Test device and test method for road performance of high-viscosity asphalt mortar under multi-factor coupling

Abstract

The present invention discloses a test device and test method for the road performance of high-viscosity asphalt mortar under the coupling of multiple factors; the device includes a dynamic load pull rod, an ultraviolet lamp, a chuck device, a test platform, an in-situ tensile test instrument and a detection device; the method includes loading the high-viscosity asphalt mortar under the coupling of aging-vehicle-water damage, measuring the material performance decay index, and calculating the performance attenuation coefficient. The test device and test method of the present invention can be used to evaluate the performance of high-viscosity asphalt mortar under the coupling of aging-vehicle-water damage, and further evaluate the performance of porous asphalt mixtures. The present invention can be used to evaluate the performance of high-viscosity asphalt mortar under the coupling of aging-vehicle-water damage, and further evaluate the performance of porous asphalt mixtures. It can simulate the actual environmental traffic load during the service of porous asphalt pavement, and can measure the performance decay curve of the same asphalt mortar specimen, reduce errors, and effectively evaluate the road performance of porous asphalt mixtures.

Description

Technical Field

[0001] The present invention designs a device and a method for testing the road performance of high-viscosity asphalt mortar under the coupling effect of multiple factors, and belongs to the field of road engineering. Background Art

[0002] In recent years, with the development of my country's highway industry, research on functional pavements has gradually gained attention. Drainage asphalt pavements, in particular, have garnered widespread attention from both the public and the industry due to their water-dissipating and noise-reducing properties. Drainage asphalt pavements are constructed using porous asphalt mixtures and are characterized by a high void content, typically between 18% and 20%. This high void content makes the surface more susceptible to the effects of oxygen and sunlight than dense asphalt pavements. Asphalt mixtures can be considered to consist of two components: coarse aggregate and high-viscosity asphalt mortar. High-viscosity asphalt mortar, primarily composed of small aggregate particles and an asphalt binder, serves to bond the aggregate and resist pavement deformation. Compared to dense asphalt mixtures, the asphalt mortar in porous asphalt mixtures has a more critical performance and bonding role. Therefore, high-viscosity asphalt is often used, offering better resistance to deformation. However, due to the larger voids, the mortar is more susceptible to environmental factors.

[0003] The damage to drainage asphalt pavement is affected by many factors, such as sunlight. The ultraviolet rays in the sunlight will cause the asphalt mortar to age. The oxygen in the air will also cause the asphalt mortar to age. When there is water on the road surface, driving will cause the road surface to be affected by dynamic water pressure. The current performance testing mainly focuses on asphalt mixtures and fails to pay attention to the asphalt mortar level. At the same time, the influencing factors considered by existing technologies are relatively single and not comprehensive enough. Summary of the Invention

[0004] The purpose of the present invention is to provide a device and method for testing the road performance of high-viscosity asphalt mortar under the influence of multiple coupling factors, thereby overcoming the shortcomings of the current existing technology. The test device can comprehensively consider the coupling of multiple factors, including dynamic load, dynamic water damage, and photo-oxidative aging. The test method can measure the performance of high-viscosity asphalt mortar materials damaged by photo-oxidative aging and dynamic water damage, and ultimately use the performance attenuation coefficient to describe the performance of the tested high-viscosity asphalt mortar, thereby evaluating the performance of porous asphalt mixtures.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A device for testing the road performance of high-viscosity asphalt mortar under the coupling of multiple factors, comprising a dynamic load rod, a chuck device, an aluminum sheet, an ozone-type ultraviolet lamp, a test platform, and an in-situ tensile tester;

[0007] The in-situ tensile tester and ozone-type UV lamp are installed on the test platform;

[0008] One of the chuck devices corresponds to one in-situ tensile tester, the pulling directions of the two in-situ tensile testers are opposite, and one in-situ tensile tester is fixedly connected to one chuck device via a dynamic load pull rod;

[0009] The clamping device includes an upper clamping surface and a lower clamping surface. Screw holes are opened at corresponding positions above and below the upper clamping surface and penetrated by bolts. Two aluminum sheets for clamping the test piece are arranged between the upper clamping surface and the lower clamping surface. Both aluminum sheets are penetrated by bolts.

[0010] Two chuck devices clamp the two ends of the specimen respectively;

[0011] An ozone-type UV lamp is located above the test piece.

