CN110702516A

CN110702516A - Direct tensile test device for FRP (fiber reinforced Plastic) reinforcement concrete member and use method

Info

Publication number: CN110702516A
Application number: CN201910991065.XA
Authority: CN
Inventors: 郑愚; 李皓天; 张黎飞; 夏立鹏; 李明
Original assignee: Dongguan University of Technology
Current assignee: Dongguan University of Technology
Priority date: 2019-10-18
Filing date: 2019-10-18
Publication date: 2020-01-17
Anticipated expiration: 2039-10-18
Also published as: CN110702516B

Abstract

The invention discloses a direct tensile test device and a use method of an FRP (fiber reinforced Plastic) bar concrete member, wherein the test device comprises the FRP bar concrete member and a fixed machine platform, and the FRP bar concrete member comprises an FRP bar, a concrete part, a front end steel pipe, a rear end steel pipe, a patch, I-shaped steel, light steel wires, a front end clamp, a rear end clamp, a first LVDT (linear variable differential transformer) displacement sensor, a second LVDT displacement sensor and a third LVDT displacement sensor; the fixing machine table comprises a horizontal table base and a counterforce wall, wherein a test piece bearing and placing support is arranged at the upper end part of the horizontal table base, and a rolling shaft assembly is arranged on a support placing surface of the test piece bearing and placing support; the front end side of the test piece bearing support is provided with an actuator, and the rear end of the loading end of the actuator is hinged with a seat and is provided with a front end clamping piece anchorage device; the reverse-force support at the rear end side of the test piece bearing support is provided with a rear-end clamping piece anchorage device. The test device can effectively perform direct tensile test on the FRP reinforcement concrete member. The use method can effectively use the test device.

Description

Direct tensile test device for FRP (fiber reinforced Plastic) reinforcement concrete member and use method

Technical Field

The invention relates to the technical field of civil engineering, in particular to a direct tensile test device for an FRP reinforcement concrete member and a using method thereof.

Background

Since the reinforced concrete has been widely used in the civil engineering field, the problem of corrosion of the reinforcing steel has been a serious safety and economic problem, especially in corrosive environments. In recent years, Fiber Reinforced Polymers (FRP) have been widely used in the engineering industry because of their advantages such as light weight, high strength, and corrosion resistance.

It should be pointed out that, the FRP reinforcement material as a reinforcing material to replace the steel bar in the concrete is a solution with a wide prospect. The FRP reinforcement has higher strength and lower elastic modulus than the steel bar, so that the deflection and the crack width of the structure under the normal use load action become the control standards in the design; therefore, the contribution of concrete in the tension zone becomes an important factor in determining the deflection and crack width. Although concrete is prone to cracking in tension, tests have shown that it still provides additional stiffness to the overall performance of the structure after cracking, a phenomenon known as the "tensile stiffening effect" which contributes significantly to the overall structural performance. The tensile rigidization effect has great significance for accurately predicting the deflection and the crack width of the member under the condition of lower load.

Compared with an FRP (fiber reinforced plastic) reinforced concrete member, the 'tensile rigidization effect' of reinforced concrete is well researched in the design and analysis of structural performance, and in order to introduce the influence of the 'tensile rigidization effect' in the deflection calculation of a bent member, the reinforced concrete member specification ACI318-05 adopts a method that the section rigidity of the reinforced concrete is gradually reduced from an uncracked state to a cracked state. At present, several design suggestions and principles are designed for FRP reinforcement concrete members, wherein the ACI equations based on ACI318-05 are the most authoritative set of suggestions at present, but the prediction of the service capability limit state performance of the FRP reinforcement concrete members by the equations is unsafe. Other specifications of FRP reinforced concrete member design principles including JSCE (1997), ISIS (2001) and ACI (2003) (ACI 440.1R-03) and the like also underestimate the deflection of the member under the use load, especially under the low reinforcement ratio. In addition, different researchers have different treatments for the effective moment of inertia of the partial fracture section in the equation, and no consensus is made on how to explain the stretching rigidifying effect. Therefore, the conventional reinforced concrete structure has the following problems:

1. the traditional reinforced concrete structure is widely applied, but the corrosion of the steel bar is a serious safety and economic problem;

2. the Fiber Reinforced Polymer (FRP) is a novel material, has the characteristics of high strength and low elastic modulus, and has larger performance difference compared with the reinforcing steel bar;

3. the FRP reinforcement material is used as a reinforcing reinforcement material to work together with concrete, the analysis method is different from that of a reinforced concrete member, and the deflection and the crack width of the FRP reinforcement material become control factors;

4. the existing standard underestimates the deflection of the FRP reinforcement concrete member under the use load;

5. the phenomenon that the concrete in the tension zone provides additional rigidity after cracking is called the 'tension stiffening effect', and the analysis of the 'tension stiffening effect' by different researchers has not reached consensus;

6. no researchers are engaged in relevant research in China, and the existing device cannot be used for the test research of the tensile and rigidifying performance of reinforced bar concrete at present.

Disclosure of Invention

The invention aims to provide a direct tensile test device for an FRP rib concrete member, aiming at the defects of the prior art, the direct tensile test device for the FRP rib concrete member has novel structural design, can effectively perform direct tensile test on the FRP rib concrete member, and can be effectively applied to the test research on the tensile and rigidifying performance of reinforced rib concrete.

Another object of the present invention is to provide a method for using a direct tensile test apparatus for an FRP reinforced concrete member, which can effectively perform a direct tensile test of the FRP reinforced concrete member using the direct tensile test apparatus for the FRP reinforced concrete member, that is, can be effectively applied to a test study of a tensile and rigidifying performance of reinforced concrete members.

In order to achieve the above object, the present invention is achieved by the following technical solutions.

