CN110793865A - System and method for measuring interface heat resistance of FRP reinforced concrete beam - Google Patents

System and method for measuring interface heat resistance of FRP reinforced concrete beam Download PDF

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Publication number
CN110793865A
CN110793865A CN201911093425.0A CN201911093425A CN110793865A CN 110793865 A CN110793865 A CN 110793865A CN 201911093425 A CN201911093425 A CN 201911093425A CN 110793865 A CN110793865 A CN 110793865A
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China
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temperature
loading
heating device
heated
reinforced concrete
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CN201911093425.0A
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Inventor
董坤
荆范华
刘洋
杜德润
蒋济同
杨松
刘辉
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Ocean University of China
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Ocean University of China
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
    • G01N3/18—Performing tests at high or low temperatures
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M5/00—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings
    • G01M5/0041—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings by determining deflection or stress
    • G01M5/005—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings by determining deflection or stress by means of external apparatus, e.g. test benches or portable test systems
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00—Ohmic-resistance heating
    • H05B3/02—Details
    • H05B3/06—Heater elements structurally combined with coupling elements or holders
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N2203/0014—Type of force applied
    • G01N2203/0023—Bending
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N2203/0058—Kind of property studied
    • G01N2203/0076—Hardness, compressibility or resistance to crushing
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N2203/02—Details not specific for a particular testing method
    • G01N2203/022—Environment of the test
    • G01N2203/0222—Temperature
    • G01N2203/0226—High temperature; Heating means

Abstract

The invention belongs to the technical field of civil engineering reinforcement and discloses a system and a method for measuring the interface heat resistance of an FRP reinforced concrete beam, wherein a heat insulation layer is arranged on the inner side of an external protective shell, an electric heating wire is laid on the edge of the heat insulation layer on the inner side of a heating device, and the electric heating wire is connected with a temperature controller through a lead-out wire; the front end of the heating device is plugged with a first heat insulation end plate, and the rear end of the heating device is plugged with a second heat insulation end plate; the lower ends of the first heat-insulating end plate and the second heat-insulating end plate are provided with side supporting plates; the support is positioned on the sliding track and is provided with a component to be heated at the bottom; two side covers of the bottom component to be heated are provided with top cover plates; the base is fixed with a loading frame, a jack is fixed on the loading frame through a bolt, a displacement meter is fixed on the loading frame through a magnetic base, and the jack and the displacement meter are respectively electrically connected with a loading control and data acquisition system through connecting wires. The invention uses the heating wire controlled by the temperature controller to heat, the heating range can be 0-800 ℃, the operation is simple and convenient, and the resources are saved.

Description

System and method for measuring interface heat resistance of FRP reinforced concrete beam
Technical Field
The invention belongs to the technical field of civil engineering reinforcement, and particularly relates to a system and a method for measuring interface heat resistance of an FRP reinforced concrete beam.
Background
Currently, the closest prior art: the reinforcing technology of adhering Fiber Reinforced Polymer (FRP) is to utilize epoxy resin material to adhere fiber material to the outer surface of concrete member so as to reach the aims of improving structure function and reinforcing. Compared with other reinforcement technologies, the FRP reinforced concrete technology has the advantages of light weight, high strength, convenience and quickness in construction, corrosion resistance, flexibility, easiness in cutting and the like. However, the fire resistance of the bonded fiber reinforced concrete structure is poor. Most of the matrix materials in the fiber composite material and the adhesive materials used for pasting are epoxy organic matters, the fiber composite material has high sensitivity to temperature, the glass transition temperature Tg of the fiber composite material is generally 65-80 ℃, and the fiber composite material gradually loses bonding strength and rigidity at high temperature. Under the high temperature environment, once the gluing agent softens and loses efficacy, will mean that FRP withdraws from work to cause the reinforcement to lose efficacy, cause the reinforced structure under the high temperature to be more dangerous. Therefore, the research on the high-temperature performance of the FRP reinforced concrete structure is actively carried out, and the improvement response measure is provided, which is the key for ensuring the structure safety and accelerating the technical popularization, and has important theoretical and practical significance.
