Test method for temperature and humidity balance in and out of a reduced scale asphalt pavement structure

Abstract

The application provides a test method for temperature and humidity balance of a scaled asphalt pavement structure, and belongs to the technical field of road engineering. The method uses a temperature and humidity balance test device for the scaled asphalt pavement structure to simulate natural basic working conditions, standard regulation working conditions, non-standard regulation working conditions and water-related regulation working conditions. The test device is composed of a temperature and humidity isolation support frame, an environment control system, a scaled asphalt pavement structure and a sensor monitoring system. Through rapid regulation of the temperature and humidity parameters of the scaled asphalt pavement structure composed of test pieces in the laboratory, the basic law of temperature and humidity balance of the actual asphalt pavement when the natural basic working conditions reach the specified standard or non-standard working conditions can be conveniently and effectively simulated, and basic test data can be accumulated, so that the energy consumption and cost required for testing are greatly reduced, and the basis for formulating a specified temperature and humidity environment regulation scheme in a full-scale accelerated loading experiment is laid.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of road engineering, in particular to a test method for internal and external temperature and humidity balance of a scaled asphalt pavement structure. BACKGROUND

[0002] As an important part of China's transportation infrastructure, the service performance and life of asphalt pavement in its natural environment are crucial to China's economic development. The service environment of asphalt pavement is all-weather, and in different seasons of the year and different time periods of the day, there is a temperature and relative humidity gradient difference between the bottom of the pavement structure and the top of the air, so that the overall temperature and humidity of the asphalt pavement structure is in a state of dynamic balance. Effective simulation and accurate control of temperature and humidity environment through experimental means is the basis for related research on the structural behavior characteristics and material performance of asphalt pavement in the field of road engineering under specified service environment.

[0003] Generally, a large environmental control system is used to fully simulate the service environment of the asphalt pavement structure, which is mainly used in the field of full-scale accelerated loading test to achieve the control of the asphalt pavement test road to a specified temperature and humidity balance state for test preparation. However, due to the high energy consumption and high cost of the large environmental control system during operation, there is a lack of important systematic basic test data such as the basic laws of "high and low temperature mutual regulation", "high and low relative humidity mutual adjustment" and "the influence of different temperature changes on relative humidity", and the waiting time for the internal and external balance of the corresponding asphalt pavement structure. In particular, for example, "low temperature environment simulation in summer high temperature weather" and "high temperature environment simulation in winter low temperature weather" involve large temperature difference regulation. At present, there is a lack of an economical and feasible test method to effectively realize the rapid regulation, monitoring and basic test data accumulation of the temperature and humidity balance of the asphalt pavement structure, which restricts the development of the field of full-scale accelerated loading research, especially involving environmental control.

[0004] Therefore, in order to efficiently simulate the service environment of the asphalt pavement structure and accumulate basic data such as the balance state and waiting time of the internal and external temperature and humidity parameter regulation, it is necessary to develop a simple test method for internal and external temperature and humidity balance of a scaled asphalt pavement structure. SUMMARY

[0005] In order to solve the technical problems existing in the prior art, the embodiments of the present application provide a test method for internal and external temperature and humidity balance of a scaled asphalt pavement structure, which realizes the rapid regulation, monitoring and basic test data accumulation of the temperature and humidity balance of the asphalt pavement structure. The technical solution is as follows:

[0006] A test method for temperature and humidity balance inside and outside a scaled asphalt pavement structure, which uses a test device for temperature and humidity balance inside and outside a scaled asphalt pavement structure to perform the following tests:

[0007] (1) Simulate a natural basic condition:

[0008] By adjusting the bottom circulating temperature control elbow pipe and the top circulating temperature control fin of the test device, the temperature parameters of the bottom and top of the scaled asphalt pavement structure are set to be consistent with the temperature state of the actual asphalt pavement structure soil subgrade and road surface air in the specified natural basic condition, the temperature change process and waiting time of the whole scaled asphalt pavement structure reaching temperature balance are recorded, and the natural basic condition is simulated.

