A kind of durability test device for anticorrosive coating layer of cross-sea bridge deck

Abstract

The present application relates to the technical field of cross-sea bridge construction, and particularly discloses a kind of cross-sea bridge beam plate anticorrosive coating layer durability test device, including test box, test box one side is equipped with box door, test box inside top is equipped with sea water spraying device, test box is equipped with the steel structure beam plate to be tested inside, steel structure beam plate one side is equipped with test device, test device includes integrated box, integrated box is rotatably connected in test box, opposite sides of integrated box are equipped with through slot, test rod is arranged in integrated box, both ends of test rod respectively extend from through slot to outside of integrated box, adjusting device is arranged in integrated box, and adjusting device is used to adjust the length of both ends of test rod extending outside integrated box.The present application has the beneficial effects that: low-frequency bending is generated when extruding wheel extends, high-frequency impact is generated when touching rod extends, top torque device applies torsional moment to beam plate, and bending load is superimposed to form a composite stress state, which more truly simulates the actual stress working condition of bridge beam plate.

Description

Technical Field

[0001] This invention relates to the field of construction technology for cross-sea bridges, and in particular to a durability testing device for anti-corrosion coatings on cross-sea bridge beams. Background Technology

[0002] When steel beams of cross-sea bridges serve in splash zones, they are subjected to alternating bending stresses caused by wave impacts, as well as corrosion from salt spray and alternating wet and dry environments. The coupling effect of mechanical loads and corrosive environments is the main cause of cracking, debonding, and substrate corrosion of anti-corrosion coatings. Therefore, when performing anti-corrosion construction on steel beams, it is necessary to test the durability of the anti-corrosion coating in a laboratory. Current technologies typically use salt spray test chambers and cyclic corrosion test chambers, where specimens are installed in the salt spray test chamber and then mechanical loads are applied to test the durability of the anti-corrosion coating. However, these mechanical loads are constant static loads or alternating loads of a single frequency, which cannot simulate the actual stress conditions of the specimens during actual use, thus reducing the accuracy of the test results. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies by proposing a durability testing device for anti-corrosion coatings on cross-sea bridge beams.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A durability testing device for anti-corrosion coatings on cross-sea bridge beams includes a test chamber with a door on one side and a seawater spraying device on the top inside the chamber. The test chamber contains the steel beam to be tested, and a testing device is located on one side of the steel beam. The testing device includes an integrated box that is rotatably connected inside the test chamber. Both sides of the integrated box have through slots, and a test rod is located inside the integrated box. The two ends of the test rod extend from the through slots to the outside of the integrated box. An adjustment device is located inside the integrated box to adjust the length of the two ends of the test rod extending outside the integrated box.

[0005] Preferably, a sleeve is fixedly connected to one side of the test box via a bracket, and a first connecting shaft is fixedly connected to one end of the integrated box. The first connecting shaft is rotatably connected inside the sleeve. A spiral groove is provided on the inner wall of the sleeve, and a slider is fixedly connected to the first connecting shaft. The slider slides inside the spiral groove.

[0006] Preferably, the adjustment device includes an adjustment plate, a first connecting shaft with a clearance hole at one end, a fixed shaft rotatably connected inside the sleeve, the fixed shaft extending from the clearance hole into the integrated box and fixed to the adjustment plate, an adjustment groove on one side of the adjustment plate, and a sliding column fixedly connected to the middle of the test rod, the sliding column extending into the adjustment groove and being able to slide back and forth along the adjustment groove.

[0007] Preferably, the regulating channel includes a first horizontal section and two second horizontal sections, each of which is connected to the first horizontal section via an inclined section.

[0008] Preferably, a drive ring is rotatably connected to the test box, and an axial positioning groove is provided on the inner ring surface of the drive ring. One end of the integrated box is fixedly connected to a second connecting shaft, and a positioning rod is fixedly connected to the outer surface of the second connecting shaft. The positioning rod is slidably connected in the positioning groove. A motor is installed on the test box, and the motor is used to drive the drive ring to rotate.

