Intelligent digital image pavement material interface adhesion tester and method thereof

Abstract

The present application relates to a kind of intelligent digital image pavement material interface adhesion tester and method thereof, belong to the field of highway engineering in transportation engineering.Highway engineering interface adhesion tester includes forming test mould, upper forming pad, middle forming device, lower forming pad, fixed base, force measuring device, loading device, image acquisition device and image analysis display device and other structures.The present application tests the adhesion between the interface of pavement material under the condition of fixed contact area and contact thickness, and can observe the failure morphology of aggregate interface after failure, to evaluate the service performance, durability of pavement material in actual service process, and provide important data support for pavement maintenance design.

Description

Technical Field

[0001] This invention belongs to the field of highway engineering technology in transportation engineering, and specifically relates to an intelligent digital image pavement material interface adhesion tester and method. Background Technology

[0002] Highway pavement materials can be analyzed using two-phase material theory. Crushed stone aggregate acts as the skeleton, while asphalt, cement, and other binders act as the binder. It is precisely this mutual bonding and support between the two phases that gives highway pavement materials sufficient structural strength and durability, enabling them to function properly. Highway pavement materials operate in complex environments, subjected to repeated and continuous loading from different vehicles and long-term erosion from natural elements such as rain, fog, and snow. Under these complex conditions, pavement materials undergo significant degradation over time. This degradation largely originates from a weakening of the bond between the aggregate and binder interfaces, gradually leading to pavement structural failure. Therefore, accurate testing of the bond between pavement material interfaces is a crucial indicator for evaluating the performance and durability of pavement materials, and also provides essential data for pavement maintenance design.

[0003] However, current methods for testing the interfacial bond strength of pavement materials rely on splitting crack tests to indirectly evaluate the bonding effect between internal pavement materials. This involves preparing a specimen of a specific size, placing fixed blocks above and below it, and applying force using a pressure testing machine until the specimen completely fails due to fatigue. The fatigue failure force is then used to indirectly evaluate the bonding effect between internal pavement materials. A significant drawback of existing splitting crack tests is that they fail to directly evaluate the interfacial bond strength. The results only indicate the overall stress on the pavement specimen and do not reveal the interfacial bond strength, particularly the bond effect between aggregates and binders. Secondly, existing splitting crack tests cannot accurately measure the bonding effect of binders between aggregates of different sizes in pavement materials. The aggregate particle sizes used in highway pavement materials are generally classified into three categories: 0-5mm, 5-10mm, and 10-20mm, with more detailed particle size classifications also available. Current splitting crack tests cannot accurately evaluate the bonding effect of binders filling aggregates of different particle sizes. Furthermore, existing splitting tests only evaluate macroscopic mechanical properties and cannot observe the microscopic cracking and deformation of the pavement material interface during the failure process, or the microscopic morphology of the interface after failure.