A direct tensile test device for an FRP reinforcement concrete member comprises the FRP reinforcement concrete member, wherein the FRP reinforcement concrete member comprises an FRP reinforcement and a concrete part which is poured on the periphery of the FRP reinforcement and forms an integrated structure with the FRP reinforcement, the FRP reinforcement is positioned at the core part of the concrete part and extends along the length direction of the concrete part, the front end part of the FRP reinforcement extends forwards to the front end side of the front end surface of the concrete part, and the rear end part of the FRP reinforcement extends backwards to the rear end side of the rear end surface of the concrete part; a front steel pipe is sleeved on the periphery of the front end part of the FRP rib material, and an expansion cement layer formed by filling expansion cement is arranged between the inner wall of the front steel pipe and the front end part of the FRP rib material; a rear-end steel pipe is sleeved on the periphery of the rear end part of the FRP rib material, and an expansion cement layer formed by filling expansion cement is also arranged between the inner wall of the rear-end steel pipe and the rear end part of the FRP rib material;

the direct tensile test device for the FRP rib concrete member further comprises a fixed machine table, wherein the fixed machine table comprises a horizontal table seat which is horizontally and transversely arranged, a reaction wall which is vertically arranged and the upper end of which extends to the upper end side of the horizontal table seat is arranged at the front end of the horizontal table seat, a test piece bearing and placing support is arranged at the upper end of the horizontal table seat, the upper surface of the test piece bearing and placing support is a support placing surface which is in a horizontal plane shape, a rolling shaft assembly is placed on the support placing surface, the FRP rib concrete member is horizontally placed on the upper end side of the test piece bearing and placing support through the rolling shaft assembly;

the front end side of the test piece bearing support is provided with an actuator, the reaction wall is tightly screwed with a front end hinge seat corresponding to the actuator, and the fixed end of the actuator is hinged with the front end hinge seat; the loading end of the actuator is hinged with a rear end hinged seat, the rear end hinged seat is provided with a front end clamping piece anchorage device, and the front end clamping piece anchorage device anchors a front end steel pipe of the FRP reinforcement concrete member; the rear end side of the test piece bearing support is provided with a counter-force support, the counter-force support is screwed and fastened at the upper end part of the horizontal platform seat, the counter-force support is screwed and fastened with an inherent anchorage device mounting frame, the anchorage device mounting frame is provided with a rear end clamping piece anchorage device, and the rear end clamping piece anchorage device anchors a rear end steel pipe of the FRP rib material concrete component;

for the FRP reinforcement concrete member, four iron sheets which are uniformly distributed in a circumferential annular shape at intervals are fixedly bonded on the front end face of the concrete part through epoxy resin adhesives, I-shaped steel is fixedly bonded on the edge part of the rear end of the concrete part corresponding to each iron sheet through the epoxy resin adhesives respectively, each I-shaped steel is arranged in front and back alignment with the corresponding iron sheet respectively, each I-shaped steel is provided with a first LVDT displacement sensor in a threaded manner respectively, light steel wires horizontally extending along the front and back directions are arranged between each I-shaped steel and the corresponding iron sheet respectively, the front end parts of the light steel wires are fixedly connected with the corresponding iron sheets respectively, and the rear end parts of the light steel wires are connected with the measuring ends of the corresponding first LVDT displacement sensors respectively; the front end part of the FRP reinforcement is fastened with a front end clamp between a front end steel pipe and the front end face of the concrete part, the rear end part of the FRP reinforcement is fastened with a rear end clamp between a rear end steel pipe and the rear end face of the concrete part, the front end clamp is provided with three second LVDT displacement sensors which are distributed in a circumferential annular uniform interval manner, the rear end clamp is provided with three third LVDT displacement sensors which are distributed in a circumferential annular uniform interval manner, the measuring end of each second LVDT displacement sensor is respectively in contact with the front end face of the concrete part, and the measuring end of each third LVDT displacement sensor is respectively in contact with the rear end face of the concrete part.

The roller component comprises roller groups which are sequentially arranged from front to back in an interval and aligned mode, and each roller group comprises two rollers which are right and left and are arranged at intervals.

The upper end side of the actuator is provided with a traction support, the upper end part of the traction support is connected with the reaction wall, and the lower end part of the traction support is connected with the shell of the actuator.

The reaction support comprises a front end reaction support and a rear end reaction support located on the rear end side of the front end reaction support, the front end reaction support and the rear end reaction support are arranged at intervals, the front end reaction support and the rear end reaction support are respectively screwed and fastened at the upper end of the horizontal platform seat, the anchor mounting frame is screwed on the front end reaction support, a jack which is horizontally and transversely arranged is installed between the front end reaction support and the rear end reaction support, the front end of the jack is connected with the front end reaction support, and the rear end of the jack is connected with the rear end reaction support.

The front end clamp comprises a front end steel sleeve in a circular ring shape, the front end steel sleeve is sleeved at the front end part of the FRP rib material and is positioned between the front end surface of the front end steel pipe and the front end surface of the concrete part, a threaded hole which completely penetrates in the radial direction is formed in the outer circumferential surface of the front end steel sleeve, a front end fastening screw is screwed in the threaded hole of the front end steel sleeve, and the front end fastening screw tightly presses the front end part of the FRP rib material;

the rear end clamp comprises a rear end steel sleeve in a circular ring shape, the rear end steel sleeve is sleeved at the rear end part of the FRP rib material and is located between the rear end steel pipe and the rear end surface of the concrete part, a threaded hole which completely penetrates in the radial direction is formed in the outer circumferential surface of the rear end steel sleeve, a rear end fastening screw is arranged in the threaded hole in a threaded manner, the rear end fastening screw is screwed in the threaded hole of the rear end steel sleeve, and the rear end fastening screw tightly presses the rear end part of the FRP rib material.

The use method of the direct tensile test device for the FRP reinforcement concrete member comprises the following steps:

a. manufacturing an FRP reinforcement concrete member: placing the FRP reinforcement material in a forming mould, then pouring concrete into the forming mould, and forming an FRP reinforcement material concrete member after the concrete is solidified, wherein the FRP reinforcement material concrete member comprises the FRP reinforcement material and a concrete part which is poured on the periphery of the FRP reinforcement material by the concrete and forms an integral structure with the FRP reinforcement material; the FRP reinforcement is positioned in the core part of the concrete part and extends along the length direction of the concrete part, the front end part of the FRP reinforcement extends forwards to the front end side of the front end surface of the concrete part, and the rear end part of the FRP reinforcement extends backwards to the rear end side of the rear end surface of the concrete part;

b. sleeving a front steel pipe on the periphery of the front end part of the FRP reinforcement material, and filling expansion cement in a gap between the inner wall of the front steel pipe and the front end part of the FRP reinforcement material to form an expansion cement layer between the inner wall of the front steel pipe and the front end part of the FRP reinforcement material;

c. sleeving a rear-end steel pipe on the periphery of the rear end part of the FRP reinforcement material, and filling expansion cement in a gap between the inner wall of the rear-end steel pipe and the rear end part of the FRP reinforcement material to form an expansion cement layer between the inner wall of the rear-end steel pipe and the rear end part of the FRP reinforcement material;

