High-temperature tensile test device for high-ductility concrete

Abstract

The invention discloses a high-ductility concrete high-temperature tensile test device, and belongs to the technical field of concrete detection.The high-ductility concrete high-temperature tensile test device comprises a mounting frame and a concrete block, an operation table is fixedly mounted at the top end of the mounting frame, a concrete piece is arranged in the operation table, and a heat supply mechanism is arranged in the operation table; the heat supply mechanism comprises a sealing box fixedly installed in the operation table, a concrete part slidably penetrates through the interior of the sealing box, and an air pump and a heating box are fixedly installed at the top end of the installation frame. The concrete part can be dried and preheated through the preheating assembly, heat flow can be divided and scattered step by step in cooperation with a dispersion block, and local heat flow concentration is avoided; meanwhile, the air flow driving roller drives the heating assembly to integrally rotate, so that the heat flow wraps the concrete piece in an omnibearing and dead-corner-free manner, and the temperature gradient between the surface and the interior of the test piece is effectively eliminated. In addition, a preset valve on the heat collecting pipe can realize partition heat flow control, so that the high-temperature working condition is accurately simulated, and the high-temperature mechanical property of the high-ductility concrete is truly reflected.

Description

Technical Field

[0001] This invention relates to the field of concrete testing technology, and in particular to a high-temperature tensile testing device for high-ductility concrete. Background Technology

[0002] High-ductility concrete, as a new type of building material combining high strength and excellent deformation capacity, is increasingly widely used in earthquake resistance, fire resistance, and post-disaster repair of building structures due to its good crack resistance, energy dissipation performance, and durability. During the service life of building structures, extreme conditions such as fires and high-temperature environments can easily lead to the deterioration of the internal microstructure of high-ductility concrete, resulting in a significant decrease in mechanical properties (such as tensile strength, ductility, and modulus of elasticity), directly affecting the load-bearing safety and stability of the structure. Currently, existing high-temperature tensile testing devices for high-ductility concrete often employ static furnace heating or single-spray heating in their high-temperature heating system designs. This uneven heat distribution can easily lead to localized overheating of the concrete specimen surface and excessive internal and external temperature gradients, resulting in inconsistent decomposition of hydration products within the specimen and failing to accurately reflect the overall mechanical properties of the specimen at high temperatures. Furthermore, in some devices, the free water and capillary water contained within the high-ductility concrete are prone to rapid vaporization during high-temperature heating, generating enormous internal pressure and causing specimen bursting, leading to test interruption and reducing the success rate. Summary of the Invention

[0003] The purpose of this invention is to provide a high-ductility concrete high-temperature tensile testing device to solve the problem mentioned in the background art, which is that local overheating of the concrete specimen surface and excessive internal and external temperature gradients result in inconsistent decomposition of hydration products inside the specimen, making it impossible to truly reflect the overall mechanical properties of the specimen at high temperatures.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a high-ductility concrete high-temperature tensile testing device, comprising a mounting frame and a concrete block, an operating platform fixedly mounted on the top of the mounting frame, a concrete component disposed inside the operating platform, a heating mechanism disposed inside the operating platform, the heating mechanism comprising a sealed box fixedly mounted inside the operating platform, the concrete component slidingly penetrating the interior of the sealed box, an air pump and a heating box fixedly mounted on the top of the mounting frame, a heat inlet pipe connected to the output end of the air pump, the heat inlet pipe communicating with the interior of the sealed box through the heating box, a preheating assembly disposed inside the sealed box, the preheating assembly comprising an annular tube rotatably mounted inside the sealed box, a support ring rotatably mounted on the outer surface of the annular tube communicating with the heat inlet pipe, and the support ring communicating with the annular tube, a plurality of heat collection pipes connected to the outer side of the annular tube, and a jet plate for heating the concrete component connected to the surface of the heat collection pipe.

[0005] As a preferred embodiment of the present invention, the top of the mounting frame is provided with a tensioning mechanism, the tensioning mechanism includes movable rods symmetrically installed inside the operating table, one end of the movable rod is fixedly installed with a fixing plate, the side wall of the fixing plate is fixedly installed with a hydraulic cylinder, the output end of the hydraulic cylinder is provided with a limit plate, and the concrete block is placed between the two limit plates.

