JP2006226045A - Dry hybrid reinforced fiber tendon - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dry hybrid reinforced fiber tendon which enables introduction of higher tensioning force without impregnation, in a tension bonding method using an unimpregnated carbon fiber material. <P>SOLUTION: The dry hybrid reinforced fiber tendon is obtained as follows. Namely, at least continuous carbon fibers 2A and fibers 3A with an energy absorption capacity higher than that of the carbon fibers 2A are uniformly arranged and arrayed in one direction for hybridization to make a hybrid reinforced fiber material 1. Then, a tensioning force of about several percent of a maximum tensioning force introduced to a reinforced fiber material is introduced to the hybrid reinforced fiber material 1 for preliminary tensioning. After that, the fiber material 1 is partly impregnated with a resin, cured, and released from the tensioning force. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is, for example, a concrete structure or a steel structure that is a building or a civil engineering structure by a reinforcing fiber sheet tension bonding method (in the present specification, a concrete structure and a steel structure are simply referred to as “structure”). ) Is a dry hybrid reinforced fiber tendon that can be used for reinforcement.

  In recent years, as a method for reinforcing a structure, an adhesive method has been developed in which a continuous reinforcing fiber sheet is attached to or wound around the surface of an existing or new structure using an adhesive.

  However, the above-mentioned bonding method is only simple bonding, and there is a limit to the improvement of the ultimate strength reinforcement effect due to the early destruction of the structure due to the peeling of the fiber reinforced resin (FRP) reinforcing material. There is a limit to the effect of suppressing cracks. In addition, the high performance of the FRP reinforcement is often not utilized effectively.

  In order to improve such a problem, a tension bonding method using a reinforcing fiber sheet has been proposed. For example, in Patent Document 1, a tensile force is introduced by a tension device through a jig to a fiber material composed of a carbon fiber sheet containing at least carbon fiber as a reinforcing fiber, a cloth and a prepreg impregnated with resin, A tension bonding method is disclosed in which a fiber material is adhered to the surface of a concrete member with an adhesive, and then a jig and a tensioning device are removed.

  In particular, in such a tension bonding method, from the viewpoint of workability and the like, when the tension force is introduced to the reinforcing fiber sheet, the resin impregnation and curing steps of the reinforcing fiber sheet are not performed in advance, that is, the non-impregnated process is not performed. It is desirable to be able to introduce tension.

  However, when carbon fiber is used as the reinforcing fiber, the tension force introduced into the reinforcing fiber sheet is not uniformly applied in the width direction of the reinforcing fiber sheet due to slight slyness or inclination when the tensioning device is attached. Or when the quality of the reinforcing fiber itself varies, the reinforcing fiber sheet is twisted or broken in the longitudinal direction.

  According to the results of the research experiment conducted by the present inventors, it was found that the carbon fiber breaks when a tensile force of about 10 to 40% of the original tensile strength of the carbon fiber is introduced.

  On the other hand, the present inventors, in such a reinforcing fiber sheet tension adhesive construction method, as a reinforcing fiber of the reinforcing fiber sheet, in particular, continuous carbon fiber, excellent in energy absorption capacity than carbon fiber, and excellent in shock absorption. When a hybrid reinforcing fiber sheet mixed with continuous fibers with high energy absorption such as PBO (polyparaphenylene benzbisoxazole) fiber is used, carbon is used as the reinforcing fiber in the on-site resin-free impregnation tension introduction. It has been found that a greater tension can be introduced as compared with a reinforcing fiber sheet using only fibers, and that the fiber is not bent or bent when the sheet is impregnated with resin.

  In particular, when introducing tension to the hybrid reinforcing fiber sheet, preliminarily introduce a tension of a certain tension level (prestress), perform partial impregnation and curing of the resin in this state, It has been found that the maximum tensile stress ratio can be increased by increasing the tension to the maximum tension.

  The above fact is not limited to the dry hybrid reinforcing fiber tension material in which the reinforcing fiber material is formed into a sheet shape, but can also be applied to a dry hybrid reinforcing fiber tension material in a rope shape (string shape).

  Therefore, according to such a dry hybrid reinforcing fiber tension material, a carbon fiber having high rigidity and a high energy absorbing fiber such as PBO fiber are used, and the fracture strength of the structure is increased by the carbon fiber having high rigidity. Increases the fracture toughness of the structure with PBO fibers that have high energy absorption to prevent breakage immediately, and prevents timely destruction even when cracked in the structure. Can be extended.

The present invention is based on such novel findings of the present inventors.
Japanese Patent Laid-Open No. 11-182061

  An object of the present invention is to provide a dry hybrid reinforcing fiber tension material that can introduce a greater tension force without impregnation by, for example, a tension bonding method using an unimpregnated carbon fiber material.

  Another object of the present invention is, for example, that it is possible to introduce a greater tension force without impregnation in a tension bonding method using a non-impregnated carbon fiber material, and that the fiber can be twisted and bent during resin impregnation. This is to provide a dry hybrid reinforced fiber tension material that is highly reliable and has improved proof strength at the time of failure.