d. the front end face of the concrete part is bonded and fixed with four iron sheets through an epoxy resin adhesive, the four iron sheets are uniformly distributed at intervals in a circumferential ring shape, the edge part of the rear end of the concrete part corresponds to each iron sheet and is bonded and fixed with I-shaped steel through the epoxy resin adhesive, each I-shaped steel is arranged with the corresponding iron sheet in a front-back alignment mode, each I-shaped steel is respectively screwed with a first LVDT displacement sensor, light steel wires horizontally extending along the front-back direction are respectively installed between each I-shaped steel and the corresponding iron sheet, the front end parts of the light steel wires are respectively fastened and connected with the corresponding iron sheets, and the rear end parts of the light steel wires are respectively connected with the measuring ends of the corresponding first DT LVDT displacement sensors;

e. a front end clamp is tightly installed at the front end part of the FRP reinforcement material and is positioned between the front end steel pipe and the front end surface of the concrete part; after the front-end clamp is fastened, screwing three second LVDT displacement sensors on the front-end clamp, wherein the three second LVDT displacement sensors are uniformly distributed at intervals in a circumferential annular shape, and the measuring ends of the second LVDT displacement sensors are respectively in contact with the front end face of the concrete part;

f. a rear end clamp is tightly installed at the rear end part of the FRP rib material, and the rear end clamp is positioned between the rear end steel pipe and the rear end face of the concrete part; after the rear-end clamp is fastened, three third LVDT displacement sensors are screwed on the rear-end clamp and uniformly distributed in a circumferential annular shape at intervals, and the measuring end of each third LVDT displacement sensor is in contact with the rear end face of the concrete part;

g. placing a plurality of rollers on a support placing surface of a test piece bearing support, wherein two rollers form a roller group, the two rollers of the same roller group are right and left opposite and are arranged at intervals, and the roller groups are sequentially arranged at intervals and in alignment from front to back;

h. the FRP reinforcement concrete member is stably placed on the rollers, and the light steel wire at the lowest position penetrates through a gap between two rollers of the same roller group;

i. anchoring the front end clamping piece anchorage device to the front end steel pipe and anchoring the rear end clamping piece anchorage device to the rear end steel pipe;

j. respectively connecting each first LVDT displacement sensor, each second LVDT displacement sensor and each third LVDT displacement sensor with a computer;

k. the starting actuator loads the FRP reinforcement, and the first LVDT displacement sensor, the second LVDT displacement sensor and the third LVDT displacement sensor respectively send the acquired displacement data to the computer.

The invention has the beneficial effects that: the invention relates to a direct tensile test device for an FRP (fiber reinforced Plastic) bar concrete member, which comprises the FRP bar concrete member, wherein the FRP bar concrete member comprises an FRP bar and a concrete part which is poured on the periphery of the FRP bar and forms an integrated structure with the FRP bar, the FRP bar is positioned in the core part of the concrete part, the FRP bar extends along the length direction of the concrete part, the front end part of the FRP bar extends forwards to the front end side of the front end surface of the concrete part, and the rear end part of the FRP bar extends backwards to the rear end side of the rear end surface of the concrete part; a front steel pipe is sleeved on the periphery of the front end part of the FRP rib material, and an expansion cement layer formed by filling expansion cement is arranged between the inner wall of the front steel pipe and the front end part of the FRP rib material; a rear-end steel pipe is sleeved on the periphery of the rear end part of the FRP rib material, and an expansion cement layer formed by filling expansion cement is also arranged between the inner wall of the rear-end steel pipe and the rear end part of the FRP rib material; the direct tensile test device for the FRP rib concrete member further comprises a fixed machine table, wherein the fixed machine table comprises a horizontal table seat which is horizontally and transversely arranged, a reaction wall which is vertically arranged and the upper end of which extends to the upper end side of the horizontal table seat is arranged at the front end of the horizontal table seat, a test piece bearing and placing support is arranged at the upper end of the horizontal table seat, the upper surface of the test piece bearing and placing support is a support placing surface which is in a horizontal plane shape, a rolling shaft assembly is placed on the support placing surface, the FRP rib concrete member is horizontally placed on the upper end side of the test piece bearing and placing support through the rolling shaft assembly; the front end side of the test piece bearing support is provided with an actuator, the reaction wall is tightly screwed with a front end hinge seat corresponding to the actuator, and the fixed end of the actuator is hinged with the front end hinge seat; the loading end of the actuator is hinged with a rear end hinged seat, the rear end hinged seat is provided with a front end clamping piece anchorage device, and the front end clamping piece anchorage device anchors a front end steel pipe of the FRP reinforcement concrete member; the rear end side of the test piece bearing support is provided with a counter-force support, the counter-force support is screwed and fastened at the upper end part of the horizontal platform seat, the counter-force support is screwed and fastened with an inherent anchorage device mounting frame, the anchorage device mounting frame is provided with a rear end clamping piece anchorage device, and the rear end clamping piece anchorage device anchors a rear end steel pipe of the FRP rib material concrete component; for the FRP reinforcement concrete member, four iron sheets which are uniformly distributed in a circumferential annular shape at intervals are fixedly bonded on the front end face of the concrete part through epoxy resin adhesives, I-shaped steel is fixedly bonded on the edge part of the rear end of the concrete part corresponding to each iron sheet through the epoxy resin adhesives respectively, each I-shaped steel is arranged in front and back alignment with the corresponding iron sheet respectively, each I-shaped steel is provided with a first LVDT displacement sensor in a threaded manner respectively, light steel wires horizontally extending along the front and back directions are arranged between each I-shaped steel and the corresponding iron sheet respectively, the front end parts of the light steel wires are fixedly connected with the corresponding iron sheets respectively, and the rear end parts of the light steel wires are connected with the measuring ends of the corresponding first LVDT displacement sensors respectively; the front end part of the FRP reinforcement is fastened with a front end clamp between a front end steel pipe and the front end face of the concrete part, the rear end part of the FRP reinforcement is fastened with a rear end clamp between a rear end steel pipe and the rear end face of the concrete part, the front end clamp is provided with three second LVDT displacement sensors which are distributed in a circumferential annular uniform interval manner, the rear end clamp is provided with three third LVDT displacement sensors which are distributed in a circumferential annular uniform interval manner, the measuring end of each second LVDT displacement sensor is respectively in contact with the front end face of the concrete part, and the measuring end of each third LVDT displacement sensor is respectively in contact with the rear end face of the concrete part. Through the structural design, the test device has the advantage of novel structural design, can effectively perform direct tensile test on the FRP reinforcement concrete member, and can be effectively suitable for the tensile rigidification performance test research of the reinforced reinforcement concrete.