[0006] As a preferred embodiment of the present invention, a motor is fixedly mounted on the top of the mounting bracket, a first bevel gear is fixedly mounted on the output shaft of the motor, a support sleeve is fixedly mounted on the top of the mounting bracket, a bidirectional screw is rotatably mounted inside the support sleeve, a second bevel gear is fixedly mounted on the outer surface of the bidirectional screw, and the first bevel gear meshes with the second bevel gear. Opposite threaded grooves are provided at both ends of the bidirectional screw, a moving plate is fixedly mounted on the free end of the moving rod, and a ball is rotatably mounted on the inner wall of the moving plate, and the ball is slidably mounted inside the threaded groove.

[0007] As a preferred embodiment of the present invention, a buffer assembly is provided on the surface of the fixing plate near the concrete component. The buffer assembly includes a high-temperature elastic coupling and a pad. The high-temperature elastic coupling is fixedly installed on the surface of the fixing plate near the concrete component, and the pad is fixedly installed on the free end of the high-temperature elastic coupling.

[0008] As a preferred embodiment of the present invention, a plurality of arc-shaped guide plates are fixedly installed on the inner wall of the annular tube, and a plurality of rollers for driving the support ring to rotate are rotatably installed on the inner wall of the annular tube near the support ring. A plurality of spiral wind-receiving blades are evenly distributed on the outer surface of the rollers, and one end of the annular tube is connected to the interior of the heat collection tube through a connecting pipe.

[0009] As a preferred embodiment of the present invention, the outer surface of the heat collection tube is provided with a plurality of preset valves for zoned heat flow control, and the interior of the preset valve is provided with a buffer shaft for buffering airflow impact. The input end of the air pump is connected to the interior of the sealed box through the heat outlet pipe.

[0010] As a preferred embodiment of the present invention, the cross-section of the jet plate is conical, and a plurality of triangular dispersion blocks for diverting heat flow are fixedly installed inside the jet plate.

[0011] As a preferred embodiment of the present invention, the sealing box is fixedly installed with fixing rings at both ends near the concrete component, and a sealing bladder is installed on the inner wall of the fixing ring. The sealing bladder is connected to one end of the heat inlet pipe through an air pipe.

[0012] As a preferred embodiment of the present invention, the top of the sealed box is provided with a detection component for detecting the surface temperature of the concrete component, and a protective plate is provided on the inner wall of the sealed box near the detection component, and a pre-embedded armored thermocouple is provided in the middle of the concrete component.

[0013] As a preferred embodiment of the present invention, the top of the operating table is provided with a control panel, the air pump is equipped with a frequency converter, the detection component includes an infrared thermal imager, and the control panel is configured to independently adjust the opening degree of preset valves on different heat collection tubes according to the temperature difference distribution map of the concrete surface fed back by the infrared thermal imager.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] 1. This invention constructs a three-dimensional heating structure consisting of a "ring pipe + multiple heat collection pipes + conical jet plate" using a preheating component. Combined with the arc-shaped guide plate on the inner wall of the ring pipe and the triangular dispersion blocks within the jet plate, the heat flow is progressively divided and dispersed, preventing localized heat concentration. Simultaneously, airflow-driven rollers rotate the support ring and heating component as a whole, ensuring the heat flow comprehensively and without blind spots envelops the concrete component, effectively eliminating the temperature gradient between the surface and interior of the specimen. Furthermore, pre-set valves on the heat collection pipes enable zoned heat flow control, and buffer shafts weaken airflow impact, further ensuring temperature field stability, accurately simulating high-temperature conditions, and truly reflecting the high-temperature mechanical properties of high-ductility concrete.

[0016] 2. This invention employs a motor-driven bevel gear meshing transmission, combined with a ball drive structure of a bidirectional screw and a moving plate, to drive the moving rods on both sides to move synchronously in opposite directions. This ensures that the force axis of the concrete component is strictly aligned with the tensile direction, avoiding test distortion caused by eccentric tension. At the same time, a high-temperature elastic coupling is added between the fixed plate and the pad, which can absorb the impact load and vibration during the tensile process and compensate for the thermal deformation of the clamping components under high temperature. This effectively prevents the ends of the concrete component from crushing and chipping, ensuring that the fracture location is concentrated in the gauge length section and improving the accuracy of the test.