[0009] Preferably, one end of the test rod is rotatably connected to an extrusion wheel, and a scraper is provided on one side of the extrusion wheel. The scraper is fixed to the test rod by a scraper holder.

[0010] Preferably, the other end of the test rod is fixedly connected to a mounting plate, and multiple touch rods are fixedly connected to the mounting plate.

[0011] The beneficial effects of this invention are as follows: low-frequency bending is generated when the extrusion wheel extends, high-frequency impact is generated when the contact rod extends, and the top torque device applies torsional moment to the beam plate, which is superimposed with the bending load to form a composite stress state. This more realistically simulates the stress condition of steel structure beam plates under eccentric load and lateral force of waves, and accelerates the debonding and cracking of the anti-corrosion coating layer under bending and torsional composite stress. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the basic structure of the present invention; Figure 2 yes Figure 1 Cross-sectional view; Figure 3 This is a schematic diagram of the basic structure of the testing device; Figure 4 This is a schematic diagram of the connection structure between the test rod and the adjustment device. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0014] like Figures 1-4As shown in the figure, this embodiment provides a durability testing device for the anti-corrosion coating layer of a cross-sea bridge beam, including a test chamber 1. The test chamber 1 is a sealed box structure made of stainless steel resistant to seawater corrosion, and a door 11 is provided on one side of the test chamber 1. The test chamber 1 contains a steel structure beam 100 to be tested, and the surface of the steel structure beam 100 is coated with an anti-corrosion coating layer. A seawater spraying device 15 is provided on the top of the inner side of the test chamber 1. The seawater spraying device 15 is connected to an external seawater storage tank and pump set through pipelines. The seawater spraying device 15 sprays seawater onto the surface of the test piece to simulate the seawater immersion and scouring environment in the splash zone.

[0015] A first clamping device 14 is installed at the bottom of the test chamber 1, and a second clamping device 13 is rotatably connected to the top of the test chamber 1 via a rotating shaft 12. The upper end of the rotating shaft 12 extends out of the test chamber 1, and a torque device is installed at the upper end of the rotating shaft 12. The torque device is prior art and is not shown in the attached drawings, so it will not be described in detail here. The upper and lower ends of the steel structure beam 100 are clamped by the second clamping device 13 and the first clamping device 14, respectively. A torque is applied to the rotating shaft 12 through the torque device, which causes the second clamping device 13 to rotate around the rotating shaft 12, applying a torsional moment to the steel structure beam 100, so that the beam 100 is subjected to combined bending and torsional stress during the test.

[0016] A testing device 3 is provided on one side of the steel structure beam 100. The testing device 3 includes an integrated box 31, which is a hollow rectangular or cylindrical structure. A first connecting shaft 38 and a second connecting shaft 33 are respectively provided at both ends of the integrated box 31. Through slots 32 are provided on opposite sides of the integrated box 31, and both through slots 32 are radially connected to the integrated box 31. A testing rod 5 is provided inside the integrated box 31, with both ends extending from the through slots 32 to the outside of the integrated box 31. One end of the testing rod 5 is rotatably connected to an extrusion wheel 52, which can be made of polyurethane or nylon to reduce mechanical damage to the coating surface. A scraper 54 is provided on one side of the extrusion wheel 52, and the scraper 54 is fixed to the testing rod 5 by a tool holder 53. When the extrusion roller 52 exerts extrusive force on the surface of the steel structure beam 100, the scraper 54 applies shear peeling force to the surface of the anti-corrosion coating layer on the side of the extruded area of ​​the steel structure beam 100. This peeling force can simulate the shearing and scouring effect of ocean waves on the surface of the anti-corrosion coating layer, stimulating the tendency of the anti-corrosion coating layer to de-adhere to the surface of the steel structure beam 100. The other end of the test rod 5 is fixedly connected to the mounting plate 55, and multiple contact rods 56 are fixedly connected to the mounting plate 55.