[0009] (2) Simulate a standard regulation condition:

[0010] After reaching the specified natural basic condition, the temperature of the top circulating temperature control fin of the test device is adjusted according to the experimental requirements, the temperature change process and waiting time of the whole scaled asphalt pavement structure reaching temperature balance are recorded, and the standard regulation condition is simulated.

[0011] (3) Simulate a non-standard regulation condition:

[0012] After reaching the specified natural basic condition, the temperature of the bottom circulating temperature control elbow pipe and the top circulating temperature control fin of the test device are adjusted according to the experimental requirements, the temperature change process and waiting time of the whole scaled asphalt pavement structure reaching temperature balance are recorded, and the non-standard regulation condition is simulated.

[0013] (4) Simulate a water-related regulation condition:

[0014] After reaching the specified natural basic condition, the bottom water seepage pipe and the top water spraying nozzle of the test device are adjusted according to the experimental requirements, the humidity change process and waiting time of the whole scaled asphalt pavement structure reaching relative humidity balance are recorded, and after the humidity balance, the temperature of the bottom circulating temperature control elbow pipe and the top circulating temperature control fin of the test device are further adjusted, the relative humidity change process and waiting time under different temperatures are recorded.

[0015] The natural basic condition refers to the natural temperature state of the actual asphalt pavement structure in the structure thickness range from the soil subgrade to the road surface air in different seasons of a year and different time periods of a day, and during the experiment, the temperature state of the actual asphalt pavement structure in a selected time period is selected as the specified natural basic condition.

[0016] The standard regulation working condition refers to that the temperature parameters of the air on the road surface are changed only on the basis of the natural basic working condition of the internal and external temperature balance of the scaled asphalt pavement structure, so that the scaled asphalt pavement structure gradually reaches the overall temperature balance from top to bottom; it is usually applicable to the test of high-temperature regulation in hot summer weather, low-temperature regulation in cold winter weather, small-temperature-difference regulation in comfortable spring and autumn weather and the like.

[0017] The non-standard regulation working condition refers to that the temperature parameters of the air on the road surface and the temperature parameters of the soil subgrade are simultaneously increased or decreased on the basis of the natural basic working condition of the internal and external temperature balance of the scaled asphalt pavement structure, so that the scaled asphalt pavement structure gradually reaches the overall temperature balance from top to bottom and from bottom to top; it is usually applicable to the test of low-temperature regulation in hot summer weather and high-temperature regulation in cold winter weather and the like.

[0018] The water-involved regulation working condition refers to that the relative humidity parameters of the air on the road surface and the soil subgrade are changed on the basis of any one of the natural basic working condition, the standard regulation working condition and the non-standard regulation working condition, so that the scaled asphalt pavement structure gradually reaches the overall relative humidity balance.

[0019] The test device is composed of a temperature and humidity insulation support frame, an environment control system, a scaled asphalt pavement structure and a sensor monitoring system;

[0020] The temperature and humidity insulation support frame is composed of a support frame and a temperature and humidity insulation layer,

[0021] The environment control system is composed of a circulating temperature control heat dissipation fin, a water spraying nozzle, a ventilation fan blade, a circulating temperature control elbow and a water seepage pipe,

[0022] The sensor monitoring system is composed of a temperature sensor and a relative humidity sensor;

[0023] The support frame is located at the outermost side of the whole test device and provides a support function, and the temperature and humidity insulation layer is close to the edge of the scaled asphalt pavement structure, so as to ensure that the gradient difference of temperature and humidity can only be transmitted in the scaled asphalt pavement structure from top to bottom and from bottom to top;

[0024] There is a reserved space between the upper part of the scaled asphalt pavement structure and the temperature and humidity insulation layer, the circulating temperature control heat dissipation fin is installed at the top of the reserved space, the water spraying nozzle is installed at the center of the top of the reserved space, the ventilation fan blade is installed on the side wall of the reserved space, and a group of temperature sensors and relative humidity sensors are installed in the reserved space; the circulating temperature control elbow is installed close to the bottom surface of the scaled asphalt pavement structure at the bottom of the scaled asphalt pavement structure, and the water seepage pipe is installed at the lower part of the circulating temperature control elbow;

[0025] The temperature sensor and the relative humidity sensor are arranged along the vertical direction on the surface of each layer of the scaled asphalt pavement structure.

