A device and method for detecting the strength of adhesion under a bidirectional coupling action

Abstract

The present application belongs to the technical field of road surface material performance detection, and provides a bonding strength detection device and method under bidirectional coupling. The device comprises an environment box, a motor, a shaft coupling, a force transmission rod, a threaded pipe, a contact disc and a controller. The environment box is provided with a sample holding plate that can be lifted. The center of the sample holding plate is provided with a concave holding area. The threaded pipe is fixedly connected to the lower end of the cover of the environment box. The motor is slidingly connected to the sliding seat fixedly connected to the upper end of the cover of the environment box. The output shaft of the motor is connected to the force transmission rod through the shaft coupling. The force transmission rod extends into the environment box through the threaded pipe and is connected to the contact disc at the bottom. The force transmission rod is threadedly connected to the threaded pipe. The output shaft of the motor and the force transmission rod are respectively provided with a torque sensor and a tension sensor. The controller is used for receiving and processing torque and tension signals. The present application can truly simulate the damage of the road surface bonding layer, so that the measurement result is more stable and accurate.

Description

Technical Field

[0001] This invention belongs to the field of pavement material performance testing technology, specifically relating to a device and method for testing adhesion strength under bidirectional coupling. Background Technology

[0002] Effective bonding between asphalt pavement layers plays a crucial role in improving pavement quality and service life. Well-bonded interlayers of asphalt pavement in good working condition can ensure the integrity of the pavement layer system, thereby effectively transferring vehicle loads from the pavement surface to the subgrade and distributing the loads, thus reducing pavement damage.

[0003] Based on the operating environment of asphalt pavement surface treatment technology, the materials between asphalt pavement layers jointly bear the combined effects of vertical and horizontal forces from vehicle loads. When the adhesion between the surface layer and the base layer is insufficient, it will quickly peel off under repeated vehicle loads, causing surface layer damage, mainly manifested as cracking and spalling, and subsequently requiring repair of the surface layer. The adhesion between layers is closely related to the performance and amount of the bonding material. Furthermore, the bonding strength of the bonding material itself has a significant impact on the bonding ability between asphalt bonding layers.

[0004] Currently, interlayer shear strength is mostly used to evaluate the bonding performance between pavement layers. This involves measuring the interlayer shear strength to assess the impact of the bonding layer's material type, dosage, curing time, and surface condition on the interlayer shear performance. Shear strength is generally calculated by applying direct shear force or torque to a composite specimen, using the maximum direct shear force or torque per unit area at specimen failure.

[0005] Invention patent CN111929177A discloses a device and method for testing the interlayer torsional shear strength of asphalt, but its device achieves the test of bond strength through a single method of torsional shear. Invention patent CN108240965A discloses a device and method for testing the interlayer bond strength of asphalt pavement, which achieves the test of bond strength through a single method of direct shear test. Invention patent CN106092880A discloses a device and method for on-site testing of the interlayer bond pull-out strength of bridge deck pavement, which tests the interlayer bond strength through a single force of pull-out test. These single-directional failure modes cannot meet the failure conditions of real pavement. Moreover, none of these testing devices can meet the requirements of testing under different temperature and humidity conditions.

[0006] Therefore, the following drawbacks exist: when using a pure shear test, the stress mode can only reflect the shear strength of the material in a single direction, either vertical or horizontal; when testing the strength of the adhesive layer, there are no constant environmental conditions, and changes in the environment may lead to test results that differ from those in actual engineering applications. Summary of the Invention

[0007] In order to solve at least one of the above-mentioned technical problems in the prior art, the present invention provides a device for detecting adhesive strength under bidirectional coupling.

[0008] The present invention is achieved by the following technical solution: a bonding strength testing device under bidirectional coupling, comprising an environmental chamber, a motor, a coupling, a force transmission rod, a threaded tube, a contact plate, and a controller. The environmental chamber has a liftable sample holding plate with a concave holding area at the center. The threaded tube is fixed to the lower end of the environmental chamber cover. The motor is slidably connected to a slide fixed to the upper end of the environmental chamber cover. The output shaft of the motor is connected to the force transmission rod through the coupling. The force transmission rod extends into the environmental chamber through the threaded tube and is connected to the contact plate at its bottom end. The force transmission rod is threadedly connected to the threaded tube. A torque sensor and a tension sensor are respectively installed on the output shaft of the motor and the force transmission rod. The controller is used to receive and process torque and tension signals.