The above objective is accomplished by a dry hybrid reinforcing fiber tendon according to the present invention. In summary, the present invention is a reinforcing fiber material in which continuous reinforcing fibers are aligned in the longitudinal direction, tensioned without impregnation with resin, and then impregnated with resin,
Uniformly aligning continuous carbon fibers and fibers with higher energy absorption capacity than carbon fibers, producing hybrid reinforced fiber material that is hybridized by arranging in one direction,
Next, the hybrid reinforcing fiber material is pre-tensioned by introducing a tension force of about several percent of the maximum tension force introduced into the reinforcing fiber material, and then partially impregnated with the resin in the tension-introduced state. It is a dry hybrid reinforcing fiber tension material characterized by releasing tension after curing.

  According to an embodiment of the present invention, the fiber having higher energy absorption capacity than the carbon fiber is selected from continuous, PBO (polyparaphenylene benzbisoxazole) fiber, aramid fiber, polyarylate fiber, and high molecular weight polyethylene fiber. One or more types of fibers.

  According to another aspect of the present invention, the hybrid reinforcing fiber material has a resin-impregnated cured region in which resin is impregnated and cured at a plurality of locations along the longitudinal direction.

  According to the dry hybrid reinforcing fiber tension material of the present invention, for example, in a tension bonding method using an unimpregnated carbon fiber material, particularly, it is possible to introduce a greater tension force without impregnation, and at the time of resin impregnation. As a result, there is no kinking or bending of the fibers, the proof stress of the structure at the time of breaking is improved, and the reliability can be improved.

  Hereinafter, the dry hybrid reinforcing fiber tendon according to the present invention will be described in more detail with reference to the drawings.

Example 1
The dry hybrid reinforcing fiber tendon of the present invention has a sheet shape or a rope shape (string shape). Such a dry hybrid reinforcing fiber tension material is suitably used for, for example, a reinforcing fiber material tension bonding method in which continuous reinforcing fibers are aligned in the longitudinal direction, tensioned without impregnation with resin, and then impregnated with resin. .

  The dry hybrid reinforcing fiber tendon of the present invention is at least uniformly aligned with continuous carbon fibers and high energy absorbing fibers having higher energy absorption capacity than carbon fibers, that is, excellent in impact resistance. A hybrid reinforced fiber material arranged in a hybrid is prepared, and then a tension of about several percent of the maximum tension force introduced at the time of the tension adhesive construction method is introduced into this hybrid reinforced fiber material, and a preliminary tension is introduced. Then, the resin is partially impregnated with this preliminary tension introduced, and the resin is cured and then the tension is released.

The ratio of the high energy absorptive fiber in the hybrid reinforcing fiber material is 30% or more with respect to the basis weight of the carbon fiber (unit weight: g / m ² ). When the amount is less than 30%, the intended effect of the present invention, such as improvement of the tension performance of the hybrid reinforcing fiber sheet, cannot be achieved.

  Below, the reinforcing fiber tension material made into the sheet form which is one Example of the dry hybrid reinforcement fiber tension material which concerns on this invention is demonstrated.

  FIG. 1 shows a hybrid reinforcing fiber sheet 1 before introduction of tension and partial resin impregnation for producing a dry hybrid reinforcing fiber tendon. In the present embodiment, the carbon fiber 2A and the high energy absorbing fiber 3A constituting the hybrid reinforcing fiber sheet 1 are the carbon fiber sheet 2 and the high energy absorbing fiber sheet 3, respectively. Is produced by laminating the carbon fiber sheet 2 and the high energy absorbing fiber sheet 3 to form a hybrid.

  In the present embodiment, the high energy absorbing fiber sheet 3 is described as using a PBO fiber sheet, but the present invention is not limited to this as described later.

  In this embodiment, preferably, the carbon fiber sheet 2 forms a surface layer at the time of reinforcement, and the PBO fiber sheet 3 as the high energy absorbing fiber sheet is a lower layer of the carbon fiber sheet 2, that is, a surface to be reinforced of the structure. Construct an inner layer facing the side. In FIG. 1, the carbon fiber sheet 2 and the PBO fiber sheet 3 are each shown as one layer. However, the carbon fiber sheet 2 is not limited to this. For example, the carbon fiber sheet 2 includes one to five layers, PBO. The fiber sheet 3 can be made into 1 layer-5 layers.

The carbon fiber sheet 2 is a reinforcing fiber sheet in which the continuous carbon fibers 2A are uniformly aligned and closely arranged in one direction, and the PBO fiber sheet 3 is a continuous PBO (polyparaphenylene benzbisoxazole). ) A reinforcing fiber sheet in which the fibers 3A are uniformly aligned and closely arranged in one direction. Each of the reinforcing fiber sheets 2 and 3 has a predetermined basis weight (unit weight: g / m ² ), and the length (L) and width (W) of the hybrid reinforcing fiber sheet 1 are concrete to be reinforced. It is determined appropriately according to the size and shape of the structure. Normally, the basis weight of the carbon fiber sheet 2 is a ^{100g / m 2 ~600g / m 2} , the basis weight of PBO fiber sheet 3 can be a ^{100g / m 2 ~1200g / m 2} .