[0004] In practical engineering, pavement materials are subjected to complex effects from vehicle loads, environmental factors, and other aspects. The change in the bonding force between the material interfaces is a crucial parameter characterizing the impact of microstructural failure on the pavement material's macrostructure. Considering the actual application scenarios of pavement materials and the current limitations of interfacial bonding force testing—namely, the indirect evaluation method of splitting crack testing—which cannot directly evaluate the bonding force between pavement material interfaces, accurately test the bonding effect of binders on aggregates of different sizes, or observe the microscopic cracking of the interface during failure and the microscopic morphology of the interface after failure, overcoming these shortcomings is a pressing issue in the field of highway engineering technology in transportation engineering. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing an intelligent digital image-based pavement material interfacial adhesion tester and method. This invention employs a spatially confined test method that directly controls the contact area and thickness between pavement material aggregates. It simulates the contact state between aggregate particles and, after fixing them in place, uses an intelligent uniform-speed loading operation to test the interfacial adhesion between pavement materials under fixed contact area and thickness conditions, thereby evaluating the interfacial adhesion between aggregates with different contact areas. Simultaneously, during the testing of pavement material interfacial adhesion, image acquisition and analysis are performed, allowing real-time observation of cracking and damage at the aggregate interface, as well as the post-damage morphology of the aggregate interface. This enables the prediction of the long-term performance of pavement materials and provides accurate data for highway pavement maintenance design.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An intelligent digital image pavement material interfacial adhesion tester includes a molding mold, an upper molding pad, a middle molding device, and a lower molding pad. In the molding trial mold, the lower molding pad, the middle molding device, and the upper molding pad are placed sequentially from bottom to top; The intermediate forming device includes a first filling mold and an intermediate contact filling mold; A first filling mold is provided on each of the left and right sides of the intermediate contact filling mold, and a through hole is provided in the middle of the intermediate contact filling mold, which is connected to the first filling molds on the left and right sides through the through hole. The middle contact filler mold and the first filler molds on its left and right sides are fixed by the first fixing component; The first packing mold has a connecting ring at the end away from the middle contact packing mold; It also includes a fixed base, a force measuring device, a loading device, an image acquisition device, and an image analysis and display device; The fixed base is used to fix the first filler mold on the left side of the middle forming device; One end of the force measuring device is connected to the connecting ring on the first filler mold on the right side of the middle forming device; the other end of the force measuring device is connected to the loading end of the loading device. The image acquisition device is fixedly installed directly above the fixed base and is used to acquire images of the central forming device on the fixed base; The image analysis and display device is connected to the image acquisition device and is used to analyze the images acquired by the image acquisition device to obtain the microscopic morphology of the interface of the contact surface after fracture. Then, the interface contact area and contact morphology between aggregates on the fracture surface are analyzed, and the ratio of the interface contact area to the total contact hole area is displayed. This ratio is called the effective contact area ratio. At the same time, the morphological image of the fracture surface is displayed.

[0007] Furthermore, preferably, the fixed base is engaged with the first filler mold on the left side of the central forming device.

[0008] Furthermore, preferably, the fixed base is fixedly connected to the first filling mold on the left side of the central forming device by a plurality of second fasteners.

[0009] Furthermore, preferably, the molding test mold is a hollow cylinder with an inner diameter of 101.6 mm and a height of 70 mm; the upper molding pad is a solid cylinder with a diameter of 101 mm and a height of 20 mm; the lower molding pad is a solid cylinder with a diameter of 101 mm and a height of 20 mm; and the middle molding device has a height of 30 mm.

[0010] Furthermore, preferably, the cross-section of the through hole is circular or rectangular.

[0011] Furthermore, preferably, the image acquisition device is connected to the fixed base via a height adjustment device.

[0012] This invention also provides a method for testing the interfacial adhesion of pavement materials based on intelligent digital image technology, using the aforementioned intelligent digital image pavement material interfacial adhesion tester, and comprising the following steps: First, place the lower molding pad at the bottom of the molding test mold; The first filling mold and the intermediate contact filling mold in the middle forming device are firmly fixed by the first fixing member so that they do not shift or slide during the forming process; Place the middle forming device in the forming mold, and place it on the lower forming pad; Then, the required road test material is filled into the first filler mold; After the filling is completed, the upper molding pad is placed in the molding mold, placed on the middle molding device, and then the molding mold is placed on the compaction device to compact the specimen. After the molding test mold is compacted, the lower molding pad, the middle molding device and the upper molding pad inside are removed together, and then the molded test piece is placed for maintenance. Remove the upper and lower forming pads, fix the first filling mold on the left side of the middle forming device onto the fixed base to prevent it from sliding during the test; remove the first fixing part and the middle contact filling mold, and connect the first filling mold on the right side of the middle forming device to the force measuring device. The image acquisition device is fixed by the height adjustment device, and the image analysis and display device is turned on. Then the loading device is turned on, which drives the force measuring device to start the interfacial adhesion test of the road material. The first filler mold on the right side of the middle forming device moves under the action of the force measuring device until it is completely separated from the first filler mold on the left side of the middle forming device. At this time, the adhesive material between the first filler molds on the left and right sides of the middle forming device 3 is destroyed, thus completing the interfacial adhesion test process of the road material. During the experiment, the image acquisition device acquires images of the road material interface failure in real time. When the road material interface is completely destroyed, the failure interface of the first filler mold on the right side of the middle forming device is placed directly below the image acquisition device for image acquisition and transmission. The image analysis and display device analyzes and displays the characteristics of road material interface failure and cracking and interface morphology features in real time. During the test, the force measuring device displays the change curve of the adhesion force of the pavement material in real time during the loading process, and records and displays the peak value of the interfacial adhesion force of the pavement material after the test. After the test, the force measuring device, loading device, image analysis and display device, and image acquisition device were turned off.