[0009] Preferably, the lower end of the coupling has a connecting sleeve, which is connected to the upper end of the force transmission rod by a pin. The part of the force transmission rod located inside the connecting sleeve is a smooth rod, and the outer diameter of the connecting sleeve is smaller than the outer diameter of the threaded part of the force transmission rod.

[0010] Preferably, the upper end of the threaded tube is fixedly connected to a ring that matches its outer diameter, and the ring is connected to the cover of the environmental chamber by a pin; the cover of the environmental chamber is detachable and has a channel.

[0011] Preferably, the horizontal projection of the contact plate is located in the central area of ​​the holding area, and the sample holding plate is raised and lowered by a hydraulic rod.

[0012] The present invention also provides a method for detecting the adhesive strength under bidirectional coupling, comprising the following steps: S1: Adjust the temperature and humidity of the environmental chamber to the corresponding values ​​for the required simulated environment; S2: Select contact plates of different diameters according to the type of sample to be tested, and install the contact plates at the lower end of the force transmission rod; S3: Calculate the amount of sample needed based on the diameter of the contact plate and the coating rate, and apply the sample evenly to the holding area of ​​the sample holding plate. S4: Control the sample holding plate to rise until it contacts the contact plate, and continuously apply pressure until the pressure displayed on the controller panel reaches the preset standard compression load F. After the first preset time T1, stop loading and then keep it warm for a second preset time T2 to ensure that the contact plate and the sample in the holding area are fully bonded. S5: Start the motor to move the contact plate away from the sample holding plate; S6: Read the torque, tension, and maximum breaking shear stress at the moment the contact plate and sample container plate disconnect on the controller panel, and record the data; S7: Clean the instrument and reset all components.

[0013] Preferably, when the sample is asphalt with a grade less than or equal to 70, the diameter of the contact disc is 12.7 mm; when the sample is asphalt with a grade greater than 70, the diameter of the contact disc is 25.4 mm; when the sample is undiluted emulsion, the diameter of the contact disc is 50.8 mm; and when the sample is diluted emulsion, the diameter of the contact disc is 127.0 mm.

[0014] Preferably, the amount of sample used The calculation formula is as follows: In the formula, The diameter of the contact plate; This represents the coating rate.

[0015] Preferably, the maximum failure shear stress The calculation formula is as follows: In the formula, The diameter of the contact plate; The torque is measured by the torque sensor.

[0016] Compared with the prior art, the beneficial effects of the present invention are: This invention can be used to test the failure under the combined action of vertical tension and horizontal shear to simulate the combined action of vertical and horizontal forces on the interlayer materials of asphalt pavement under vehicle loads, which leads to the failure of the interlayer bonding material.

[0017] The motor drives the force transmission rod to rotate and rise, thereby providing a combined effect of tension and torque. This combined destructive effect is more in line with the situation where the interlayer adhesion is broken in real roads. By applying normal pressure to the contact plate and the sample holding plate coated with the sample, and recording the tension or torque required to break the adhesive layer between the two, the adhesion strength of the adhesive layer is determined.

[0018] Meanwhile, the environmental chamber in this invention can control the temperature and humidity of the sample, which can more realistically simulate the working conditions of the road surface adhesive layer under certain temperature and humidity, making the measurement results more stable and accurate. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a partial structural connection diagram of the present invention; Figure 3 This is a schematic diagram of the present invention applying pressure to the contact plate; Figure 4 This is a schematic diagram of the present invention applying tension and torque to the contact plate.