[0017] An adjustment device 4 is provided inside the integrated box 31. The adjustment device 4 is used to adjust the length of both ends of the test rod 5 extending out of the integrated box 31. The adjustment device 4 includes an adjustment plate 40, a clearance hole at one end of the first connecting shaft 38, a fixed shaft 44 rotatably connected inside the sleeve 2, the fixed shaft 44 extending into the integrated box 31 through the clearance hole and fixed to the adjustment plate 40, an adjustment groove 45 on one side of the adjustment plate 40, and a sliding column 51 fixedly connected to the middle of the test rod 5. The sliding column 51 extends into the adjustment groove 45 and can slide back and forth along the adjustment groove 45. The adjustment groove 45 includes a first horizontal section 41 and two second horizontal sections 42 that are staggered. Each second horizontal section 42 is connected to the first horizontal section 41 through an inclined section 43.

[0018] One side of the test chamber 1 is fixedly connected to the sleeve 2 via a bracket 21. One end of the integrated box 31 is fixedly connected to the first connecting shaft 38, which is rotatably connected within the sleeve 2. The inner wall of the sleeve 2 is provided with a spiral groove 22. A slider 39 is fixedly connected to the first connecting shaft 38, and the slider 39 slides within the spiral groove 22. When the first connecting shaft 38 rotates within the sleeve 2, the slider 39 is constrained by the spiral groove 22, forcing the first connecting shaft 38 to move axially along the sleeve 2 while rotating, thereby driving the entire integrated box 31 and the test rod 5 to reciprocate axially. A drive ring 35 is rotatably connected to the test chamber 1. The inner ring surface of the drive ring 35 is provided with an axial positioning groove. One end of the integrated box 31 is fixedly connected to the second connecting shaft 33, and a positioning rod 34 is fixedly connected to the outer surface of the second connecting shaft 33. The positioning rod 34 slides within the positioning groove. A motor 36 is mounted on the test chamber 1, which is used to drive the drive ring 35 to rotate clockwise or counterclockwise.

[0019] In use, the chamber door 11 is opened, and the steel structure beam 100 to be tested, coated with an anti-corrosion coating, is placed vertically. The lower end of the steel structure beam 100 is clamped and fixed by the first clamping device 14, and the upper end is clamped and fixed by the second clamping device 13. Simultaneously, a torque device is installed on the rotating shaft 12, and a set torque is applied to the steel structure beam 100 according to the test requirements. Then, the motor 36 drives the drive ring 35 to rotate. Since the positioning rod 34 is embedded in the positioning groove of the drive ring 35, the rotational motion of the drive ring 35 is transmitted to the second connecting shaft 33, thereby driving the integrated box 31, the first connecting shaft 38, and the test rod 5 to rotate together. Simultaneously, the first connecting shaft 38 rotates within the sleeve 2, and the sliding ball 39 slides along the spiral groove 22. The constraint of the spiral groove 22 forces the first connecting shaft 38 to move axially along the sleeve 2 while rotating, thereby driving the integrated box 31 and the test rod 5 to move together. The axial movement of the integrated box 31 causes the sliding column 51 on the test rod 5 to slide within the adjusting groove 45 on the fixed adjusting plate 40. When the sliding column 51 is located within the first horizontal section 41, the end of the test rod 5 equipped with the extrusion wheel 52 extends a relatively long distance. When rotating at this time, the extrusion wheel 52 can contact the steel structure beam 100 and apply extrusion force to the steel structure beam 100, causing the steel structure beam 100 to undergo low-frequency bending deformation. The low-frequency bending deformation causes the interface between the anti-corrosion coating layer and the steel structure beam 100 to be subjected to alternating tensile and compressive stresses, accelerating the initiation and expansion of debonding at the interface of the steel structure beam 100. At the same time, the scraper 54 on the side of the extrusion wheel 52 applies a synchronous shear peeling force to the surface of the anti-corrosion coating layer in the extruded area of ​​the steel structure beam 100. At this time, the contact rod 56 does not contact the steel structure beam 100.

