Compression-shear testing apparatus for testing interlayer bond performance of airport runway pavement under complex environments.

Abstract

This invention provides a compression-shear testing device for testing the interlayer bonding performance of airport runway surfaces under complex environments. The device includes a test frame, an axial loading system mounted on the test frame, and a test chamber. The test chamber contains a shear clamping device and a heating device. The axial loading system is connected to the shear clamping device. The test chamber is also connected to an injection system, through which test liquid is injected into the test chamber. This invention can simultaneously simulate the synergistic effects of alternating high and low temperatures, water immersion, chemical corrosion from de-icing agents, and compression-shear coupled loads, accurately reproducing the actual service conditions of airport runways. It employs multi-stage environmental simulation with gradient transitions to closely match the actual seasonal environmental changes of airport runways. Through dynamic medium circulation and pressure control, it simulates dynamic conditions such as de-icing agent scouring and changes in accumulated water pressure. The gradient compression-shear coupled loading fully deforms the interlayer interface of the specimen, allowing for the acquisition of creep, relaxation, and other characteristic data.

Description

Technical Field

[0001] This invention relates to the field of testing equipment technology, and in particular to a compression-shear testing device for testing the interlayer bonding performance of airport runway pavement under complex environments. Background Technology

[0002] Airport runways are typically composed of multiple layers, including an asphalt surface layer, a base layer, and a subbase layer. The interlayer bonding performance between these layers directly determines the overall load-bearing capacity and fatigue resistance of the runway.

[0003] With the increasing construction of hub airports, coastal airports, and airports in cold regions, the service environment of runways is becoming more complex. In summer, the surface temperature of runways can reach 60-80°C, causing the asphalt binder to soften and the interlayer shear strength to decrease. During the rainy season, when heavy rainfall occurs, water can enter the interlayer interface, causing the binder to absorb water, soften, peel, slip, and fatigue deteriorate. Airports in cold regions use a large amount of de-icing agents containing potassium acetate, calcium magnesium acetate, chloride salts, and urea. These chemical components can cause chemical corrosion between the interlayers and accelerate interlayer degradation.

[0004] However, existing testing equipment can only perform room temperature direct shear, high temperature shear, or simple water immersion tests, and cannot simultaneously simulate the real effects of complex environments such as high and low temperatures, water environments, and de-icing agent chemical solutions on interlayer interfaces. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a compression-shear testing device for testing the interlayer bonding performance of airport runways under complex environments. This invention can simultaneously simulate high and low temperatures, water immersion, chemical corrosion from de-icing agents, and compression-shear coupled loads, closely matching the actual service conditions of airport runways, thereby improving the accuracy of the test results.

[0006] In a first aspect, the technical solution provided by the present invention is: a compression-shear testing device for testing the interlayer bonding performance of airport runway pavement under complex environments, comprising a test frame, an axial loading system and a test chamber disposed on the test frame; the test chamber is provided with a shear clamping device and a heating device; the axial loading system is connected to the shear clamping device.

[0007] The test chamber is also connected to a liquid injection system, through which test liquid is injected into the test chamber.

[0008] Preferably, the test frame includes an upper crossbeam, a lower crossbeam, and multiple columns, with the lower ends of the multiple columns connected to the base plate, and the upper and lower crossbeams fitted onto the upper and lower ends of the columns.

[0009] Preferably, the axial loading system includes a loading cylinder and a transmission rod. The loading cylinder is mounted on the upper crossbeam, and the piston rod of the loading cylinder extends downward and is connected to the transmission rod, which extends into the test chamber.

[0010] Preferably, the transmission rod is also equipped with a force sensor and a displacement sensor, both of which are connected to the control terminal; the force sensor and displacement sensor are used to measure the loading force applied by the loading cylinder and the deformation of the test sample.

[0011] Preferably, the test chamber includes a shell and a transparent cover disposed on the shell, and the transparent cover is also provided with a liquid inlet and a liquid outlet, the liquid inlet being connected to the liquid injection system through a pipe.

[0012] Preferably, the shearing clamping device includes an upper pressure head, a lower pressure head, an upper shear box, and a lower shear box. The upper pressure head is located inside the housing and connected to the transmission rod. The lower pressure head is disposed on a pressure bearing seat at the lower end of the housing. The upper pressure head is provided with an upper shear box at its lower end. The lower pressure head is provided with a lower shear box. Both the upper and lower shear boxes are L-shaped structures.

[0013] Preferably, the heating device includes a temperature sensor and a heating element disposed on the side walls of the upper and lower shear boxes, and both the heating element and the temperature sensor are electrically connected to the control terminal.