[0021] In the diagram: 1-Environmental chamber; 1.1-Channel; 2-Motor; 3-Coupling; 3.1-Connecting sleeve; 4-Force transmission rod; 5-Threaded pipe; 6-Contact plate; 7-Controller; 8-Sample holding plate; 8.1-Holding area; 9-Slide; 10-Torque sensor; 11-Tension sensor; 12-Hydraulic rod; 13-Pin; 14-Ring. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] It should be noted that the structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should fall within the scope of the technical content disclosed in the present invention. It should be noted that in this specification, relational terms such as "first" and "second" are only used to distinguish one entity from several other entities, and do not necessarily require or imply any actual relationship or order between these entities.

[0024] Example 1: A device for testing adhesive strength under bidirectional coupling includes an environmental chamber 1, a motor 2, a coupling 3, a force transmission rod 4, a threaded tube 5, a contact plate 6, and a controller 7. The environmental chamber 1 has a liftable sample holding plate 8, with a concave holding area 8.1 at the center of the sample holding plate 8. The threaded tube 5 is fixed to the lower end of the cover of the environmental chamber 1. The motor 2 is slidably connected to a slide block 9 fixed to the upper end of the cover of the environmental chamber 1. The output shaft of the motor 2 is connected to the force transmission rod 4 through the coupling 3. The force transmission rod 4 passes through the threaded tube 5 and extends into the environmental chamber 1, with the bottom end connected to the contact plate 6. The force transmission rod 4 is threadedly connected to the threaded tube 5. A torque sensor 10 and a tension sensor 11 are respectively installed on the output shaft of the motor 2 and the force transmission rod 4. The controller 7 is used to receive and process torque and tension signals.

[0025] In this embodiment, the horizontal projection of the contact plate 6 is located in the central area of ​​the holding area 8.1, and the sample holding plate 8 is controlled to rise and fall by a hydraulic rod 12. The upper end of the threaded tube 5 is fixedly connected to a ring 14 that matches its outer diameter, and the ring 14 is connected to the cover of the environmental chamber 1 by a pin 13; the cover of the environmental chamber 1 is detachable and has a channel 1.1. The lower end of the coupling 3 has a connecting sleeve 3.1, which is connected to the upper end of the force transmission rod 4 by a pin 13. The part of the force transmission rod 4 located inside the connecting sleeve 3.1 is a smooth rod, and the outer diameter of the connecting sleeve 3.1 is smaller than the outer diameter of the threaded part of the force transmission rod 4.

[0026] A method for detecting adhesive strength under bidirectional coupling, relying on an adhesive strength detection device under bidirectional coupling, includes the following steps: S1: Adjust the temperature and humidity of environmental chamber 1 to the corresponding values ​​for the required simulated environment; S2: Rotate the force transmission rod 4 from bottom to top through the threaded tube 5 and fix it to the connecting sleeve 3.1 with the pin 13. Select a contact plate 6 of different diameter according to the type of sample to be tested, and install the contact plate 6 at the lower end of the force transmission rod 4. S3: Calculate the amount of sample needed based on the diameter and coating rate of the contact plate 6, and apply the sample evenly to the holding area 8.1 of the sample holding plate 8. S4: Control the sample holding plate 8 to rise until it contacts the contact plate 6, and continuously apply pressure until the pressure displayed on the controller panel reaches the preset standard compression load F. After the first preset time T1, stop loading and then keep warm for the second preset time T2 to ensure that the contact plate 6 and the sample in the holding area 8.1 are fully bonded. S5: Start motor 2, which drives contact plate 6 to move away from sample holding plate 8; S6: Read the torque, tension, and maximum breaking shear stress at the moment when the contact plate 6 and the sample container plate 8 are disconnected on the controller panel, and record the data; S7: Clean the instrument and reset all components.

[0027] When the sample is asphalt with a grade less than or equal to 70, the diameter of contact disc 6 is 12.7 mm; when the sample is asphalt with a grade greater than 70, the diameter of contact disc 6 is 25.4 mm; when the sample is undiluted emulsion, the diameter of contact disc 6 is 50.8 mm; when the sample is diluted emulsion, the diameter of contact disc 6 is 127.0 mm. Sample dosage... The calculation formula is as follows: In the formula, The diameter of the contact plate; This represents the coating rate.