However, the conventional method for researching the heat resistance of the FRP reinforced concrete member is to place the member in an environmental chamber for heating, and then take out the member for loading. In the mode, the component to be heated is not placed in a closed environment, the component can be naturally cooled in the taking-out and loading processes to cause temperature reduction and deviation from the target temperature, and the heating effect is unstable. In addition, in a non-closed environment, the temperature change of the environment cannot be controlled by the temperature control device, the high-temperature and fire environment cannot be effectively simulated, and the temperature action and the loading are asynchronous, so that the high-temperature resistance of the component cannot be effectively researched; in contrast, although a large-scale high-temperature furnace experiment can effectively simulate a high-temperature fire scene and realize synchronous loading, the cost is huge.
In summary, the problems of the prior art are as follows:
(1) the existing FRP reinforced concrete member heat resistance test does not place the member to be heated in a closed environment, the heating effect is unstable, the high-temperature and fire environment cannot be effectively simulated, and the temperature action and the loading are asynchronous, so that the high-temperature resistance of the member cannot be effectively researched.
(2) Although a large-scale high-temperature furnace experiment can effectively simulate a high-temperature scene and realize synchronous loading, the cost is huge.
The difficulty of solving the technical problems is as follows: the domestic and foreign standard specifies the FRP reinforcing method and the construction method of the concrete structure at normal temperature in more detail, the guidance on high temperature is not deep, a certain high temperature resistant effect is achieved only by specifying a series of limiting measures such as reinforcing quantity, using temperature range and the like, and the heat resistance is not quantitatively guided and is difficult to ensure.
The significance of solving the technical problems is as follows: the invention fills the gap, is used for simulating the states of environmental temperature difference, fire high temperature and the like, and carries out a constant load heating or constant temperature loading test on the FRP reinforced concrete member through the measuring device, so that the influence of temperature change on the reinforcing performance of the member can be simulated, and the influence of high temperature on the ultimate bonding bearing capacity of an interface can also be simulated, thereby researching the damage form, the bearing capacity, the deformation process and the like of the concrete member under the high-temperature condition, and providing an important theoretical basis and a key technical support for the theoretical perfection and the practical application of the technology.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a system and a method for measuring the interface heat resistance of an FRP reinforced concrete beam.
The invention is realized in this way, a system for measuring the interface heat resistance of FRP reinforced concrete beam is provided with:
the device comprises a heating device, a loading device, a supporting device and a test piece;
the heating device is provided with an external protective shell, a heat insulation layer is arranged on the inner side of the external protective shell, a heating wire is laid on the edge of the heat insulation layer on the inner side of the heating device, and the heating wire is connected with the temperature controller through a leading-out wire;
the front end of the heating device is plugged with a first heat insulation end plate, and the rear end of the heating device is plugged with a second heat insulation end plate; the lower ends of the first heat-insulating end plate and the second heat-insulating end plate are provided with side supporting plates;
the base of the heating device is provided with a sliding rail, and the base is provided with a sliding rail which is flush with the sliding rail in the base of the heating device;
the support is positioned on the sliding track and is provided with a component to be heated at the bottom; two side covers of the bottom component to be heated are provided with top cover plates;
the base is fixed with a loading frame, a jack is fixed on the loading frame through a bolt, a displacement meter is fixed on the loading frame through a magnetic base, and the jack and the displacement meter are respectively electrically connected with a loading control system through a connecting wire.
Further, a jack fixed on the loading frame is positioned at the upper end of the member to be heated at the bottom.
Further, the displacement meter is arranged at the right end of the loading frame, the position of the displacement meter can be adjusted according to actual conditions, and a measuring needle of the displacement meter is in contact with the bottom to-be-heated component.
Furthermore, the heat insulation layer, the top cover plate, the heat insulation end plate and the heat insulation end plate are all made of high-temperature resistant material ceramic fibers.
Further, the heating device is of a groove type.
Further, the temperature controller controls the temperature to be 0-800 ℃ according to the performance of the electric heating wire.
Further, the cross section of the bottom part to-be-heated component is matched with the side plate support in the heating device; the height of the heating device and the positions of the supports at the two ends of the supporting device can be adjusted, so that the length of the test piece is not limited.
Further, the heating device and the test piece are respectively placed on the supporting device, and the heating device and the test piece are not in direct contact; the heating device is of a groove type, and a closed space is formed between the heating device and the bottom of the test piece through the plurality of high-temperature-resistant baffles, so that the bottom of the test piece is heated.