[0014] Preferably, the liquid injection system includes a water storage bottle, a corrosive liquid storage bottle, and a flow pump. The water storage bottle and the corrosive liquid storage bottle are respectively connected to the liquid inlet of the test chamber through corresponding pipelines and the flow pump, thereby injecting water or corrosive liquid into the test chamber.

[0015] Secondly, the present invention also provides a compression-shear test method for testing the interlayer bonding performance of airport runway pavement under complex environments, comprising the following steps:

[0016] S1) Place the sample in the upper shear box and the lower shear box, and adjust the position of the sample so that the upper shear box and the lower shear box are in close contact with the sample surface.

[0017] S2) Set environmental simulation parameters, which are divided into low temperature stage, normal humidity stage, chemical corrosion stage and high temperature stage. Environmental simulation is carried out in sequence or in combination. Each stage maintains a preset time to simulate the actual seasonal changes and environmental conditions of the airport runway.

[0018] S3) During the environmental simulation process, the injection system is activated to realize the dynamic circulation of water and / or de-icing agent chemical solution. The medium ratio, circulation flow rate and water pressure in the high and low temperature chemical water environment cavity are adjusted in real time by the flow pump to simulate the actual service conditions of runway water accumulation, de-icing agent flushing and groundwater pressure. At the same time, the temperature of the medium and the sample is monitored in real time by the temperature sensor.

[0019] S4) By controlling the downward pressure of the upper pressure head to generate shear force in the medium, a gradient loading method is used to apply a compression-shear coupling load to the sample. After each gradient loading, the load is kept stable for a preset time, and the force-displacement data and sample deformation state at the corresponding stage are recorded.

[0020] S5) After the gradient loading is completed, continue to apply the compression-shear coupling load at the preset constant loading rate until obvious damage occurs between the sample layers or the load drops to below 70% of the peak load. Stop loading and simultaneously collect multi-dimensional data on loading force, sample displacement, temperature, water pressure, and medium ratio. At the same time, observe and record the failure mode and crack propagation path of the sample through the transparent cover.

[0021] S6) Replace the specimens with specimens from the same batch, adjust the environmental simulation parameters, compression-shear stress ratio, and loading rate, and conduct repeated tests under multiple working conditions.

[0022] S7) Plot force-displacement curves, interlaminar shear strength-temperature curves, and degradation degree-corrosion time curves to analyze the degradation law and failure mechanism of interlaminar bonding performance of specimens under different complex environments. Combined with the actual service requirements of airport runways, evaluate the interlaminar bonding performance and material adaptability of specimens.

[0023] Preferably, in step S2), the temperature of the low-temperature stage is set to -40℃ to 0℃, and the holding time is 2 to 12 hours.

[0024] During the normal humidity stage, the water pressure is set at 0.05~0.3MPa and maintained for 4~24h; during the chemical corrosion stage, the de-icing agent solution concentration is 5%~20% and maintained for 12~72h.

[0025] The temperature during the high-temperature phase is set at 40℃~90℃, and the holding time is 2~12h;

[0026] The transition between each stage adopts a gradient transition of temperature and pressure, with a transition time of 0.5 to 2 hours.

[0027] Preferably, in step S4), the load gradient of the gradient loading is 5% to 15% of the peak estimated load, the holding time of each gradient load is 10 to 30 minutes, and the peak estimated load is determined according to the airport runway design specifications and the performance of the specimen material.

[0028] Preferably, in step S5), the constant loading rate is 0.05~0.5 mm / min, and the failure modes of the specimen include interlaminar cohesion failure, bond failure, and mixed failure; the failure process of the specimen is captured in real time by a camera.

[0029] Preferably, in step S6), the evaluation indexes for interlayer bonding performance of the specimen include interlayer shear strength, bond strength retention rate, critical failure displacement, and degradation rate constant. By observing the variation patterns of each index, a degradation model for the interlayer bonding performance of airport runway pavement under complex environments is established.

[0030] The beneficial effects of this invention are as follows:

[0031] 1. This invention can simultaneously simulate the synergistic effects of alternating high and low temperatures, water immersion, chemical corrosion from de-icing agents, and compression-shear coupling loads. The temperature control range is -40℃ to 90℃, accurately reproducing the actual service conditions of airport runways and solving the problem that existing equipment cannot simulate multiple environments simultaneously.