The invention has the following beneficial effects: the invention relates to a use method of a direct tensile test device for an FRP reinforcement concrete member, which comprises the following steps: a. manufacturing an FRP reinforcement concrete member: placing the FRP reinforcement material in a forming mould, then pouring concrete into the forming mould, and forming an FRP reinforcement material concrete member after the concrete is solidified, wherein the FRP reinforcement material concrete member comprises the FRP reinforcement material and a concrete part which is poured on the periphery of the FRP reinforcement material by the concrete and forms an integral structure with the FRP reinforcement material; the FRP reinforcement is positioned in the core part of the concrete part and extends along the length direction of the concrete part, the front end part of the FRP reinforcement extends forwards to the front end side of the front end surface of the concrete part, and the rear end part of the FRP reinforcement extends backwards to the rear end side of the rear end surface of the concrete part; b. sleeving a front steel pipe on the periphery of the front end part of the FRP reinforcement material, and filling expansion cement in a gap between the inner wall of the front steel pipe and the front end part of the FRP reinforcement material to form an expansion cement layer between the inner wall of the front steel pipe and the front end part of the FRP reinforcement material; c. sleeving a rear-end steel pipe on the periphery of the rear end part of the FRP reinforcement material, and filling expansion cement in a gap between the inner wall of the rear-end steel pipe and the rear end part of the FRP reinforcement material to form an expansion cement layer between the inner wall of the rear-end steel pipe and the rear end part of the FRP reinforcement material; d. the front end face of the concrete part is bonded and fixed with four iron sheets through an epoxy resin adhesive, the four iron sheets are uniformly distributed at intervals in a circumferential ring shape, the edge part of the rear end of the concrete part corresponds to each iron sheet and is bonded and fixed with I-shaped steel through the epoxy resin adhesive, each I-shaped steel is arranged with the corresponding iron sheet in a front-back alignment mode, each I-shaped steel is respectively screwed with a first LVDT displacement sensor, light steel wires horizontally extending along the front-back direction are respectively installed between each I-shaped steel and the corresponding iron sheet, the front end parts of the light steel wires are respectively fastened and connected with the corresponding iron sheets, and the rear end parts of the light steel wires are respectively connected with the measuring ends of the corresponding first DT LVDT displacement sensors; e. a front end clamp is tightly installed at the front end part of the FRP reinforcement material and is positioned between the front end steel pipe and the front end surface of the concrete part; after the front-end clamp is fastened, screwing three second LVDT displacement sensors on the front-end clamp, wherein the three second LVDT displacement sensors are uniformly distributed at intervals in a circumferential annular shape, and the measuring ends of the second LVDT displacement sensors are respectively in contact with the front end face of the concrete part; f. a rear end clamp is tightly installed at the rear end part of the FRP rib material, and the rear end clamp is positioned between the rear end steel pipe and the rear end face of the concrete part; after the rear-end clamp is fastened, three third LVDT displacement sensors are screwed on the rear-end clamp and uniformly distributed in a circumferential annular shape at intervals, and the measuring end of each third LVDT displacement sensor is in contact with the rear end face of the concrete part; g. placing a plurality of rollers on a support placing surface of a test piece bearing support, wherein two rollers form a roller group, the two rollers of the same roller group are right and left opposite and are arranged at intervals, and the roller groups are sequentially arranged at intervals and in alignment from front to back; h. the FRP reinforcement concrete member is stably placed on the rollers, and the light steel wire at the lowest position penetrates through a gap between two rollers of the same roller group; i. anchoring the front end clamping piece anchorage device to the front end steel pipe and anchoring the rear end clamping piece anchorage device to the rear end steel pipe; j. respectively connecting each first LVDT displacement sensor, each second LVDT displacement sensor and each third LVDT displacement sensor with a computer; k. the starting actuator loads the FRP reinforcement, and the first LVDT displacement sensor, the second LVDT displacement sensor and the third LVDT displacement sensor respectively send the acquired displacement data to the computer. Through the design of the steps, the use method can effectively utilize the direct tensile test device of the FRP reinforcement concrete member to carry out the direct tensile test of the FRP reinforcement concrete member, and can be effectively suitable for the tensile and rigidifying performance test research of the reinforced reinforcement concrete member.

Drawings

The invention will be further described with reference to the drawings to which, however, the embodiments shown in the drawings do not constitute any limitation.

Fig. 1 is a schematic structural view of an FRP reinforcement concrete member of the present invention.

Fig. 2 is a schematic structural view of another view of the FRP reinforcement concrete member of the present invention.

Fig. 3 is a schematic structural diagram of the present invention.

FIG. 4 is a schematic view of another embodiment of the present invention.

FIG. 5 is a schematic view of another embodiment of the present invention.

Fig. 1 to 5 include:

1-FRP reinforcement concrete member 11-FRP reinforcement

12-concrete part 131-front end steel pipe

132-rear end steel pipe 141-iron sheet

142-I-steel 143-light steel wire

15-front end clamp 151-front end steel sleeve

152-front end fastening screw 16-rear end clamp

161 rear end steel sleeve 162 rear end fastening screw

171-first LVDT displacement sensor 172-second LVDT displacement sensor

173-third LVDT displacement sensor 2-fixed machine

21-horizontal platform base 22-counterforce wall

3-test piece bearing support 31-support placing surface

4-roller Assembly 41-roller

51-actuator 52-front end hinged seat

61 front end clip anchor 62 rear end clip anchor

71-reaction force support 711-front end reaction force support

712-rear reaction force support 713-jack

72-anchor mounting rack 8-traction support

And 9, hinging the rear end to the base.

Detailed Description

The present invention will be described below with reference to specific embodiments.

As shown in fig. 1 to 5, a direct tensile test apparatus for an FRP reinforcement concrete member includes an FRP reinforcement concrete member 1, the FRP reinforcement concrete member 1 includes an FRP reinforcement 11, a concrete portion 12 formed by pouring concrete around the FRP reinforcement 11 and forming an integral structure with the FRP reinforcement 11, the FRP reinforcement 11 is located at a core of the concrete portion 12, the FRP reinforcement 11 extends along a length direction of the concrete portion 12, a front end of the FRP reinforcement 11 extends forward to a front end side of a front end surface of the concrete portion 12, and a rear end of the FRP reinforcement 11 extends backward to a rear end side of a rear end surface of the concrete portion 12; a front steel pipe 131 is sleeved on the periphery of the front end part of the FRP rib material 11, and an expansion cement layer formed by filling expansion cement is arranged between the inner wall of the front steel pipe 131 and the front end part of the FRP rib material 11; the rear end steel pipe 132 is fitted around the rear end of the FRP rib 11, and an expanded cement layer filled with expanded cement is provided between the inner wall of the rear end steel pipe 132 and the rear end of the FRP rib 11.