Another object of the present invention is to provide a method for measuring the interface heat resistance of an FRP reinforced concrete beam, the method specifically including the steps of:
assembling a testing device, adjusting the position of a support, placing an FRP reinforcing member to be heated at the bottom in a groove-shaped heating device, covering high-temperature-resistant top cover plates on two sides of the top member of the device, pushing high-temperature-resistant first heat-insulating end plates and high-temperature-resistant second heat-insulating end plates along side plate supports on two sides of the device, and enabling the first heat-insulating end plates and the second heat-insulating end plates to be attached to the member to be heated, so that a closed space is formed by the whole heating device;
step two, heating the component to be heated at the bottom, burying an electric heating wire at the bottom of the heating device, connecting the electric heating wire with a temperature controller through a leading-out wire, and operating the temperature controller to adjust the temperature in the heating groove so as to heat the component to be heated;
step three, loading the member to be heated at the bottom, after the member to be heated is heated to a target temperature and is kept at the constant temperature for a certain time, operating a jack by using a loading control system to carry out loading, wherein the loading mode can be single-point loading or multi-point loading until a test piece is damaged, and the whole loading process is controlled by the loading control system; the loading and heating processes can also be carried out synchronously, or the loading is carried out after the temperature is firstly increased to the preset temperature;
step four, during the test, displacement data, namely the deflection of the FRP reinforced concrete beam, can be obtained through a displacement meter; the loading control system can also display the load applied to the component; the temperature controller can effectively control the temperature in the heating device;
and fifthly, observing a high-temperature damage mechanism and a performance degradation rule of the FRP reinforced concrete beam, researching the damage form, the bearing capacity, the deformation development process and the like of the reinforced beam after the adhesive is softened at high temperature, analyzing the influence of the interface bonding anchoring failure process on the bending resistance of the whole reinforced member, and establishing the FRP strength utilization coefficient calculation method.
In summary, the advantages and positive effects of the invention are: the invention is used for simulating high-temperature environments such as fire and the like and is used for researching the reinforcing effect of the fiber material reinforced concrete beam at high temperature. The device uses the heating wire of temperature controller control to heat up, through setting up heating power and arranging the heating wire, the intensification scope can realize 0 ~ 800 ℃, and easy and simple to handle and resources are saved. Meanwhile, by combining an external loading device, synchronous loading of temperature and load can be realized, the high-temperature damage mechanism and the performance degradation rule of the FRP reinforced concrete beam can be conveniently researched, and an important theoretical basis and key technical support can be provided for theoretical perfection and practical application of the FRP reinforcement technology.
Drawings
Fig. 1 is a schematic structural diagram of a system for measuring heat resistance of an FRP reinforced concrete beam according to an embodiment of the present invention.
Fig. 2 is a schematic structural diagram of an external protective shell, a thermal insulation layer and a heating wire according to an embodiment of the present invention.
Fig. 3 is a schematic structural diagram of a cover plate of a heating device according to an embodiment of the present invention.
Fig. 4 is a schematic structural view of a first insulated end panel, a second insulated end panel and a side panel bracket according to an embodiment of the present invention.
Fig. 5 is a schematic structural diagram of a heating device according to an embodiment of the present invention.
Fig. 6 is a flowchart of a method for measuring a heat resistance of an FRP reinforced concrete beam according to an embodiment of the present invention.
In the figure: 1. an outer protective shell; 2. a thermal insulation layer; 3. an electric heating wire; 4. a temperature controller; 5. an outgoing line; 6. a top cover plate; 7. a first insulated end plate; 8. a second insulated end plate; 9. a bottom to-be-heated member; 10. a side plate support; 11. a displacement meter; 12. a loading frame; 13. loading a control and data acquisition system; 14. a support; 15. a sliding track; 16. a jack; 17. a base.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Aiming at the problems in the prior art, the invention provides a system and a method for measuring the heat resistance of an FRP reinforced concrete beam, and the invention is described in detail with reference to the accompanying drawings.
As shown in fig. 1 to 5, an FRP reinforced concrete beam heat resistance measurement system according to an embodiment of the present invention includes: the device comprises a heating device, a loading device, a supporting device and a test piece.
The heating device includes: the heat insulation device comprises an external protective shell 1, a heat insulation layer 2, a heating wire 3, a temperature controller 4, a leading-out wire 5, a top cover plate 6, a first heat insulation end plate 7 and a second heat insulation end plate 8.
The loading device comprises: the device comprises a loading frame 9, a jack 10, a displacement meter 11, a connecting line 12 and a loading control and data acquisition system 13.
The supporting device comprises: a support 14 and a sliding track 15.
The inside of the external protection shell 1 is provided with a heat insulation layer 2, the edge of the heat insulation layer on the inner side of the heating device is paved with a heating wire 3, and the heating wire 3 is connected with a temperature controller 4 through a leading-out wire 5.