[0013] Furthermore, preferably, the product is maintained at 20℃±5℃ for 24 hours.

[0014] Compared with the prior art, the beneficial effects of this invention are as follows: This invention provides an intelligent digital image pavement material interfacial adhesion tester and method. It employs a spatially constrained test method that directly controls the contact area and thickness between pavement aggregates to simulate the contact state between aggregate particles. After being fixed in shape, an intelligent uniform-speed loading operation is used, typically controlled in strain mode at a rate of 1 mm / 10 s. The operation method and speed can be adjusted according to actual conditions to test the interfacial adhesion between pavement materials under fixed contact area and thickness. The contact thickness is generally controlled at 2 mm, but can be adjusted as needed. The contact area between aggregates is generally divided into three types of hollow circular contact areas with diameters of 20 mm, 10 mm, and 5 mm, and three types of hollow rectangular contact areas with cross-sections of 20 mm * 30 mm, 10 mm * 30 mm, and 5 mm * 30 mm. The form and size of the cross-sectional area can also be adjusted according to actual conditions to evaluate the interfacial adhesion between aggregates with different contact areas. Simultaneously, during the testing of the interfacial adhesion of road materials, image acquisition and analysis can be performed to observe the cracking and damage of the aggregate interface in real time, and to observe the damage morphology of the aggregate interface after damage.

[0015] This invention overcomes the shortcomings of existing technologies, such as the inability to directly evaluate the bonding force between pavement material interfaces, the inability to accurately test the interfacial bonding force between aggregates under different contact conditions, and the inability to observe the micro-cracking of interfaces during failure and the micro-morphology of interfaces after failure. It fills the gap in testing equipment and methods for interfacial bonding force of pavement materials both domestically and internationally. It provides significant support for predicting the performance and durability of pavement materials under long-term complex vehicle loads and environmental erosion conditions, as well as for pavement maintenance design, and has significant economic and social benefits.

[0016] Existing methods for evaluating the interfacial bond strength of pavement materials, namely the splitting test, involve applying force to the top and side of the asphalt mixture after it has been formed, causing it to crack and break. This method cannot directly evaluate the bond strength between pavement material interfaces, accurately test the bonding effect of the binder on aggregates of different sizes, or observe the micro-cracking of the interface during the failure process and the micro-morphology of the interface after failure. In contrast, this patented technology uses the interfacial bond strength between aggregates as the test index, which provides a more accurate evaluation of the interfacial bond strength of pavement materials and allows for direct observation of the morphological characteristics of the interfacial bond between aggregates.

[0017] Existing methods for evaluating the interfacial bond strength of pavement materials, namely the splitting test, involve applying force to the top and side of the asphalt mixture after it has been formed, causing it to crack and break. This method cannot directly evaluate the bond strength between pavement material interfaces, accurately test the bonding effect of the binder on aggregates of different sizes, or observe the micro-cracking of the interface during the failure process and the micro-morphology of the interface after failure. In contrast, this invention uses the interfacial bond strength between aggregates as the test index, which provides a more accurate evaluation of the interfacial bond strength of pavement materials and allows for direct observation of the morphological characteristics of the interfacial bond between aggregates. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art 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.

[0019] Figure 1 This is a schematic diagram of the main structure of the molding mold of the present invention after the lower molding pad, the middle molding device and the upper molding pad are installed inside the mold. Figure 2 This is a schematic diagram of the upper molded pad block; Figure 3 This is a schematic diagram of the middle forming device; Figure 4 This is a schematic diagram of the lower molding pad. Figure 5 This is a top view of the molded test mold of the present invention after the lower molding pad and the middle molding device are installed inside. Figure 6 This is a top view of the pavement material interfacial adhesion tester of the present invention during testing. Figure 7 This is a schematic diagram of the front view structure of the pavement material interfacial adhesion tester during testing according to the present invention; Figure 8 A schematic diagram of an intermediate contact filler mold structure with a circular cross-section of 20mm in diameter; Figure 9 A schematic diagram of an intermediate contact filler mold structure with a circular cross-section of 10mm in diameter; Figure 10 A schematic diagram of the intermediate contact filler mold structure with a circular cross-section of 5mm in diameter through hole; Figure 11 A schematic diagram of the intermediate contact filler mold structure with a rectangular through-hole cross-section of 20mm*30mm; Figure 12A schematic diagram of the intermediate contact filler mold structure with a rectangular through-hole cross-section of 10mm*30mm; Figure 13 A schematic diagram of the intermediate contact filler mold structure with a through-hole cross-section of 5mm*30mm; In the figure, 1 is the molding test mold, 2 is the upper molding pad, 3 is the middle molding device, 4 is the lower molding pad, 5 is the first filling mold, 6 is the intermediate contact filling mold, 7 is the first fixing component, 8 is the connecting ring, 9 is the second fixing component, 10 is the force measuring device, 11 is the loading device, 12 is the image analysis and display device, 13 is the image acquisition device, 14 is the height adjustment device, and 15 is the fixed base. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the embodiments.

