Shear fatigue test device and method for steel bridge deck pavement bonding layer, and composite test piece assembly method

Abstract

The application relates to a shearing fatigue test device and method for a steel bridge deck pavement bonding layer and a composite test piece assembly method. The test device comprises a bearing platform unit; a composite test piece composed of a first steel plate, a bonding layer and a concrete layer; a vertical loading unit arranged on the bearing platform unit and capable of sliding in the vertical direction, used for cooperating with a microcomputer-controlled electro-hydraulic servo compression and shearing testing machine to implement vertical shearing behavior on the bonding layer; a test piece fixing unit arranged on the vertical loading unit, used for fixing the composite test piece; a horizontal loading unit horizontally and slidably connected to the test piece fixing unit, used for cooperating with the microcomputer-controlled electro-hydraulic servo compression and shearing testing machine to apply a horizontal force to the bonding layer; and a longitudinal loading unit arranged on the bearing platform unit, used for applying pressure to the composite test piece to simulate tire pressure. The application can test the fatigue characteristics of the steel bridge deck pavement bonding layer under the complex stress state of tensile shearing and compressive shearing under the action of vehicle load.

Description

Technical Field

[0001] This application relates to the technical field of bonding layers for steel bridge deck pavement, and in particular to a shear fatigue testing device, method, and composite specimen assembly method for bonding layers for steel bridge deck pavement. Background Technology

[0002] Steel bridge deck pavement is a composite structure composed of a pavement layer, an adhesive layer, and steel bridge deck panels. The adhesive layer serves to waterproof the pavement and bond the various structural layers together, thus its mechanical properties significantly impact the overall pavement structure. Research indicates that under repeated traffic loads, the adhesive layer of steel bridge deck pavement is subjected to complex stress states, such as tension-shear and compression-shear, making it highly susceptible to fatigue failure and a potential interface for the failure of the entire pavement structure. Therefore, evaluating the waterproofing and bonding mechanical properties of steel bridge deck pavement is crucial for practical engineering projects.

[0003] Currently, scholars both domestically and internationally often use shear strength and pull-out strength as evaluation indicators to assess the bonding characteristics between pavement layers, and have developed various testing devices, such as pull-out testing devices, tension-shear testing devices, and compression-shear testing devices. Although there are many existing devices, each with its own advantages, they still cannot fully meet the needs of practical applications. For example, the tension-shear testing device can only simulate the stress state where interfacial normal tensile stress and shear stress coexist. The actual pavement stress is more complex. Under wheel loads, the bond layer may experience a transition from compression-shear stress to tension-shear stress, meaning that the bond layer simultaneously bears compression-shear and tension-shear conditions. Therefore, this invention provides a method and testing device for evaluating the mechanical properties of the bond layer of steel bridge deck pavement. This device can test the shear fatigue characteristics of the bond layer of steel bridge deck pavement under simultaneous compression-shear and tension-shear stress states. Summary of the Invention

[0004] To test the shear fatigue characteristics of the bonding layer of steel bridge deck pavement under simultaneous compressive-shear and tensile-shear stress states, this application provides a shear fatigue testing device, method, and composite specimen assembly method for the bonding layer of steel bridge deck pavement, which can reflect the stress characteristics of the bonding layer under simultaneous compressive-shear and tensile-shear stress states.

[0005] Firstly, this application provides a shear fatigue testing device for the bonding layer of steel bridge deck pavement, which adopts the following technical solution:

[0006] A shear fatigue testing device for the bonding layer of steel bridge deck pavement includes:

[0007] Foundation plate unit;

[0008] The composite specimen consists of a first steel plate, an adhesive layer, and a concrete layer.

[0009] A vertical loading unit is disposed on the support plate unit and can slide vertically to cooperate with a microcomputer-controlled electro-hydraulic servo compression-shear testing machine to perform vertical shearing on the adhesive layer; a specimen fixing unit is provided on the vertical loading unit to fix the composite specimen;

[0010] A transverse loading unit is horizontally slidably connected to the specimen fixing unit and is used in conjunction with a microcomputer-controlled electro-hydraulic servo compression-shear testing machine to apply a transverse horizontal force to the adhesive layer.