  In this embodiment, the hybrid reinforcing fiber sheet 1 is a hybrid sheet having a carbon fiber sheet 2 and a PBO fiber sheet 3, and therefore, the high energy absorbing fiber sheet 3 is a continuous PBO (polyparaffin). (Phenylene benzbisoxazole) fibers are used, but in addition, aramid fibers, polyarylate fibers, and high molecular weight polyethylene fibers can also be used.

  That is, the high energy absorbing fiber forming the high energy absorbing fiber sheet 3 is one kind selected from PBO fiber, aramid fiber, polyarylate fiber and high molecular weight polyethylene fiber, or a mixture of plural kinds of fibers. Can be used.

  Also, the fiber sheets such as the carbon fiber sheet 2 and the PBO fiber sheet 3 are made of a reinforcing fiber layer in which reinforcing fibers 2A or reinforcing fibers 3A are arranged in one direction as shown in FIG. One side or both sides may be configured to be supported by a mesh-like support sheet 4 made of glass fiber or organic fiber having a diameter of 2 to 50 μm, for example.

  As a method for holding the reinforcing fiber sheet 2 or the reinforcing fiber sheet 3 with the mesh-like support sheet 4, for example, a low melting point type thermoplastic resin on the surface of the warp yarn 6 and the weft yarn 7 constituting the mesh-like support sheet 4. Is impregnated in advance, and the mesh-like support sheet 4 is laminated on one or both sides of the reinforcing fiber layer and heated and pressurized to weld the warp 6 and weft 7 portions of the mesh-like support sheet 4 to the reinforcing fiber layer. .

  Alternatively, as shown in FIG. 3, the reinforcing fibers 2A (or 3A) are separated from the reinforcing fibers 2A (or 3A) perpendicularly to the reinforcing fibers 2A (or 3A) arranged in one direction. It is also possible to drive the fibers 5 as wefts at regular intervals to form a sheet having a structure like a so-called woven fabric (cross). As the fiber 5, glass fiber or organic fiber having a diameter of 2 to 50 μm, for example, can be used in the same manner as described above. The double-structured composite fiber as arranged has a great effect of preventing the fiber bundle from being loosened and is preferably used. Although there is no particular limitation on the weft driving distance (p) in this method, it is usually selected in the range of 1 to 15 mm in consideration of the handleability of the produced sheet.

  A feature of the present invention is that a tension force is introduced into the hybrid reinforcing fiber sheet 1 having the above configuration to perform preliminary tension, and in this state, the resin is partially impregnated, and after the resin is completely cured, the tension force is released. There is.

  Next, a method for introducing tension will be described.

  First, as described with reference to FIGS. 1 to 3, a carbon fiber sheet 2 and a high-energy-absorbing fiber sheet, in this embodiment, a PBO fiber sheet 3 are prepared and laminated to hybrid reinforcing fibers. A sheet 1 is produced.

  As shown in FIG. 4, the carbon fiber sheet 2 and the PBO fiber sheet 3 are aligned to the same length, and if necessary, the longitudinal ends 1a and 1b of the hybrid reinforcing fiber sheet 1 extend over the longitudinal length Lh. The resin R is impregnated and cured to form a holding portion for introducing tension.

  As shown in FIG. 5, the tension device 200 for introducing the tension force includes a steel frame 201 assembled in a rectangular shape as a base, a fixed mounting portion 200 </ b> A including a load cell 203, and a jack 206. The movable attachment part 200B is provided. The hybrid reinforcing fiber sheet 1 is attached between the fixed attachment portion 200A and the movable attachment portion 200B.

  That is, the fixed mounting portion 200 </ b> A disposed on one end side of the steel frame 201 is provided with the steel bolt 202 penetrating, and the load cell 203 is connected to the outer end located outside the frame of the steel bolt 202 by the nut 204. It is attached. A PC steel rod connecting coupler 22 to which a steel plate 21 as a sheet holding portion is welded is connected to an inner end located inside the frame of the steel bolt 202.

  Further, the movable mounting portion 200B disposed on the other end side of the steel frame 201 is provided with a steel bolt 205 passing therethrough, and a center hole jack 206 is a nut at an outer end located outside the frame of the steel bolt 205. It is attached at 207. A PC steel rod connecting coupler 22 attached to a steel plate 21 serving as a sheet holding portion is connected to an inner end located inside the frame of the steel bolt 205.

  One end holding portion 1a of the hybrid reinforcing fiber sheet 1 is sandwiched between the two steel plates 21 of the fixed mounting portion 200A, and is detachably fixed with bolts. Similarly, the other end holding portion 1b is sandwiched between two steel plates 21 of the movable attachment portion 200B and is detachably fixed with bolts.

