be reduced.

In particular, when the reinforcing sheet is formed of a polyester nonwoven fabric, carbon can be stained on the surface to further improve the tensile strength.

In addition, when reinforcing the concrete structure, the composite fiberboard is attached and then anchoring bolts are introduced to improve the load-bearing capacity against bending tensile. In the case of bending and shear reinforcement, mechanical anchors Mechanical anchor system can be installed to perform bending tensile and shear reinforcement at the same time.

Also, reinforcement can be performed while preventing the deterioration of the concrete structure by confirming the position of the reinforcing bar embedded in the concrete structure when the shear reinforcement due to the shear crack is confirmed.

In addition, when shear reinforcement is applied, anchoring plates and nuts are successively joined to the chemical anchor rods of the mechanical anchor or chemical anchor system to tighten the shear strains, and shear reinforcement can be additionally performed. In particular, It is a useful invention in which the shape of the anchoring plate is deformed and the tightening work of the nut can be smoothly performed.

1 is an exploded perspective view showing a composite fiber board according to the present invention;
2 is a sectional view showing a state in which a composite fiberboard according to the present invention is used to perform bending tensile and seismic performance enhancement reinforcement.
FIG. 3 is a detailed view of FIG. 2A. FIG.
4 is a cross-sectional view showing a reinforced state in which bending tensile, shear reinforcement and seismic performance are improved by using a composite fiber board and a mechanical anchor or chemical anchor system according to the present invention.
FIG. 5 is a cross-sectional view showing bending tensile, shear reinforcement, and reinforced seismic performance enhancement when a triangular anchoring plate is applied in shear reinforcement in the present invention.
6 is a schematic view of a bending tensile test of an unreinforced RC-T beam.
Fig. 7 is a schematic view showing a bending tensile test of an RC-T beam after reinforcing the composite fiberboard with an epoxy bonding method; Fig.
FIG. 8 is a schematic view showing a bending tensile test of an RC-T beam after reinforcing the composite fiberboard epoxy + both ends with anchor bolts.
FIG. 9 is a schematic view showing a bending tensile test of an RC-T beam after reinforcing the composite fiberboard epoxy with anchoring at regular intervals in the epoxy bonding + shear zone.
FIG. 10 is a schematic view showing a bending tensile test of an RC-T beam after reinforcement by anchoring at a composite fiberboard epoxy + two anchor bolts at both ends + four shear zones.
11 is a graph showing the results of the tests in Figs. 6 to 10. Fig.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a configuration of the present invention will be described in detail with reference to the accompanying drawings.

First, the composite fiberboard 30 in the present invention is composed of a unidirectional fiberboard 10 and a reinforcing sheet 20 as shown in Fig.

The unidirectional fiberboard 10 has a plate shape in which fiber yarns extend in one direction and is composed of 80 to 90% by weight of the total weight of the composite fiberboard 30.

The unidirectional fiberboard 10 has a structure in which a plurality of fiber bundles each composed of a plurality of fiber yarns are formed in one direction.

Here, the unidirectional fiberboard 10 may be formed of carbon fiber or glass fiber.

If the unidirectional fiberboard 10 is made of carbon fiber, a plurality of carbon fiber strands having 800 to 1600 Tex (thickness) or 12,000 to 24,000 carbon fiber yarns are combined. The unidirectional carbon fiber board has a tensile strength of 2,200 ~ 3,200 MPa and a modulus of elasticity of 160 to 250 GPa.

In addition, when the unidirectional fiberboard 10 is made of glass fiber, a plurality of glass fiber strands having 1,200 to 2,400 Tex (thickness) are combined. The unidirectional glass fiberboard has a tensile strength of 1,700 to 3,000 MPa and an elastic modulus of 65 The unidirectional glass fiber board 10 having a diameter of 70 GPa is used.

On the other hand, the reinforcing sheet 20 is formed in a sheet form of 10 to 20% by weight of the total weight of the composite fiberboard 30, and is disposed on one side or both sides of the unidirectional fiberboard 10, If the reinforcing sheet 20 is formed on the upper and lower sides of the unidirectional fiberboard 10, the weight of the reinforcing sheet 20 is divided by a factor of two to form the same reinforcing sheet 20 at two points, To be adhered to the fiber board (10).

