Load loading device in fire endurance test of steel structure fireproof coating

Abstract

The invention belongs to the technical field of building material quality detection, and particularly relates to a load loading device in a fire endurance test of a steel structure fire retardant coating, the load loading device comprises a base, the lower surface of the base is fixedly connected with two supporting plates, the outer walls of the two supporting plates are jointly and fixedly connected with a transverse plate, and the top end of the transverse plate is provided with a through hole; the hole wall of the through hole is fixedly connected with a rolling bearing, and the inner wall of the rolling bearing is fixedly connected with a rotating rod. According to the invention, the load loading device in the fire endurance test of the steel structure fireproof coating not only has the functions of vertical load, lateral load and torsional load simulation loading, but also has the functions of comprehensive heating of a standard I-shaped steel structure test piece and accurate positioning of a load loading position; therefore, more reliable conditions are provided for the fire endurance test of the steel structure fireproof coating, the accuracy of the fire endurance test result of the steel structure fireproof coating can be effectively improved, and meanwhile, the credibility and effectiveness of the device in the test are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of building material quality detection, and in particular relates to a load loading device in a fire resistance limit test of a steel structure fire retardant coating. Background Art

[0002] Steel structure fire retardant coating is mainly applied on the surface of steel structure, and its purpose is to improve the fire resistance limit of steel structure. At present, the fire resistance limit performance test of steel structure fire retardant coating is mainly carried out according to GB14907-2002 standard. The fire retardant coating is firstly applied on the standard I-beam, and then placed on the fire resistance limit test furnace. The fire resistance test is carried out while loading vertically downward. For example, the patent authorization announcement number is CN206556990U, which discloses a load loading device for the fire resistance limit test of steel structure fire retardant coating. The fire resistance limit test of fire retardant coating is to ensure the safety of the building, ensure the bearing capacity of the steel structure under fire and meet the fire protection design requirements of the building, and to evaluate the heat insulation performance of the steel structure fire retardant coating and the protection of the mechanical properties of the steel structure.

[0003] When conducting fire resistance limit test of fire retardant coating on steel structure, the existing load loading device has many shortcomings. As far as load loading is concerned, most of the current methods use unilateral loading to apply load to steel structure. This method makes the load on steel structure in fire resistance limit test of fire retardant coating significantly different from the stress conditions in actual use. In actual steel structure use scenarios, the horizontal direction will bear extrusion load, and the vertical direction will bear not only load-bearing load, but also torsional load due to external wind force. The existing unilateral loading method is difficult to accurately simulate these complex stress conditions, which leads to inaccurate simulation of steel structure load. The impact of this problem is multifaceted. On the one hand, it directly affects the accuracy of the fire resistance limit test results of steel structure fire retardant coating, making the test results unable to truly reflect the performance of fire retardant coating under actual working conditions; on the other hand, it also has a negative impact on the reliability and effect of the use of the load loading device itself, reducing the credibility and effectiveness of the device in the test; In addition, in the testing of refractory materials on the surface of steel structures, when using a load loading device to test the fire resistance limit of steel structure fire retardant coatings, the steel structure coated with fire retardant coatings is usually placed in a heating furnace for single-sided heating at the bottom. This heating method will cause uneven heating of the refractory materials on the surface of the steel structure, which is seriously inconsistent with the heating conditions of the refractory materials of the steel structure at the actual fire scene. Because at the actual fire scene, all surfaces of the steel structure may be attacked by flames, and heat is transmitted from multiple directions. This uneven heating situation will have an adverse effect on the accuracy of the fire resistance limit test results of the steel structure fire retardant coating, and may ultimately lead to deviations in the performance evaluation of the steel structure fire retardant coating.

[0004] To this end, we proposed a load loading device for the fire resistance limit test of steel structure fire retardant coatings to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a load loading device for fire resistance limit test of steel structure fire retardant coating in view of the above problems.