  In the present embodiment, the tension device 200 configured as described above is used to measure the load with the load cell 203 installed on one end of the hybrid reinforcing fiber sheet 1, and the jack 1 is used to measure the sheet 1 at a speed of, for example, about 5 kN / min. Tension is applied to the hybrid reinforcing fiber sheet 1 with a constant stress. At this time, it is preferable to measure the sheet strain with the wire strain gauge 210 installed at one end side of the hybrid reinforcing fiber sheet 1, in this embodiment, the impregnated end holding portion 1b portion on the movable mounting portion 200B side.

  Moreover, at the time of tension | tensile_strength introduction, it is confirmed whether the carbon fiber sheet 2 and the PBO fiber sheet 3 are arrange | equalized with the same length, and are strained. At this time, if it is confirmed that there is a problem in the lengths of the carbon fiber sheet 2 and the PBO fiber sheet 3, the tension introduction process is stopped.

  The tension force is a tension force of about several percent of the maximum tension force introduced to the hybrid reinforcing fiber sheet 1 at the time of construction of the reinforcing fiber sheet tension bonding method, for example.

  When a predetermined tension force is introduced, the resin is partially impregnated while maintaining this state, and after the resin is completely cured, the tension force introduced to the hybrid reinforcing fiber sheet 1 is released.

  In this way, as will be described in detail later, a dry hybrid reinforcing fiber tension material 1A partially impregnated with resin as shown in FIG. 7 is produced.

  The dry hybrid reinforcing fiber tendon 1A is taken out from the tensioning device 200 by removing both end portions 1a and 1b from the attachment portions 200A and 200B of the tensioning device 200. The tension is released by operating the jack 206 while measuring the load with the load cell 203.

Experimental Example In order to see the effect of the dry hybrid reinforcing fiber tension material 1A of the present invention, first, various test pieces S were prepared with the hybrid reinforcing fiber sheet 1 shown in FIG. 4 and other reinforcing fiber fiber sheets. A tensile test was performed. This tensile test was performed using the tension device 200 described above.

  The test piece S used for the tensile test had the same shape and size as the hybrid reinforcing fiber sheet 1 shown in FIG. That is, the width W of the test piece S was 80 mm, and the end holding portions 1a and 1b were formed by impregnating the resin R only in the both end regions Lh.

  In this tensile test, the end portions 1a and 1b of the test piece S were sandwiched between two steel plates 21 at the fixed mounting portion 200A and the movable mounting portion 200B, respectively, adhered with resin, and fixed with bolts. At this time, the end portions 1a and 1b were impregnated with resin and cured to form holding portions for the attachment portions 200A and 200B of the tensioning device 200. As a result, as shown in FIG. 6, the length L0 of the test piece S between the steel plates 21 and 21 was 2200 mm (resin non-impregnated span length L1 = 2000 mm).

  While measuring the load with the load cell 203 installed at one end of the test piece S with the tension device 200 having the above configuration, the center hole jack 206 tensions the reinforcing fiber sheet 1 at a speed of about 5 kN / min. The sheet strain was measured with a wire strain gauge 210 installed at one end-side impregnated portion.

  The reinforcing fiber sheets of the test pieces (Experimental Examples 1 to 3 and Comparative Examples 1 to 4) shown in Table 1 were produced as follows.

  The test pieces S of Experimental Examples 1 to 3 according to the present invention are hybrid reinforcing fiber sheets 1, and as shown in FIGS. 1 to 4, one layer of carbon fiber sheet 2 and one layer of PBO fiber sheet 3. And laminated. As described above, the width W of the reinforcing fiber sheet was 80 mm, and the end holding portions 1a and 1b were formed by impregnating the resin R only in the both end regions Lh. Therefore, as described above, the length L0 of the hybrid reinforcing fiber sheet 1 between the steel plates 21 and 21 was 2200 mm (resin non-impregnated span length L1 = 2000 mm).

The carbon fiber sheet 2 uses a fiber bundle (strand) obtained by converging 24,000 high-strength and high-elasticity carbon fiber filaments having a tensile strength of 3400 MPa and an elastic modulus of 230 GPa. The carbon fibers 2A were uniformly arranged and closely arranged in one direction. The thickness (t1) of the carbon fiber sheet 2 was 0.111 mm (fiber basis weight 200 g / m ² ).

The PBO fiber sheet 3 uses a fiber bundle in which approximately 2000 monofilaments having a tensile strength of 3500 MPa and an elastic modulus of 235 GPa and a single yarn denier of 1.5 denier are converged, that is, PBO fibers 3A. 3A was uniformly aligned and closely arranged in one direction. The thickness t2 of the PBO fiber sheet 3 was 0.128 mm (fiber basis weight 200 g / m ² ).