The reinforcing sheet 20 may be made of any one of polyester nonwoven fabrics made of polyester fiber yarns or carbon fiber nonwoven fabrics made of carbon fibers.

Here, the method of manufacturing the reinforcing sheet 20 in the form of a nonwoven fabric can be variously manufactured, for example, by making punches through needle punching or by chemical bonding using chemicals. At this time, the nonwoven fabric has tensile strength Is 20 to 80 kN / m and weighs 20 to 100 g / m2.

The reinforcing sheet 20 is attached to the unidirectional fiberboard 10 so that when the operator intends to form a hole through a punching means such as a hammer drill to firmly attach the composite fiberboard 30 to the concrete structure C, So as to prevent the fibrous sheet 10 from cracking.

Hereinafter, a reinforcing method of a concrete structure using the composite fiberboard 30 will be described.

1. Flexural tensile, seismic performance enhancement reinforcement

a. Concrete structure surface preparation step

First, referring to FIG. 2, the work of arranging the surface for reinforcement of the flexural tensile in the concrete structure (C) should be preceded.

That is, the foreign matter on the surface of the concrete structure (C) is removed and cleaned. In particular, when the flatness of the concrete structure (C) is not matched, do.

b. Attachment of composite fiberboard

In this step, the composite fiberboard 30 described above is attached to the surface of the concrete structure C having been subjected to surface preparation.

As described above, the composite fiberboard 30 includes a reinforcing sheet 20 made of a material selected from polyester or probing fibers on one or both sides of the upper and lower sides of the unidirectional fiberboard 10 in the form of a nonwoven fabric It is made of adhesive type.

That is, depending on the degree of reinforcement of the concrete structure C, the material of the unidirectional fiberboard 10 and the material of the reinforcing sheet 20 are differently applied. If necessary, the unidirectional fiberboard 10 may be provided on the upper side, The reinforcing sheet 20 may be used.

In the case where the reinforcing sheet 20 constituting the composite fiberboard 30 is formed on only one surface, a semi-solid adhesive is applied to the surface of the unidirectional fiberboard 10 on which the reinforcing sheet 20 is not formed, (C).

Particularly, when the semi-solid type adhesive is applied to the composite fiberboard 30, the amount of the adhesive applied to the center portion in the width direction perpendicular to the longitudinal direction of the composite fiberboard 30 is more than the average application amount, The composite fiberboard 30 is allowed to uniformly disperse the adhesive on the entire surface of the composite fiberboard 30 in contact with the concrete structure C by applying an amount smaller than the average application amount to both edges of the composite fiberboard 30.

That is, when the composite fiberboard 30 is attached to reinforce the concrete structure C, the central portion of the composite fiberboard 30 is first pressed to press the both sides of the concrete structure C in a state of being adhered to the concrete structure C, The composite fiberboard 30 is attached to the concrete structure C.

If the adhesive applied on the central portion and both edges of the composite fiberboard 30 is applied in a flat state, the adhesive applied to the center portion is pushed to both sides, and the amount of adhesive in the center portion is increased The adhesive strength of the composite fiberboard 30 may be lowered due to adhesion to the concrete structure C in a state where the adhesive is not evenly applied to the entire area of the composite fiberboard 30.

Particularly, at the edges of the composite fiberboard 30, a large amount of adhesive is formed on the both edges of the adhesive due to the joining of the adhesive pushed from the center portion. Therefore, the adhesive agent is protruded from the composite fiberboard 30, ) Or dropping phenomenon occurs, which causes waste of the adhesive, and a process for arranging the same must be further performed.