[0006] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a load loading device for fire resistance limit test of steel structure fire retardant coating, comprising a base, the lower surface of the base is fixedly connected with two support plates, the outer walls of the two support plates are commonly fixedly connected with a cross plate, the top of the cross plate is provided with a through hole, and the hole wall of the through hole is fixedly connected with a rolling bearing, the inner wall of the rolling bearing is fixedly connected with a rotating rod, the upper surface of the base is provided with a circular hole, and the hole wall of the circular hole is fixedly connected with a connecting bearing, the inner wall of the connecting bearing is fixedly connected with a connecting seat, and the upper surface of the cross plate is fixedly connected with a torsion load simulation mechanism; The upper surface of the base is fixedly connected with a lateral load simulation mechanism, and the upper surface of the base is fixedly connected with a support tube and a heat preservation tube; The outer wall of the support cylinder is fixedly sleeved with a fixing cylinder, the hole wall of the fixing cylinder is connected with a connecting rod through a fixed bearing, the upper surface of the connecting rod is fixedly connected with a top seat, the upper surface of the top seat is provided with a mounting through hole, and the hole wall of the mounting through hole is fixedly connected with a heat-resistant rubber ring, the inner wall of the heat-resistant rubber ring is fixedly connected with an insulating limit seat, and the upper surface of the top seat is fixedly connected with a vertical load simulation mechanism; An insulating heat-insulating sleeve, a first electromagnetic valve and a second electromagnetic valve are fixedly embedded on the outer walls of the support tube and the heat-insulating tube, and a temperature sensor is fixedly embedded on the inner wall of the insulating heat-insulating sleeve.

[0007] In the above-mentioned load loading device for the fire resistance limit test of steel structure fire retardant coating, the torsion load simulation mechanism includes a U-shaped limit frame fixedly connected to the upper surface of the horizontal plate, the inner wall of the U-shaped limit frame is movably connected with a rack, the rod wall of the rotating rod is fixedly sleeved with a gear that meshes with the rack, one of the side walls of the support plates is provided with a circular hole, and the hole wall of the circular hole is fixedly connected with a first electric hydraulic rod, the moving end of the first electric hydraulic rod is fixedly connected to the side end of the rack, the lower surface of the horizontal plate is fixedly connected with a U-shaped frame, the inner wall of the U-shaped frame is fixedly connected with a torsion force sensor, and the measuring end of the torsion force sensor is fixedly connected to the bottom end of the rotating rod.

[0008] In the above-mentioned load loading device for the fire resistance limit test of steel structure fire retardant coating, the lateral load simulation mechanism includes a fixed frame fixedly connected to the upper surface of the base, the side wall of the fixed frame is provided with two through holes, and the hole wall of the through hole is fixedly connected with a thermal insulation sleeve, the side end of the thermal insulation sleeve passes through the inner wall of the support tube and the insulation tube, the side end of the thermal insulation sleeve is fixedly embedded with a second electric hydraulic rod, the side end of the thermal insulation sleeve away from the second electric hydraulic rod is movably sleeved with an insulating pressure sleeve, the inner wall of the insulating pressure sleeve is fixedly connected with a pressure sensor, the side end hole wall of the insulating pressure sleeve is movably connected with a moving rod, and the side end of the moving rod is fixedly connected to the side end of the second electric hydraulic rod.

[0009] In the above-mentioned load loading device for the fire resistance limit test of steel structure fire retardant coating, the rod wall of the movable rod is movably sleeved with a reset spring, and the two ends of the reset spring are respectively fixedly connected to the rod wall of the movable rod and the inner wall of the insulation sleeve, and the outer walls of the movable rod, the insulation sleeve and the insulation sleeve are all provided with wire through holes.

[0010] In the above-mentioned load loading device for the fire resistance limit test of steel structure fire retardant coating, the vertical load simulation mechanism includes a U-shaped top frame fixedly connected to the upper surface of the top seat, a third electric hydraulic rod is fixedly embedded in the top of the U-shaped top frame, a PLC controller, an alarm and a display screen are fixedly connected to the top outer wall of the U-shaped top frame, the bottom end of the third electric hydraulic rod is fixedly connected to an insulating ring, the inner wall of the insulating ring is movably connected to a semicircular ring, the bottom end of the semicircular ring is fixedly connected to the upper surface of the insulating limit seat, the bottom end of the insulating ring is fixedly connected to a first conductive spike block, and the upper surface of the insulating limit seat is fixedly connected to a second conductive spike block that matches the first conductive spike block.

[0011] In the above-mentioned load loading device for the fire resistance limit test of steel structure fire retardant coating, the upper surfaces of the support tube and the insulation tube and the lower surface of the top seat are on the same horizontal plane.

[0012] In the above-mentioned load loading device for the fire resistance limit test of steel structure fire retardant coating, the top seat is fixedly connected with a nut away from the outer wall of the fixed tube, the inner wall of the nut is threadedly connected with a limiting bolt, and the outer wall of the support tube is provided with a threaded blind hole matching the side end of the limiting bolt.

[0013] In the above-mentioned load loading device for the fire resistance limit test of steel structure fire retardant coating, the side opposite to the connecting seat and the insulating limit seat are provided with an I-shaped steel side end placement groove.