[0021] Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be construed as limiting the scope of the invention. Where specific techniques or conditions are not specified in the embodiments, they are performed in accordance with the techniques or conditions described in the literature in the field or according to the product instructions. Materials or equipment whose manufacturers are not specified are all conventional products that can be obtained by purchase.

[0022] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is “connected” to another element, it can be directly connected to the other element, or there may be an intermediate element. Furthermore, the term “connected” as used herein can include wireless connections. The term “and / or” as used herein includes any and all combinations of one or more of the associated listed items.

[0023] In the description of this invention, unless otherwise stated, "a plurality of" means two or more. The terms "inner," "upper," "lower," etc., indicate the orientation or state relationship based on the orientation or state relationship shown in the drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "equipped with" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art will understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein.

[0026] Definitions: Filler: This is a verb with an action, meaning to fill the road surface with material.

[0027] Materials: In this context, it refers to road surface materials. Road surface materials are composed of many different components, the main components of which include asphalt, aggregates, mineral powder, admixtures, and fibers. Aggregates are a part of the road surface materials.

[0028] Aggregate: Aggregate is a part of road surface materials. It is composed of crushed stone (usually called gravel) with different particle sizes, generally ranging from 0 to 30 mm. In the professional field, it is collectively referred to as aggregate.

[0029] The main indicator tested in this invention is the interfacial adhesion between aggregates of different sizes.

[0030] like Figures 1-13 As shown, an intelligent digital image pavement material interfacial adhesion tester includes a molding mold 1, an upper molding pad 2, a middle molding device 3, and a lower molding pad 4. In the molding test mold 1, the lower molding pad 4, the middle molding device 3, and the upper molding pad 2 are placed sequentially from bottom to top. The middle forming device 3 includes a first filling mold 5 and an intermediate contact filling mold 6; A first filling mold 5 is provided on the left and right sides of the intermediate contact filling mold 6, and a through hole is provided in the middle of the intermediate contact filling mold 6, which is connected to the first filling molds 5 on the left and right sides through the through hole. The intermediate contact filler mold 6 and the first filler molds 5 on its left and right sides are fixed by the first fixing member 7; The first packing mold 5 is provided with a connecting ring 8 at the end away from the middle contact packing mold 6; It also includes a fixed base 15, a force measuring device 10, a loading device 11, an image acquisition device 13, and an image analysis and display device 14; The fixed base 15 is used to fix the first filler mold 5 on the left side of the middle forming device 3; One end of the force measuring device 10 is connected to the connecting ring 8 on the first filling mold 5 on the right side of the middle forming device 3; the other end of the force measuring device 10 is connected to the loading end of the loading device 11. The image acquisition device 13 is fixedly installed directly above the fixed base 15 and is used to acquire images of the central forming device 3 on the fixed base 15. The image analysis and display device 14 is connected to the image acquisition device 13 and is used to analyze the images acquired by the image acquisition device 13 to obtain the microscopic morphology of the interface of the contact surface after fracture. Then, the interface contact area and contact morphology between aggregates on the fracture surface are analyzed, and the ratio of the interface contact area to the total contact hole area is displayed. This ratio is called the effective contact area ratio. At the same time, the morphological image of the fracture surface is displayed.

[0031] In a preferred embodiment, the fixed base 15 is engaged with the first filler mold 5 on the left side of the central forming device 3.