However, in the present invention, a small amount of adhesive smaller than the average coating amount is applied to both edges of the composite fiberboard 30, and an adhesive is formed in the center portion of the composite fiberboard 30 in an amount larger than the average coating amount.

c. Completion phase of construction

When the adhesive of the semi-solid state is cured after a certain period of time after the composite fiberboard 30 is attached as described above and the attachment of the composite fiberboard 30 to the concrete structure C is completed, Anchoring grooves h2 are formed to penetrate the composite fiberboard 30 to a predetermined depth of the concrete structure C and then the anchoring bolts A3 are inserted and then the anchoring plates W and the nuts N So that the composite fiberboard 30 can be prevented from falling off prematurely, thereby completing the construction.

In general, adhesion of the composite fiberboard 30 through an adhesive is advantageous in that it can be easily applied in addition to high adhesive strength of the adhesive. On the other hand, early detachment occurs at both ends of the composite fiberboard 30 during long- There is a problem that early dropping occurs.

Therefore, in the present invention, the composite fiberboard 30 is bonded to the concrete structure C by joining the anchor bolt A3, the anchor plate W and the nut N by drilling the anchor grooves h2 at both ends of the composite fiberboard 30, And prevent early fall-off phenomenon caused by fire.

Particularly, the composite fiberboard 30 of the present invention has a structure in which the reinforcing sheet 20 is formed on the unidirectional fiberboard 10 capable of coping with the flexural tensile of the concrete structure C as described above, So that the unidirectional fiberboard 10 constituting the fiberboard 30 can be prevented from being split, and the structural reinforcement due to the bending tensile force can be maintained.

One or more anchoring bolts (A3) formed at both ends of the composite fiberboard (30) are formed at the respective ends, and a plurality of anchoring bolts (A3) can be additionally provided at portions where shear moments act have.

The anchoring bolts A3 for connecting the composite fiberboard 30 and the concrete structure C are tightened at a constant torque by using a torque wrench during the installation of the anchoring bolts A3, (A3) is allowed within the allowable range of shear stress.

For example, when the diameter of the anchoring bolt A3 is 10 mm (M10), it is preferable to perform the tightening operation with a torque of about 50 Nm, which is the allowable maximum shear stress range.

In order to prevent corrosion of the anchoring bolts A3, the anchoring plates W and the nuts N, an additional cap (not shown) may be further formed after the installation, and the anchoring bolts A3 may be inserted An epoxy resin (A) is formed around the anchoring bolts A between the composite fiberboard 30 and the anchoring plate W to prevent corrosion by water that may flow into the anchor grooves h2 formed in the concrete structure C. [ E1) may be further applied. Through such a construction process, the reinforcement construction according to the bending tensile strength can be completed.

Particularly, in the present invention, the width of the anchoring plate W may be equal to or slightly larger than the width of the composite fiberboard 30, thereby improving the supporting force of the composite fiberboard 30.

2. Flexural tensile, shear crack and seismic performance reinforcement

a. Steps to Identify Shear Reinforcement Range

Referring to FIG. 4, the step of confirming the shear reinforcement range is performed by visually confirming the shear crack S generated in the concrete structure C, and then, when the shear crack S is confirmed, Check whether shear cracks (S) are further generated and indicate the shear reinforcement position and range.

Here, as described above, the precise diagnosis after visual confirmation can be carried out through a normal nondestructive test.

b. Shear crack directionality confirmation step

In the step of confirming the direction of shear cracking, the angle of the shear crack S is measured by checking the direction of the shear crack S generated on the surface of the concrete structure C, and in the step of confirming the shear reinforcement range, (Angle) of the shear crack S when the shear crack S is generated inside the shear crack S.

c. Anchor location step

The position where the mechanical anchor A1 can be inserted is selected to reinforce the shear crack S generated on the surface or inside of the concrete structure C determined through the step of confirming the shear reinforcement range.

In this anchor positioning step, the nondestructive inspection is performed within the range of the shear crack (S) of the concrete structure (C), and the position of the reinforcing bar embedded in the concrete structure (C) The position where the mechanical anchor A1 can be installed is selected.

d. Concrete structure surface preparation step

When the pre-irradiation work is completed as described above, the foreign matter on the surface of the concrete structure C is removed and cleaned. Particularly, when the flatness of the concrete structure C is not matched, Perform maintenance work after removing foreign matter.

e. Attachment of composite fiberboard

In this step, the composite fiberboard 30 described above is attached to the surface of the concrete structure C having been subjected to surface preparation.