Further, this direct tensile test device of FRP muscle material concrete component is still including fixed board 2, fixed board 2 is including being horizontal arrangement's horizontal platform seat 21, vertical arrangement and the upper end extend to the distolateral reaction wall 22 on horizontal platform seat 21 have been installed to the preceding tip of horizontal platform seat 21, the test piece has been installed to the upper end of horizontal platform seat 21 and has been held support 3, the upper surface that support 3 was held to the test piece is for being the support of horizontal plane shape place face 31, roller bearing subassembly 4 has been placed to support place face 31, FRP muscle material concrete component 1 level is placed in the test piece and is held the upper end side of support 3 and FRP muscle material concrete component 1 and pass through roller bearing subassembly 4 roll support.

Furthermore, the front end side of the test piece bearing and placing support 3 is provided with an actuator 51, the reaction wall 22 is fixedly screwed with a front end hinge seat 52 corresponding to the actuator 51, and the fixed end of the actuator 51 is hinged with the front end hinge seat 52; the loading end of the actuator 51 is hinged with a rear end hinge seat 9, the rear end hinge seat 9 is provided with a front end clip anchorage 61, and the front end clip anchorage 61 anchors a front end steel pipe 131 of the FRP reinforcement concrete member 1; the rear end side of the test piece bearing support 3 is provided with a reaction support 71, the reaction support 71 is screwed and fastened at the upper end part of the horizontal platform seat 21, the reaction support 71 is screwed and fastened with an inherent anchor mounting frame 72, the anchor mounting frame 72 is provided with a rear end clamping piece anchor 62, and the rear end clamping piece anchor 62 anchors the rear end steel pipe 132 of the FRP rib concrete member 1.

In addition, for the FRP reinforcement concrete member 1, four iron sheets 141 distributed uniformly at intervals in a circumferential ring shape are fixedly bonded to the front end surface of the concrete part 12 through an epoxy adhesive, i-beams 142 are fixedly bonded to the rear end edge of the concrete part 12 corresponding to the iron sheets 141 through an epoxy adhesive, the i-beams 142 are aligned with the corresponding iron sheets 141 in the front-rear direction, the i-beams 142 are respectively screwed with first LVDT displacement sensors 171, light steel wires 143 horizontally extending in the front-rear direction are respectively mounted between the i-beams 142 and the corresponding iron sheets 141, the front ends of the light steel wires 143 are respectively fastened to the corresponding iron sheets 141, and the rear ends of the light steel wires 143 are respectively connected to the measuring ends of the corresponding first LVDT displacement sensors 171; a front end clamp 15 is fastened between the front end steel pipe 131 and the front end surface of the concrete part 12 at the front end part of the FRP reinforcement material 11, a rear end clamp 16 is fastened between the rear end steel pipe 132 and the rear end surface of the concrete part 12 at the rear end part of the FRP reinforcement material 11, three second LVDT displacement sensors 172 which are uniformly distributed at intervals in a circumferential ring shape are screwed on the front end clamp 15, three third LVDT displacement sensors 173 which are uniformly distributed at intervals in a circumferential ring shape are screwed on the rear end clamp 16, the measuring end of each second LVDT displacement sensor 172 is respectively contacted with the front end surface of the concrete part 12, and the measuring end of each third LVDT displacement sensor 173 is respectively contacted with the rear end surface of the concrete part 12.

It should be explained that the roller assembly 4 includes the roller 41 groups which are sequentially spaced from front to back and aligned, and each roller 41 group includes two rollers 41 which are opposite from left to right and spaced.

In order to ensure that the actuator 51 can be horizontally placed and ensure that the actuator 51 can provide a horizontal pulling force to act on the FRP rib material 11, the upper end side of the actuator 51 is provided with a traction bracket 8, the upper end part of the traction bracket 8 is connected with the reaction wall 22, and the lower end part of the traction bracket 8 is connected with the shell of the actuator 51.

The reaction force support 71 of the present invention can be designed by the following structure, specifically: the reaction force support 71 comprises a front reaction force support 711 and a rear reaction force support 712 located on the rear end side of the front reaction force support 711, the front reaction force support 711 and the rear reaction force support 712 are arranged at intervals, the front reaction force support 711 and the rear reaction force support 712 are respectively screwed and fastened on the upper end of the horizontal platform seat 21, the anchor mounting frame 72 is screwed on the front reaction force support 711, a jack 713 horizontally and transversely arranged is installed between the front reaction force support 711 and the rear reaction force support 712, the front end of the jack 713 is connected with the front reaction force support 711, and the rear end of the jack 713 is connected with the rear reaction force support 712. It should be noted that, for the reaction force support 71 composed of the front reaction force support 711, the rear reaction force support 712 and the jack 713, by adding the structure of the jack 713 between the front reaction force support 711 and the rear reaction force support 712, the rigidity of the whole reaction force support 71 can be effectively enhanced, and the deformation occurring during the loading process can be further reduced, so as to reduce the experimental error.

The front end jig 15 and the rear end jig 16 of the present invention may be designed to have the following structures: the front end clamp 15 comprises a front end steel sleeve 151 in a circular ring shape, the front end steel sleeve 151 is sleeved at the front end part of the FRP rib 11 and is positioned between the front end steel pipe 131 and the front end surface of the concrete part 12, a threaded hole which completely penetrates in the radial direction is formed in the outer circumferential surface of the front end steel sleeve 151, a front end fastening screw 152 is screwed in the threaded hole, the front end fastening screw 152 is screwed in the threaded hole of the front end steel sleeve 151, and the front end fastening screw 152 tightly presses the front end part of the FRP rib 11; similarly, the rear clamp 16 includes a rear steel sleeve 161 in a circular ring shape, the rear steel sleeve 161 is sleeved on the rear end portion of the FRP rib 11 and located between the rear steel tube 132 and the rear end surface of the concrete portion 12, a threaded hole completely penetrating in the radial direction is formed in the outer circumferential surface of the rear steel sleeve 161, a rear fastening screw 162 is screwed in the threaded hole of the rear steel sleeve 161, and the rear fastening screw 162 tightly presses the rear end portion of the FRP rib 11.