[0032] In a preferred embodiment, the fixed base 15 is fixedly connected to the first filling mold 5 on the left side of the central forming device 3 by a plurality of second fixing parts 9.

[0033] In the preferred embodiment, the molding mold 1 is a hollow cylinder with an inner diameter of 101.6 mm and a height of 70 mm; the upper molding pad 2 is a solid cylinder with a diameter of 101 mm and a height of 20 mm; the lower molding pad 4 is a solid cylinder with a diameter of 101 mm and a height of 20 mm; and the middle molding device 3 has a height of 30 mm.

[0034] In a preferred embodiment, the cross-section of the through hole is circular or rectangular.

[0035] In a preferred embodiment, the image acquisition device 13 is connected to the fixed base 15 via a height adjustment device 14.

[0036] In this invention: Molding mold 1 is a hollow cylinder with sufficient rigidity and strength to withstand impact loads of 1kN or more. Its dimensions are typically an inner diameter of 101.6mm and a height of 70mm, but can be adjusted as needed. Molding mold 1 is preferably a standard asphalt Marshall mold commonly used in highway engineering.

[0037] The upper molded pad 2 is a solid cylinder with sufficient rigidity and strength to withstand impact loads of 1kN or more. Its dimensions are typically 101mm in diameter and 20mm in height, but can be adjusted according to test requirements.

[0038] The central forming device 3 is a hollow, figure-eight shaped mold, including a first filling mold 5, an intermediate contact filling mold 6, a first fixing component 7, and a connecting ring 8. This device can be placed inside the forming mold 1. There is a first filling mold 5 on each side, which can hold road material for fixing and shaping. The intermediate contact filling mold 6 controls the contact state of the aggregate within the left and right first filling molds 5. A lower forming pad 4 is placed at the bottom, and an upper forming pad 2 is placed on top. After filling, it can withstand an impact load of not less than 1 kN and has sufficient rigidity and strength.

[0039] The lower molded pad 4 is a solid cylinder with sufficient rigidity and strength to withstand impact loads of 1kN or more. Its dimensions are generally 101mm in diameter and 20mm in height, but can be adjusted according to test requirements.

[0040] The first filler mold 5 is a component of the central forming device 3. There is one first filler mold 5 on each side of the central forming device 3, arranged symmetrically in a figure-eight shape. Different sizes of road materials, such as asphalt mixture, can be filled into them. Each first filler mold 5 has an edge length of 46mm and a height of 30mm, possessing sufficient rigidity and strength to withstand the impact of loads of 1kN or more.

[0041] The intermediate contact filler mold 6 is a component of the intermediate forming device 3. It has a through hole in the center. By using different models of intermediate contact filler molds 6, the contact thickness and contact area between the road material interfaces in the left and right first filler molds 5 of the intermediate forming device 3 can be adjusted. Generally, the contact thickness is circular or rectangular, with its size controlled within 2mm. The contact area is controlled as a circle with diameters of 20mm, 10mm, and 5mm, or a rectangle with cross-sectional areas of 20*30mm, 10*30mm, and 5*30mm. The contact state and size can be adjusted according to test requirements. It has sufficient rigidity and strength to withstand impact loads of 1kN and above. The intermediate contact filler mold 6 has a two-part structure. Before forming, the two parts are combined to form a through hole contact surface in the middle. After forming, during test preparation, the two parts of the intermediate contact filler mold 6 are disassembled, allowing real-time observation of the damage to the intermediate aggregate bonding area.

[0042] The first fixing member 7, as a component of the central forming device 3, possesses sufficient strength and rigidity to fix the relative positions of the intermediate contact filler mold 6 and the first filler molds 5 on its left and right sides during the forming process. This ensures that the symmetrical left and right parts of the central forming device 3 become a single unit during the forming process, and it can be easily disassembled during the testing of the interfacial adhesion of the road material. Preferably, the first fixing member 7 adopts a threaded nail-type structure, with one end being a threaded tip that connects to the threaded hole in the center of the intermediate contact filler mold 6, thereby fixing the relative positions of the intermediate contact filler mold 6 and the first filler molds 5 on its left and right sides.

[0043] The connecting ring 8 has sufficient strength and rigidity to serve as a connector for conducting interfacial adhesion tests on road materials. Preferably, the connecting ring 8 is a ring at one end and a threaded nail at the other end.