  The hybrid reinforcing fiber sheet 1 produced in this manner is attached to the tension device 200, and the load is measured by the load cell 203 installed at one end of the hybrid reinforcing fiber sheet 1, while the jack is used to measure the sheet at a speed of about 5 kN / min. 1 was tensioned and a predetermined tension was introduced into the hybrid reinforcing fiber sheet 1. In addition, it was confirmed that the carbon fiber sheet 2 and the PBO fiber sheet 3 were aligned with the same length and were in tension when the tension was introduced.

  The hybrid reinforcing fiber sheet produced as described above was used as the test piece S of Experimental Examples 1 to 3 according to the present invention.

  For comparison, a reinforcing fiber sheet test piece (Comparative Examples 1 and 2) made only of the PBO fiber sheet 3 and a reinforcing fiber sheet test piece (Comparative Examples 3 and 4) made only of the carbon fiber sheet 2 were prepared. These single PBO fiber sheets and carbon fiber sheets had a width W of 80 mm and a length L0 of 2200 mm (span length of 2000 m).

  As shown in Table 1, it can be seen that the PBO fiber sheets of Comparative Examples 1 and 2 can be tensioned to a design strength of about 90%.

  On the other hand, in the test (Experimental Examples 1 to 3) of the hybrid reinforcing fiber sheet of the carbon fiber sheet 2 and the PBO fiber sheet 3 which is the hybrid reinforcing fiber sheet 1 according to the present invention, the hybrid reinforcing fiber sheet leads to breakage. In the process, as in the case of the reinforcing fiber sheet including only the carbon fiber sheet shown in Comparative Examples 3 and 4, after the weak breaking sound is continuously generated, the breaking sound suddenly increases and a part of the carbon fiber sheet 2 is formed. Fractured, and immediately after that, the carbon fiber sheet 2 was completely broken.

  As shown in Table 1, the tensile stress at this time was improved by about 10 to 20% as compared with the reinforcing fiber sheet of Comparative Examples 3 and 4 containing only carbon fibers.

  In the case of the hybrid reinforcing fiber sheet according to the present invention, the PBO fiber sheet 3 does not break even after the carbon fiber sheet breaks, and there is no minute breaking sound in the process of tension after that, and finally the design of the PBO fiber sheet It broke at around 90% of the strength. From this, it was found that the PBO fiber sheet was not damaged by the carbon fiber sheet breakage.

  In this experimental example, when only the rupture of the carbon fiber sheet 2 preceded, the tensile stress at the time of rupture of the carbon fiber sheet was taken as the rupture strength.

  The dry hybrid reinforcing fiber tendon 1A of the present invention will be described.

  FIG. 7 shows an example of the dry hybrid reinforcing fiber tendon 1A partially impregnated in this example.

  In this embodiment, the hybrid reinforcing fiber sheet 1 before introduction of tension and partial impregnation is the hybrid reinforcing fiber sheet 1 described with reference to FIGS.

  According to the present embodiment, a tension force is introduced into the hybrid reinforcing fiber sheet 1 with a constant stress by the tension device 200.

  Also in the present embodiment, the tension force is a tension force of about several percent of the maximum tension force introduced at the time of construction of the reinforcing fiber sheet tension bonding method with respect to the dry hybrid reinforcing fiber tension material 1A.

  When a predetermined tension is introduced, the resin is partially impregnated in this tension application state. Then, after the resin is completely cured, the introduced preliminary tension is released.

  In this way, as described above, the dry hybrid reinforcing fiber tendon 1A is produced. The both ends 1a and 1b of the dry hybrid reinforcing fiber tendon 1A are removed from the attachment portions 200A and 200B of the tension device 200, and then removed from the tension device 200.

  According to the present embodiment, as shown in FIG. 7, in addition to both end portions 1 a and 1 b of the hybrid reinforcing fiber sheet 1, the length along the longitudinal direction at a plurality of locations along the longitudinal direction of the reinforcing fiber sheet 1. g, and the resin-impregnated cured region R which is impregnated and cured over the entire width W of the reinforcing fiber sheet 1. The resin impregnated cured region length g is usually formed at 30 mm to 500 mm. Of course, this hardening region gap g may be constant or different.

  The interval L1 in the longitudinal direction of the resin impregnated cured region R is usually 400 mm to 2000 mm. If it is smaller than 400 mm, there is a problem that the construction efficiency is poor, and if it is larger than 2000 mm, the effect of partial impregnation is lowered.

  The partial impregnation hardening region width g and the partial impregnation interval L1 are appropriately determined by the length L and the width W of the reinforcing fiber sheet 1 that are appropriately determined according to the size and shape of the concrete structure to be reinforced.

  For example, in the present embodiment, in the partially impregnated hybrid reinforcing fiber sheet 1 used for reinforcing concrete beams, the length L in the longitudinal direction is 10 m and the width W is 300 mm to 500 mm. Good results could be obtained by setting the cured region length g and the partial impregnation interval L1 to 100 mm and 2000 mm, respectively.