[0017] 3. This invention uses a fixed ring to assemble a sealing bladder, and the sealing bladder is connected to the heat inlet pipe through an air pipe. It can be inflated and expanded by the hot air flow in the heat inlet pipe, tightly fitting the gap between the concrete component and the sealing box. It adapts to the thermal expansion and deformation of various components under high temperature. Compared with traditional rigid seals or ordinary elastic seals, the sealing effect is better, which can effectively block heat leakage and maintain a constant high temperature environment inside the box for a long time, reducing the impact of temperature fluctuations on the test results.

[0018] 4. This invention employs a dual temperature measurement mode of "surface detection + internal pre-embedded" technology. The detection component at the top of the sealed chamber can monitor the surface temperature of the concrete component in real time, while the armored thermocouple pre-embedded in the middle of the specimen can directly acquire internal temperature data, avoiding parameter distortion caused by monitoring only the ambient temperature. At the same time, the high-temperature resistant high-speed camera inside the sealed chamber is electrically connected to the control panel, which can record the tensile process of the gauge section of the concrete component in real time. This facilitates subsequent analysis of the entire process of specimen deformation, cracking, and fracture, providing intuitive evidence for the traceability of test data and mechanism research.

[0019] 5. This invention uses a motor drive and hydraulic cylinder assisted clamping to flexibly adapt to high-ductility concrete parts of different sizes. The preheating component is driven to rotate autonomously by airflow, without the need for an additional power source, which simplifies the structure and reduces energy consumption. At the same time, all operations can be centrally controlled through the control panel. Combined with closed-loop heat flow circulation and automatic synchronous stretching, it greatly improves the degree of automation and efficiency of the test. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0021] Figure 2 This is a schematic diagram of the internal structure of the sealing box of the present invention;

[0022] Figure 3 This is a schematic diagram of the heating box structure of the present invention;

[0023] Figure 4 This is a schematic diagram of the buffer component structure of the present invention;

[0024] Figure 5 This is a schematic diagram of the concrete component structure of the present invention;

[0025] Figure 6 This is a schematic diagram of the composite sealing bladder structure of the present invention;

[0026] Figure 7 This is a schematic diagram of the heat collection tube structure of the present invention;

[0027] Figure 8 This is a schematic diagram of the annular tube cross-section structure of the present invention;

[0028] Figure 9 This is a schematic diagram of the cross-sectional structure of the heat collection tube of the present invention.

[0029] In the diagram: 1. Mounting frame; 2. Operating table; 3. Tensioning mechanism; 31. Motor; 32. First bevel gear; 33. Second bevel gear; 34. Bidirectional screw; 35. Support sleeve; 36. Moving plate; 37. Moving rod; 38. Fixed plate; 39. Buffer assembly; 310. Hydraulic cylinder; 311. Limiting plate; 4. Concrete component; 5. Control panel; 6. Heating mechanism; 61. Air pump; 62. Heat inlet pipe; 63. Heat outlet pipe; 64. Heating box; 65. Sealing box; 66. Preheating assembly; 661. Annular pipe; 664. Roller; 663. Guide plate; 662. Support ring; 665. Connecting pipe; 666. Heat collection pipe; 667. Jet plate; 668. Preset valve; 669. Dispersion block; 6610. Buffer shaft; 67. Air pipe; 68. Fixed ring; 69. Sealing bladder; 7. Detection component. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Please see Figure 1-9 This invention provides a high-ductility concrete high-temperature tensile testing device, including a mounting frame 1 and a concrete block. An operating platform 2 is fixedly installed at the top of the mounting frame 1. A concrete component 4 is disposed inside the operating platform 2. A heating mechanism 6 is disposed inside the operating platform 2. The heating mechanism 6 includes a sealed box 65 fixedly installed inside the operating platform 2, and the concrete component 4 slides through the interior of the sealed box 65. An air pump 61 and a heating box 64 are fixedly installed at the top of the mounting frame 1. A heat inlet pipe 62 is connected to the output end of the air pump 61. The heat inlet pipe 62 is connected to the interior of the sealed box 65 through the heating box 64. A preheating component 66 is disposed inside the sealed box 65. The preheating component 66 includes an annular pipe 661 rotatably installed inside the sealed box 65. A support ring 662 connected to the heat inlet pipe 62 is rotatably installed on the outer surface of the annular pipe 661, and the support ring 662 is connected to the annular pipe 661. Multiple heat collection pipes 666 are connected to the outer side of the annular pipe 661, and a jet plate 667 for heating the concrete component 4 is connected to the surface of the heat collection pipes 666.