[0026] The layers of the reduced-scale asphalt pavement structure are consistent with those of the actual full-scale asphalt pavement structure, and are composed of an asphalt surface layer, a cement stabilized macadam base layer, a lime-fly ash stabilized macadam base layer and a soil base layer.

[0027] The asphalt surface layer is divided into 2-3 layers, each layer has a thickness of 2cm-10cm, and the interfaces between the layers are filled with asphalt mortar;

[0028] The cement stabilized macadam base layer is divided into two layers, each layer has a thickness of 10-50cm, and the interfaces between the layers are filled with cement mortar;

[0029] The lime-fly ash stabilized macadam base layer is one layer, has a thickness of 10-50cm, and the top surface uses cement mortar as a bonding agent;

[0030] The soil base layer is one layer, has a thickness of 10-100cm, and the top surface is subjected to roughening treatment.

[0031] The reduced-scale asphalt pavement structure has a length and a width that are not less than 30cm, preferably 30cm-60cm, and a height that is not less than 1m, preferably 1m-2m.

[0032] The temperature sensors and the relative humidity sensors in the reduced-scale asphalt pavement structure are symmetrically arranged in the middle of the surface of each layer of the reduced-scale asphalt pavement structure in the horizontal direction, and the cables are led out through lead holes.

[0033] The reserved space has a height of 10-30cm, preferably 20cm; and the circulating temperature control cooling fins cover the top of the reserved space.

[0034] The group of temperature sensors and the relative humidity sensors in the reserved space are installed at 1 / 2 of the height of the reserved space and on the side wall.

[0035] The distance between the water seepage pipe and the circulating temperature control elbow pipe is 3-10cm, preferably 5cm; and the distance between the water seepage pipe and the bottom temperature and humidity isolation layer is 3-10cm, preferably 3cm.

[0036] The temperature regulation range of the top circulating temperature control cooling fins and the bottom circulating temperature control elbow pipe of the test device is -30℃-100℃, the relative humidity regulation range is 0-100%RH, the water seepage amount regulation range is 0-0.5L / min, and the water spraying amount regulation range is 0-10mm / h.

[0037] The thickness of the temperature and humidity isolation layer is 5cm-10cm.

[0038] The technical scheme provided by the embodiment of the application has at least the following beneficial effects:

[0039] (1) The indoor forming test piece is spliced by using the same structure layer material and thickness as the actual asphalt pavement, so that the temperature and humidity balance experimental data obtained by the scale asphalt pavement structure according to the application can effectively provide reference for the environment adjustment of the actual full-size pavement, thereby realizing low energy consumption and low cost to explore the basic law of temperature and humidity balance.

[0040] (2) The application can conveniently and quickly control the temperature, relative humidity and other parameters of the top and bottom of the scale asphalt pavement structure, can realize the simulation of the temperature state of the actual asphalt pavement structure in any season period, and can realize rapid and accurate regulation of a large temperature difference range on this basis, thereby effectively accumulating basic experimental data of temperature and humidity balance under such extreme working conditions, and laying a foundation for formulating a specified temperature and humidity environment regulation scheme in full-size accelerated loading experiment. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0042] Figure 1 is a vertical surface structure schematic diagram of a test device for temperature and humidity balance inside and outside a scale asphalt pavement structure provided by the embodiments of the application;

[0043] Figure 2 is a top view of sensor arrangement in each structure layer of the scale asphalt pavement in the embodiments of the application;

[0044] Figure 3 is a vertical surface schematic diagram of the scale asphalt pavement structure in the embodiments of the application.

[0045] Wherein: 1-support frame; 2-temperature and humidity isolation layer; 3-scale asphalt pavement structure; 4-temperature sensor; 5-relative humidity sensor; 6-circulating temperature control cooling fin; 7-water spray head; 8-ventilating fan blade; 9-circulating temperature control elbow; 10-permeable pipe; 11-wiring hole; 31-asphalt surface layer; 32-cement stabilized macadam base; 33-lime stabilized macadam base; 34-soil base. DETAILED DESCRIPTION

[0046] The technical solutions in the application will be described below with reference to the drawings.