[0044] The second fastener 9 has sufficient strength and rigidity, and multiple fasteners are provided. It is used to fix the first filler mold 5 during the test to ensure that the left side of the first filler mold 5 does not move, so as to carry out the interfacial adhesion test of the road material.

[0045] The force measuring device 10 is connected to the first filler mold 5 on the right side via the connecting ring 8. It is used to test the interfacial adhesion force of the road material. During the test, it can output the adhesion force change curve and display the adhesion force peak value.

[0046] The force measuring device 10 preferably includes a hook end for connecting the test piece, an intermediate helical screw, a force measuring device, and a port connected to the loading device. The test pieces can be connected together via the hook. The rotation of the helical screw causes the test pieces to move uniformly. The force measuring device records the force and displacement values ​​in real time during the test, and can display the maximum destructive force. Furthermore, through a software system connected to a computer, the curves formed by the force and displacement can be observed in real time. The rotational power and movement rate control of the helical screw are both implemented on the loading device 11.

[0047] The loading device 11, connected to the force measuring device 10, can apply uniform loading to the force measuring device 10 using an intelligent strain control mode. The loading rate is typically controlled at 1 mm / 10 s, but can be adjusted according to experimental requirements. Preferably, the loading device 11 is a variable frequency motor, which can control the rotational speed of the screw in the force measuring device 10 by changing the motor's frequency, thereby changing the loading rate and achieving uniform loading.

[0048] The image analysis and display device 12 is used to analyze the cracking process and contact surface morphology of the acquired images and to display the image analysis results in real time. The image analysis and display device 12 analyzes the images acquired by the image acquisition device 13 to obtain the microscopic morphology of the interface of the contact surface after fracture. Then, it analyzes the interface contact area and contact morphology between the aggregates on the fracture surface, displays the ratio of the interface contact area to the total contact hole area, which is called the effective contact area ratio, and simultaneously displays the morphological image of the fracture surface.

[0049] Image acquisition device 13 is used to acquire images of interface failure and cracking between the first filler mold 5 and the intermediate contact filler mold 6 during the road material interface adhesion test, as well as images of the morphological features between the interfaces after failure. The acquired data is then transmitted to image analysis and display device 12 for image feature analysis and display.

[0050] The height adjustment device 14 is used to adjust the height of the image acquisition device 13, so as to facilitate the installation, disassembly and image acquisition during the test.

[0051] The fixed base 15, possessing sufficient strength and rigidity, is used to fix the first filler mold 5 for conducting interfacial adhesion tests on pavement materials. The fixed base 15 has sufficient counterweight and an anti-slip design at the bottom, preventing displacement and slippage during the test. The fixed base 15 is the bottom support and load-bearing component, primarily used to fix the left mold of the first filler mold 5. At this time, the left mold of the first filler mold 5 contains pre-formed asphalt mixture. It serves as the bottom component to ensure that the left mold does not move during the test, thus ensuring the accuracy of the interfacial adhesion test.

[0052] The method of using the tester of this invention is as follows: First, place the lower molding pad 4 at the bottom of the molding test mold 1; The first filling mold 5 and the intermediate contact filling mold 6 in the middle forming device 3 are firmly fixed by the first fixing member 7 to prevent displacement and slippage during the forming process. It is possible to manually adjust the contact thickness and contact area shape and size of the filling in the left and right first filling molds 5 by changing different intermediate contact filling molds 6 according to the test requirements. The contact thickness is generally controlled at 2mm, and the contact area is generally a circle with a diameter of 20mm, 10mm and 5mm. It can also be a rectangle with a cross section of 20*30mm, 10*30mm and 5*30mm. The contact thickness and contact area shape and size can also be adjusted according to the test requirements. The middle forming device 3 is placed in the forming mold 1 and placed on the lower forming pad 4; Then, the required road test material is filled into the first filling mold 5. When filling the road material, a certain loose paving coefficient is required according to the compaction degree. That is, the actual filling road material should be higher than the middle forming device 3 according to the material characteristics to facilitate material compaction. After the filling is completed, the upper molding pad 2 is placed in the molding mold 1 and placed on the middle molding device 3. Then the molding mold 1 is placed on the compaction device specified in the test and the specimen is compacted and molded. The test specification here refers to the compaction device specified in the "Test Procedure for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011).