[0032] 2. This invention employs multi-stage environmental simulation and sets gradient transitions to closely match the actual environmental changes of airport runways during seasonal transitions. Through dynamic medium circulation and pressure regulation, it simulates dynamic working conditions such as de-icing agent flushing and changes in water pressure. Gradient compression-shear coupling loading is used to fully deform the interlayer interface of the specimen, thereby obtaining characteristic data such as creep and relaxation, which makes up for the shortcomings of existing constant rate loading.

[0033] 3. This invention achieves simultaneous acquisition of multi-dimensional data such as loading force, displacement, temperature, water pressure, and medium ratio. Combined with repeated testing under multiple working conditions and data correction, it improves the reliability of test data. By plotting various characteristic curves, it analyzes the deterioration law and failure mechanism of interlayer bonding performance, establishes a deterioration model, and realizes the extension from basic performance testing to mechanism analysis and life prediction. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the device in Embodiment 1 of the present invention;

[0035] In the figure, 1-test frame; 2-axial loading system; 3-test chamber; 4-shear clamping device; 5-liquid injection system;

[0036] 11-Base plate; 12-Upper crossbeam; 13-Lower crossbeam; 14-Column;

[0037] 21-Loading cylinder; 22-Drive rod; 23-Force sensor; 24-Displacement sensor;

[0038] 31-Shell; 32-Transparent cover; 33-Liquid inlet; 34-Liquid outlet;

[0039] 41-Upper pressure head; 42-Lower pressure head; 43-Upper shear box; 44-Lower shear box; 45-Pressure bearing seat;

[0040] 51-Water storage bottle; 52-Corrosive liquid storage bottle; 53-Flow pump. Detailed Implementation

[0041] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings:

[0042] Example 1

[0043] like Figure 1 As shown, this embodiment provides a compression-shear testing device for testing the interlayer bonding performance of airport runway pavement under complex environments, including a test frame 1, an axial loading system 2 and a test chamber 3 disposed on the test frame 1; the test chamber 3 is provided with a shear clamping device 4 and a heating device; the axial loading system 2 is connected to the shear clamping device 4.

[0044] The test chamber 3 is also connected to the injection system 5, through which test liquid is injected into the test chamber 3.

[0045] In this embodiment, the test frame 1 includes an upper crossbeam 12, a lower crossbeam 13, and multiple uprights 14. The lower ends of the multiple uprights 14 are connected to the base plate 11, and the upper crossbeam 12 and lower crossbeam 13 are fitted onto the upper and lower ends of the uprights 14. In this embodiment, two uprights 14 are provided.

[0046] In some embodiments, four columns 14 may be provided.

[0047] In this embodiment, the axial loading system 2 includes a loading cylinder 21 and a transmission rod 22. The loading cylinder 21 is mounted on the upper crossbeam 12, and the piston rod of the loading cylinder 21 extends downward and is connected to the transmission rod 22. The transmission rod 22 extends into the test chamber 3.

[0048] In this embodiment, a force sensor 23 and a displacement sensor 24 are also provided on the transmission rod 22. Both the force sensor 23 and the displacement sensor 24 are connected to the control terminal. The force sensor 23 and the displacement sensor 24 are used to measure the loading force applied by the loading cylinder 21 and the deformation of the test sample.

[0049] In this embodiment, the test chamber 3 includes a shell 31 and a transparent cover 32 disposed on the shell 31. The transparent cover 32 is also provided with a liquid inlet 33 and a liquid outlet 34. The liquid inlet 33 is connected to the liquid injection system 5 through a pipe.

[0050] In this embodiment, the shearing clamping device 4 includes an upper pressure head 41, a lower pressure head 42, an upper shear box 43, and a lower shear box 44. The upper pressure head 41 is located inside the housing 31 and connected to the transmission rod 22. The lower pressure head 42 is disposed on a pressure bearing seat 45 at the lower end inside the housing 31. The upper pressure head 41 is provided with an upper shear box 43 at its lower end. The lower pressure head 42 is provided with a lower shear box 44. Both the upper shear box 43 and the lower shear box 44 are L-shaped structures.

[0051] In this embodiment, the heating device includes a temperature sensor and a heating element disposed on the side walls of the upper shear box 43 and the lower shear box 44, and both the heating element and the temperature sensor are electrically connected to the control terminal.

[0052] In this embodiment, the liquid injection system 5 includes a water storage bottle 51, a corrosive liquid storage bottle 52, and a flow pump 53. The water storage bottle 51 and the corrosive liquid storage bottle 52 are respectively connected to the inlet 33 of the test chamber 3 through corresponding pipelines and the flow pump 53, thereby injecting water or corrosive liquid into the test chamber 3.