[0032] The air pump 61 outputs airflow, which is sent to the heating chamber 64 via the heat inlet pipe 62. The heated airflow then enters the preheating component 66 inside the sealed chamber 65. The preheating component 66 is rotatably mounted via the support ring 662. The annular pipe 661 receives the hot airflow from the heat inlet pipe 62 and distributes it to multiple heat collection pipes 666. Finally, the jet plate 667 on the heat collection pipes 666 sprays hot airflow onto the concrete component 4 in a directional manner, thus expelling water vapor and achieving preheating and continuous high-temperature heating. The rotational characteristics of the support ring 662 allow the concrete component 4 to be heated more comprehensively, avoiding excessive local temperature differences and providing a stable high-temperature environment for subsequent precise tensile tests. It also accommodates the displacement requirements of the concrete component 4 during the tensile process. In addition, under test conditions where the air source pressure is insufficient or precise speed control is required, the support ring 662 can also be driven by an external micro auxiliary motor through gear meshing to ensure the stability of the rotational heating.

[0033] In some embodiments, a tensioning mechanism 3 is provided at the top of the mounting frame 1. The tensioning mechanism 3 includes movable rods 37 symmetrically installed inside the operating table 2. A fixing plate 38 is fixedly installed at one end of the movable rod 37. A hydraulic cylinder 310 is fixedly installed on the side wall of the fixing plate 38. A limit plate 311 is provided at the output end of the hydraulic cylinder 310. A concrete block is placed between the two limit plates 311.

[0034] The symmetrically arranged moving rods 37 drive the two end fixing plates 38 to move synchronously. The hydraulic cylinders 310 on the fixing plates 38 can drive the limiting plates 311 to extend and retract, thereby clamping and adjusting the tightness of the concrete part 4. The concrete part 4 is firmly limited between the two limiting plates 311, which can flexibly adapt to concrete parts 4 of different sizes. The clamping is firm and not easy to damage the specimen. The reverse movement of the moving rods 37 applies axial tensile force to the concrete part 4, reducing the risk of eccentric force and improving the stability of the tensile test.

[0035] In some embodiments, a motor 31 is fixedly mounted on the top of the mounting bracket 1, a first bevel gear 32 is fixedly mounted on the output shaft of the motor 31, a support sleeve 35 is fixedly mounted on the top of the mounting bracket 1, a bidirectional screw 34 is rotatably mounted inside the support sleeve 35, a second bevel gear 33 is fixedly mounted on the outer surface of the bidirectional screw 34, and the first bevel gear 32 meshes with the second bevel gear 33. Opposite threaded grooves are opened at both ends of the bidirectional screw 34, a moving plate 36 is fixedly mounted on the free end of the moving rod 37, a ball is rotatably mounted on the inner wall of the moving plate 36, and the ball is slidably mounted inside the threaded groove.

[0036] In this system, motor 31 drives the first bevel gear 32 to rotate, which in turn drives the second bevel gear 33 to rotate. The second bevel gear 33 then drives the bidirectional screw 34 to rotate synchronously. The opposite threaded grooves at both ends of the bidirectional screw 34 engage with the ball bearings on the inner wall of the moving plate 36, converting the rotational motion of the screw into the linear motion of the moving plate 36. This, in turn, drives the moving rod 37 to move synchronously in the opposite direction, achieving uniform stretching of the concrete component 4 after it is clamped by the two side limit plates 311. This allows for precise control of the stretching rate and displacement, avoiding eccentric tension on the concrete component 4 due to asynchronous movements on both sides, and significantly improving the accuracy of the tensile test.

[0037] In some embodiments, a buffer assembly 39 is provided on the surface of the fixed plate 38 near the concrete component 4. The buffer assembly 39 includes a high-temperature elastic coupling and a pad. The high-temperature elastic coupling is fixedly installed on the surface of the fixed plate 38 near the concrete component 4, and the pad is fixedly installed on the free end of the high-temperature elastic coupling.