[0014] 1. By setting up the torsion load simulation mechanism, lateral load simulation mechanism and vertical load simulation mechanism, when the steel structure fire retardant coating needs to be subjected to the fire resistance limit test, the strength of the standard I-shaped steel structure test piece is first tested by the torsion load simulation mechanism, the lateral load simulation mechanism and the vertical load simulation mechanism to see if it is qualified. After the test is qualified, the fire resistance limit test of the steel structure fire retardant coating is then carried out. In the fire resistance limit test of the steel structure fire retardant coating, the torsion load simulation mechanism, the lateral load simulation mechanism and the vertical load simulation mechanism can be used to apply simulated loads in multiple directions to the standard I-shaped steel structure test piece. At the same time, observe whether the alarm sounds, and record the time T0 from the start of the fire resistance limit test of the standard I-shaped steel structure test piece sprayed with the fire retardant coating to the alarm of the alarm. The larger the value of the time T0, the better the fire resistance performance of the steel structure fire retardant coating. The mechanism enables the load loading device in the fire resistance limit test of the steel structure fire retardant coating to have the functions of simulating vertical load, lateral load and torsion load, thereby providing more reliable conditions for the fire resistance limit test of the steel structure fire retardant coating, and can effectively improve the accuracy of the fire resistance limit test results of the steel structure fire retardant coating.

[0015] 2. By setting the connecting seat, rack, gear and first electric hydraulic rod, when the standard I-shaped steel structure test piece sprayed with steel structure fire retardant coating is installed on the load loading device again, the self-locking ability of the first electric hydraulic rod, rack and gear can avoid the position of the connecting seat from changing, thereby ensuring that the installation position of the standard I-shaped steel structure test piece sprayed with fire retardant coating remains unchanged from that during the previous strength test, thereby ensuring that the load loading position of the standard I-shaped steel structure test piece does not change when the fire resistance limit test of the fire retardant coating is carried out, thereby avoiding interference of different load loading positions to the fire resistance limit test of the fire retardant coating. This mechanism enables the load loading device to have the function of accurately positioning the load loading position in the fire resistance limit test of the steel structure fire retardant coating, which can not only ensure the accuracy of the fire resistance limit test results of the steel structure fire retardant coating, but also improve the reliability and effect of the use of the load loading device.

[0016] 3. By setting up the support tube and the insulation tube, the double-layer structure design of the support tube and the insulation tube, and cooperating with the base and the top seat, the fire resistance limit test of the steel structure fire retardant coating is in a sealed state, and the steel structure fire retardant coating on the surface of the standard I-shaped steel structure test piece can be fully heated, thereby better simulating the situation of the steel structure fire retardant coating in an actual fire scene, and in a sealed environment, the heat used for the fire resistance limit test of the steel structure fire retardant coating is not easy to lose, thereby increasing the speed of temperature increase in the fire resistance limit test of the steel structure fire retardant coating. This mechanism enables the load loading device to have the function of fully heating the fire retardant coating in the fire resistance limit test of the steel structure fire retardant coating, which can effectively improve the accuracy of the fire resistance limit test results of the steel structure fire retardant coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1It is a structural schematic diagram of a load loading device in a fire resistance limit test of a steel structure fire retardant coating provided by the present invention; Figure 2 It is a schematic structural diagram of a cross-section of a load loading device in a fire resistance limit test of a steel structure fire retardant coating provided by the present invention; Figure 3 yes Figure 2 A schematic diagram of the structure of a partial cross-section of the middle lateral load simulation mechanism; Figure 4 It is a structural schematic diagram of part A of a load loading device in a fire resistance limit test of a steel structure fire retardant coating provided by the present invention; Figure 5 It is a structural schematic diagram of the rack and gear parts in a load loading device in a fire resistance limit test of a steel structure fire retardant coating provided by the present invention; Figure 6 It is a structural schematic diagram of a limit bolt part in a load loading device in a fire resistance limit test of a steel structure fire retardant coating provided by the present invention; Figure 7 It is a structural schematic diagram of a connecting seat part in a load loading device in a fire resistance limit test of a steel structure fire retardant coating provided by the present invention.