  The resin impregnated to form the resin-impregnated cured region R is the same as the matrix resin impregnated in the hybrid reinforcing fiber sheet when the structure reinforcing method using the hybrid reinforcing fiber sheet 1 is performed. Is done. That is, the matrix resin can be a thermosetting resin, and as the thermosetting resin, a room temperature curing type or a thermosetting type epoxy resin, a vinyl ester resin, an MMA resin, an unsaturated polyester resin, or a phenol resin. Can be suitably used. Further, the resin impregnation amount in the resin impregnation hardening region R is 30 to 70% by weight, preferably 40 to 60% by weight.

Experimental Example In order to see the effect of the dry hybrid reinforcing fiber tension material 1A of the present example, test pieces as Experimental Examples 11 to 19 and Comparative Examples 11 to 23 shown below were prepared, and tension was introduced. The relationship between the stress ratio and the partial impregnation interval L1 was examined. The results are shown in Table 2, Table 3, and FIG.

  The configuration of the test piece and tensioning device used was the same as that of the test piece S and tensioning device 200 described in Example 1.

  The dry hybrid reinforcing fiber tendon 1A according to the present example was produced as follows.

  As described above, the hybrid reinforcing fiber sheet 1 for the dry hybrid reinforcing fiber tension material 1A was formed by laminating one layer of carbon fiber sheet 2 and one layer of PBO fiber sheet 3. The width W of the hybrid reinforcing fiber sheet 1, that is, the dry hybrid reinforcing fiber tension material 1A was 80 mm, and the length L0 was 2200 mm.

The carbon fiber sheet 2 uses a fiber bundle (strand) obtained by converging 24,000 high-strength and high-elasticity carbon fiber filaments having a strength of 3400 MPa and an elastic modulus of 230 GPa, that is, the carbon fiber 2A. Were uniformly aligned and closely arranged in one direction. The thickness (t1) of the carbon fiber sheet 2 was 0.111 mm (fiber basis weight 200 g / m ² ).

Further, the PBO fiber sheet 3 uses a fiber bundle in which about 2000 monofilaments having a strength of 3500 MPa and an elastic modulus of 235 GPa and a single yarn denier of 1.5 denier converged, that is, PBO fibers 3A. The fibers 3A were uniformly arranged and closely arranged in one direction. The thickness t2 of the PBO fiber sheet 3 was 0.128 mm (fiber basis weight 200 g / m ² ).

  The thus prepared hybrid reinforcing fiber sheet 1 is attached to the tensioning device 200, and the load 1 is measured with a load cell installed at one end of the hybrid reinforcing fiber sheet 1, while a jack 1 is used at a speed of about 5 kN / min. And a predetermined tension force was introduced into the hybrid reinforcing fiber sheet 1. Then, under the introduction of tension, the resin was partially impregnated, the resin was completely cured, and then the tension was released.

  As shown in FIGS. 9A, 9 </ b> B, 9 </ b> C, and 9 </ b> D, four test pieces were prepared with intervals L <b> 1 of the resin-impregnated cured region R of 400, 600 mm, 850 mm, and 1000 mm. The cured length g of the resin impregnated cured region R was 50 mm.

  The resin impregnation and curing region R uses an epoxy resin, and the resin impregnation amount in the resin impregnation and curing region is 50% by weight.

  The test results of the dry hybrid reinforcing fiber tension material 1A of this example are shown in Table 2 as Experimental Examples 11 to 19, and are indicated by “x” on FIG.

  As a comparative example, a partially impregnated reinforcing fiber sheet consisting of only one layer of the carbon fiber sheet 2 was used. In Table 3, it shows as Comparative Examples 11-21, and the test result is shown by "□" on FIG. Further, as a comparative example, two layers of partially impregnated reinforcing fiber sheets made of only the carbon fiber sheet 2 of this example were used. In Table 3, it shows as Comparative Examples 22 and 23, and the test result is shown by "(circle)" on FIG.

  Moreover, in FIG. 8, as a comparative example, a partially impregnated reinforcing fiber sheet made of only the PBO fiber sheet 3 similar to that shown in Comparative Examples 1 and 2 of Table 1 is used and partially impregnated at an interval L1 = 1000 mm. The test results are indicated by “Δ”.

  From FIG. 8, according to the present Example, when the partial impregnation interval L1 is 400 mm to 1000 mm, the tensile stress ratio at break is that of Comparative Examples 11 to 23 (tensile stress ratio 33 to 49%) which is only a carbon fiber sheet. More than 10% higher than the case, the hybrid effect can be seen.

  In addition, as understood from comparison between Comparative Examples 11 to 21 and Comparative Examples 22 and 23, the results are unchanged even when the number of layers of the carbon fiber sheet 2 is increased from one layer to two layers. , There was no effect.

  FIGS. 10 to 13 show the strain (tensile strain) measured by the strain gauges 210 installed in the carbon fiber sheet 2 and the PBO fiber sheet 3 as shown in FIGS. 9 (a) to 9 (d). The relationship between average value and tensile stress is shown.