[0038] Among them, the high-temperature elastic coupling can withstand the high-temperature environment inside the sealed box 65, avoiding failure under high temperature. At the same time, the elastic deformation capacity of the high-temperature elastic coupling buffers the impact load during the tensile process, preventing the concrete part 4 from being damaged locally due to excessive instantaneous force. The pad increases the contact area with the concrete part 4, disperses the clamping pressure, avoids crushing the concrete part 4 at the clamping end, ensures that the fracture position of the specimen is concentrated in the gauge length section, and improves the stability of the test.

[0039] In some embodiments, a plurality of arc-shaped guide plates 663 are fixedly installed on the inner wall of the annular tube 661, and a plurality of rollers 664 for airflow to drive the rotation of the support ring 662 are rotatably installed on the inner wall of the annular tube 661 near the support ring 662. A plurality of spiral wind-receiving blades are evenly distributed on the outer surface of the rollers 664, and one end of the annular tube 661 is connected to the interior of the heat collection tube 666 through a connecting pipe 665.

[0040] Among them, the arc-shaped guide plate 663 optimizes the heat flow distribution and improves the heat flow uniformity. At the same time, it guides part of the airflow to circulate inside the annular pipe 661. When the hot airflow in the annular pipe 661 flows through at high speed, the airflow impacts the wind-receiving blades and drives the roller 664 to rotate. Then, through the friction between the roller 664 and the inner wall of the annular pipe 661, it drives the support ring 662 and the entire preheating component 66 to rotate, so that the heat flow can fully wrap the concrete component 4, eliminate the dead zone of heat, and further improve the stability of the temperature field. The connecting pipe 665 realizes the stable connection between the annular pipe 661 and the heat collection pipe 666, ensuring the smooth delivery of hot airflow.

[0041] In some embodiments, the outer surface of the heat collection tube 666 is provided with a plurality of preset valves 668 for zoned heat flow control, and the interior of the preset valves 668 is provided with a buffer shaft 6610 for buffering airflow impact. The input end of the air pump 61 is connected to the interior of the sealed box 65 through the heat outlet tube 63.

[0042] Among them, the preset valve 668 on the heat collection pipe 666 can independently adjust the heat flow rate of the corresponding area, and can accurately control the heat flow for different areas of the concrete component 4, adapt to the temperature requirements of each part of the specimen, and improve the accuracy of high temperature simulation; the buffer shaft 6610 inside the preset valve 668 weakens the impact of hot air flow through its own structural deformation, and avoids excessive air flow impact from affecting the stability of the specimen; the input end of the air pump 61 is connected to the sealed box 65 through the heat outlet pipe 63, forming a closed-loop circulation system to reduce heat loss.

[0043] In some embodiments, the jet plate 667 has a conical cross-section, and a plurality of triangular dispersion blocks 669 for diverting heat flow are fixedly installed inside the jet plate 667.

[0044] Among them, the jet plate 667 adopts a conical cross-section design, which can gather the hot airflow and improve the jet flow effect; the triangular dispersion block 669 inside the jet plate 667 disperses and diverts the concentrated hot airflow delivered by the heat collection pipe 666, so that the hot airflow is ejected from the jet plate 667 at a uniform flow rate and acts on the surface of the concrete component 4, effectively avoiding the problem of local overheating, ensuring that the surface of the concrete component 4 is heated evenly, and reducing the local deterioration of the specimen caused by the concentration of heat flow.

[0045] In some embodiments, fixing rings 68 are fixedly installed at both ends of the sealing box 65 near the concrete component 4. A sealing bladder 69 is installed on the inner wall of the fixing ring 68. The sealing bladder 69 is connected to one end of the heat inlet pipe 62 through the air pipe 67.

[0046] Among them, the fixing rings 68 at both ends of the sealing box 65 provide an installation carrier for the sealing bladder 69. The sealing bladder 69 is connected to the heat inlet pipe 62 through the air pipe 67. It is inflated by the hot air flow in the heat inlet pipe 62. After expansion, the sealing bladder 69 fits tightly against the gap between the concrete part 4 and the sealing box 65 to form a flexible sealing structure that can adapt to the displacement deformation of the concrete part 4 during the stretching process.