[0018] In the figure: 1 base, 2 support plate, 3 cross plate, 4 rolling bearing, 5 rotating rod, 6 connecting bearing, 7 torsion load simulation mechanism, 71 U-shaped limit frame, 72 rack, 73 gear, 74 first electric hydraulic rod, 75 U-shaped frame, 76 torsion force sensor, 8 lateral load simulation mechanism, 81 fixed frame, 82 insulation sleeve, 83 second electric hydraulic rod, 84 insulation pressure sleeve, 85 pressure sensor, 86 moving rod, 9 vertical load simulation mechanism, 91 U-shaped top frame, 92 third electric hydraulic rod, 93 PLC control device, 94 alarm, 95 display screen, 96 insulating ring, 97 semicircular ring, 98 first conductive tip block, 99 second conductive tip block, 10 connecting seat, 11 supporting tube, 12 heat preservation tube, 13 fixing tube, 14 connecting rod, 15 top seat, 16 heat-resistant rubber ring, 17 insulating limit seat, 18 insulating heat insulation sleeve, 19 first electromagnetic valve, 20 second electromagnetic valve, 21 reset spring, 22 wire through hole, 23 nut, 24 limit bolt, 25 threaded blind hole, 26 I-shaped steel side end placement groove, 27 temperature sensor. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] like Figure 1-Figure 7 As shown, a load loading device for fire resistance limit test of fire retardant coating for steel structure comprises a base 1, two support plates 2 are fixedly connected to the lower surface of the base 1, a cross plate 3 is fixedly connected to the outer walls of the two support plates 2, a through hole is formed at the top of the cross plate 3, a rolling bearing 4 is fixedly connected to the hole wall of the through hole, a rotating rod 5 is fixedly connected to the inner wall of the rolling bearing 4, a circular hole is formed on the upper surface of the base 1, a connecting bearing 6 is fixedly connected to the hole wall of the circular hole, a connecting seat 10 is fixedly connected to the inner wall of the connecting bearing 6, a torsion load simulation mechanism 7 is fixedly connected to the upper surface of the cross plate 3, and the torsion load simulation mechanism 7 comprises a U-shaped limit frame 71 fixedly connected to the upper surface of the horizontal plate 3, the inner wall of the U-shaped limit frame 71 is movably connected with a rack 72, the rod wall of the rotating rod 5 is fixedly sleeved with a gear 73 meshing with the rack 72, a round hole is opened in the side wall of one of the support plates 2, and the hole wall of the round hole is fixedly connected with a first electric hydraulic rod 74, the moving end of the first electric hydraulic rod 74 is fixedly connected to the side end of the rack 72, the lower surface of the horizontal plate 3 is fixedly connected with a U-shaped frame 75, the inner wall of the U-shaped frame 75 is fixedly connected with a torsion force sensor 76, and the measuring end of the torsion force sensor 76 is fixedly connected to the bottom end of the rotating rod 5.

[0021] The upper surface of the base 1 is fixedly connected with a lateral load simulation mechanism 8, which includes a fixing frame 81 fixedly connected with the upper surface of the base 1, and the side wall of the fixing frame 81 is provided with two through holes, and the hole wall of the through hole is fixedly connected with a heat insulating sleeve 82, and the side end of the heat insulating sleeve 82 passes through the inner wall of the support tube 11 and the heat preservation tube 12, and the side end of the heat insulating sleeve 82 is fixedly embedded with a second electric hydraulic rod 83, and the side end of the heat insulating sleeve 82 away from the second electric hydraulic rod 83 is movably sleeved with a heat insulating pressure sleeve 84, and the heat insulating pressure sleeve 84 is fixedly sleeved with a second electric hydraulic rod 83. 4 is fixedly connected with a pressure sensor 85, a moving rod 86 is movably connected to the side end hole wall of the heat insulating sleeve 84, the side end of the moving rod 86 is fixedly connected to the side end of the second electric hydraulic rod 83, a return spring 21 is movably sleeved on the rod wall of the moving rod 86, and both ends of the return spring 21 are respectively fixedly connected to the rod wall of the moving rod 86 and the inner wall of the heat insulating sleeve 84, and the outer walls of the moving rod 86, the heat insulating sleeve 84 and the heat insulating sleeve are all provided with a wire through hole 22, which can facilitate the wire connection of the pressure sensor 85.

[0022] A support tube 11 and an insulation tube 12 are fixedly connected to the upper surface of the base 1, a fixed tube 13 is fixedly sleeved on the outer wall of the support tube 11, a connecting rod 14 is connected to the hole wall of the fixing tube 13 through a fixed bearing, a top seat 15 is fixedly connected to the upper surface of the connecting rod 14, a mounting through hole is provided on the upper surface of the top seat 15, a heat-resistant rubber ring 16 is fixedly connected to the hole wall of the mounting through hole, an insulating limit seat 17 is fixedly connected to the inner wall of the heat-resistant rubber ring 16, an I-shaped steel side end placement groove 26 is provided on the opposite side of the connecting seat 10 and the insulating limit seat 17, the I-shaped steel side end placement groove 26 can ensure the accurate installation position of the standard I-shaped steel structure test piece installed by the load loading device, and at the same time can improve the convenience of installation of the standard I-shaped steel structure test piece.