[0020] When the sliding column 51 moves from the first horizontal section 41 to the second horizontal section 42 along the inclined section 43, the end of the test rod 5 equipped with the contact rod 56 extends a relatively long distance, while the extrusion wheel 52 does not contact the steel structure beam 100. At this time, the contact rod 56 contacts the surface of the steel structure beam 100 when the integrated box 31 rotates, and multiple contact rods 56 quickly contact the beam surface, applying high-frequency micro-amplitude excitation to the beam. The high-frequency excitation forms elastic stress waves inside the anti-corrosion coating layer, continuously exciting the micro-defects at the interface. The combination of high-frequency excitation and low-frequency bending deformation accelerates the failure process of the anti-corrosion coating layer, improving the acceleration factor and the fidelity of the failure mechanism.

[0021] Simultaneously, the seawater spraying device 15 continuously or intermittently sprays seawater onto the surface of the steel structure beam 100, keeping the surface moist or simulating alternating wet and dry conditions, thus synchronizing the mechanical loading with seawater immersion. As the integrated box 31 rotates continuously, due to the combined action of the spiral groove 22 and the adjusting channel 45, the two ends of the test rod 5 extend alternately, alternating between low-frequency loading by the extrusion wheel 52 and high-frequency loading by the contact rod 56. While the low-frequency and high-frequency loading alternate, the torque device continuously applies torque to the rotating shaft 12, causing the steel structure beam 100 to bear torsional moment. This torque generates shear stress on the cross-section of the steel structure beam 100, which, combined with the bending normal stress, forms a composite stress state, more realistically simulating the stress conditions of the steel structure beam 100 under eccentric loading and lateral wave forces, accelerating the debonding and cracking of the anti-corrosion coating layer under combined bending and torsional stress. After the test is completed, the tested steel structure beam 100 is taken out and analyzed using existing technology.

[0022] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A durability testing device for anti-corrosion coatings on cross-sea bridge beams, characterized in that: The test box (1) is provided with a door (11) on one side and a seawater spraying device (15) on the top of the inner side of the test box (1). The test box (1) contains a steel structure beam (100) to be tested. A test device (3) is provided on one side of the steel structure beam (100). The test device (3) includes an integrated box (31) which is rotatably connected inside the test box (1). The integrated box (31) has through slots (32) on both sides opposite to each other. The integrated box (31) contains a test rod (5). The two ends of the test rod (5) extend from the through slots (32) to the outside of the integrated box (31). The integrated box (31) contains an adjustment device (4) which is used to adjust the length of the two ends of the test rod (5) extending out of the integrated box (31). The test box (1) is fixedly connected to the sleeve (2) by the bracket (21) on one side, and the integrated box (31) is fixedly connected to the first connecting shaft (38) at one end. The first connecting shaft (38) is rotatably connected inside the sleeve (2). The inner wall of the sleeve (2) is provided with a spiral groove (22). A slider (39) is fixedly connected to the first connecting shaft (38). The slider (39) slides inside the spiral groove (22). The adjustment device (4) includes an adjustment plate (40), a clearance hole is provided at one end of the first connecting shaft (38), a fixed shaft (44) is rotatably connected inside the sleeve (2), the fixed shaft (44) extends from the clearance hole into the integrated box (31) and is fixed to the adjustment plate (40), an adjustment groove (45) is provided on one side of the adjustment plate (40), a sliding column (51) is fixedly connected to the middle of the test rod (5), the sliding column (51) extends into the adjustment groove (45) and can slide back and forth along the adjustment groove (45); The regulating channel (45) includes a first horizontal section (41) and two second horizontal sections (42), and each second horizontal section (42) is connected to the first horizontal section (41) through an inclined section (43); The test box (1) is rotatably connected to a drive ring (35). The inner ring surface of the drive ring (35) is provided with an axial positioning groove. One end of the integrated box (31) is fixedly connected to a second connecting shaft (33). The outer surface of the second connecting shaft (33) is fixedly connected to a positioning rod (34). The positioning rod (34) is slidably connected in the positioning groove. The test box (1) is equipped with a motor (36). The motor (36) is used to drive the drive ring (35) to rotate. One end of the test rod (5) is rotatably connected to the extrusion wheel (52), and a scraper (54) is provided on one side of the extrusion wheel (52). The scraper (54) is fixed on the test rod (5) by a tool holder (53). The other end of the test rod (5) is fixedly connected to the mounting plate (55), and multiple touch rods (56) are fixedly connected to the mounting plate (55).

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