[0028] Maximum breaking shear stress The calculation formula is as follows: In the formula, The diameter of the contact plate; The torque is measured by the torque sensor.

[0029] Specifically, this embodiment selects to test the adhesive bond strength of a base bitumen material with a strength greater than 70 under low-temperature conditions: 1. A 25.4 mm contact plate 6 was used to test the adhesive for base bitumen materials with a strength greater than 70, and the environmental chamber 1 was set to 0°C and 60% relative humidity to simulate a common low-temperature and dry environment.

[0030] 2. At 0.23 L / m 2 To prepare a 0.12 ml sample, use a syringe to apply the sample volume to the holding area 8.1 of the sample holding plate 8, so that the sample is evenly distributed in the area.

[0031] 3. Control the sample holding plate 8 to rise until it contacts the contact plate 6, and continue to apply pressure, such as... Figure 3 As shown, the loading continues until the pressure displayed on the controller panel reaches a standard compression load of 178N for 60 seconds, after which the loading stops. Then, the temperature is maintained for half an hour to ensure that the contact plate 6 and the sample holding plate 8 are fully bonded.

[0032] 4. Start motor 2, which will move contact plate 6 away from sample holding plate 8, as follows. Figure 4 As shown; read the torque, tension, and maximum breaking shear stress at the moment the contact plate 6 and sample holding plate 8 disconnect on the controller panel, and record the data; clean the instrument and reset each component.

[0033] Example 2: The structure used in Example 2 is the same as that in Example 1. In this example, the adhesive strength of the undiluted emulsion material was tested under medium temperature and humidity conditions.

[0034] 1. A 50.8 mm contact plate 6 was used to test the adhesive of undiluted emulsion materials, and the ambient chamber 1 was set to a temperature of 30°C and a relative humidity of 75% to simulate common medium temperature and medium humidity environmental conditions.

[0035] 2. At 0.23 L / m 2 To prepare a 0.46 ml sample, use a syringe to apply the sample volume to the holding area 8.1 of the sample holding plate 8, so that the sample is evenly distributed in the area.

[0036] 3. Control the sample holding plate 8 to rise until it contacts the contact plate 6, and continue to apply pressure, such as... Figure 3 As shown, the loading continues until the pressure displayed on the controller panel reaches a standard compression load of 178N for 60 seconds, after which the loading stops. Then, the temperature is maintained for half an hour to ensure that the contact plate 6 and the sample holding plate 8 are fully bonded.

[0037] 4. Start motor 2, which will move contact plate 6 away from sample holding plate 8, as follows. Figure 4 As shown; read the torque, tension, and maximum breaking shear stress at the moment the contact plate 6 and sample holding plate 8 disconnect on the controller panel, and record the data; clean the instrument and reset each component.

[0038] Example 3: The structure used in Example 3 is the same as that in Example 1. In this example, the adhesive strength of the diluted emulsion material under high temperature and humidity conditions is selected.

[0039] 1. A 127.0 mm contact plate 6 was used to test the adhesive for diluted emulsion materials. The ambient chamber 1 was set to a temperature of 60°C and a relative humidity of 90% to simulate common high temperature and humidity environmental conditions.

[0040] 2. At 0.23 L / m 2 To prepare a 2.91 ml sample, use a syringe to apply the sample volume to the holding area 8.1 of the sample holding plate 8, so that the sample is evenly distributed in the area.

[0041] 3. Control the sample holding plate 8 to rise until it contacts the contact plate 6, and continue to apply pressure, such as... Figure 3 As shown, the loading continues until the pressure displayed on the controller panel reaches a standard compression load of 178N for 60 seconds, after which the loading stops. Then, the temperature is maintained for half an hour to ensure that the contact plate 6 and the sample holding plate 8 are fully bonded.

[0042] 4. Start motor 2, which will move contact plate 6 away from sample holding plate 8, as follows. Figure 4As shown; read the torque, tension, and maximum breaking shear stress at the moment the contact plate 6 and sample holding plate 8 disconnect on the controller panel, and record the data; clean the instrument and reset each component.