[0023] The upper surface of the top seat 15 is fixedly connected with a vertical load simulation mechanism 9, which includes a U-shaped top frame 91 fixedly connected to the upper surface of the top seat 15, a third electric hydraulic rod 92 is fixedly embedded at the top of the U-shaped top frame 91, a PLC controller 93, an alarm 94 and a display screen 95 are fixedly connected to the outer wall of the top of the U-shaped top frame 91, an insulating ring 96 is fixedly connected to the bottom end of the third electric hydraulic rod 92, and a semicircular ring 97 is movably connected to the inner wall of the insulating ring 96, and the bottom end of the semicircular ring 97 is connected to the insulating limit The upper surface of the seat 17 is fixedly connected, the bottom end of the insulating ring 96 is fixedly connected with a first conductive spike 98, and the upper surface of the insulating limit seat 17 is fixedly connected with a second conductive spike 99 that matches the first conductive spike 98, so that the load loading device in the fire resistance limit test of the steel structure fire retardant coating not only has the function of simulating vertical load, lateral load and torsional load loading, but also has the function of accurately locating the load loading position of the standard I-type steel structure test piece, thereby providing more reliable conditions for the fire resistance limit test of the steel structure fire retardant coating.

[0024] The outer walls of the support tube 11 and the insulation tube 12 are fixedly embedded with an insulating sleeve 18, a first electromagnetic valve 19 and a second electromagnetic valve 20, and the inner wall of the insulating sleeve 18 is fixedly embedded with a temperature sensor 27, so that the load loading device in the fire resistance limit test of the steel structure fire retardant coating has the function of fully heating the standard I-type steel structure test piece, thereby providing more reliable conditions for the fire resistance limit test of the steel structure fire retardant coating, and can effectively improve the accuracy of the fire resistance limit test results of the steel structure fire retardant coating.

[0025] The upper surfaces of the support tube 11 and the insulation tube 12 and the lower surface of the top seat 15 are on the same horizontal plane, thereby ensuring the sealing of the connection between the top seat 15 and the support tube 11 and the insulation tube 12. The top seat 15 is fixedly connected with a nut 23 away from the outer wall of the fixed tube 13. The inner wall of the nut 23 is threadedly connected with a limiting bolt 24. The outer wall of the support tube 11 is provided with a threaded blind hole 25 that matches the side end of the limiting bolt 24. After the limiting bolt 24 can be connected with the threaded blind hole 25, the stability of the connection of the top seat 15 can be improved.

[0026] The pressure sensor 85, the temperature sensor 27 and the torsional force sensor 76 are electrically connected to the input end of the PLC controller 93 through wires, the conductive branches of the first conductive tip block 98 and the second conductive tip block 99 are electrically connected to the input end of the PLC controller 93, the first electric hydraulic rod 74, the second electric hydraulic rod 83, the first electromagnetic valve 19, the second electromagnetic valve 20, the alarm 94, the display screen 95 and the third electric hydraulic rod 92 are all electrically connected to the output end of the PLC controller 93 through wires, wherein the display screen 95 can display the changes in data during the load loading device test in real time, and the above-mentioned power-on equipment and electrical connections are prior art and will not be repeated here.