The heating device base is provided with sliding rails 15, while the base 17 is provided with sliding rails 15 which are flush with the sliding rails inside the heating device base.
The support 14 is positioned on the sliding rail 15, and the bottom to-be-heated component 9 is placed on the support 14; the bottom to-be-heated member 9 is flanked by top cover plates 6.
A loading frame 12 is fixed on the base 17, a jack 16 and a displacement meter 11 are fixed on the loading frame 12 through bolts, and the jack 16 and the displacement meter 11 are electrically connected with a loading control and data acquisition system 13 through connecting wires respectively.
The front end of the heating device is plugged with a first heat insulation end plate 7, and the rear end of the heating device is plugged with a second heat insulation end plate 8; the lower ends of the first heat insulation end plate 7 and the second heat insulation end plate 8 are provided with side supporting plates 10.
Preferably, the jacks 16 fixed on the loading frame 12 are positioned at the upper end of the bottom member to be heated 9;
preferably, the displacement gauge 11 is located at the right end of the loading frame 12, and the displacement gauge 11 measures the needle in contact with the bottom heated member 9.
Preferably, the heat insulation layer 2, the top cover plate 6, the heat insulation end plate 7 and the heat insulation end plate 8 are all made of high-temperature resistant material ceramic fibers.
Preferably, the heating means is of the trough type.
Preferably, the temperature controller controls the temperature to be 0-800 ℃ according to the performance of the heating wire.
Preferably, the cross-sectional dimension of the bottom member to be heated 9 is adapted to the heating device (side plate holder); the length of the test piece is not limited because the height of the heating device and the positions of the supports 14 at the two ends of the supporting device can be adjusted.
Preferably, the heating device and the test piece are respectively placed on the supporting device, and the heating device and the test piece are not in direct contact; the heating device is of a groove type, and a closed space is formed between the heating device and the bottom of the test piece through the plurality of high-temperature-resistant baffles, so that the bottom of the test piece is heated.
As shown in fig. 6, a method for determining a heat resistance of an FRP reinforced concrete beam according to an embodiment of the present invention includes the following steps:
s101, assembling the testing device, adjusting the position of a support, placing the FRP reinforcing member to be heated at the bottom in the groove-shaped heating device, covering high-temperature-resistant top cover plates on two sides of the top member of the device, pushing the high-temperature-resistant first heat-insulating end plate and the high-temperature-resistant second heat-insulating end plate into the two sides of the device along the side plate supports, and enabling the first heat-insulating end plate and the second heat-insulating end plate to be attached to the member to be heated, so that the whole heating device.
And S102, heating the component to be heated at the bottom, burying a heating wire at the bottom of the heating device, connecting the heating wire with a temperature controller through a lead wire, and operating the temperature controller to adjust the temperature in the heating groove so as to heat the component to be heated.
S103, loading the member to be heated at the bottom, keeping the temperature constant for a certain time after the member to be heated at the bottom is heated to a target temperature, and then using a loading control system to control a jack to load, wherein the loading mode can be single-point loading or multi-point loading until the whole loading process of the test piece damage is controlled by the loading control system; the loading and heating processes can also be carried out synchronously, or the loading is carried out after the temperature is firstly increased to the preset temperature.
S104, acquiring displacement data, namely the deflection of the FRP reinforced concrete beam, by using a displacement meter during the test; the loading control system can also display the load applied to the component; the temperature controller can effectively control the temperature in the heating device.
S105, observing a high-temperature damage mechanism and a performance degradation rule of the FRP reinforced concrete beam, researching the damage form, the bearing capacity, the deformation development process and the like of the reinforced beam after the adhesive is softened at high temperature, analyzing the influence of the interface bonding and the anchoring failure process on the bending resistance of the whole reinforced member, and establishing the FRP strength utilization coefficient calculation method.
The working principle of the invention is as follows:
assembling a testing device: the position of the support 14 is adjusted, the FRP reinforcing component to be heated at the bottom is placed in the groove-shaped heating device, high-temperature-resistant top cover plates 6 are added on two sides of the component at the top of the device, and high-temperature-resistant first heat-insulating end plates 7 and second heat-insulating end plates 8 are pushed into two sides of the device along the side plate supports 10 to be attached to the component to be heated, so that the whole heating device forms a closed space.