The direct tensile test device for the FRP reinforcement concrete member can be used and operated by adopting the following using method, in particular to the using method for the direct tensile test device for the FRP reinforcement concrete member, which comprises the following steps:

a. manufacturing an FRP reinforcement concrete member 1: placing the FRP reinforcement material 11 in a forming mould, then pouring concrete into the forming mould, and forming an FRP reinforcement material concrete member 1 after the concrete is solidified, namely the FRP reinforcement material concrete member 1 comprises the FRP reinforcement material 11 and a concrete part 12 which is poured on the periphery of the FRP reinforcement material 11 by the concrete and forms an integral structure with the FRP reinforcement material 11; the FRP rib 11 is positioned at the core part of the concrete part 12, the FRP rib 11 extends along the length direction of the concrete part 12, the front end part of the FRP rib 11 extends forwards to the front end side of the front end surface of the concrete part 12, and the rear end part of the FRP rib 11 extends backwards to the rear end side of the rear end surface of the concrete part 12;

b. sleeving a front steel pipe 131 on the periphery of the front end part of the FRP rib material 11, and filling expansion cement into a gap between the inner wall of the front steel pipe 131 and the front end part of the FRP rib material 11 to form an expansion cement layer between the inner wall of the front steel pipe 131 and the front end part of the FRP rib material 11; it should be explained that, by filling the gap between the inner wall of the front steel tube 131 and the front end of the FRP reinforcement 11 with the expansive cement, the formed expansive cement layer can provide the bonding bond force, thereby preventing the slippage between the front steel tube 131 and the FRP reinforcement 11; when the subsequent front-end clip anchorage 61 is anchored, the front-end steel pipe 131 can effectively prevent the front-end clip anchorage 61 from directly contacting and clamping the front end part of the FRP reinforcement material 11, so as to prevent the FRP reinforcement material 11 from being pinched off;

c. sleeving a rear end steel pipe 132 on the periphery of the rear end part of the FRP rib material 11, and filling expansion cement into a gap between the inner wall of the rear end steel pipe 132 and the rear end part of the FRP rib material 11 to form an expansion cement layer between the inner wall of the rear end steel pipe 132 and the rear end part of the FRP rib material 11; it should be explained that, by filling the gap between the inner wall of the rear end steel tube 132 and the rear end of the FRP reinforcement 11 with the expansive cement, the formed expansive cement layer can provide the bonding bond force, thereby preventing the sliding phenomenon between the rear end steel tube 132 and the FRP reinforcement 11; when the subsequent rear-end clip anchorage device 62 is anchored, the rear-end steel tube 132 can effectively prevent the rear-end clip anchorage device 62 from directly contacting and clamping the rear end part of the FRP reinforcement material 11, so as to prevent the FRP reinforcement material 11 from being pinched off;

d. four iron sheets 141 are fixedly bonded on the front end face of the concrete part 12 through an epoxy resin adhesive, the four iron sheets 141 are uniformly distributed at intervals in a circumferential ring shape, the edge part of the rear end of the concrete part 12 corresponds to each iron sheet 141 and is respectively bonded and fixed with an I-steel 142 through the epoxy resin adhesive, each I-steel 142 is respectively arranged with the corresponding iron sheet 141 in a front-back alignment manner, each I-steel 142 is respectively screwed with a first LVDT displacement sensor 171, a light steel wire 143 horizontally extending along the front-back direction is respectively installed between each I-steel 142 and the corresponding iron sheet 141, the front end part of each light steel wire 143 is respectively fastened and connected with the corresponding iron sheet 141, and the rear end part of each light steel wire 143 is respectively connected with the measuring end of the corresponding first LVDT displacement sensor 171; it should be explained that the four first LVDT displacement sensors 171 of the present invention are uniformly distributed in a circumferential ring at intervals, that is, an included angle between two adjacent first LVDT displacement sensors 171 is 90 degrees, and the structural design can effectively avoid a test error caused by eccentric tension;

e. a front end clamp 15 is tightly installed at the front end part of the FRP reinforcement material 11, and the front end clamp 15 is positioned between the front end steel pipe 131 and the front end surface of the concrete part 12; after the front end clamp 15 is fastened, three second LVDT displacement sensors 172 are screwed in the front end clamp 15, the three second LVDT displacement sensors 172 are uniformly distributed at intervals in a circumferential ring shape, and the measuring end of each second LVDT displacement sensor 172 is respectively contacted with the front end surface of the concrete part 12; it should be explained that, in the process that the actuator 51 loads the FRP reinforcement 11 and deforms the FRP reinforcement 11, the second LVDT displacement sensors 172 can measure the slippage between the FRP reinforcement 11 and the concrete part 12, and three second LVDT displacement sensors 172 are uniformly distributed at intervals in a circumferential ring shape, that is, an included angle between two adjacent second LVDT displacement sensors 172 is 120 degrees, and the structural design can effectively increase the test accuracy;

f. a rear end clamp 16 is tightly installed at the rear end part of the FRP rib material 11, and the rear end clamp 16 is positioned between the rear end steel pipe 132 and the rear end surface of the concrete part 12; after the rear end clamp 16 is fastened, three third LVDT displacement sensors 173 are screwed in the rear end clamp 16, the three third LVDT displacement sensors 173 are uniformly distributed at intervals in a circumferential ring shape, and the measuring ends of the third LVDT displacement sensors 173 are respectively in contact with the rear end face of the concrete part 12; it should be explained that, in the process that the actuator 51 loads the FRP reinforcement 11 and deforms the FRP reinforcement 11, the third LVDT displacement sensor 173 can measure the slippage between the FRP reinforcement 11 and the concrete part 12, and three third LVDT displacement sensors 173 are uniformly distributed in a circumferential ring shape at intervals, that is, an included angle between two adjacent second LVDT displacement sensors 172 is 120 degrees, and the structural design can effectively increase the test accuracy;

g. placing a plurality of rollers 41 on the support placing surface 31 of the test piece bearing support 3, wherein two rollers 41 form a roller 41 group, the two rollers 41 of the same roller 41 group are right and left opposite and are arranged at intervals, and the roller 41 groups are sequentially arranged at intervals and aligned from front to back;

h. the FRP reinforcement concrete member 1 is stably placed on the rollers 41, and the light steel wire 143 at the lowest position passes through the gap between the two rollers 41 of the same roller 41 group; it should be explained that, for the roller assembly 4 of the present invention, it can effectively avoid the direct contact between the concrete part 12 of the FRP reinforcement concrete member 1 and the bracket placing surface 31 of the test piece bearing bracket 3, so as to avoid the contact friction between the concrete part 12 and the bracket placing surface 31 of the test piece bearing bracket 3 to cause the test error;

i. anchoring the front end clip anchorage 61 to the front end steel pipe 131 and the rear end clip anchorage 62 to the rear end steel pipe 132;

j. the first LVDT displacement sensor 171, the second LVDT displacement sensor 172 and the third LVDT displacement sensor 173 are respectively connected with a computer;

k. the starting actuator 51 loads the FRP reinforcement 11, and the first LVDT displacement sensor 171, the second LVDT displacement sensor 172 and the third LVDT displacement sensor 173 respectively transmit the acquired displacement data to the computer.