[0027] The operating principle of the present invention is described as follows: When the fire retardant coating of the steel structure needs to be tested for fire resistance limit, the standard I-shaped steel structure test piece is first placed in the load loading device for strength qualification test. The test process is multi-directional load loading test through the torsion load simulation mechanism 7, the lateral load simulation mechanism 8 and the vertical load simulation mechanism 9. At this time, the bottom end of the standard I-shaped steel structure test piece is placed in the I-shaped steel side end placement groove 26 in the connecting seat 10, and the top seat 15 is rotated by the connecting rod 14 so that the top seat 15 is aligned with the support The cylinder 11 is closed, and the limit bolt 24 on the nut 23 is connected to the threaded blind hole 25. At the same time, the connecting seat 10 is not easy to rotate and misalign due to the self-locking limit of the gear 73, the rack 72 and the first electric hydraulic rod 74. The top of the standard I-shaped steel structure test piece is aligned with the I-shaped steel side end placement groove 26 on the insulating limit seat 17. Then, the third electric hydraulic rod 92 is fully extended through the PLC controller 93. The first half of the third electric hydraulic rod 92 pushes the insulating limit seat 17 downward through the insulating ring 96 and the semicircular ring 97, and the standard I-shaped steel structure test piece is aligned with the I-shaped steel side end placement groove 26 on the insulating limit seat 17. The top of the steel structure test piece is connected to the side end placement slot 26 of the insulating limit seat 17. The second half of the extension of the third electric hydraulic rod 92 simulates the vertical load loading work. After the third electric hydraulic rod 92 is fully extended, it can simulate the maximum vertical load F1 of the standard steel structure test piece. Then observe whether the alarm 94 alarms. The standard steel structure test piece is deformed, and the first conductive tip block 98 and the second conductive tip block 99 are disconnected at the tip. The PLC controller 93 interrupts the electrical signal input and controls the alarm 94 to alarm, indicating that the standard steel structure test piece is deformed and there are test hazards, which affects the accuracy of the fire retardant coating fire resistance performance detection. On the contrary, the standard steel structure test piece is not deformed, and the connection between the first conductive tip block 98 and the second conductive tip block 99 is not disconnected, then the input end of the PLC controller 93 does not have an electrical signal change, then the PLC controller 93 controls the alarm 94 not to alarm, and the vertical load bearing capacity of the standard steel structure test piece is qualified, and then the PLC controller 93 controls the lateral load simulation mechanism 8 to work; After the second electric hydraulic rod 83 in the lateral load simulation mechanism 8 is controlled and started by the PLC controller 93, the second electric hydraulic rod 83 pushes the moving rod 86 to move, and the moving rod 86 pushes the heat-insulating pressure sleeve 84 through the pressure sensor 85 to squeeze the side of the standard I-shaped steel structure test piece, simulating the environment where the steel structure is loaded laterally. While the second electric hydraulic rod 83 pushes the heat-insulating pressure sleeve 84 to verify the side end load, the pressure sensor 85 monitors the size of the loading pressure. The result detected by the pressure sensor 85 is sent to the PLC controller 93 in the form of an electrical signal. When the result detected by the pressure sensor 85 reaches When the maximum lateral bearing load F2 of the steel structure preset by the PLC controller 93 is reached, the PLC controller 93 controls the second electric hydraulic rod 83 to stop extending to avoid excessive lateral load and damage to the standard I-shaped steel structure test piece, and observes whether the alarm 94 sounds an alarm at this time. If the alarm 94 sounds an alarm, it means that the standard I-shaped steel structure test piece is deformed and unqualified. On the contrary, if the alarm 94 does not sound an alarm, it means that the connection between the tips of the first conductive tip block 98 and the second conductive tip block 99 is not disconnected, and the standard I-shaped steel structure test piece is not deformed and qualified. Then the PLC controller 93 controls the torsion load simulation mechanism 7 to work; The PLC controller 93 controls the extension of the first electric hydraulic rod 74, and the first electric hydraulic rod 74 pushes the rack 72 to move on the U-shaped limit frame 71. When the rack 72 moves, it pushes the gear 73 to rotate, and the gear 73 makes the rotating rod 5 have a rotation tendency, and through the connecting seat 10, the standard I-shaped steel structure test piece has a torsional force, and simulates the environment in which the steel structure is subjected to the torsional load caused by the external wind force during actual use, and the torsional load on the standard I-shaped steel structure test piece can be detected through the torsional force sensor 76, the rotating rod 5 and the connecting seat 10, and the torsional force sensor 76 can transmit the detection result in the form of an electrical signal. The torque sensor 76 sends the torque to the PLC controller 93 in the form of a torque sensor. If the torque detected by the torque sensor 76 reaches the maximum torque bearing load F3 of the steel structure preset by the PLC controller 93, the PLC controller 93 controls the first electric hydraulic rod 74 to stop extending to avoid deformation and damage of the standard I-shaped steel structure test piece caused by excessive torque. At this time, observe whether the alarm 94 sounds an alarm. If the alarm 94 sounds an alarm, it means that the standard I-shaped steel structure test piece is deformed and unqualified. On the contrary, if the alarm 94 does not sound an alarm, it means that the connection between the tips of the first conductive tip block 98 and the second conductive tip block 99 is not disconnected, and the standard I-shaped steel structure test piece is not deformed and qualified. When the structural strength of the standard I-shaped steel structure test piece is verified to be qualified, the PLC controller 93 controls the first electric hydraulic rod 74, the second electric hydraulic rod 83 and the third electric hydraulic rod 92 to fully retract and return the standard I-shaped steel structure test piece to the initial position, and then takes the standard I-shaped steel structure test piece out of the load loading device for fire retardant coating spraying. After the fire retardant coating is sprayed, the standard I-shaped steel structure test piece is placed inside the load loading device. At this time, due to the self-locking ability of the first electric hydraulic rod 74, the rack 72 and the gear 73, the position of the connecting seat 10 can be prevented from changing. , ensuring that the installation position of the standard I-shaped steel structure test piece sprayed with fire retardant coating remains unchanged, thereby ensuring that the load loading position does not change when the standard I-shaped steel structure test piece is subjected to the fire resistance limit test of the fire retardant coating, ensuring the accuracy of the load loading position, and avoiding interference of different load loading positions to the fire resistance limit test of the fire retardant coating. This mechanism enables the load loading device to have the function of accurately positioning the load loading position in the fire resistance limit test of the steel structure fire retardant coating, which can not only ensure the accuracy of the fire resistance limit test results of the steel structure fire retardant coating, but also improve the reliability and effect of the use of the load loading device; When the standard I-shaped steel structure test piece is undergoing a fire resistance limit test in the load loading device, the PLC controller 93 controls the torsional load simulation mechanism 7, the lateral load simulation mechanism 8 and the vertical load simulation mechanism 9 to perform a multi-directional load loading test on the standard I-shaped steel structure test piece sprayed with fire retardant coating. The vertical load simulation mechanism 9 applies a load of F1 in the vertical direction of the standard I-shaped steel structure test piece, the lateral load simulation mechanism 8 applies a load of F2 in the lateral direction of the standard I-shaped steel structure test piece, and the torsional load simulation mechanism 7 applies a torsional load of F3 on the standard I-shaped steel structure test piece. The first electromagnetic valve 19 and the second electromagnetic valve 20 are connected to the pipeline of the heating device so that the heat of the heating device is transported to the load loading device. At the same time, the load loading device is monitored by the temperature sensor 27. Whether the internal temperature rise meets the standard of the standard temperature rise curve, heating is carried out according to the standard temperature rise curve specified in the international standard ISO834, simulating the actual fire, the temperature is gradually rising, from the lower temperature at the beginning of the fire to the high temperature at the development stage of the fire, to achieve a comprehensive evaluation of the fire retardant coating's protection performance on the steel structure at different temperature stages, at the same time, observe whether the alarm 94 alarms, and record the time T0 from the start of the fire resistance limit test of the standard I-shaped steel structure test piece sprayed with the fire retardant coating to the alarm 94 alarm. The alarm 94 alarm indicates that the heat insulation of the fire retardant coating fails, and the standard I-shaped steel structure test piece is damaged by the high temperature in the load loading device, and deformed under the load. The larger the value of time T0, the better the fire resistance performance of the steel structure fire retardant coating; In addition, the load loading device is designed with a double-layer structure of the support tube 11 and the insulation tube 12, and cooperates with the base 1 and the top seat 15, so that the fire resistance limit test of the steel structure fire retardant coating is in a sealed state, and the steel structure fire retardant coating on the surface of the standard I-type steel structure test piece can be fully heated, thereby better simulating the situation of the steel structure fire retardant coating in an actual fire scene, and in a sealed environment, the heat used for the fire resistance limit test of the steel structure fire retardant coating is not easy to lose, thereby increasing the temperature increase rate in the fire resistance limit test of the steel structure fire retardant coating. This mechanism enables the load loading device in the fire resistance limit test of the steel structure fire retardant coating to have the function of simulating vertical load, lateral load and torsional load loading, and the device also has the function of being fully heated in the fire resistance limit test of the steel structure fire retardant coating, which can effectively improve the accuracy of the fire resistance limit test results of the steel structure fire retardant coating, while improving the credibility and effectiveness of the device in the test.