[0053] Example 2

[0054] This embodiment provides a compression-shear test method for testing the interlayer bonding performance of airport runway pavement in complex environments, including the following steps:

[0055] S1. Place the asphalt layer-base layer bonding sample with dimensions of 100mm×100mm×50mm in the upper shear box 43 and the lower shear box 44, and adjust the position of the sample so that the upper shear box 43 and the lower shear box 44 are in close contact with the sample surface.

[0056] S2. Set environmental simulation parameters and perform environmental simulations in sequence for low temperature stage, chemical corrosion stage, and high temperature stage. The temperature of the low temperature stage is -20℃ and is maintained for 6 hours; the mass concentration of the de-icing agent solution in the chemical corrosion stage is 10% and is maintained for 24 hours; the temperature of the high temperature stage is set to 60℃ and is maintained for 4 hours; the gradient transition time for each stage is 1 hour.

[0057] S3. During the environmental simulation, the injection system 5 is activated to achieve dynamic circulation of water and de-icing agent. The circulation flow rate of water and de-icing agent is 2L / min, and the water pressure in the test chamber 3 is 0.1MPa. The actual service conditions of runway water accumulation, de-icing agent flushing, and groundwater pressure are simulated. At the same time, the temperature of the medium and the sample is monitored in real time by a temperature sensor.

[0058] S4. By controlling the downward pressure of the upper pressure head 41, the medium generates shear force. A gradient loading method is used to apply a compression-shear coupling load to the sample. After each gradient loading, the load is kept stable for a preset time, and the force-displacement data and sample deformation state at the corresponding stage are recorded. In this embodiment, the peak estimated load is 50kN, and a 10% load gradient is used for gradient loading. Each load is held for 20min.

[0059] S5. After the gradient loading is completed, continue to apply the compression-shear coupling load at the preset constant loading rate of 0.2 mm / min until obvious damage occurs between the sample layers or the load drops to below 70% of the peak load. Stop loading and simultaneously collect multi-dimensional data on loading force, sample displacement, temperature, water pressure, and medium ratio. At the same time, observe and record the failure mode and crack propagation path of the sample through the transparent cover 32.

[0060] S6. Replace three specimens from the same batch, adjust the snow removal agent concentration to 15% and the compressive-shear stress ratio to 2:1, and conduct repeated tests under multiple working conditions.

[0061] S7. Plot force-displacement curves, interlaminar shear strength-temperature curves, and degradation degree-corrosion time curves to analyze the degradation law and failure mechanism of interlaminar bonding performance of specimens under different complex environments. Combined with the actual service requirements of airport runways, evaluate the interlaminar bonding performance and material adaptability of the specimens.

[0062] Analysis revealed that the interlayer bonding performance of the specimens deteriorated by 35% at a concentration of 15% de-icing agent compared to that at 10%. Considering the service requirements of airports in cold regions, the bonding material was deemed to have only moderate adaptability to high-concentration de-icing agent environments and required modification treatment.

[0063] The embodiments and descriptions above are merely illustrative of the principles and preferred embodiments of the present invention. Various changes and modifications may be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. A compression-shear test device for testing the interlayer bonding performance of a pavement layer of an airport runway under complex environment, characterized in that, It includes a test frame (1), an axial loading system (2) and a test chamber (3) set on the test frame (1); the test chamber (3) is provided with a shear clamping device (4) and a heating device; the axial loading system (2) is connected to the shear clamping device (4); The test chamber (3) is also connected to the injection system (5), through which test liquid is injected into the test chamber (3).

2. The compression-shear testing apparatus according to claim 1, characterized in that: The test frame (1) includes an upper crossbeam (12), a lower crossbeam (13), and multiple columns (14). The lower ends of the multiple columns (14) are connected to the base plate (11), and the upper crossbeam (12) and lower crossbeam (13) are fitted on the upper and lower ends of the columns (14).

3. The compression-shear testing apparatus according to claim 2, characterized in that: The axial loading system (2) includes a loading cylinder (21) and a transmission rod (22). The loading cylinder (21) is mounted on the upper crossbeam (12), and the piston rod of the loading cylinder (21) extends downward and is connected to the transmission rod (22). The transmission rod (22) extends into the test chamber (3).

4. The compression-shear testing apparatus according to claim 3, characterized in that: The transmission rod (22) is also equipped with a force sensor (23) and a displacement sensor (24), both of which are connected to the control end. The force sensor (23) and displacement sensor (24) are used to measure the loading force applied by the loading cylinder (21) and the deformation of the test sample.