[0043] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A device for detecting adhesive strength under bidirectional coupling, characterized in that: The system includes an environmental chamber (1), a motor (2), a coupling (3), a force transmission rod (4), a threaded tube (5), a contact plate (6), and a controller (7). The environmental chamber (1) has a liftable sample holding plate (8), and the sample holding plate (8) has a concave holding area (8.1) at its center. The threaded tube (5) is fixed to the lower end of the cover of the environmental chamber (1). The motor (2) is slidably connected to a slide (9) fixed to the upper end of the cover of the environmental chamber (1). The output shaft of the motor (2) is connected to the force transmission rod (4) through the coupling (3). The force transmission rod (4) passes through the threaded tube (5) and extends into the environmental chamber (1), with the bottom end connected to the contact plate (6). The force transmission rod (4) is threadedly connected to the threaded tube (5). The output shaft of the motor (2) is... A torque sensor (10) and a tension sensor (11) are respectively installed on the shaft and the force transmission rod (4). The controller (7) is used to receive and process torque and tension signals. The lower end of the coupling (3) has a connecting sleeve (3.1). The connecting sleeve (3.1) is connected to the upper end of the force transmission rod (4) through a pin (13). The part of the force transmission rod (4) located inside the connecting sleeve (3.1) is a smooth rod. The outer diameter of the connecting sleeve (3.1) is smaller than the outer diameter of the threaded part of the force transmission rod (4). The upper end of the threaded tube (5) is fixedly connected to a ring (14) that matches its outer diameter. The ring (14) is connected to the cover of the environmental box (1) through a pin (13). The cover of the environmental box (1) is detachable and has a channel (1.1).

2. The adhesive strength testing device under bidirectional coupling according to claim 1, characterized in that: The horizontal projection of the contact plate (6) is located in the center of the holding area (8.1), and the sample holding plate (8) is controlled to rise and fall by hydraulic rod (12).

3. A method for detecting adhesive strength under bidirectional coupling, based on the adhesive strength detection device under bidirectional coupling as described in any one of claims 1 to 2, characterized in that, Includes the following steps: S1: Adjust the temperature and humidity of the environmental chamber (1) to the corresponding values ​​under the required simulated environment; S2: Select a contact plate (6) of different diameter according to the type of sample to be tested, and install the contact plate (6) at the lower end of the force transmission rod (4); S3: Calculate the amount of sample to be used based on the diameter and coating rate of the contact plate (6), and apply the sample evenly to the holding area (8.1) of the sample holding plate (8). S4: Control the sample holding plate (8) to rise until it contacts the contact plate (6) and continue to apply pressure until the pressure displayed on the controller panel reaches the preset standard compression load F. Stop loading after the first preset time T1 and then keep warm for the second preset time T2 so that the contact plate (6) and the sample in the holding area (8.1) are fully bonded. S5: Start the motor (2) to drive the contact plate (6) to move away from the sample holding plate (8); S6: Read the torque, tension and maximum breaking shear stress at the moment the contact plate (6) and the sample holding plate (8) are disconnected on the controller panel, and record the data; S7: Clean the instrument and reset all components.

4. The method for detecting adhesive strength under bidirectional coupling according to claim 3, characterized in that: When the sample is asphalt with a grade less than or equal to 70, the diameter of the contact plate (6) is 12.7 mm; when the sample is asphalt with a grade greater than 70, the diameter of the contact plate (6) is 25.4 mm; when the sample is undiluted emulsion, the diameter of the contact plate (6) is 50.8 mm; when the sample is diluted emulsion, the diameter of the contact plate (6) is 127.0 mm.

5. The method for detecting adhesive strength under bidirectional coupling according to claim 4, characterized in that: The amount of the sample The calculation formula is as follows: In the formula, The diameter of the contact plate; This represents the coating rate.

6. The method for detecting adhesive strength under bidirectional coupling according to claim 5, characterized in that: The maximum breaking shear stress The calculation formula is as follows: In the formula, The diameter of the contact plate; The torque is measured by the torque sensor.

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