[0047] In the embodiments of the present application, the words such as "example", "for example", etc. are used to represent an example, illustration or description. Any embodiment or design scheme described as "example" in the present application should not be interpreted as more preferred or more advantageous than other embodiments or design schemes. Rather, the word "example" is intended to present the concept in a specific manner. In addition, in the embodiments of the present application, the meaning expressed by "and / or" can be both, or can be one of the two.

[0048] In order to make the technical problems, technical solutions and advantages to be solved by the present application clearer, the following will be described in detail in combination with the drawings and specific embodiments.

[0049] The embodiments of the present application provide a test method for temperature and humidity balance inside and outside a scaled asphalt pavement structure. The method uses a scaled asphalt pavement structure temperature and humidity balance test device to perform the following tests:

[0050] (1) Simulate a natural basic working condition: by adjusting and controlling the bottom circulating temperature control elbow pipe and the top circulating temperature control heat sink of the test device, the temperature parameters of the bottom and top of the scaled asphalt pavement structure are respectively set to be consistent with the temperature state of the actual asphalt pavement structure soil subgrade and road surface air under a specified natural basic working condition, the temperature change process with time and the waiting time of the whole scaled asphalt pavement structure reaching temperature balance are recorded, and the natural basic working condition is simulated.

[0051] (2) Simulate a standard control working condition: after reaching the specified natural basic working condition, the temperature of the top circulating temperature control heat sink of the test device is adjusted and controlled according to experimental requirements, the temperature change process with time and the waiting time of the whole scaled asphalt pavement structure reaching temperature balance are recorded;

[0052] (3) Simulate a non-standard control working condition: after reaching the specified natural basic working condition, the temperature of the bottom circulating temperature control elbow pipe and the top circulating temperature control heat sink of the test device are adjusted and controlled at the same time according to experimental requirements, the temperature change process with time and the waiting time of the whole scaled asphalt pavement structure reaching temperature balance are recorded;

[0053] (4) Simulate a water-related control working condition: after reaching the specified natural basic working condition, the bottom water seepage pipe and the top water spraying nozzle of the test device are respectively adjusted and controlled alone or at the same time according to experimental requirements, the humidity change process with time and the waiting time of the whole scaled asphalt pavement structure reaching relative humidity balance are recorded, after the humidity balance, the temperature of the bottom circulating temperature control elbow pipe and the top circulating temperature control heat sink of the test device is further adjusted and controlled, and the relative humidity change process with time and the waiting time under different temperatures are recorded.

[0054] The natural basic working condition refers to a natural temperature state of an actual asphalt pavement structure in a structural thickness range from an air of a soil subgrade to a road surface in different seasons of a year and different time periods of a day.

[0055] The standard regulation working condition refers to that a temperature parameter of the air of the road surface is changed only to make the scaled asphalt pavement structure gradually reach overall temperature balance from top to bottom on the basis of the natural basic working condition of reaching internal and external temperature balance.

[0056] The non-standard regulation working condition refers to that temperature parameters of the air of the road surface and the soil subgrade are simultaneously increased or decreased to make the scaled asphalt pavement structure gradually reach overall temperature balance from top to bottom and from bottom to top on the basis of the natural basic working condition of reaching internal and external temperature balance.

[0057] The water-involved regulation working condition refers to that relative humidity parameters of the air of the road surface and the soil subgrade are changed to make the scaled asphalt pavement structure gradually reach overall relative humidity balance on the basis of any one of the natural basic working condition, the standard regulation working condition and the non-standard regulation working condition.

[0058] As shown in Figure 1 The test device is composed of a temperature and humidity insulation support frame, an environment control system, a scaled asphalt pavement structure 3 and a sensor monitoring system.

[0059] The temperature and humidity insulation support frame is composed of a support frame 1 and a temperature and humidity insulation layer 2,

[0060] The environment control system is composed of a circulating temperature control heat dissipation fin 6, a water spraying nozzle 7, a ventilation fan blade 8, a circulating temperature control elbow pipe 9 and a water seepage pipe 10,

[0061] The sensor monitoring system is composed of a temperature sensor 4 and a relative humidity sensor 5.