[0053] After the molding mold 1 is compacted, the lower molding pad 4, the middle molding device 3 and the upper molding pad 2 inside it are slowly removed together. This operation is generally carried out using a demolding device to ensure the integrity of the molded specimen. After removal, the molded specimen is placed at room temperature (20℃±5℃) for curing for 24 hours. The curing conditions and time can be adjusted according to the different road materials. Then, slowly remove the upper forming pad 2 and the lower forming pad 4 respectively, fix the first filling mold 5 on the left side of the middle forming device 3 on the fixed base 15 so that it does not slide during the test, remove the first fixing part 7 and the middle contact filling mold 6, so that the first filling molds 5 on the left and right sides of the middle forming device 3 are separated from the mechanical connection, and only the road material interface bonding effect exists in a certain range in the middle. At this time, the first filling mold 5 on the right side of the middle forming device 3 is not fixed, so that it is connected to the force measuring device 10. The image acquisition device 13 is fixed in an appropriate position by the height adjustment device 14, and the image analysis and display device 12 is turned on. Then the loading device 11 is turned on, and the force measuring device 10 is driven to start the road material interface adhesion test. The first filler mold 5 on the right side of the middle forming device 3 moves under the action of the force measuring device 10 until it is completely separated from the first filler mold 5 on the left side of the middle forming device 3. At this time, the adhesive material between the first filler molds 5 on the left and right sides of the middle forming device 3 is destroyed, thus completing the interfacial adhesion test process of the road material. During the experiment, the image acquisition device 13 acquires images of the road material interface failure in real time. When the road material interface is completely destroyed, the failure interface of the first filling mold 5 on the right side of the middle forming device 3 is placed directly below the image acquisition device 13 for image acquisition and transmission. The image analysis and display device 12 analyzes and displays the characteristics of road material interface failure and cracking and interface morphology features in real time. During the test, the force measuring device 10 displays the change curve of the adhesion force of the road material in real time during the loading process. After the test, the peak value of the adhesion force at the interface of the road material can be recorded and displayed. After the test, turn off the force measuring device 10, loading device 11, image analysis and display device 12, and image acquisition device 13. Put all parts of the instrument back in their proper place for the next test. The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. An intelligent digital image-based interfacial adhesion tester for road surface materials, characterized in that, Including established scenarios and test scenarios; The molding process includes a molding test mold (1), an upper molding pad (2), a middle molding device (3), and a lower molding pad (4). In the molding test mold (1), the lower molding pad (4), the middle molding device (3), and the upper molding pad (2) are placed from bottom to top. The middle forming device (3) includes a first filling mold (5) and an intermediate contact filling mold (6); A first filling mold (5) is provided on the left and right sides of the intermediate contact filling mold (6), and a through hole is provided in the middle of the intermediate contact filling mold (6), which is connected to the first filling mold (5) on the left and right sides through the through hole. The intermediate contact filling mold (6) and the first filling molds (5) on its left and right sides are fixed by the first fixing member (7); The first filling mold (5) has a connecting ring (8) at one end away from the middle contact filling mold (6); During molding, the lower molding pad (4) is first placed at the bottom of the molding test mold (1); The first filling mold (5) and the intermediate contact filling mold (6) in the middle forming device (3) are firmly fixed by the first fixing member (7); Place the middle forming device (3) in the forming mold (1) and place it on the lower forming pad (4); then fill the required road test material into the first filling mold (5); Place the upper molding pad (2) in the molding mold (1), place it on the middle molding device (3), and then place the molding mold (1) on the compaction device specified in the test to compact the specimen. After the molding test mold (1) is compacted, the lower molding pad (4), the middle molding device (3) and the upper molding pad (2) inside it are slowly removed together; The test scenario also includes a fixed base (15), a force measuring device (10), a loading device (11), an image acquisition device (13), and an image analysis and display device (12). The fixed base (15) is used to fix the first filler mold (5) on the left side of the middle forming device (3); One end of the force measuring device (10) is connected to the connecting ring (8) on the first filling mold (5) on the right side of the middle forming device (3); the other end of the force measuring device (10) is connected to the loading end of the loading device (11); The image acquisition device (13) is fixedly installed directly above the fixed base (15) and is used to acquire images of the central forming device (3) on the fixed base (15); The image analysis and display device (12) is connected to the image acquisition device (13) and is used to analyze the image acquired by the image acquisition device (13) to obtain the micro-morphology of the interface of the contact surface after fracture. Then, the interface contact area and contact morphology between the aggregates on the fracture surface are analyzed, and the ratio of the interface contact area to the total contact hole area is displayed. This ratio is called the effective contact area ratio, and the morphology image of the fracture surface is displayed at the same time. The fixed base (15) is engaged with the first filler mold (5) on the left side of the middle forming device (3); During the test, the upper forming pad (2) and the lower forming pad (4) are removed, and the first filling mold (5) on the left side of the middle forming device (3) is fixed on the fixed base (15). The first fixing part (7) and the middle contact filling mold (6) are removed, so that the first filling molds (5) on the left and right sides of the middle forming device (3) are disconnected from the mechanical connection. At this time, the first filling mold (5) on the right side of the middle forming device (3) is not fixed, so that it is connected to the force measuring device (10). The image analysis display device (12) is turned on, and then the loading device (11) is turned on, which drives the force measuring device (10) to start the road material interface adhesion test.