[0011] A longitudinal loading unit, disposed on the support plate unit, is used to apply pressure to the composite specimen to simulate tire pressure.

[0012] By adopting the above technical solution, the test device is placed in a microcomputer-controlled electro-hydraulic servo compression-shear testing machine. Then, the longitudinal loading unit applies longitudinal horizontal pressure to the bond layer, the transverse loading device of the compression-shear testing machine applies transverse horizontal force in conjunction with the transverse loading unit, and the compression-shear testing machine applies vertical shear behavior in conjunction with the vertical loading unit. This can reflect the stress characteristics of the bond layer under the simultaneous existence of compression-shear and tension-shear stress. Therefore, it can reflect the stress characteristics of the bond layer under the simultaneous existence of compression-shear and tension-shear stress.

[0013] Optionally, the support plate unit includes:

[0014] Base plate;

[0015] Two support columns are fixedly connected to one end of the base plate and are distributed on both sides of the base plate.

[0016] The support platform is fixedly connected to the other end of the base plate.

[0017] Optionally, the two supporting columns have first slots on their opposite sidewalls; the vertical loading unit is slidably connected to the first slot, the vertical loading unit has a groove, a first bolt is fixedly connected to the first steel plate, the first bolt can pass through the groove, and the first steel plate can be placed in the groove.

[0018] Optionally, the specimen fixing unit includes:

[0019] Two baffles, each with a second slot on its separate sidewall, allow the transverse loading unit to slide and connect within the second slot; a supporting steel plate is fixedly connected between the two baffles, and the composite specimen is placed on the supporting steel plate;

[0020] The second bolt rod passes through and is connected to the two baffles, and is used to fix the two baffles.

[0021] Optionally, both baffles are equipped with rollers.

[0022] By adopting the above technical solution, the specimen fixing unit can be driven to move along the bearing plate.

[0023] Optionally, the testing apparatus further includes:

[0024] The long column steel plate includes a steel column and at least two second steel plates, the second steel plates being fixedly connected to the steel column at intervals, and a plurality of ball bearings being embedded on the outer side of the second steel plates away from the composite specimen; the longitudinal loading unit is used to apply pressure to the second steel plates.

[0025] By adopting the above technical solution, the ball can roll along the longitudinal loading unit, minimizing the impact of friction.

[0026] Secondly, this application provides a shear fatigue test method for the bonding layer of steel bridge deck pavement, which adopts the following technical solution:

[0027] A shear fatigue test method for the bonding layer of steel bridge deck pavement includes:

[0028] Assemble the above-mentioned test apparatus;

[0029] Place the test apparatus into a microcomputer-controlled electro-hydraulic servo compression-shear testing machine;

[0030] A longitudinal horizontal pressure σ1 is applied to the bonding layer by a longitudinal loading unit;

[0031] A transverse horizontal force σ2 is applied by the transverse loading device of the compression-shear testing machine in conjunction with the transverse loading unit.

[0032] Vertical shear behavior was applied using a compression-shear testing machine in conjunction with a vertical loading unit, with the stress ratio set to 0.4;

[0033] The relationship between shear fatigue parameters and various influencing factors was obtained by fitting experimental data, as shown in the following formula: Where, lgN SF σ1 represents the logarithmic shear fatigue life; σ2 represents the transverse horizontal force; σ1 represents the longitudinal horizontal force; and a, b, c, and d are fitting parameters.

[0034] By adopting the above technical solution, the measured data can be substituted into the relational formula to obtain the shear fatigue parameters, thereby reflecting the stress characteristics of the bond layer under the simultaneous compression-shear and tension-shear stress states, thus reducing the test error.