As described above, the composite fiberboard 30 is formed by adhering a reinforcing sheet 20 made of woven fabric or nonwoven fabric to one or both of the upper and lower sides of the unidirectional fiberboard 10.

That is, in order to improve the reinforcing strength according to the bending tensile strength, the reinforcing sheet 20 may be formed on both the upper side and the lower side of the unidirectional fiberboard 10.

When a reinforcing sheet 20 is formed on only one side of the composite fiberboard 30, a semi-solid adhesive is applied to the surface of the unidirectional fiberboard 10 on which the reinforcing sheet 20 is not formed, .

Particularly, when the semi-solid type adhesive is applied to the composite fiberboard 30, the amount of the adhesive applied to the center portion in the width direction perpendicular to the longitudinal direction of the composite fiberboard 30 is more than the average application amount, The composite fiberboard 30 is allowed to uniformly disperse the adhesive on the entire surface of the composite fiberboard 30 in contact with the concrete structure C by applying an amount smaller than the average application amount to both edges of the composite fiberboard 30.

That is, when the composite fiberboard 30 is attached to reinforce the concrete structure C, the central portion of the composite fiberboard 30 is first pressed to press the both sides of the concrete structure C in a state of being adhered to the concrete structure C, The composite fiberboard 30 is attached to the concrete structure C.

If the adhesive applied on the central portion and both edges of the composite fiberboard 30 is applied in a flat state, the adhesive applied to the central portion is pushed to both sides, and the amount of adhesive in the center portion is increased The adhesive strength of the composite fiberboard 30 may be lowered due to adhesion to the concrete structure C in a state where the adhesive is not evenly applied to the entire area of the composite fiberboard 30.

Particularly, at the edges of the composite fiberboard 30, a large amount of adhesive is formed on the both edges of the adhesive due to the joining of the adhesive pushed from the center portion. Therefore, the adhesive agent is protruded from the composite fiberboard 30, ) Or dropping phenomenon occurs, which causes waste of the adhesive, and a process for arranging the same must be further performed.

However, in the present invention, a small amount of adhesive smaller than the average coating amount is applied to both edges of the composite fiberboard 30, and an adhesive is formed in the center portion of the composite fiberboard 30 in an amount larger than the average coating amount.

f. Completion phase of construction

When the adhesive of the semi-solid state is cured after a certain period of time after the composite fiberboard 30 is attached as described above and the attachment of the composite fiberboard 30 to the concrete structure C is completed, Anchoring grooves h2 are formed to penetrate the composite fiberboard 30 to a predetermined depth of the concrete structure C and then the anchoring bolts A3 are inserted and then the anchoring plates W and the nuts N So that the composite fiberboard 30 can be prevented from falling off prematurely.

In general, adhesion of the composite fiberboard 30 through an adhesive is advantageous in that it can be easily applied in addition to high adhesive strength of the adhesive. On the other hand, early detachment occurs at both ends of the composite fiberboard 30 during long- There is a problem that early dropping occurs.

Therefore, in the present invention, the composite fiberboard 30 is bonded to the concrete structure C by joining the anchor bolt A3, the anchor plate W and the nut N by drilling the anchor grooves h2 at both ends of the composite fiberboard 30, And prevent early fall-off phenomenon caused by fire.

As described above, the composite fiberboard 30 of the present invention has a structure in which the reinforcing sheet 20 is formed on the unidirectional fiberboard 10 that can cope with the flexural tensile of the concrete structure C, It is possible to prevent the unidirectional fiberboard 10 of the fiberboard 30 from cracking and to maintain the strength of the structural reinforcement due to the bending tension.

One or more anchoring bolts (A3) formed at both ends of the composite fiberboard (30) are formed at the respective ends, and a plurality of anchoring bolts (A3) can be additionally provided at portions where shear moments act have.