2. The intelligent digital image pavement material interfacial adhesion tester according to claim 1, characterized in that, The molding test mold (1) is a hollow cylinder with an inner diameter of 101.6 mm and a height of 70 mm; the upper molding pad (2) is a solid cylinder with a diameter of 101 mm and a height of 20 mm; the lower molding pad (4) is a solid cylinder with a diameter of 101 mm and a height of 20 mm; and the middle molding device (3) has a height of 30 mm.

3. The intelligent digital image pavement material interfacial adhesion tester according to claim 1, characterized in that, The cross-section of the through hole is circular or rectangular.

4. The intelligent digital image pavement material interfacial adhesion tester according to claim 1, characterized in that, The image acquisition device (13) is connected to the fixed base (15) via the height adjustment device (14).

5. A method for testing the interfacial adhesion strength of pavement materials based on intelligent digital image technology, using the intelligent digital image pavement material interfacial adhesion strength tester as described in any one of claims 1 to 4, characterized in that, Includes the following steps: First, place the lower molding pad at the bottom of the molding test mold; The first filling mold and the intermediate contact filling mold in the middle forming device are firmly fixed by the first fixing member so that they do not shift or slide during the forming process; Place the middle forming device in the forming mold, and place it on the lower forming pad; Then, the required road test material is filled into the first filler mold; After the filling is completed, the upper molding pad is placed in the molding mold, placed on the middle molding device, and then the molding mold is placed on the compaction device to compact the specimen. After the molding test mold is compacted, the lower molding pad, the middle molding device and the upper molding pad inside are removed together, and then the molded test piece is placed for maintenance. Remove the upper and lower forming pads, fix the first filling mold on the left side of the middle forming device onto the fixed base to prevent it from sliding during the test; remove the first fixing part and the middle contact filling mold, and connect the first filling mold on the right side of the middle forming device to the force measuring device. The image acquisition device is fixed by the height adjustment device, and the image analysis and display device is turned on. Then the loading device is turned on, which drives the force measuring device to start the interfacial adhesion test of the road material. The first filler mold on the right side of the middle forming device moves under the action of the force measuring device until it is completely separated from the first filler mold on the left side of the middle forming device. At this time, the adhesive material between the first filler molds on the left and right sides of the middle forming device is destroyed, thus completing the interfacial adhesion test process of the road material. During the experiment, the image acquisition device acquires images of the road material interface failure in real time. When the road material interface is completely destroyed, the failure interface of the first filler mold on the right side of the middle forming device is placed directly below the image acquisition device for image acquisition and transmission. The image analysis and display device analyzes and displays the characteristics of road material interface failure and cracking and interface morphology features in real time. During the test, the force measuring device displays the change curve of the adhesion force of the pavement material in real time during the loading process, and records and displays the peak value of the interfacial adhesion force of the pavement material after the test. After the test, the force measuring device, loading device, image analysis and display device, and image acquisition device were turned off.

6. The method for testing the interfacial adhesion of road materials based on intelligent digital imaging technology according to claim 5, characterized in that: Maintain at 20℃±5℃ for 24 hours.

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