[0012] A test method for a high-viscosity asphalt mortar road performance test device under the coupling effect of multiple factors includes the following steps:

[0013] Step 1: According to the designed gradation and asphalt dosage, a rotary compactor is used to form a high-viscosity asphalt mortar specimen. The molding temperature is 170℃~185℃, and the rotary compaction is performed 50 times. The specimen size is 150mm±2mm in diameter and 170mm±2.5mm in height. After molding, it is cured indoors for 24 hours, demoulded, and then cut with a cutting machine to obtain a specimen with a length of 20mm±1mm, a width of 10mm±1mm, and a height of 10mm±1mm. Then, a drill is used to drill holes with a diameter of 1mm and a depth of 8mm at 3x3 points arranged with 8mm, 10mm, and 12mm in the length direction and 3mm, 5mm, and 7mm in the width direction to obtain the specimen. The specimen is then fixed on the chuck with the drill hole facing up for standby use;

[0014] Step 2: Fill the borehole with water and seal it with wax oil, keeping the wax seal upright. Turn the ozone UV lamp to 90°, connect the chuck device to the dynamic load rod, and connect the dynamic load rod to the in-situ tensile tester. Set the maximum displacement value to 30μm, apply the displacement load according to the sine wave, set the frequency to 1Hz, and input the displacement-time function to control the application of the displacement load. The specific relationship is as follows:

[0015] y=30sin(2πt)

[0016] Where y is the displacement in μm, t is the time in seconds. At the same time, the ozone-type UV lamp is turned on and ozone is released. The process lasts for 10 minutes. The specimen is removed, the wax seal is removed, the water is poured out, and the specimen is dried in an oven at 60°C to constant weight.

[0017] Step 3: Fix the specimen on the chuck device, keep the drilled hole facing upward, keep the dynamic load rod connected to the in-situ tensile tester, set the maximum displacement value to 10μm, set the frequency to 10Hz, and control the application of displacement load by inputting the displacement-time function. The specific relationship is as follows:

[0018] y = 10sin(20πt), where y is displacement in μm and t is time in seconds. Apply a displacement load as a sinusoidal wave, repeating the action 200 times. Read the load and displacement of the last five waveforms and calculate the modulus eigenvalue, E.

[0019] Step 4: Repeat steps 2 to 3, record the modulus values ​​E in sequence, use the number of repetitions as the horizontal axis and the measured modulus value as the vertical axis, draw the modulus attenuation curve of high-viscosity asphalt mortar, and calculate the attenuation coefficient α;

[0020] Step 5: Simulate different road conditions by adjusting the duration of the second step and the amount of water in the borehole. When repeating the second step, if the high-viscosity asphalt mortar has obvious cracks or a large change in shape, it is considered completely destroyed and the cycle is terminated. Otherwise, it can be repeated 5 times.

[0021] As a further preferred solution, the power of the ozone UV lamp is 60W, and the UV radiation intensity is 145μW / cm 2 , it can release ozone while being exposed to light, and the material used is resistant to high temperatures.

[0022] As a further preferred solution, the third step of calculating the modulus E is as follows:

[0023] Use an external device to read the load-displacement curves of the last five waveforms, record the average load amplitude P (N) and the recoverable average axial displacement amplitude L (mm), and then calculate the axial stress amplitude σ (MPa), axial strain amplitude ε (mm / mm), and modulus characteristic value E (MPa) according to the following formula:

[0024]

[0025]

[0026]

[0027] As a further preferred solution, the fourth step of calculating the attenuation coefficient α is as follows:

[0028] S1: After the specimen is formed, the third step is performed first to obtain the initial modulus characteristic value E0;

[0029] S2: After each second and third step, record the modulus characteristic value E in turn. 1、 E2、 E 3、 E 4、 E5;

[0030] S3: With the number of cycles as the horizontal axis and E0, E1, E2, E3, E4, and E5 as the vertical axes, draw the modulus attenuation curve and calculate the attenuation coefficient α according to the following formula;

[0031]

[0032] Beneficial effects

[0033] 1. The experimental device can integrate the coupling effects of multiple factors such as water damage, dynamic load, dynamic water damage, and photo-oxidation aging. The implementation method is simple and effective. The experimental method can measure the performance of high-viscosity asphalt mortar damaged by photo-oxidation aging and dynamic water damage, and ultimately use the performance attenuation coefficient to describe the performance of the tested high-viscosity asphalt mortar, thereby evaluating the performance of porous asphalt mixtures.