5. The compression-shear testing apparatus according to claim 3, characterized in that: The test chamber (3) includes a shell (31) and a transparent cover (32) disposed on the shell (31). The transparent cover (32) is also provided with a liquid inlet (33) and a liquid outlet (34). The liquid inlet (33) is connected to the liquid injection system (5) through a pipe.

6. The compression-shear testing apparatus according to claim 5, characterized in that: The shearing clamping device (4) includes an upper pressure head (41), a lower pressure head (42), an upper shear box (43), and a lower shear box (44). The upper pressure head (41) is located inside the housing (31) and connected to the transmission rod (22). The lower pressure head (42) is set on the pressure seat (45) at the lower end inside the housing (31). The upper pressure head (41) is provided with an upper shear box (43) at its lower end. The lower pressure head (42) is provided with a lower shear box (44). Both the upper shear box (43) and the lower shear box (44) are L-shaped structures.

7. A compression-shear test method for testing the interlayer bonding performance of airport runway pavement under complex environments, characterized in that, The method, performed using the apparatus according to any one of claims 1-6, includes the following steps: S1) Place the sample in the upper shear box (43) and the lower shear box (44), and adjust the position of the sample so that the upper shear box (43) and the lower shear box (44) are in close contact with the sample surface. S2) Set environmental simulation parameters, which are divided into low temperature stage, normal humidity stage, chemical corrosion stage and high temperature stage. Environmental simulation is carried out in sequence or in combination. Each stage maintains a preset time to simulate the actual seasonal changes and environmental conditions of the airport runway. S3) During the environmental simulation process, the injection system is activated to realize the dynamic circulation of water and / or de-icing agent chemical solution. The medium ratio, circulation flow rate and water pressure in the high and low temperature chemical water environment cavity are adjusted in real time by the flow pump to simulate the actual service conditions of runway water accumulation, de-icing agent flushing and groundwater pressure. At the same time, the temperature of the medium and the sample is monitored in real time by the temperature sensor. S4) By controlling the pressure head (41) to press down, the medium generates shear force. The sample is subjected to a compression-shear coupling load by gradient loading. After each gradient loading, the load is kept stable for a preset time. The force-displacement data and sample deformation state of the corresponding stage are recorded. S5) After the gradient loading is completed, continue to apply the compression-shear coupling load at the preset constant loading rate until obvious damage occurs between the sample layers or the load drops to below 70% of the peak load. Stop loading and simultaneously collect multi-dimensional data on loading force, sample displacement, temperature, water pressure, and medium ratio. At the same time, observe and record the failure mode and crack propagation path of the sample through the transparent cover. S6) Replace the specimens with specimens from the same batch, adjust the environmental simulation parameters, compression-shear stress ratio, and loading rate, and conduct repeated tests under multiple working conditions. S7) Plot force-displacement curves, interlaminar shear strength-temperature curves, and degradation degree-corrosion time curves to analyze the degradation law and failure mechanism of interlaminar bonding performance of specimens under different complex environments. Combined with the actual service requirements of airport runways, evaluate the interlaminar bonding performance and material adaptability of specimens.

8. The compression-shear test method according to claim 7, characterized in that, In step S2), the temperature of the low-temperature stage is set to -40℃ to 0℃, and the holding time is 2 to 12 hours. During the normal humidity stage, the water pressure is set at 0.05~0.3MPa and maintained for 4~24h; during the chemical corrosion stage, the de-icing agent solution concentration is 5%~20% and maintained for 12~72h. The temperature during the high-temperature phase is set at 40℃~90℃, and the holding time is 2~12h; The transition between each stage adopts a gradient transition of temperature and pressure, with a transition time of 0.5 to 2 hours.

9. The compression-shear test method according to claim 7, characterized in that, In step S4), the load gradient of the gradient loading is 5% to 15% of the peak estimated load, and the holding time of each gradient load is 10 to 30 minutes. In step S5), the constant loading rate is 0.05~0.5 mm / min, and the failure modes of the specimen include interlaminar cohesion failure, bond failure, and mixed failure; the failure process of the specimen is captured in real time by a camera.

10. The compression-shear test method according to claim 7, characterized in that, In step S6), the evaluation indexes for interlayer bonding performance of the specimen include interlayer shear strength, bond strength retention rate, critical failure displacement, and degradation rate constant. By observing the variation patterns of each index, a degradation model for the interlayer bonding performance of airport runway pavement under complex environments is established.

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