[0062] The support frame 1 is located at the outermost side of the whole test device and provides a support function, and the temperature and humidity insulation layer 2 is close to the edge of the scaled asphalt pavement structure 3 to ensure that the gradient difference of temperature and humidity can only be transferred in the internal range of the scaled asphalt pavement structure 3 from top to bottom and from bottom to top.

[0063] The reserved space between the upper part of the reduced-scale asphalt pavement structure 3 and the temperature and humidity insulation layer 2 has a circulating temperature control fin 6 installed at the top, a water spraying nozzle 7 installed at the center of the top, a ventilation fan blade 8 installed on the side wall, and a group of temperature sensors and relative humidity sensors installed inside the reserved space; the circulating temperature control bend pipe 9 is installed at the bottom of the reduced-scale asphalt pavement structure 3, and the water seepage pipe 10 is installed at the lower part of the circulating temperature control bend pipe 9.

[0064] The temperature sensor 4 and the relative humidity sensor 5 are arranged along the vertical direction on the surface of each layer of the reduced-scale asphalt pavement structure.

[0065] As Figure 3 , the reduced-scale asphalt pavement structure 3 is consistent with the material setting of the actual full-scale asphalt pavement structure, which is composed of an asphalt surface layer 31, a cement stabilized gravel base layer 32, a lime-fly ash stabilized gravel base layer 33, and a soil base layer 34.

[0066] As Figure 2 , the temperature sensor 4 and the relative humidity sensor 5 in the reduced-scale asphalt pavement structure are symmetrically arranged in the middle of the surface of each layer of the reduced-scale asphalt pavement structure along the horizontal direction, and the cable is led out through the lead hole 11.

[0067] The following will be described in conjunction with specific embodiments.

[0068] In the specific experiment, first, the test piece is formed in the indoor laboratory (i.e., the material of each layer of the reduced-scale asphalt pavement structure is made), and then the reduced-scale asphalt pavement structure is spliced. The reduced-scale asphalt pavement structure 3 is consistent with the material setting of the actual full-scale asphalt pavement structure, which is mainly composed of an asphalt surface layer 31, a cement stabilized gravel base layer 32, a lime-fly ash stabilized gravel base layer 33, and a soil base layer 34. Among them, the asphalt surface layer 31 is composed of an SMA-16 upper surface layer with a thickness of 4 cm, an AC-20 middle surface layer with a thickness of 6 cm, and an ATB-25 lower surface layer with a thickness of 8 cm from top to bottom, the cement stabilized gravel layer 32 is spliced by two layers of structure layer with a thickness of 18 cm, the lime-fly ash stabilized gravel base layer 33 has a thickness of 18 cm, and the soil base layer 34 has a thickness of 28 cm. It should be noted that the type, material, and thickness of each structure layer of the reduced-scale asphalt pavement structure 3 can be arbitrarily combined and selected according to the research needs, and the reduced-scale asphalt pavement structure 3 of the present embodiment is only one of the typical asphalt pavement structures in road engineering.

[0069] Then the temperature and humidity insulation layer 2 is tightly wrapped around the scaled asphalt pavement structure 3, and the circulating temperature control heat dissipation fins 6, water spray nozzles 7, ventilation fan blades 8 and a set of temperature sensors 4 and relative humidity sensors 5 are arranged on the top of the scaled asphalt pavement structure 3, temperature sensors 4 and relative humidity sensors 5 are arranged on each layer of the scaled asphalt pavement structure 3, and a circulating temperature control coil 9 and a water permeation pipe 10 are arranged at the bottom of the scaled asphalt pavement structure 3; finally, the above-mentioned whole is wrapped and supported by the support frame 1.