[0034] 2. The present invention primarily considers environmental factors such as photo-oxidative aging and dynamic water effects. Appropriate experimental methods are used to evaluate the performance of high-viscosity asphalt mortar. This device can simulate the effects of photo-oxidative aging and dynamic water damage on drained asphalt pavements, allowing for a realistic assessment of the actual conditions of high-viscosity asphalt mortar during pavement use. Furthermore, this device can apply greater loads to high-viscosity asphalt mortar, allowing for the study of the process and form of damage to high-viscosity asphalt mortar under the coupled effects of multiple factors after water immersion.

[0035] 3. Compared with existing experimental devices, this project incorporates the study of porous asphalt mixtures at the microscopic scale. Through the study of high-viscosity asphalt mortar, the mechanism of mixture damage and performance degradation is further revealed. The large voids in porous asphalt mixtures inevitably cause the performance degradation of high-viscosity asphalt mortar, thus affecting the overall performance decline. Therefore, the present invention comprehensively considers the combined effects of multiple factors on high-viscosity asphalt mortar, which is more meaningful for the study of porous asphalt mixtures.

[0036] 4. The designed modulus test experiment is conducted at a small strain level, which is within the material's recoverable deformation range. Therefore, the modulus measurement experiment can be considered to cause no damage to the material. Therefore, the entire test process can be performed on the same specimen, avoiding errors caused by changing the specimen.

[0037] 5. Compared with the previous performance test method that only considers the performance of porous asphalt mixtures, the object considered in the present invention is more direct and specific. At the same time, the simulated damage conditions selected are relatively unfavorable, which is a safer consideration. A larger trend of material performance changes can be obtained in a shorter period. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram of the structure of a test device for the road performance of high-viscosity asphalt mortar under the coupling of multiple factors;

[0039] Figure 2 The schematic diagram of the structure of the specimen used in the test device for high-viscosity asphalt mortar road performance under the coupling of multiple factors is shown in the figure. Figure 2 (a) is the top view of the specimen, Figure 2 (b) is the side view of the specimen;

[0040] Figure 3 This is a detailed structural diagram of the chuck device used in a test device for high-viscosity asphalt mortar road performance under multi-factor coupling, where: Figure 3 (a) is the side view of the chuck device, Figure 3 (b) is a top view of the chuck device;

[0041] Figure 4 This is a modulus attenuation curve diagram of a test method for the road performance of high-viscosity asphalt mortar under the coupling of multiple factors;

[0042] Explanation of the accompanying symbols: 1. dynamic load pull rod; 2. chuck device; 3. aluminum sheet; 4. ozone type ultraviolet lamp; 5. test platform. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0044] Example 1

[0045] like Figure 1 Figure 2 shows a test device for the road performance of high-viscosity asphalt mortar under the influence of multiple coupling factors. The test device mainly includes a dynamic load rod 1, a clamping device 2, an aluminum sheet 3, an ozone-type ultraviolet lamp 4, and a test platform 5. The horizontal center lines of the dynamic load rod 1 and the clamping device 2 are aligned, and the devices are placed on the test platform 5.

[0046] The chuck device 2 is made of iron alloy plates and consists of two identical sub-component assemblies. Each sub-component contains three iron plates and six bolts. The three iron plates include two iron plates a with a length of 22 mm, a width of 20 mm, and a thickness of 2 mm, and one iron plate b with a length of 22 mm, a width of 12 mm, and a thickness of 5 mm. They can be connected together by four bolts, and another two bolts can be used to fix the specimen. The iron plate with a length of 22 mm, a width of 12 mm, and a thickness of 5 mm can be connected to the dynamic load rod.

[0047] The aluminum sheet 3 is made of aluminum alloy plates, 10 mm long, 10 mm wide, and 1 mm thick, and there are four pieces in total.

[0048] The base of the ozone-type ultraviolet lamp 4 is 300mm long and a square base with a side length of 100mm. It can be stably placed on the experimental platform 5. The power is 60w and the ultraviolet radiation illumination is 145μW / cm2. It can release ozone while irradiating light, and the manufacturing material is resistant to high temperature.

[0049] The experimental platform 5 is 400 mm long × 300 mm wide × 20 mm thick and is made of wood board.

[0050] After the specimen is prepared, the aluminum sheet should be aligned with the four tops of the upper and lower sides of the specimen, and Figure 1 As shown, it is installed in the chuck device and fixed with bolts. One end of the dynamic load rod 1 is connected to the chuck device, and the other end is connected to the in-situ tensile tester.