Also, the shear reinforcement groove h1 for reinforcement according to the shear cracks selected in the anchor positioning step is formed in the same manner as described above.

Particularly, in the step of confirming the direction of shear cracking, when the shear crack S is formed in an oblique shape, the shear reinforcement groove h1 is punctured in a direction perpendicular to the direction of the shear crack.

Thereafter, any one of the mechanical anchor A1 or the chemical anchor system A2 is inserted into the front end reinforcement groove h1, and then the anchoring plate W and the nut N are sequentially engaged, .

Here, the selection of the mechanical anchor A1 and the chemical anchor system A2 should be selected in accordance with the progress of the shear crack S,

That is, when the progress of the shear crack S of the concrete structure C is high, the construction is performed using the chemical anchor system A2 having a high shear strength. When the progress of the crack shear step S is low, (A1).

Here, the adhesive force of the mechanical anchor A1 is formed by a physical frictional force with the shear reinforcement grooves h1 formed in the concrete structure C.

Therefore, it is relatively inexpensive compared to the chemical anchor system (A2), which is less susceptible to fire and has a limited range of shear reinforcement, in which a separate equipment is required to inject the chemical anchor (a1).

In order to improve the adhesion and shear strength of the mechanical anchor A1 during the anchoring through the mechanical anchor A1, additional fillers F such as mortar or epoxy may be further formed.

Since the chemical anchor system (A2) is chemically bonded, the adhesive force can be expected to increase by about 10 to 15% compared with the mechanical anchor (A1), and the shear reinforcement range is wider, the price is lowered .

In the present invention, the chemical anchor A1 and the chemical anchor rod a2 of the chemical anchor system A2 may be formed of a stainless steel material free from rust.

In particular, when the shear crack S is formed by an oblique line, the tightening operation is difficult by tightening the nut N. In the present invention, as shown in FIG. 7, the anchoring plate W, The angle of the upper portion of the anchoring plate W is formed to be the same as the directionality of the shear crack S so that the anchoring plate W is completely in contact with the concrete structure C, The problem can be solved.

Meanwhile, the tightening of the nut (N) to be engaged after the connection of the mechanical anchor (A1), the chemical anchor system (A2) and the anchoring bolt (A3) is performed by using a torque wrench, The shear stress of the anchor A1, the chemical anchor system A2, and the anchor bolt A3 is allowed.

For example, when the diameter of the mechanical anchor A1, the chemical anchor system A2, and the anchor bolt A3 is 10 mm (M10), it is preferable to perform the tightening operation with a torque of about 50 Nm, which is the allowable maximum shear stress range.

In order to prevent corrosion of the mechanical anchor A1, the chemical anchor system A2, the anchor bolt A3, the anchor plate W and the nut N, a separate cap (not shown) The anchor grooves h2 and the shear reinforcement grooves h1 formed in the concrete structure C for inserting the mechanical anchor A1 or the chemical anchor system A2 and the anchor bolts A3 An epoxy resin E1 is attached to the periphery of the mechanical anchor A1 or the chemical anchor system A2 between the composite fiberboard 30 and the anchoring plate W and the anchoring bolts A3 in order to prevent corrosion by water And it is possible to complete reinforcement construction by bending tensile and shear crack through such a construction process.

As described above, according to the present invention, the introduction of the composite fiberboard 30 and the mechanical anchor A1 or the chemical anchor system A2 allows the shear, flexural reinforcement, and seismic performance to be improved at the same time, 30, it is possible to maintain the function of the composite fiberboard 30 which improves the load bearing capacity against loads generated in various directions.

Particularly, the direction and direction for proper shear reinforcement are checked in advance through the directional inspection of the shear crack (S) and the reinforcing bar inspection at the shear reinforcement, and then the mechanical anchor (A1) or the chemical anchor system (A2) Reinforcing can be performed and a role of gathering the portions opened due to the shear crack S by using the anchoring plate W and the nut N is performed and also when the direction of the shear crack S is diagonal, The anchoring plate W can be introduced and an effect that the tightening work can be smoothly performed through the nut N can be obtained.