[0028] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A load loading device for testing the fire resistance limit of steel structure fire retardant coatings, comprising a base (1), characterized in that: The lower surface of the base (1) is fixedly connected to two support plates (2), the outer walls of the two support plates (2) are commonly fixedly connected to a transverse plate (3), the top of the transverse plate (3) is provided with a through hole, and the hole wall of the through hole is fixedly connected to a rolling bearing (4), the inner wall of the rolling bearing (4) is fixedly connected to a rotating rod (5), the upper surface of the base (1) is provided with a circular hole, and the hole wall of the circular hole is fixedly connected to a connecting bearing (6), the inner wall of the connecting bearing (6) is fixedly connected to a connecting seat (10), and the upper surface of the transverse plate (3) is fixedly connected to a torsional load simulation mechanism (7); the upper surface of the base (1) is fixedly connected to a lateral load simulation mechanism (8), and the upper surface of the base (1) is fixedly connected to a support tube (11) and a heat preservation tube (12); The outer wall of the support tube (11) is fixedly sleeved with a fixed tube (13); the hole wall of the fixed tube (13) is connected to a connecting rod (14) via a fixed bearing; the upper surface of the connecting rod (14) is fixedly connected to a top seat (15); the upper surface of the top seat (15) is provided with a mounting through hole, and the hole wall of the mounting through hole is fixedly connected to a heat-resistant rubber ring (16); the inner wall of the heat-resistant rubber ring (16) is fixedly connected to an insulating limit seat (17); and the upper surface of the top seat (15) is fixedly connected to a vertical load simulation mechanism (9); the outer walls of the support tube (11) and the heat-insulating tube (12) are jointly fixedly embedded with an insulating heat-insulating sleeve (18), a first electromagnetic valve (19) and a second electromagnetic valve (20); and the inner wall of the insulating heat-insulating sleeve (18) is fixedly embedded with a temperature sensor (27).