[0051] Example 2

[0052] The test method for the road performance of high-viscosity asphalt mortar under the coupling of multiple factors, the road performance evaluation of high-viscosity asphalt mortar, and the performance evaluation of porous asphalt mixtures include the following steps:

[0053] Step 1: According to the gradation passing rate in the table below, select modified SBS asphalt with a dosage of 18%, and add 10% domestic asphalt high-viscosity modifier (asphalt internal admixture). The modifier is mixed in the form of dry mixing.

[0054] Grading quality pass rate (%)

[0055]

[0056] A rotary compactor was used to form high-viscosity asphalt mortar specimens. The molding temperature was between 170℃ and 185℃, and the specimens were rotary compacted 50 times. The specimen dimensions were 150mm±2mm in diameter and 170mm±2.5mm in height. After molding, they were cured indoors for 24 hours, demoulded, and then cut using a cutting machine to obtain specimens with a length of 20mm±1mm, a width of 10mm±1mm, and a height of 10mm±1mm. Holes with a diameter of 1mm and a depth of 8mm were then drilled using a drill at 9 points (3x3) arranged with diameters of 8mm, 10mm, and 12mm in the length direction and 3mm, 5mm, and 7mm in the width direction to obtain the specimens. The specimens were then fixed on the chuck with the drill holes facing upwards for later use.

[0057] Step 2: Fill the borehole with water and seal it with wax oil, keeping the wax seal upright. Turn on the ozone-type UV lamp, rotate the UV lamp tube to 90°, connect the chuck to the dynamic load rod, and connect the other end of the rod to the in-situ tensile tester. Set the maximum displacement value to 30μm, apply the displacement load according to the sine wave, and set the frequency to 1Hz. At the same time, turn on the ozone-type UV lamp and release ozone. The process lasts for 10 minutes. Remove the specimen, remove the wax seal, pour out the water, and dry it in an oven at 60℃ to constant weight.

[0058] Step 3: Fix the specimen on the chuck, keep the drilled hole facing upward, connect the pull rod to the in-situ tensile tester, set the maximum displacement value to 10μm, set the frequency to 10Hz, apply the displacement load according to the sine wave, repeat the action 200 times, read the load and displacement of the last five waveforms, and calculate the modulus characteristic value E.

[0059] The load-displacement curves of the last five waveforms were read using an external device. The average load amplitude P (N) and the recoverable average axial displacement amplitude L (mm) were recorded. The axial stress amplitude σ (MPa), axial strain amplitude ε (mm / mm), and modulus characteristic value E (MPa) were then calculated using the following formulas.

[0060]

[0061]

[0062]

[0063] Step 4: Repeat steps 2 to 3, and record the modulus value E in turn. Use the number of repetitions as the horizontal coordinate and the measured modulus value as the vertical coordinate to draw the modulus attenuation curve of the porous asphalt mixture asphalt mortar, and calculate the attenuation coefficient α. After the experiment, the data are shown in the table below. Draw the attenuation curve of the asphalt mortar modulus characteristic value, and calculate α=0.55. The performance evaluation is carried out according to the evaluation standard, indicating that the high-viscosity asphalt mortar obtained under this mix ratio has good road performance, and the performance of the porous asphalt mixture composed of this mortar ratio is also good.

[0064] Modulus characteristic value measurement

[0065]

[0066] It is recommended to evaluate the road performance of high-viscosity asphalt mortar with this mix ratio according to the following standards:

[0067] It is believed that the high-viscosity asphalt mortar with this mix ratio has superior road performance and the porous asphalt mixture has superior performance.

[0068] It is believed that the high-viscosity asphalt mortar with this mix ratio has better road performance and the porous asphalt mixture has better performance.

[0069] It is believed that the road performance of the high-viscosity asphalt mortar with this mix ratio is qualified, and the performance of the porous asphalt mixture is qualified.

[0070] It is believed that the road performance of high-viscosity asphalt mortar with this mix ratio is poor, and the performance of porous asphalt mixture is poor.