[0035] Thirdly, this application provides a composite specimen assembly method, which adopts the following technical solution:

[0036] A method for assembling a composite specimen, comprising:

[0037] S1 steel plate sandblasting treatment: Take a steel plate with a length and width of 300mm*300mm and a thickness of 15mm, and perform sandblasting treatment to achieve a cleanliness level of Sa2.5 and a roughness of 50μm~100μm;

[0038] For S2 steel plate curing, polyurethane-modified epoxy resin is evenly sprayed onto the steel plate surface at a dosage of 2.0 g / m². 2 Then, before the adhesive surface dries, an excessive amount of 3mm-5mm basalt gravel is spread, at a rate of 12.0kg / m². 2 After seven hours of rest and recuperation, remove any loose stones.

[0039] S3 is a repeat of S2, wherein the amount of polyurethane-modified epoxy resin used is 3.5 kg / m³. 2 The amount of crushed stone used is 18.0 kg / m³. 2 ;

[0040] After the S4 adhesive layer has been formed and cured for the required time, a hot-melt modified epoxy resin is applied at a dosage of 1.2 kg / m². 2 This ultimately forms a thin layer of polyurethane-modified epoxy resin adhesive layer approximately 1.5 cm thick.

[0041] S5 composite specimen molding: The steel plate forming the bonding layer is placed into the mold of the asphalt mixture rutting specimen molding machine; after the binder has developed a certain strength, SMA-13 ​​asphalt mixture is placed in it, and the asphalt mixture rutting specimen molding machine is started for wheel rolling molding, with a wheel rolling number of 50 times.

[0042] S6 cooling and cutting: After the composite specimen has cooled, it is cut with a cutting machine to make the composite specimen dimensions 150mm*150mm (length*width). Attached Figure Description

[0043] Figure 1 This is a flowchart of the composite specimen composition method of this application;

[0044] Figure 2 This is a schematic diagram of the overall structure of the experimental device of this application;

[0045] Figure 3 yes Figure 2 Structural schematic diagram of the central support plate unit and the vertical loading unit;

[0046] Figure 4 yes Figure 3 The left view;

[0047] Figure 5 This is a structural schematic diagram of the specimen fixing unit;

[0048] Figure 6 This is a structural schematic diagram of a long steel plate column.

[0049] Explanation of reference numerals in the attached drawings: 100, foundation plate unit; 110, base plate; 120, support column; 121, first slot; 130, foundation; 140, first bolt rod; 200, composite specimen; 210, first steel plate; 220, bonding layer; 230, concrete layer; 300, vertical loading unit; 310, groove; 320, first bolt hole; 400, specimen fixing unit; 410, baffle; 411, second slot; 412, roller; 413, second bolt hole; 420, support steel plate; 430, second bolt rod; 500, transverse loading unit; 600, longitudinal loading unit; 700, long column steel plate; 710, steel column; 720, second steel plate; 721, ball bearing. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will be described in conjunction with the appendices in the embodiments of the present invention. Figure 1 -Appendix Figure 6 The technical solutions in the embodiments of the present invention are clearly and completely described herein. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0051] One embodiment of this application discloses a method for assembling composite specimens. (Refer to...) Figure 1 As one embodiment of the assembly method, the assembly method may include S1-S6:

[0052] S1 steel plate sandblasting treatment: Take a steel plate with a length and width of 300mm*300mm and a thickness of 15mm, and perform sandblasting treatment to achieve a cleanliness level of Sa2.5 and a roughness of 50μm~100μm;

[0053] For S2 steel plate curing, polyurethane-modified epoxy resin is evenly sprayed onto the steel plate surface at a dosage of 2.0 g / m². 2 Then, before the adhesive surface dries, an excessive amount of 3mm-5mm basalt gravel is spread, at a rate of 12.0kg / m². 2 After seven hours of rest and recuperation, remove any loose stones.