2. A load loading device for fire resistance limit test of steel structure fire retardant coating according to claim 1, characterized in that: The torsion load simulation mechanism (7) comprises a U-shaped limit frame (71) fixedly connected to the upper surface of the horizontal plate (3), the inner wall of the U-shaped limit frame (71) is movably connected to a rack (72), the rod wall of the rotating rod (5) is fixedly sleeved with a gear (73) meshing with the rack (72), a circular hole is opened in the side wall of one of the supporting plates (2), and a first electric hydraulic rod (74) is fixedly connected to the hole wall of the circular hole, the movable end of the first electric hydraulic rod (74) is fixedly connected to the side end of the rack (72), the lower surface of the horizontal plate (3) is fixedly connected to a U-shaped frame (75), the inner wall of the U-shaped frame (75) is fixedly connected to a torsion force sensor (76), and the measuring end of the torsion force sensor (76) is fixedly connected to the bottom end of the rotating rod (5).

3. A load loading device for fire resistance limit test of steel structure fire retardant coating according to claim 1, characterized in that: The lateral load simulation mechanism (8) comprises a fixing frame (81) fixedly connected to the upper surface of the base (1), the side wall of the fixing frame (81) being provided with two through holes, and the hole walls of the through holes being fixedly connected to a heat insulating sleeve (82), the side ends of the heat insulating sleeve (82) passing through the inner walls of the support tube (11) and the heat preservation tube (12), the side ends of the heat insulating sleeve (82) being fixedly embedded with a second electric hydraulic rod (83), the side ends of the heat insulating sleeve (82) away from the second electric hydraulic rod (83) being movably sleeved with a heat insulating compression sleeve (84), the inner wall of the heat insulating compression sleeve (84) being fixedly connected to a pressure sensor (85), the side end hole wall of the heat insulating compression sleeve (84) being movably connected to a moving rod (86), and the side ends of the moving rod (86) being fixedly connected to the side ends of the second electric hydraulic rod (83).

4. A load loading device for fire resistance limit test of steel structure fire retardant coating according to claim 3, characterized in that: The rod wall of the movable rod (86) is movably sleeved with a return spring (21), and the two ends of the return spring (21) are respectively fixedly connected to the rod wall of the movable rod (86) and the inner wall of the heat-insulating compression sleeve (84), and the outer walls of the movable rod (86), the heat-insulating compression sleeve (84) and the heat-insulating sleeve are all provided with wire through holes (22).

5. The load loading device for fire resistance limit test of steel structure fire retardant coating according to claim 1, characterized in that: The vertical load simulation mechanism (9) comprises a U-shaped top frame (91) fixedly connected to the upper surface of the top seat (15); a third electric hydraulic rod (92) is fixedly embedded at the top of the U-shaped top frame (91); a PLC controller (93), an alarm (94) and a display screen (95) are fixedly connected to the outer wall of the top of the U-shaped top frame (91); an insulating ring (96) is fixedly connected to the bottom end of the third electric hydraulic rod (92); a semicircular ring (97) is movably connected to the inner wall of the insulating ring (96); the bottom end of the semicircular ring (97) is fixedly connected to the upper surface of the insulating limit seat (17); a first conductive tip block (98) is fixedly connected to the bottom end of the insulating ring (96); and a second conductive tip block (99) matching the first conductive tip block (98) is fixedly connected to the upper surface of the insulating limit seat (17).

6. A load loading device for fire resistance limit test of steel structure fire retardant coating according to claim 1, characterized in that: The upper surfaces of the support tube (11) and the heat-insulating tube (12) and the lower surface of the top seat (15) are located on the same horizontal plane.

7. A load loading device for fire resistance limit test of steel structure fire retardant coating according to claim 1, characterized in that: A nut (23) is fixedly connected to the outer wall of the top seat (15) away from the fixing tube (13); a limit bolt (24) is threadedly connected to the inner wall of the nut (23); and a threaded blind hole (25) matching the side end of the limit bolt (24) is formed on the outer wall of the support tube (11).

8. The load loading device for fire resistance limit test of steel structure fire retardant coating according to claim 1, characterized in that: The connecting seat (10) and the insulating limit seat (17) are both provided with an I-shaped steel side end placement groove (26) on the opposite side.

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