From the above situation, it can be seen that through the above structural design, the direct tensile test device for the FRP reinforced concrete member of the present invention has the advantage of novel structural design, and can effectively perform the direct tensile test of the FRP reinforced concrete member, that is, can be effectively applied to the test research of the tensile rigidifying performance of the reinforced concrete member. In addition, the use method of the direct tensile test device for the FRP rib concrete member can effectively utilize the direct tensile test device for the FRP rib concrete member to carry out the direct tensile test of the FRP rib concrete member, namely can be effectively applied to the test research on the tensile and rigidifying performance of reinforced rib concrete.

The above description is only a preferred embodiment of the present invention, and for those skilled in the art, the present invention should not be limited by the description of the present invention, which should be interpreted as a limitation.

Claims

1. The utility model provides a direct tensile test device of FRP muscle material concrete member which characterized in that: the FRP reinforcement concrete member comprises an FRP reinforcement concrete member (1), wherein the FRP reinforcement concrete member (1) comprises an FRP reinforcement (11) and a concrete part (12) which is poured on the periphery of the FRP reinforcement (11) by concrete and forms an integrated structure with the FRP reinforcement (11), the FRP reinforcement (11) is positioned at the core part of the concrete part (12), the FRP reinforcement (11) extends along the length direction of the concrete part (12), the front end part of the FRP reinforcement (11) extends forwards to the front end side of the front end surface of the concrete part (12), and the rear end part of the FRP reinforcement (11) extends backwards to the rear end side of the rear end surface of the concrete part (12); a front steel pipe (131) is sleeved on the periphery of the front end part of the FRP rib material (11), and an expansion cement layer formed by filling expansion cement is arranged between the inner wall of the front steel pipe (131) and the front end part of the FRP rib material (11); a rear end steel pipe (132) is sleeved on the periphery of the rear end part of the FRP rib material (11), and an expansion cement layer formed by filling expansion cement is also arranged between the inner wall of the rear end steel pipe (132) and the rear end part of the FRP rib material (11);

the direct tensile test device for the FRP reinforcement concrete member further comprises a fixed machine table (2), the fixed machine table (2) comprises a horizontal table seat (21) which is horizontally and transversely arranged, a reaction wall (22) which is vertically arranged and the upper end of which extends to the upper end side of the horizontal table seat (21) is arranged at the front end of the horizontal table seat (21), a test piece bearing and placing support (3) is arranged at the upper end of the horizontal table seat (21), a support placing surface (31) which is horizontal in shape is arranged on the upper surface of the test piece bearing and placing support (3), a roller assembly (4) is placed on the support placing surface (31), the FRP reinforcement concrete member (1) is horizontally placed on the upper end side of the test piece bearing and placing support (3), and the FRP reinforcement concrete member (1) is supported by the roller assembly (4) in a rolling manner;

the front end side of the test piece bearing support (3) is provided with an actuator (51), the reaction wall (22) is tightly screwed with a front end hinge seat (52) corresponding to the actuator (51), and the fixed end of the actuator (51) is hinged with the front end hinge seat (52); the loading end of the actuator (51) is hinged with a rear end hinge seat (9), the rear end hinge seat (9) is provided with a front end clip anchorage device (61), and the front end clip anchorage device (61) anchors a front end steel pipe (131) of the FRP reinforcement concrete member (1); the rear end side of the test piece bearing support (3) is provided with a reaction support (71), the reaction support (71) is screwed and fastened at the upper end part of the horizontal platform seat (21), the reaction support (71) is screwed and fastened with an inherent anchor mounting rack (72), the anchor mounting rack (72) is provided with a rear end clamping piece anchor (62), and the rear end clamping piece anchor (62) anchors a rear end steel pipe (132) of the FRP reinforcement concrete member (1);

for the FRP reinforcement concrete member (1), four iron sheets (141) which are uniformly distributed in a circumferential annular shape at intervals are fixedly bonded on the front end face of a concrete part (12) through epoxy resin adhesives, I-shaped steels (142) are fixedly bonded on the rear end edge of the concrete part (12) corresponding to the iron sheets (141) through the epoxy resin adhesives respectively, the I-shaped steels (142) are aligned with the corresponding iron sheets (141) in the front and back direction respectively, a first LVDT displacement sensor (171) is mounted in each I-shaped steel (142) in a screwed mode respectively, light steel wires (143) horizontally extending along the front and back direction are mounted between each I-shaped steel (142) and the corresponding iron sheet (141) respectively, the front end portions of the light steel wires (143) are fixedly connected with the corresponding iron sheets (141) respectively, and the rear end portions of the light steel wires (143) are connected with the measuring ends of the corresponding first LVDT displacement sensors (171) respectively; the front end part of the FRP reinforcement (11) is fastened with a front end clamp (15) between a front end steel pipe (131) and the front end surface of the concrete part (12), the rear end part of the FRP reinforcement (11) is fastened with a rear end clamp (16) between a rear end steel pipe (132) and the rear end surface of the concrete part (12), three second LVDT displacement sensors (172) which are uniformly distributed at intervals in a circumferential ring shape are arranged on the front end clamp (15) in a threaded manner, three third LVDT displacement sensors (173) which are uniformly distributed at intervals in a circumferential ring shape are arranged on the rear end clamp (16) in a threaded manner, the measuring ends of the second LVDT displacement sensors (172) are respectively in contact with the front end surface of the concrete part (12), and the measuring ends of the third LVDT displacement sensors (173) are respectively in contact with the rear end surface of the concrete part (12).

2. The FRP tendon concrete member direct tensile test device according to claim 1, characterized in that: the roller component (4) comprises roller (41) groups which are sequentially arranged from front to back in an interval and aligned mode, and each roller (41) group comprises two rollers (41) which are right and left and are arranged oppositely at intervals.

3. The FRP tendon concrete member direct tensile test device according to claim 1, characterized in that: and a traction support (8) is arranged on the upper end side of the actuator (51), the upper end part of the traction support (8) is connected with the reaction wall (22), and the lower end part of the traction support (8) is connected with the shell of the actuator (51).

4. The FRP tendon concrete member direct tensile test device according to claim 1, characterized in that: the reaction support (71) comprises a front reaction support (711) and a rear reaction support (712) located on the rear end side of the front reaction support (711), the front reaction support (711) and the rear reaction support (712) are arranged at intervals, the front reaction support (711) and the rear reaction support (712) are respectively screwed and fastened at the upper end of the water platform base (21), the anchor mounting frame (72) is screwed on the front reaction support (711), a jack (713) horizontally and transversely arranged is arranged between the front reaction support (711) and the rear reaction support (712), the front end of the jack (713) is connected with the front reaction support (711), and the rear end of the jack (713) is connected with the rear reaction support (712).