The width of the anchoring plate W may be equal to or slightly greater than the width of the composite fiberboard 30 to improve the supporting force of the composite fiberboard 30.

6 to 11, the effect of the anchoring bolt on the bending tension of the anchor bolt will be described.

FIG. 6 is a schematic view of a bending tensile test (Beam 1) of an unreinforced RC-T beam. Referring to FIG. 11, in the case of the RC-T beam test method (Beam 1) The results of the experimental method showed that the concrete was broken at load (P) of 60kN × 2, and the beam was deformed before the fracture due to plastic deformation after plastic deformation.

FIG. 7 is a schematic view of a composite fiber board reinforced by an epoxy bonding method and then subjected to a flexural tensile test of the RC-T beam. Referring to FIG. 7, the composite fiber board 30 is attached to the RC- (Beam 2), as shown in Fig. 3 (b), shows that fracture occurs at a load (P) of 80 kN × 2. In this state, since the fracture occurs before the plastic deformation, Brittle fracture occurs because the concrete falls off.

FIG. 8 is a schematic view of a composite fiberboard epoxy laminate + reinforced both ends thereof with an anchoring bolt and then subjected to a flexural tensile test of an RC-T beam. Referring to FIG. 8, the composite fiberboard 30 is attached to an RC- (Beam 3), as shown in FIG. 11, in which the both ends of the composite fiberboard 30 are fixed by an anchoring bolts A3. It can be seen that breakage occurs at a load (P) of 92 kN × 2, Since the fracture occurs after the plastic deformation, the deformation of the beam occurs before the fracture.

Also, after the concrete breakage, the beam can support the load. At both ends fixed by the anchoring bolts (A3), small damage of the composite fiberboard 30 occurs due to the increase of the deformation of the beam, and the brittle fracture does not occur, C does not occur.

FIG. 9 is a schematic view of a composite fiberboard epoxy reinforced with an epoxy ring and an anchor ring at regular intervals in a shear zone, and then subjected to a flexural tensile test of the RC-T beam. (A3) were fixed at fixed intervals on both side shear zones where shear warpage occurred. The results are shown in FIG. 11. As a result, the load (P) is 103 kN × 2, and the same action as in (Beam 5) described later occurs.

FIG. 10 is a schematic view of the RC-T beam subjected to a flexural tensile test after reinforcing with an anchor bolt at four places of anchor bolts with composite fiberboard + epoxy at both ends + four shear zones. Referring to FIG. 10, The fiberboard 30 is attached with an adhesive and both ends of the composite fiberboard 30 are fixed with an anchoring bolts A3 and then four anchoring bolts A3 are further attached to both front ends of the composite fiberboard 30 As a result of the fixed experiment, the result (Beam 5) in FIG. 11 shows that breakage occurs at a load (P) of 117 kN × 2, and that the concrete is separated by the composite fiberboard 30 fixed by the anchor bolt (A3) The phenomenon is prevented, and the brittle fracture of the beam does not occur.

Further, it can be seen that the load carrying capacity is increased and the safety factor is improved by fixing the composite fiberboard 30 with the anchoring bolts A3 in the front end area.

At this time, the reinforced beam shows ductility.

In the case of the composite fiberboard 30 according to the present invention, since the unidirectional fiberboard 10 is bonded to the reinforcing sheet 20 in the form of a woven fabric or a nonwoven fabric, even if the unidirectional fiberboard 10 is worn or damaged The phenomenon of occurrence of the above phenomenon does not occur.

The composite fiberboard 30 described above can provide a cost-effective reinforcing material by increasing the resistance to bending tensile by combining the reinforcing sheet 20 of woven fabric or nonwoven fabric with the unidirectional fiberboard 10 having improved tensile strength It is effective.

That is, the results are summarized in the following table.