[0054] S3 is a repeat of S2, wherein the amount of polyurethane-modified epoxy resin used is 3.5 kg / m³. 2 The amount of crushed stone used is 18.0 kg / m³. 2 ;

[0055] After the S4 adhesive layer has been formed and cured for the required time, a hot-melt modified epoxy resin is applied at a dosage of 1.2 kg / m². 2 This ultimately forms a thin layer of polyurethane-modified epoxy resin adhesive layer approximately 1.5 cm thick.

[0056] For S5 composite specimen molding, the steel plate forming the bonding layer is placed into the mold of the asphalt mixture rutting specimen molding machine; after the binder has developed a certain strength (according to actual requirements or after manual observation), SMA-13 ​​asphalt mixture is placed in it, and the asphalt mixture rutting specimen molding machine is started for wheel rolling molding, with 50 wheel rolling cycles.

[0057] S6 cooling and cutting: After the composite specimen has cooled, it is cut with a cutting machine to make the composite specimen dimensions 150mm*150mm (length*width).

[0058] The second embodiment of this application discloses a shear fatigue test method for the bonding layer of steel bridge deck pavement. As one implementation of this test method, the method may include steps S110-S160:

[0059] S110, Assemble the test apparatus;

[0060] S120, the test device is placed into the microcomputer-controlled electro-hydraulic servo compression-shear test machine;

[0061] S130, longitudinal horizontal pressure σ1 is applied to the adhesive layer of the composite specimen through the longitudinal loading unit;

[0062] S140, a transverse horizontal force σ2 is applied by the transverse loading device of the compression-shear testing machine in conjunction with the transverse loading unit;

[0063] S150, vertical shear behavior is applied by a compression-shear testing machine in conjunction with a vertical loading unit, and the stress ratio is set to 0.4;

[0064] S160, the relationship between shear fatigue parameters and various influencing factors was obtained by fitting experimental data, as shown in the following formula: Where, lgN SF σ1 represents the logarithmic shear fatigue life; σ2 represents the transverse horizontal force; σ1 represents the longitudinal horizontal force; and a, b, c, and d are fitting parameters.

[0065] Specifically, the fitting parameters can be set to: a = 4.328, b = 2.016, c = 1.285, d = 2.043; resulting in the formula:

[0066] Then, take three horizontal stresses for σ1: 0.25 MPa, 0.50 MPa, 0.7 MPa, and 1.2 MPa; take three horizontal stresses for σ2: 1.2 MPa, 1.4 MPa, and 1.6 MPa; substitute them into the above formula respectively, and the shear fatigue life is the average of the three data.

[0067] The third embodiment of this application discloses a shear fatigue testing device for the bonding layer of steel bridge deck pavement. (Refer to...) Figure 2As one embodiment of the testing apparatus, the testing apparatus may include:

[0068] Foundation plate unit 100;

[0069] The composite specimen 200 consists of a first steel plate 210, an adhesive layer 220, and a concrete layer 230.

[0070] A vertical loading unit 300 is disposed on the support plate unit 100 and can slide in the vertical direction to cooperate with the microcomputer-controlled electro-hydraulic servo compression shear testing machine to perform vertical shearing behavior on the bonding layer 220; a specimen fixing unit 400 is provided on the vertical loading unit 300, which is used to fix the composite specimen 200.

[0071] The transverse loading unit 500 is horizontally slidably connected to the specimen fixing unit 400 and is used in conjunction with the microcomputer-controlled electro-hydraulic servo compression-shear testing machine to apply a transverse horizontal force to the bonding layer 220.

[0072] The longitudinal loading unit 600 is set on the support plate unit 100 and is used to apply pressure to the composite specimen 200 to simulate tire pressure.

[0073] Reference Figure 3 and Figure 4 The foundation plate unit 100 includes:

[0074] Base plate 110;

[0075] Support columns 120 are welded to one end of the base plate 110, and two columns are provided and distributed on both sides of the base plate 110; a first slot 121 is provided on one side wall opposite to the two support columns 120 along the length direction, and the vertical loading unit 300 is slidably connected in the first slot 121.