  As shown in FIG. 13, in the case of Experimental Examples 1 to 3 in Table 1 where the hybrid sheet 1 having the partial impregnation interval L1 of 2000 mm, that is, the span length L1 = 2000 mm described in Example 1 was used without partial impregnation. As described above, the carbon fiber sheet 2 was completely broken early at the same tensile stress ratio as in the unit test (Comparative Examples 11 to 23), and at the same time, a decrease in tensile stress and tensile strain was observed. After that, it became the same as the tensile test (Comparative Examples 1 and 2) with the PBO fiber sheet alone.

  As shown in FIG. 12, when the partial impregnation interval was 1000 mm, the carbon fiber sheet 2 was broken into three portions for each portion, and the decrease in tensile stress and tensile strain was reduced to about 24% of the 2000 mm interval.

  As shown in FIG. 10 and FIG. 11, when the partial impregnation interval is 400 mm and 850 mm, the tensile stress does not decrease, and the phenomenon of the tensile strain accompanying the rapid elongation associated with the microfracture of the carbon fiber sheet 2 only occurs finely. Met.

  From the above test results, it was found that the hybrid effect was particularly significant when partially impregnated within an interval of 1000 mm, and could be stably tensioned to a tensile stress ratio of about 60% within 850 mm.

Example 2
Another embodiment of the dry hybrid reinforcing fiber tendon of the present invention will be described.

  FIG. 14 shows the hybrid reinforcing fiber sheet 1 of this example before the introduction of pretension and the impregnation of the resin part. In this example, the hybrid reinforcing fiber sheet 1 is uniformly aligned with at least continuous carbon fibers 2A and, for example, continuous PBO (polyparaphenylene benzbisoxazole) fibers 3A as high energy absorbing fibers, They are closely arranged in one direction. PBO (polyparaphenylene benzbisoxazole) fiber 3A is preferably mixed uniformly in carbon fiber 2A.

The ratio of the high energy absorbing fibers 3A in the hybrid reinforcing fiber sheet 1 is 30% or more with respect to the basis weight (unit weight: g / m ² ) of the carbon fibers 2A. If it is less than 30%, the intended effect of the present invention, such as an improvement in the tension performance of the hybrid reinforcing fiber sheet, cannot be achieved.

Normally, the basis weight of the carbon fibers 2A is a ^{100g / m 2 ~600g / m 2} , the basis weight of PBO fibers 3A may be ^{100g / m 2 ~1200g / m 2} .

  In this embodiment, the hybrid reinforcing fiber sheet 1 is a hybrid sheet having carbon fibers 2A and PBO fibers 3A. However, as high energy absorbing fibers, aramid fibers, poly Arylate fibers and high molecular weight polyethylene fibers can also be used. Moreover, as a high energy absorptive fiber, although these PBO fiber, an aramid fiber, a polyarylate fiber, and high molecular weight polyethylene fiber can also be used independently, multiple types can also be mixed and produced.

  Also in this example, in order to facilitate the handling of the hybrid reinforcing fiber sheet 1, as shown in FIG. 2, one side or both sides of the reinforcing fiber layer including the reinforcing fiber 2A and the reinforcing fiber 3A are provided with, for example, a diameter of 2 It can be set as the structure supported by the method similar to having demonstrated in Example 1 with the mesh-shaped support body sheet | seat 4 produced with -50 micrometer glass fiber or organic fiber.

  Of course, as another method, as described in Example 1, as shown in FIG. 3, the reinforcing fibers 2A, orthogonal to the reinforcing fibers 2A and 3A arranged in one direction of the reinforcing fiber sheet 1, It is also possible to drive the fibers 5 as weft yarns at a constant interval as a 3A loosening stop to form a sheet having a structure like a so-called woven fabric (cross).

  The characteristics of the present invention are the same as in Example 1, the hybrid reinforcing fiber sheet 1 having the above-described configuration is strained by introducing a tension, partially impregnated with resin under this tension, and cured. It is to release tension.

  The dry hybrid reinforcing fiber tendon of the present embodiment can also achieve the same effect as the dry hybrid reinforcing fiber tendon described in the first embodiment.

  FIG. 15 shows another embodiment of a dry hybrid reinforcing fiber tendon 1A constructed according to the present invention.

  Also in this example, as described in Example 1, as shown in FIG. 15, at a plurality of locations along the longitudinal direction of the hybrid reinforcing fiber sheet 1, the length g along the longitudinal direction, The resin is impregnated over the entire width W of the reinforcing fiber sheet 1 and has a cured resin-impregnated cured region R.

  The partial impregnation hardening region width g and the partial impregnation interval L1 are appropriately determined by the length L0 and the width W of the reinforcing fiber sheet 1 that are appropriately determined according to the size and shape of the concrete structure to be reinforced.