5. The FRP tendon concrete member direct tensile test device according to claim 1, characterized in that: the front-end clamp (15) comprises a front-end steel sleeve (151) in a circular ring shape, the front-end steel sleeve (151) is sleeved at the front end part of the FRP rib (11) and is positioned between the front-end steel pipe (131) and the front end surface of the concrete part (12), a threaded hole which completely penetrates in the radial direction is formed in the outer circumferential surface of the front-end steel sleeve (151), a front-end fastening screw (152) is screwed in the threaded hole of the front-end steel sleeve (151), and the front-end fastening screw (152) tightly presses the front end part of the FRP rib (11);

the rear end clamp (16) comprises a rear end steel sleeve (161) in a circular ring shape, the rear end steel sleeve (161) is sleeved on the rear end portion of the FRP rib material (11) and located between the rear end steel pipe (132) and the rear end face of the concrete part (12), a threaded hole which completely penetrates in the radial direction is formed in the outer circumferential face of the rear end steel sleeve (161), a rear end fastening screw (162) is screwed in the threaded hole of the rear end steel sleeve (161), the rear end fastening screw (162) is screwed in the threaded hole of the rear end steel sleeve (161), and the rear end fastening screw (162) compresses the rear end portion of the FRP rib material (11).

6. The use method of the direct tensile test device for the FRP reinforcement concrete member is characterized by comprising the following steps:

a. manufacturing an FRP reinforcement concrete member (1): placing the FRP reinforcement (11) in a forming mould, then pouring concrete into the forming mould, and forming the FRP reinforcement concrete member (1) after the concrete is solidified, wherein the FRP reinforcement concrete member (1) comprises the FRP reinforcement (11) and a concrete part (12) which is formed into an integral structure with the FRP reinforcement (11) and is poured on the periphery of the FRP reinforcement (11); the FRP reinforcement (11) is positioned at the core part of the concrete part (12) and extends along the length direction of the concrete part (12), the front end part of the FRP reinforcement (11) extends forwards to the front end side of the front end surface of the concrete part (12), and the rear end part of the FRP reinforcement (11) extends backwards to the rear end side of the rear end surface of the concrete part (12);

b. sleeving a front steel pipe (131) on the periphery of the front end part of the FRP rib material (11), and filling expansion cement into a gap between the inner wall of the front steel pipe (131) and the front end part of the FRP rib material (11) to form an expansion cement layer between the inner wall of the front steel pipe (131) and the front end part of the FRP rib material (11);

c. sleeving a rear end steel pipe (132) on the periphery of the rear end part of the FRP rib material (11), and filling expansion cement in a gap between the inner wall of the rear end steel pipe (132) and the rear end part of the FRP rib material (11) to form an expansion cement layer between the inner wall of the rear end steel pipe (132) and the rear end part of the FRP rib material (11);

d. four iron sheets (141) are fixedly bonded on the front end face of a concrete part (12) through an epoxy resin adhesive, the four iron sheets (141) are uniformly distributed at intervals in a circumferential ring shape, the edge part of the rear end of the concrete part (12) corresponds to each iron sheet (141) and is fixedly bonded with I-shaped steel (142) through the epoxy resin adhesive, each I-shaped steel (142) is arranged in front and back alignment with the corresponding iron sheet (141), each I-shaped steel (142) is respectively screwed with a first LVDT displacement sensor (171), light steel wires (143) horizontally extending along the front and back direction are respectively mounted between each I-shaped steel (142) and the corresponding iron sheet (141), the front end parts of the light steel wires (143) are fixedly connected with the corresponding iron sheets (141), and the rear end parts of the light steel wires (143) are respectively connected with the measuring ends of the corresponding first LVDT displacement sensors (171);

e. a front end clamp (15) is tightly installed at the front end part of the FRP reinforcement (11), and the front end clamp (15) is positioned between the front end steel pipe (131) and the front end surface of the concrete part (12); after the front end clamp (15) is fastened, three second LVDT displacement sensors (172) are screwed on the front end clamp (15), the three second LVDT displacement sensors (172) are uniformly distributed at intervals in a circumferential annular shape, and the measuring ends of the second LVDT displacement sensors (172) are respectively in contact with the front end surface of the concrete part (12);

f. a rear end clamp (16) is tightly installed at the rear end part of the FRP reinforcement (11), and the rear end clamp (16) is positioned between the rear end steel pipe (132) and the rear end face of the concrete part (12); after the rear end clamp (16) is fastened, three third LVDT displacement sensors (173) are screwed on the rear end clamp (16), the three third LVDT displacement sensors (173) are uniformly distributed at intervals in a circumferential ring shape, and the measuring end of each third LVDT displacement sensor (173) is respectively in contact with the rear end face of the concrete part (12);

g. placing a plurality of rollers (41) on a support placing surface (31) of a test piece bearing support (3), wherein two rollers (41) form a roller (41) group, the two rollers (41) of the same roller (41) group are right and left opposite and are arranged at intervals, and the roller (41) group is sequentially arranged at intervals and in alignment from front to back;

h. the FRP reinforcement concrete member (1) is stably placed on the rollers (41), and the light steel wire (143) at the lowest position passes through the gap between the two rollers (41) of the same roller (41) group;

i. anchoring the front end clip anchor (61) to the front end steel tube (131) and the rear end clip anchor (62) to the rear end steel tube (132);

j. the first LVDT displacement sensor (171), the second LVDT displacement sensor (172) and the third LVDT displacement sensor (173) are respectively connected with a computer;

k. the starting actuator (51) loads the FRP rib (11), and the first LVDT displacement sensor (171), the second LVDT displacement sensor (172) and the third LVDT displacement sensor (173) respectively send the acquired displacement data to the computer.

7. The use method of the direct tensile test device for the FRP reinforcement concrete member according to claim 6, characterized in that: the front-end clamp (15) comprises a front-end steel sleeve (151) in a circular ring shape, the front-end steel sleeve (151) is sleeved at the front end part of the FRP rib (11) and is positioned between the front-end steel pipe (131) and the front end surface of the concrete part (12), a threaded hole which completely penetrates in the radial direction is formed in the outer circumferential surface of the front-end steel sleeve (151), a front-end fastening screw (152) is screwed in the threaded hole of the front-end steel sleeve (151), and the front-end fastening screw (152) tightly presses the front end part of the FRP rib (11);