[0047] The sealing bladder 69 is made of high-temperature resistant fluororubber composite material. The surface of the sealing bladder 69 facing the inside of the sealing box 65 is covered with a flexible heat-insulating scale layer to block heat radiation and prevent the sealing bladder 69 from aging.

[0048] In some embodiments, the top of the sealed box 65 is provided with a detection component 7 for detecting the surface temperature of the concrete component 4, and a protective plate is provided on the inner wall of the sealed box 65 near the detection component 7, and a pre-embedded armored thermocouple is provided in the middle of the concrete component 4.

[0049] Among them, the detection component 7 at the top of the sealed box 65 collects the surface temperature data of the concrete component 4 in real time, and the inner wall protective plate blocks the high temperature heat flow and radiation damage to the detection component 7; the armored thermocouple pre-embedded in the middle of the concrete component 4 directly monitors the internal temperature of the component, realizing dual monitoring of surface and internal temperatures, avoiding parameter distortion caused by only monitoring the ambient temperature, and accurately grasping the actual temperature state of the concrete component 4.

[0050] In some embodiments, the top of the operating table 2 is provided with a control panel 5, the air pump 61 is equipped with a frequency converter, the detection component 7 includes an infrared thermal imager, and the control panel 5 is configured to independently adjust the opening degree of the preset valve 668 on different heat collection tubes 666 according to the surface temperature difference distribution map of the concrete component 4 fed back by the infrared thermal imager.

[0051] Among them, the control panel 5 at the top of the operating console 2 centrally controls the operation of various components, realizing integrated operation of functions such as heating temperature, stretching rate, and temperature acquisition.

[0052] Working principle: The mounting frame 1 supports the operating platform 2 and various functional components. The sealed box 65 inside the operating platform 2 provides a closed space for the high-temperature tensile testing of the concrete component 4. The concrete component 4 slides through the sealed box 65 to accommodate the tensile displacement. During the test, the air pump 61 outputs airflow through the heat inlet pipe 62 and sends it into the heating box 64 for heating. The heated airflow then flows into the preheating component 66 inside the sealed box 65. The preheating component 66 is rotatably installed via the support ring 662. The annular pipe 661 receives the hot airflow delivered by the heat inlet pipe 62 and distributes it to multiple heat collection pipes 666. Finally... Hot air is directed onto the concrete component 4 by the jet plate 667 on the heat collection pipe 666, which completes the preheating and continuous high-temperature heating by expelling water vapor. The rotational characteristics of the support ring 662 allow the concrete component 4 to be heated more evenly, avoiding excessive local temperature differences and providing a stable high-temperature environment for subsequent precise tensile tests. In addition, the pre-set valve 668 on the heat collection pipe 666 can realize zoned heat flow control, and the buffer shaft 6610 can weaken the airflow impact, further ensuring the stability of the temperature field, so as to accurately simulate high-temperature working conditions and truly reflect the high-temperature mechanical properties of high-ductility concrete.

[0053] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of the present invention.

Claims

1. A high-temperature tensile testing device for high-ductility concrete, comprising a mounting frame (1) and a concrete block, characterized in that: An operating platform (2) is fixedly installed at the top of the mounting frame (1). A concrete component (4) is installed inside the operating platform (2). A heating mechanism (6) is installed inside the operating platform (2). The heating mechanism (6) includes a sealed box (65) fixedly installed inside the operating platform (2), and the concrete component (4) slides through the interior of the sealed box (65). An air pump (61) and a heating box (64) are fixedly installed at the top of the mounting frame (1). A heat inlet pipe (62) is connected to the output end of the air pump (61). The heat inlet pipe (62) is connected to the sealed box (64) through the heating box (64). The interior of the sealed box (65) is connected, and a preheating assembly (66) is provided inside the sealed box (65). The preheating assembly (66) includes an annular tube (661) rotatably installed inside the sealed box (65). A support ring (662) communicating with the heat inlet pipe (62) is rotatably installed on the outer surface of the annular tube (661), and the support ring (662) is communicating with the annular tube (661). A plurality of heat collection tubes (666) are connected and installed on the outer side of the annular tube (661). A jet plate (667) for heating the concrete component (4) is connected and installed on the surface of the heat collection tubes (666).