[0076] The support 130 is welded to the other end of the base plate 110; the vertical loading unit 300 has a groove 310 on one side wall near the support 130, and a first bolt hole 320 is provided in the groove 310; a first bolt rod 140 is welded on the first steel plate 210, the first bolt rod 140 can pass through the first bolt hole 320, and the first steel plate 210 can be placed in the groove 310.

[0077] Reference Figure 5 The specimen fixing unit 400 includes:

[0078] Both baffles 410 have second slots 411 on their adjacent sidewalls. The transverse loading unit 500 can slide and connect to the second slots 411 and can be fixed in a specific position by Phillips screws. Both baffles 410 have rollers 412 installed at their bottom for moving on the base plate 110. Both baffles 410 have second bolt holes 413 at their four corners.

[0079] A supporting steel plate 420 is welded between two baffles 410, and the composite specimen 200 is placed on the supporting steel plate 420.

[0080] Second bolt rod 430 (see) Figure 1 The second bolt rod 430 passes through the second bolt hole 413 and connects to the two baffles 410 to fix the two baffles 410. The second bolt rod 430 can be threaded to the two baffles 410, or the second bolt rod 430 can pass through the two baffles 410 and be screwed on with a nut.

[0081] Additionally, refer to Figure 6 The test apparatus may also include:

[0082] The long column steel plate 700 includes a steel column 710 and at least two second steel plates 720. This application uses three second steel plates 720, which are welded to the steel column 710 at intervals. Multiple ball bearings 721 are embedded on the outer side of the second steel plate 720 furthest from the composite specimen 200. A longitudinal loading unit 600 is used to apply pressure to the second steel plates 720. The longitudinal loading unit 600 can be a jack.

[0083] The implementation principle of this embodiment is as follows:

[0084] The test apparatus is placed in a microcomputer-controlled electro-hydraulic servo compression-shear testing machine. Then, longitudinal horizontal pressure is applied to the adhesive layer 220 through the longitudinal loading unit 600, and transverse horizontal force is applied through the transverse loading device of the compression-shear testing machine in conjunction with the transverse loading unit 500. Vertical shear behavior is applied through the compression-shear testing machine in conjunction with the vertical loading unit 300. This can reflect the stress characteristics of the adhesive layer 220 under the simultaneous existence of compression-shear and tension-shear stress. Therefore, it can reflect the stress characteristics of the adhesive layer 220 under the simultaneous existence of compression-shear and tension-shear stress.

[0085] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Any feature disclosed in this specification (including the abstract and drawings) may be replaced by other equivalent or similar features unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is only one example of a series of equivalent or similar features.

Claims

1. A shear fatigue testing device for the bonding layer of steel bridge deck pavement, characterized in that, include: Foundation plate unit (100); The composite specimen (200) consists of a first steel plate (210), an adhesive layer (220), and a concrete layer (230); A vertical loading unit (300) is disposed on the support plate unit (100) and can slide in the vertical direction to cooperate with the microcomputer-controlled electro-hydraulic servo compression shear testing machine to perform vertical shearing behavior on the adhesive layer (220); a specimen fixing unit (400) is provided on the vertical loading unit (300) and the specimen fixing unit (400) is used to fix the composite specimen (200). A transverse loading unit (500) is horizontally slidably connected to the specimen fixing unit (400) and is used in conjunction with a microcomputer-controlled electro-hydraulic servo compression shear testing machine to apply a transverse horizontal force to the adhesive layer (220); A longitudinal loading unit (600) is disposed on the support plate unit (100) and is used to apply pressure to the composite specimen (200) to simulate tire pressure; The long column steel plate (700) includes a steel column (710) and at least two second steel plates (720), the second steel plates (720) being fixedly connected to the steel column (710) at intervals, and a plurality of balls (721) are embedded on the outer side of the second steel plate (720) away from the composite specimen (200); the longitudinal loading unit (600) is used to apply pressure to the second steel plate (720).