  The resin impregnated to form the resin impregnated cured region R is the same as the matrix resin impregnated in the reinforcing fiber sheet 1 when the reinforcing method of the present invention is performed. That is, the matrix resin can be a thermosetting resin, and as the thermosetting resin, a room temperature curing type or a thermosetting type epoxy resin, a vinyl ester resin, an MMA resin, an unsaturated polyester resin, or a phenol resin. Can be suitably used. Further, the resin impregnation amount in the resin impregnation hardening region R is 30 to 70% by weight, preferably 40 to 60% by weight.

  According to the present embodiment, as in the case of the first embodiment, a tension force is introduced with a constant stress to the hybrid reinforcing fiber sheet 1 having the above-described configuration. The resin is partially impregnated, and after the resin is completely cured, the tension is released.

  The dry hybrid reinforcing fiber tendon 1A of the present embodiment can also achieve the same effects as the dry hybrid reinforcing fiber tendon 1A described in the first embodiment.

  For example, the dry hybrid reinforcing fiber tendon 1A described in Examples 1 and 2 described above is effective by applying the structure to a reinforced surface of a structure such as a concrete structure or a steel structure under tension. It can be effectively used as a reinforcing material for reinforcement.

  In the above embodiment, the dry hybrid reinforcing fiber tendon of the present invention has been described as having a sheet shape. However, the dry hybrid reinforcing fiber tendon of the present embodiment can also be formed in a rope shape (string shape). The same effect as 1A can be produced.

It is a perspective view which shows one Example of the hybrid reinforcement fiber sheet for producing the dry hybrid reinforcement fiber tension material which concerns on this invention. It is a perspective view which shows one Example of the hybrid reinforcement fiber sheet for producing the dry hybrid reinforcement fiber tension material which concerns on this invention. It is a perspective view which shows the other Example of the hybrid reinforcement fiber sheet for producing the dry hybrid reinforcement fiber tension material which concerns on this invention. It is a perspective view which shows one Example of the hybrid reinforcement fiber sheet before resin is impregnated at both ends, and before tension introduction and partial resin impregnation. It is a figure which shows the tension | tensile_strength apparatus for introducing tension | tensile_strength into a hybrid reinforced fiber sheet, and the hybrid reinforced fiber sheet attached to the tension | tensile_strength apparatus. It is a figure which shows the tension | tensile_strength apparatus for investigating the tensile stress and tensile stress ratio of a dry hybrid reinforcement fiber tension material, and the test piece attached to the tension apparatus. It is a perspective view which shows one Example of the dry hybrid reinforcement fiber tension material which concerns on this invention. It is a figure which shows the relationship between the tensile stress ratio of a dry hybrid reinforcement fiber tension material, and a partial impregnation space | interval. It is a figure which shows various embodiment of the dry hybrid reinforcement fiber tension material which concerns on this invention. It is a figure which shows the relationship between the tensile stress and the tensile strain in the dry hybrid reinforcement fiber tension material which concerns on this invention. It is a figure which shows the relationship between the tensile stress and the tensile strain in the dry hybrid reinforcement fiber tension material which concerns on this invention. It is a figure which shows the relationship between the tensile stress and the tensile strain in the dry hybrid reinforcement fiber tension material which concerns on this invention. It is a figure which shows the relationship between the tensile stress and the tensile strain in the dry hybrid reinforcement fiber tension material which concerns on this invention. It is a perspective view which shows the other Example of the hybrid reinforcement fiber sheet for producing the dry hybrid reinforcement fiber tension material which concerns on this invention. It is a perspective view which shows the other Example of the dry hybrid reinforcing fiber tendon which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hybrid reinforcement fiber sheet 1A Dry hybrid reinforcement fiber tension material 2 Carbon fiber sheet 2A Carbon fiber 3 PBO fiber sheet (high energy absorption fiber sheet)
3A PBO fiber (high energy absorption fiber)
4 Support 5 Detachable Fiber 200 Tensioner

Claims (3)

It is a reinforcing fiber material in which continuous reinforcing fibers are aligned in the longitudinal direction, tensioned without impregnation with resin, and then impregnated with resin,
Uniformly aligning continuous carbon fibers and fibers with higher energy absorption capacity than carbon fibers, producing hybrid reinforced fiber material that is hybridized by arranging in one direction,
Next, the hybrid reinforcing fiber material is pre-tensioned by introducing a tension force of about several percent of the maximum tension force introduced into the reinforcing fiber material, and then partially impregnated with the resin in the tension-introduced state. A dry hybrid reinforced fiber tension material characterized by releasing tension after curing.   The fiber having higher energy absorption capacity than the carbon fiber is one or more kinds of fibers selected from continuous PBO (polyparaphenylene benzbisoxazole) fiber, aramid fiber, polyarylate fiber and high molecular weight polyethylene fiber. The dry hybrid reinforcing fiber tendon according to claim 1.   3. The dry hybrid reinforcing fiber tension material according to claim 1, wherein the hybrid reinforcing fiber material has a resin impregnated cured region in which a resin is impregnated and cured at a plurality of locations along a longitudinal direction thereof.

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