2. The high-temperature tensile testing device for high-ductility concrete according to claim 1, characterized in that: The top of the mounting frame (1) is provided with a tensioning mechanism (3). The tensioning mechanism (3) includes a moving rod (37) symmetrically installed inside the operating table (2). One end of the moving rod (37) is fixedly installed with a fixing plate (38). The side wall of the fixing plate (38) is fixedly installed with a hydraulic cylinder (310). The output end of the hydraulic cylinder (310) is provided with a limit plate (311). The concrete block is placed between the two limit plates (311).

3. The high-temperature tensile testing device for high-ductility concrete according to claim 2, characterized in that: A motor (31) is fixedly installed at the top of the mounting bracket (1). A first bevel gear (32) is fixedly installed on the output shaft of the motor (31). A support sleeve (35) is fixedly installed at the top of the mounting bracket (1). A bidirectional screw (34) is rotatably installed inside the support sleeve (35). A second bevel gear (33) is fixedly installed on the outer surface of the bidirectional screw (34). The first bevel gear (32) meshes with the second bevel gear (33). Opposite threaded grooves are opened at both ends of the bidirectional screw (34). A moving plate (36) is fixedly installed at the free end of the moving rod (37). A ball is rotatably installed on the inner wall of the moving plate (36). The ball is slidably installed inside the threaded groove.

4. The high-temperature tensile testing device for high-ductility concrete according to claim 2, characterized in that: A buffer assembly (39) is provided on the surface of the fixed plate (38) near the concrete component (4). The buffer assembly (39) includes a high-temperature elastic coupling and a pad. The high-temperature elastic coupling is fixedly installed on the surface of the fixed plate (38) near the concrete component (4), and the pad is fixedly installed on the free end of the high-temperature elastic coupling.

5. The high-temperature tensile testing device for high-ductility concrete according to claim 1, characterized in that: Multiple arc-shaped guide plates (663) are fixedly installed on the inner wall of the annular tube (661). Multiple rollers (664) for airflow to drive the rotation of the support ring (662) are rotatably installed on the inner wall of the annular tube (661) near the support ring (662). Multiple spiral wind-receiving blades are evenly distributed on the outer surface of the rollers (664). One end of the annular tube (661) is connected to the interior of the heat collection tube (666) through a connecting pipe (665).

6. The high-temperature tensile testing device for high-ductility concrete according to claim 1, characterized in that: The outer surface of the heat collection tube (666) is provided with a plurality of preset valves (668) for zoned heat flow control. The interior of the preset valve (668) is provided with a buffer shaft (6610) for buffering airflow impact. The input end of the air pump (61) is connected to the interior of the sealed box (65) through the heat outlet pipe (63).

7. The high-temperature tensile testing device for high-ductility concrete according to claim 1, characterized in that: The jet plate (667) has a conical cross-section, and a plurality of triangular dispersion blocks (669) for diverting heat flow are fixedly installed inside the jet plate (667).

8. The high-temperature tensile testing device for high-ductility concrete according to claim 1, characterized in that: The sealing box (65) is fixedly installed with fixing rings (68) at both ends near the concrete component (4). The inner wall of the fixing ring (68) is connected to a sealing bladder (69). The sealing bladder (69) is connected to one end of the heat inlet pipe (62) through a gas pipe (67).

9. The high-temperature tensile testing device for high-ductility concrete according to claim 1, characterized in that: The top of the sealed box (65) is provided with a detection component (7) for detecting the surface temperature of the concrete component (4), and a protective plate is provided on the inner wall of the sealed box (65) near the detection component (7). A pre-embedded armored thermocouple is provided in the middle of the concrete component (4).

10. The high-temperature tensile testing device for high-ductility concrete according to claim 9, characterized in that: The top of the operating table (2) is equipped with a control panel (5), the air pump (61) is equipped with a frequency converter, the detection component (7) includes an infrared thermal imager, and the control panel (5) is configured to independently adjust the opening degree of the preset valve (668) on different heat collection tubes (666) according to the surface temperature difference distribution map of the concrete component (4) fed back by the infrared thermal imager.

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