[0070] The test process using the above device is as follows:

[0071] (1) Simulate the natural basic working condition:

[0072] The temperature distribution state of the actual asphalt pavement structure at noon in summer is selected as the simulation object of the natural basic working condition. Referring to the data or monitoring the actual asphalt pavement structure by the sensor to obtain the temperature data of the soil subgrade and the temperature data of the air on the road surface, which are 15℃ and 45℃ respectively; adjust the temperature of the circulating temperature control coil 9 of the test device of the application to 15℃, and adjust the temperature of the top circulating temperature control heat dissipation fin 6 to 45℃, record the temperature change process rule of the whole scaled asphalt pavement structure 3 reaching temperature balance with time and the waiting time, at this time, the natural basic working condition simulating the temperature distribution state of the actual asphalt pavement structure at noon in summer can be realized.

[0073] (2) Simulate the standard control working condition:

[0074] According to the above test process (1), first, the temperature distribution state of the scaled asphalt pavement structure 3 of the test device of the application is adjusted to the natural basic working condition simulating the temperature distribution state of the actual asphalt pavement structure at noon in summer, at this time, the temperatures of the bottom soil subgrade layer 34 and the top air on the road surface are 15℃ and 45℃ respectively; on the basis of this natural basic working condition, high temperature control research is carried out, the temperature of the top circulating temperature control heat dissipation fin 6 of the test device of the application is adjusted to 60℃, and the temperature change process rule of the whole scaled asphalt pavement structure 3 reaching temperature balance with time and the waiting time are recorded.

[0075] (3) Simulate the non-standard control working condition:

[0076] According to the above test process (1), first, the temperature distribution state of the test device scale asphalt pavement structure 3 of the application is adjusted to simulate the natural basic working condition of the temperature distribution state of the actual asphalt pavement structure at noon in summer, at this time the temperature of the bottom soil base layer 34 and the top road surface air is 15℃ and 45℃ respectively; on the basis of this natural basic working condition, low temperature regulation research is carried out, and the temperature of the bottom circulating temperature control elbow pipe 9 and the top circulating temperature control heat sink 6 of the test device of the application is-10℃ and-20℃ respectively, so as to further simulate the non-standard regulation working condition of winter severe weather on the basis of the natural basic working condition of summer hot weather, and record the temperature change process law and waiting time of the whole scale asphalt pavement structure reaching temperature balance.

[0077] (4) Simulate the water regulation working condition:

[0078] According to the above test process (1), first, the temperature distribution state of the test device scale asphalt pavement structure 3 of the application is adjusted to simulate the natural basic working condition of the temperature distribution state of the actual asphalt pavement structure at noon in summer, at this time the temperature of the bottom soil base layer 34 and the top road surface air is 15℃ and 45℃ respectively, and the relative humidity inside the scale asphalt pavement structure 3 is 70%; on the basis of this natural basic working condition, relative humidity rising regulation research is carried out, the top water spraying head 7 of the test device is opened alone, the relative humidity of the top space is regulated to 100%, the humidity change process law and waiting time of the whole scale asphalt pavement structure 3 reaching relative humidity balance are recorded; after humidity balance, the temperature of the top circulating temperature control heat sink 6 of the test device is further regulated to 60℃, the relative humidity change process law and waiting time at different temperatures are recorded.

[0079] In actual experiments, a typical full-scale accelerated loading asphalt pavement straight test road has a horizontal size of 12m 4.5m, by regulating the infrared heating tube and two sides of the circulating fan of the large environmental box located on the surface of the test road, the effective regulation of the service temperature of the road surface can be realized, wherein the power of the infrared heating tube and the two sides of the circulating fan working together is 135kW. The test device of the application can realize effective regulation of the service temperature of the top space of the scaled asphalt pavement structure 3 by regulating the circulating temperature control fin 6 and the ventilation fan blade 8, wherein the power of the circulating temperature control fin 6 and the ventilation fan blade 8 working together is 1.8kW. On the basis of the natural air temperature of 23℃, the air temperature of the full-scale accelerated loading asphalt pavement straight test road and the scaled asphalt pavement structure 3 of the test device of the application is regulated to 30℃, and the time required for the two is measured by the sensor to be 1 hour and 15 minutes and 20 minutes respectively, and the corresponding energy consumption of the two is 168.75kWh and 0.6kWh respectively. Obviously, only by regulating the air temperature of the road surface to a small extent, the test device of the application can quickly and low-energy-consumption effectively realize the regulation of the specified service environment temperature compared with the large full-scale accelerated loading test device.