Heating process: the bottom of the heating device is embedded with a heating wire 3 which is connected with a temperature controller 4 through a leading-out wire 5, and the temperature controller 4 is operated to adjust the temperature in the heating groove, so that the component to be heated is heated. Can be in the inside pre-buried thermocouple temperature testing arrangement of test piece when waiting to test the test piece preparation, can be connected thermocouple and temperature controller during the experiment to more accurate control test piece temperature is favorable to experimental success to be gone on.
And (3) loading process: after the temperature is raised to the target temperature and the temperature is kept constant for a certain time, the jack 16 is controlled by the loading control and data acquisition system 13 to carry out loading, the loading mode can be single-point loading or multi-point loading, and the whole loading process is controlled by the loading control and data acquisition system 13 until the test piece is damaged; the loading and heating processes can also be carried out simultaneously, or the loading can be carried out after the temperature is raised to the preset temperature, which depends on the content to be researched.
During the test, displacement data, namely the deflection of the FRP reinforced concrete beam can be obtained through the displacement meter 11; the load control and data acquisition system 13 may also display the magnitude of the load applied to the component; the temperature controller 4 can effectively control the temperature in the heating device;
observing a high-temperature damage mechanism and a performance degradation rule of the FRP reinforced concrete beam, researching the damage form, the bearing capacity, the deformation development process and the like of the reinforced beam after the high-temperature softening of the adhesive, analyzing the influence of the interface bonding and the anchoring failure process on the bending resistance of the whole reinforced member, establishing an FRP strength utilization coefficient calculation method, and providing an important theoretical basis and key technology support for theoretical perfection and practical application of an FRP reinforcing technology at temperature.
The technical effects of the present invention will be described in detail with reference to the experiments.
In order to further optimize the technical scheme, 6 small-proportion CFRP reinforcing beams are designed in a test, and the strength grade of concrete is C40; length 1.2m, cross-sectional dimension 150mm 200 mm; the width of the CFRP used is 50mm, and the nominal thickness is 0.167 mm; glass transition temperature T of adhesivegAt 81 ℃, the actually measured bonding strength change of the adhesive is concentrated on the glass transition temperature TgIn the range of +/-20 ℃. Testing and researching the influence of temperature on the bending resistance of the CFRP reinforcing member, and (S104)]The data include mid-span deflection omega of the FRP reinforced beam, load F applied to the member, and temperature T in the heating device. By adopting mid-span single-point loading, mid-span deflection of the reinforcing beam after the softening of the adhesive and load applied to the member at different temperatures are collected, and the FRP strength utilization coefficient (the ratio of the bearing capacity improvement value of the reinforcing member at the temperature to the normal temperature) can be calculated as shown in Table 1:
TABLE 1 FRP Strength utilization factor
Temperature T (. degree. C.) Loads F (kN) Mid-span deflection omega (mm) Coefficient of FRP strength utilization
25 (Normal temperature) 32.24 2.46 1
60 32.00 2.51 0.98
80 26.87 2.65 0.58
100 23.74 2.90 0.28
120 23.26 3.61 0.24
140 22.91 4.82 0.21
The above table shows that, as the temperature rises, the ultimate load of the FRP reinforced concrete beam gradually decreases, the corresponding mid-span deflection increases, the FRP strength utilization rate gradually decreases, and it is seen that the temperature greatly affects the bonding performance of the FRP-concrete interface, resulting in a great decrease in the bearing performance of the reinforced member.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims (10)

1. The system for measuring the interface heat resistance of the FRP reinforced concrete beam is characterized by being provided with:
a heating device;
the heating device is provided with an external protective shell, a heat insulation layer is arranged on the inner side of the external protective shell, a heating wire is laid on the edge of the heat insulation layer on the inner side of the heating device, and the heating wire is connected with the temperature controller through a leading-out wire;
the front end of the heating device is plugged with a first heat insulation end plate, and the rear end of the heating device is plugged with a second heat insulation end plate; the lower ends of the first heat-insulating end plate and the second heat-insulating end plate are provided with side supporting plates;
the base of the heating device is provided with a sliding rail, and the base is provided with a sliding rail which is flush with the sliding rail in the base of the heating device;
the support is positioned on the sliding track and is provided with a component to be heated at the bottom; two side covers of the bottom component to be heated are provided with top cover plates;
a loading frame is fixed on the base, a jack and a displacement meter are fixed on the loading frame through bolts, and the jack and the displacement meter are respectively electrically connected with a loading control system through connecting wires.