[0071] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A test method for a high-viscosity asphalt mortar road performance test device based on the coupling of multiple factors, characterized by: The high-viscosity asphalt mortar road performance test device under the multi-factor coupling effect includes a dynamic load pull rod (1), a clamping device (2), an aluminum sheet (3), an ozone-type ultraviolet lamp (4), a test platform (5), and an in-situ tensile tester; The in-situ tensile tester and the ozone-type ultraviolet lamp (4) are installed on the test platform (5); One of the chuck devices (2) corresponds to one in-situ tensile tester, the tensile forces of the two in-situ tensile testers are in opposite directions, and one in-situ tensile tester is fixedly connected to one chuck device (2) via a dynamic load pull rod (1); The clamping head device (2) comprises an upper clamping surface and a lower clamping surface, wherein screw holes are provided at corresponding upper and lower positions of the upper clamping surface and the lower clamping surface and are penetrated by bolts, and two aluminum sheets (3) for clamping the test piece are provided between the upper clamping surface and the lower clamping surface, and both aluminum sheets (3) are penetrated by bolts; Two chuck devices (2) respectively clamp the two ends of the test piece; The ozone-type ultraviolet lamp (4) is located above the test piece; The above test method comprises the following steps: Step 1: According to the designed gradation and asphalt dosage, a rotary compactor is used to form a high-viscosity asphalt mortar specimen. The molding temperature is 170℃~185℃, and the rotary compaction is performed 50 times. The specimen size is 150mm±2mm in diameter and 170mm±2.5mm in height. After molding, it is cured indoors for 24 hours, demoulded, and then cut with a cutting machine to obtain a specimen with a length of 20mm±1mm, a width of 10mm±1mm, and a height of 10mm±1mm. Then, a drill is used to drill holes with a diameter of 1mm and a depth of 8mm at 3×3 points arranged with 8mm, 10mm, and 12mm in the length direction and 3mm, 5mm, and 7mm in the width direction to obtain the specimen. The specimen is then fixed on the chuck with the drill hole facing up for standby use; Step 2: Fill the borehole with water and seal it with wax oil, keeping the wax seal upright, turn on the ozone type UV lamp (4), keep the UV lamp tube rotated to 90 degrees, connect the chuck device (2) to the dynamic load rod (1), and connect the dynamic load rod (1) to the in-situ tensile tester, set the maximum displacement value to 30μm, and control the application of displacement load by inputting the displacement-time function. The specific relationship is as follows: ， Where y is the displacement in μm, t is the time in s, and at the same time, the ozone-type UV lamp (4) is turned on and ozone is released. The process lasts for 10 min. The specimen is removed, the wax seal is removed, the water is poured out, and the specimen is dried in an oven at 60°C to constant weight. Step 3: Fix the specimen on the chuck device (2), keep the drilled hole facing upward, keep the dynamic load rod (1) connected to the in-situ tensile tester, set the maximum displacement value to 10μm, set the frequency to 10Hz, and control the application of displacement load by inputting the displacement-time function. The specific relationship is as follows: ， Where y is displacement in μm, t is time in s, and the action is repeated 200 times. The load and displacement of the last five waveforms are read and the modulus characteristic value E is calculated. Step 4: Repeat steps 2 to 3, record the modulus characteristic value E in sequence, use the number of repetitions as the horizontal axis and the measured modulus characteristic value as the vertical axis, draw the modulus attenuation curve of the high-viscosity asphalt mortar, and calculate the attenuation coefficient α, as follows: S1: After the specimen is formed, the third step is performed first to obtain the initial modulus characteristic value E0; S2: After each second and third step, record the modulus characteristic value E in turn. 1、 E 2、 E 3、 E 4、 E5; S3: With the number of cycles as the horizontal axis and E0, E1, E2, E3, E4, and E5 as the vertical axes, draw the modulus attenuation curve and calculate the attenuation coefficient α according to the following formula; ； Step 5: Simulate different road conditions by adjusting the duration of the second step and the amount of water in the borehole. When repeating the second step, if the high-viscosity asphalt mortar has obvious cracks or a large change in shape, it is considered completely destroyed and the cycle is terminated. Otherwise, it can be repeated 5 times.

2. The test method of the high-viscosity asphalt mortar road performance test device based on multi-factor coupling according to claim 1 is characterized by: The power of the ozone-type ultraviolet lamp (4) is 60W, and the ultraviolet radiation illumination is 145μW / cm 2 , releases ozone while irradiating light, and the material used is resistant to high temperatures.

3. The test method of the high-viscosity asphalt mortar road performance test device based on multi-factor coupling according to claim 1 is characterized by: The third step of calculating the modulus eigenvalue E is as follows: Read the load and displacement curves of the last five waveforms through an external device, record the average load amplitude P (N) and the recoverable average axial displacement amplitude L (mm), and then calculate the axial stress amplitude σ (MPa), axial strain amplitude ε (mm / mm), and modulus characteristic value E (MPa) according to the following formula: ， ， 。

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