[0080] The application can be better realized according to the above-mentioned mode. By regulating the temperature and humidity parameters of the scaled asphalt pavement structure composed of test pieces indoors, the actual asphalt pavement can be conveniently and effectively simulated to reach the temperature and humidity balance basic law of the specified standard or non-standard working condition from the natural basic working condition and the basic test data is accumulated, which greatly reduces the energy consumption and cost required for testing, and lays a foundation for the formulation of the specified temperature and humidity environment regulation scheme in the full-scale accelerated loading experiment. The above-mentioned specific embodiments are only better embodiments of the application, and are not used to limit the implementation range of the application (for example, the scaled asphalt pavement structure can be composed of different materials according to different thicknesses; the number of the circulating temperature control bent pipes at the bottom of the test device can be increased to realize faster temperature regulation; the temperature control mode at the top of the test device can also adopt the form of heating resistance wire combined with air conditioning refrigeration device to realize high and low temperature control, and the application only presents the simplest way of the circulating temperature control fin), accordingly, any modification of the type and size of the pavement structure, the number of the circulating temperature control bent pipe and the temperature and humidity control form made according to the content of the application is covered in the scope of the claims of the application.

[0081] The above-mentioned is only a specific embodiment of the application, but the protection scope of the application is not limited to this, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the application, which should be covered in the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims.

Claims

1. A test method for temperature and humidity balance in and out of a reduced scale asphalt pavement structure, characterized by, The method employs a scaled-down asphalt pavement structure internal and external temperature and humidity equilibrium testing device to conduct the following tests: (1) Simulate natural foundation working conditions: By adjusting the bottom circulating temperature control bend and the top circulating temperature control heat sink of the test device, the temperature parameters of the bottom and top of the scaled asphalt pavement structure are set to be consistent with the temperature state of the soil subgrade and surface air of the actual asphalt pavement structure under the specified natural foundation conditions. The temperature change process and waiting time of the scaled asphalt pavement structure reaching temperature equilibrium are recorded to simulate the natural foundation conditions. (2) Simulate standard control conditions: After reaching the specified natural basic working conditions, the temperature of the circulating temperature control heat sink at the top of the test device is adjusted according to the experimental requirements, and the temperature change process and waiting time of the scaled asphalt pavement structure reaching temperature equilibrium are recorded. (3) Simulate non-standard control conditions: After reaching the specified natural basic working conditions, according to the experimental requirements, the temperature of the bottom circulating temperature control bend and the top circulating temperature control heat sink of the test device are simultaneously adjusted, and the temperature change process and waiting time of the scaled asphalt pavement structure reaching temperature equilibrium are recorded. (4) Simulated water-related control conditions: After reaching the specified natural basic working conditions, according to the experimental requirements, the bottom seepage pipe and the top water spray nozzle of the test device are adjusted individually or simultaneously to record the humidity change process and waiting time of the overall scaled asphalt pavement structure reaching relative humidity equilibrium. After the humidity is balanced, the temperature of the bottom circulating temperature control bend and the top circulating temperature control heat sink of the test device are further adjusted to record the relative humidity change process and waiting time at different temperatures.

2. The test method for temperature and humidity balance in and out of a reduced-scale asphalt pavement structure according to claim 1, characterized by, The test apparatus consists of a thermal and moisture-proof support frame, an environmental control system, a scaled-down asphalt pavement structure, and a sensor monitoring system. The thermal and moisture-proof support frame consists of a support frame and a thermal and moisture-proof layer. The environmental control system consists of circulating temperature-controlled heat sinks, water spray nozzles, ventilation fan blades, circulating temperature-controlled bends, and drainage pipes. The sensor monitoring system consists of a temperature sensor and a relative humidity sensor; The support frame is located on the outermost side of the entire test device and provides support. The thermal and moisture insulation layer is close to the edge of the scaled asphalt pavement structure, ensuring that the temperature and humidity gradient difference can only be transmitted from top to bottom and from bottom to top within the scaled asphalt pavement structure. There is a reserved space between the upper part of the scaled-down asphalt pavement structure and the heat and moisture insulation layer. A circulating temperature control heat sink is installed on the top of the reserved space, a water spray nozzle is installed in the center of the top of the reserved space, a ventilation fan blade is installed on the side wall of the reserved space, and a set of temperature sensors and relative humidity sensors are installed in the reserved space. A circulating temperature control bend is installed close to the bottom surface of the scaled-down asphalt pavement structure, and a water seepage pipe is installed at the bottom of the circulating temperature control bend. The temperature sensor and relative humidity sensor are arranged vertically on each layer of the scaled asphalt pavement structure.