[RC-T beam test result] Reinforcement method Breaking load No reinforcement 60 kN x 2 Attach composite fiber board with epoxy 80kN x 2 Epoxy composite fiber board + two-end anchoring bolts (2 locations) installed 92 kN x 2 Epoxy composite fiber board + Anchoring bolts (6 places) at regular intervals in shear zone 103 kN x 2 Epoxy composite fiberboard + Both ends anchoring bolts (2 places) + Anchoring bolts (4 places) installed in shear area 117kN x 2

While the present invention has been described in connection with certain exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

A1: Mechanical anchor A2: Chemical anchor system a1: Chemical anchor
a2: Chemical anchor rod
A3: Anchoring bolts
h1: Shear reinforcement groove h2: Anchor groove N: Nut S: Shear crack F: Filler
W: Anchoring plate E1: Epoxy resin
30: Composite fiber board
10: unidirectional fiber board
20: reinforced sheet

Claims (16)

delete delete delete delete delete delete delete delete delete delete Identifying the shear reinforcement range to identify the location and extent for shear reinforcement by identifying the shear crack range of the concrete structure;
Shear crack directionality confirmation step to confirm the directionality of shear cracks in concrete structures;
Anchor location selecting step of selecting an anchor insertion position for shear reinforcement after confirming a reinforcing steel embedded in a concrete structure through nondestructive inspection at the shear reinforcement position and range determined in the step of confirming the shear reinforcement range;
A surface preparation step of a concrete structure to consolidate the surface of a concrete structure to be subjected to bending reinforcement;
Wherein the unidirectional fibrous sheet comprises a unidirectional fiber board having fibers arranged in one direction and having a total weight of 80 to 90% by weight and at least one of the upper and lower surfaces of the unidirectional fiberboard, Attaching the composite fiberboard to the composite fiberboard by applying adhesive means to the composite fiberboard, the fiberboard being 10 to 20% by weight of the total weight of the composite fiberboard bonded to the concrete structure for flexural reinforcement;
The composite fiberboard is passed through both ends of the composite fiberboard attached to the selected position in the anchor positioning step and the concrete structure to form a shear reinforcement groove and an anchor groove formed in a part of the concrete structure, and then a mechanical anchor or chemical anchor system and an anchor bolt And an anchoring plate and a nut. The reinforcing method for reinforcing the bending, shearing and seismic performance of the concrete structure using the composite fiber board and the mechanical anchor.
The method as claimed in claim 11, wherein, when the reinforcing sheet formed on the composite fiberboard in the step of attaching the composite fiberboard is formed on only one side of the composite fiberboard, the adhesive is applied to the surface of the carbon fiberboard on which the reinforcing sheet is not formed, Reinforced concrete beams with composite fiber boards and mechanical anchors.
12. The method as claimed in claim 11, wherein the unidirectional fiberboard is manufactured by bonding a plurality of carbon fiber strands having a Tex (thickness) of 800 to 1,600 or a carbon fiber yarn of 12,000 to 24,000, Shear strength and seismic performance of concrete structures using composite fiber boards and mechanical anchors characterized by 2,200 ~ 3,200 MPa and elastic modulus of 160 ~ 250 GPa.
12. The method of claim 11, wherein the unidirectional fiberboard is formed by bonding a plurality of fiberglass strands having a Tex (thickness) of 1,200 to 2,400 in the step of attaching the composite fiberboard, wherein the unidirectional fiberboard has a tensile strength of 1700 to 3,000 MPa, Reinforcing method of reinforced concrete structures with composite fiber boards and mechanical anchors, characterized by 65 ~ 70 GPa, flexural, shear and seismic performance.
[12] The method of claim 11, wherein the reinforcing sheet is formed of a material selected from the group consisting of a carbon fiber nonwoven fabric and a polyester nonwoven fabric. The nonwoven fabric has a tensile strength in each direction of 20 to 80 kN / Reinforced concrete structure with reinforced fiberboard and mechanical anchor, characterized by 20 ~ 100g / ㎡.
12. The method of claim 11, wherein the width of the anchoring plate at the completion of the construction step is equal to or greater than the width of the composite fiberboard, and the composite fiberboard and the mechanical anchor are used to reinforce the flexural, shear, and seismic performance enhancement of the concrete structure. Method.

Images