2. The shear fatigue testing device for the bonding layer of steel bridge deck pavement according to claim 1, characterized in that, The foundation plate unit (100) includes: Base plate (110); Support columns (120) are fixedly connected to one end of the base plate (110), and two columns are provided and distributed on both sides of the base plate (110); The support platform (130) is fixedly connected to the other end of the base plate (110).

3. The shear fatigue testing device for the bonding layer of steel bridge deck pavement according to claim 2, characterized in that, The two supporting columns (120) have a first slot (121) on their opposite sidewalls; the vertical loading unit (300) is slidably connected in the first slot (121), the vertical loading unit (300) has a groove (310), the first steel plate (210) is fixedly connected to a first bolt rod (140), the first bolt rod (140) can pass through the groove (310), and the first steel plate (210) can be placed in the groove (310).

4. The shear fatigue testing device for the bonding layer of steel bridge deck pavement according to claim 1, characterized in that, The specimen fixing unit (400) includes: Both baffles (410) have second slots (411) on their adjacent sidewalls, and the transverse loading unit (500) can be slidably connected in the second slots (411); A supporting steel plate (420) is fixedly connected between the two baffles (410), and the composite specimen (200) is placed on the supporting steel plate (420); The second bolt rod (430) passes through and is connected to the two baffles (410) for fixing the two baffles (410).

5. The shear fatigue testing device for the bonding layer of steel bridge deck pavement according to claim 4, characterized in that, Both baffles (410) are equipped with rollers (412).

6. A shear fatigue test method for the bonding layer of steel bridge deck pavement, characterized in that, include: Assemble the test apparatus as described in any one of claims 1-5; Place the test apparatus into a microcomputer-controlled electro-hydraulic servo compression-shear testing machine; Longitudinal horizontal pressure is applied to the adhesive layer by the longitudinal loading unit. ; A lateral horizontal force is applied by the lateral loading device and lateral loading unit of the compression-shear testing machine. ; Vertical shear behavior was applied using a compression-shear testing machine in conjunction with a vertical loading unit, with the stress ratio set to 0.4; The relationship between shear fatigue parameters and various influencing factors was obtained by fitting experimental data, as shown in the following formula: Among them, lg N SF For logarithmic shear fatigue life, a, b, c, d These are the fitting parameters.

7. A shear fatigue test method for the bonding layer of steel bridge deck pavement as described in claim 6, characterized in that, Composite specimen assembly methods include: S1 steel plate sandblasting treatment: Take a steel plate with a length and width of 300mm*300mm and a thickness of 15mm, and perform sandblasting treatment to achieve a cleanliness level of Sa2.5 and a roughness of 50µm~100µm; S2 steel plate curing involves evenly spreading polyurethane-modified epoxy resin on the steel plate surface, with a dosage of [amount missing]. Then, before the adhesive surface dries, excessively sprinkle 3mm~5mm basalt gravel, the amount of which is... After seven hours of rest and recuperation, remove any loose stones. S3 repeats S2, wherein the amount of polyurethane-modified epoxy resin used is: The amount of crushed stone used is ; After the S4 adhesive layer has been formed and cured for the required time, a hot-melt modified epoxy resin is applied, with a dosage of [amount missing]. This ultimately forms a thin layer of polyurethane-modified epoxy resin adhesive layer approximately 1.5 cm thick. S5 composite specimen molding: The steel plate forming the bonding layer is placed into the mold of the asphalt mixture rutting specimen molding machine; after the binder has developed a certain strength, SMA-13 ​​asphalt mixture is placed in it, and the asphalt mixture rutting specimen molding machine is started for wheel rolling molding, with a wheel rolling number of 50 times. S6 cooling and cutting: After the composite specimen has cooled, it is cut with a cutting machine to make the composite specimen dimensions 150mm*150mm (length*width).

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