3. The test method for temperature and humidity balance in and out of a reduced- scale asphalt pavement structure according to claim 1, characterized by, The natural foundation condition refers to the natural temperature state of the actual asphalt pavement structure within the structural thickness range from the subgrade to the surface air in different seasons and at different times of day. During the experiment, the actual asphalt pavement structure temperature state of a certain period is selected as the designated natural foundation condition.

4. The test method for temperature and humidity balance in and out of a reduced- scale asphalt pavement structure according to claim 1, characterized by, The standard control condition refers to the condition where, based on the natural basic condition where the internal and external temperature of the scaled asphalt pavement structure has reached equilibrium, only the temperature parameters of the air on the road surface are changed, so that the scaled asphalt pavement structure gradually reaches overall temperature equilibrium from top to bottom. The non-standard control condition refers to the condition where, based on the natural basic condition where the internal and external temperature of the scaled asphalt pavement structure has reached equilibrium, the temperature parameters of the subgrade and the surface air are simultaneously increased or decreased, so that the scaled asphalt pavement structure gradually reaches overall temperature equilibrium from top to bottom and from bottom to top.

5. The test method for the internal and external temperature and humidity balance of a scaled asphalt pavement structure according to claim 1, characterized in that, The water-related control conditions refer to changing the relative humidity parameters of the soil subgrade and surface air of the scaled-down asphalt pavement structure based on any of the following: natural basic conditions, standard control conditions, and non-standard control conditions, so that the overall scaled-down asphalt pavement structure gradually reaches relative humidity equilibrium.

6. The test method for the internal and external temperature and humidity balance of a scaled asphalt pavement structure according to claim 2, characterized in that, The scaled-down asphalt pavement structure is consistent with the material settings of each layer of the actual full-scale asphalt pavement structure, consisting of an asphalt surface layer, a cement-stabilized crushed stone base course, a lime-stabilized crushed stone base course, and a soil base course. The length and width of the scaled-down asphalt pavement structure are both not less than 30cm, and the height is not less than 1m.

7. The test method for the internal and external temperature and humidity balance of a scaled asphalt pavement structure according to claim 2, characterized in that, The temperature sensor and relative humidity sensor in the scaled-down asphalt pavement structure are symmetrically arranged in the middle of each layer of the scaled-down asphalt pavement structure along the horizontal direction, and then the cable is led out through the lead hole.

8. The test method for the internal and external temperature and humidity balance of a scaled asphalt pavement structure according to claim 2, characterized in that, The reserved space has a height of 10-30cm, and the circulating temperature control heat sink covers the top of the reserved space; A set of temperature sensors and relative humidity sensors in the reserved space are installed at 1 / 2 height of the reserved space and on the side wall; The distance between the drainage pipe and the circulating temperature control bend is 3-10cm, and the distance between the drainage pipe and the bottom heat and moisture insulation layer is 3-10cm.

9. The test method for the internal and external temperature and humidity balance of a scaled asphalt pavement structure according to claim 2, characterized in that, The temperature control range of the test device is -30℃ to 100℃, the relative humidity control range is 0 to 100%RH, the seepage rate control range is 0 to 0.5L / min, and the water spray rate control range is 0 to 10mm / h.

10. The test method for the internal and external temperature and humidity balance of a scaled asphalt pavement structure according to claim 2, characterized in that, The thickness of the thermal and moisture insulation layer ranges from 5cm to 10cm.

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