2. The system for measuring the interface heat resistance of an FRP reinforced concrete beam as claimed in claim 1, wherein the jacks fixed to the loading frame are provided at the upper ends of the members to be heated at the bottom.
3. The system for measuring the interface heat resistance of an FRP reinforced concrete beam as recited in claim 1, wherein the displacement gauge is located at the right end of the loading frame, and the measuring pin of the displacement gauge is in contact with the member to be heated at the bottom.
4. The system for measuring the interface heat resistance of an FRP reinforced concrete beam as recited in claim 1, wherein the insulating layer, the top cover plate, the insulating end plate and the insulating end plate are made of ceramic fiber which is a high temperature resistant material.
5. The system for measuring the interface heat resistance of an FRP reinforced concrete beam as recited in claim 1, wherein said heating means is a trough type.
6. The system for measuring the interface heat resistance of an FRP reinforced concrete beam as recited in claim 1, wherein the temperature controller controls the temperature to be 0 to 800 ℃ in accordance with the performance of the electric heating wire.
7. The system for measuring the interface heat resistance of an FRP reinforced concrete beam as recited in claim 1, wherein the cross-sectional dimension of the member to be heated at the bottom is adapted to the side plate bracket of the heating device; the height of the heating device and the positions of the supports at the two ends of the supporting device can be adjusted, so that the length of the test piece is not limited.
8. The system for measuring the interface heat resistance of an FRP reinforced concrete beam as recited in claim 1, wherein the heating means and the test piece are placed on the supporting means, respectively, without direct contact therebetween; the heating device is of a groove type, and a closed space is formed between the heating device and the bottom of the test piece through the plurality of high-temperature-resistant baffles, so that the bottom of the test piece is heated.
9. An FRP reinforced concrete beam interface heat resistance measurement method based on the FRP reinforced concrete beam interface heat resistance measurement system of claim 1, characterized in that the FRP reinforced concrete beam interface heat resistance measurement method comprises the following steps:
assembling a testing device, adjusting the position of a support, placing an FRP reinforcing member to be heated at the bottom in a groove-shaped heating device, covering high-temperature-resistant top cover plates on two sides of the top member of the device, pushing high-temperature-resistant first heat-insulating end plates and high-temperature-resistant second heat-insulating end plates along side plate supports on two sides of the device, and enabling the first heat-insulating end plates and the second heat-insulating end plates to be attached to the member to be heated, so that a closed space is formed by the whole heating device;
step two, heating the component to be heated at the bottom, burying an electric heating wire at the bottom of the heating device, connecting the electric heating wire with a temperature controller through a leading-out wire, and operating the temperature controller to adjust the temperature in the heating groove so as to heat the component to be heated;
step three, loading the member to be heated at the bottom, after the member to be heated is heated to a target temperature and is kept at the constant temperature for a certain time, operating a jack by using a loading control system to carry out loading, wherein the loading mode can be single-point loading or multi-point loading until a test piece is damaged, and the whole loading process is controlled by the loading control system; the loading and heating processes can also be carried out synchronously, or the loading is carried out after the temperature is firstly increased to the preset temperature;
step four, during the test, displacement data, namely the deflection of the FRP reinforced concrete beam, can be obtained through a displacement meter; the loading control system can also display the load applied to the component; the temperature controller can effectively control the temperature in the heating device;
and fifthly, observing a high-temperature damage mechanism and a performance degradation rule of the FRP reinforced concrete beam, researching the damage form, the bearing capacity and the deformation development process of the reinforced beam after the adhesive is softened at high temperature, analyzing the influence of the interface bonding and the anchoring failure process on the bending resistance of the whole reinforced member, and establishing the FRP strength utilization coefficient calculation method.
10. An application of the FRP reinforced concrete beam interface heat resistance measurement system as defined in any one of claims 1 to 8 in reinforcement by adhering fiber reinforced polymers.
CN201911093425.0A 2019-11-11 2019-11-11 System and method for measuring interface heat resistance of FRP reinforced concrete beam Pending CN110793865A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113670723A (en) * 2021-08-20 2021-11-19 湖南大学 Performance degradation acceleration test method for service rock-soil anchoring structure engineering

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113670723A (en) * 2021-08-20 2021-11-19 湖南大学 Performance degradation acceleration test method for service rock-soil anchoring structure engineering
CN113670723B (en) * 2021-08-20 2022-05-06 湖南大学 Performance degradation acceleration test method for service rock-soil anchoring structure engineering

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