Integrated testing device and testing method for water seepage and blocking characteristics of drainage asphalt pavement

Abstract

The invention discloses an integrated testing device and testing method for water seepage and blocking characteristics of a drainage asphalt pavement. The device comprises a water storage stirring circulating system, a spraying system, a water seepage coefficient testing system and a filtrate collecting system. The method comprises the following steps: adding blockages and clear water into a water storage tank, and uniformly stirring to obtain a clogging turbid solution; the clogging substance turbid liquid flows through the drainage asphalt pavement core sample, is filtered by the filter box and then enters the filtrate collection box until the clogging substance turbid liquid in the water storage box is completely pumped, and the first clogging simulation cycle is completed; repeating a plurality of blocking simulation cycles until the seepage velocity tends to be gentle, thereby completing a first blocking cycle simulation test, analyzing the blocking sensitive particle size, and testing the water seepage coefficient; and repeating a plurality of blocking cycle simulation tests until the water seepage coefficient tends to be gentle, thereby completing the integrated test of the water seepage and blocking characteristics. According to the invention, controllable and high-repeatability detection of long-period development characteristics of water seepage and blockage of the drainage asphalt pavement can be realized.

Description

Technical Field

[0001] The invention belongs to the technical field of drainage asphalt pavement characteristic testing, and in particular relates to a drainage asphalt pavement water seepage and blockage characteristic integrated testing device and testing method. Background Art

[0002] As we all know, drainage asphalt pavement is widely used in highways and urban roads due to its excellent drainage performance. It is designed with a high void ratio to quickly drain water from the road surface, reduce the formation of water film and road slippage and other safety hazards. However, as the use time increases, the voids are easily blocked by impurities such as dust, sand, and particulate matter, resulting in a significant decrease in drainage performance, thereby affecting the durability and driving safety of the asphalt pavement. Therefore, the research and testing of the void blocking characteristics of drainage asphalt pavement is of great significance.

[0003] At present, there is no unified standardized test method and evaluation standard in the study of void clogging characteristics of drained asphalt pavements at home and abroad. Although countries and regions such as Japan and Europe are relatively advanced in the application of drained asphalt pavements, they mainly rely on on-site sampling and short-term testing in void clogging simulation tests, and lack standardized test simulation methods for the clogging process. This will lead to a lack of comparability of test results between different studies and it is difficult to provide a unified technical reference for engineering practice. In addition, existing research mainly focuses on the evaluation of initial drainage performance, but pays less attention to performance changes during long-term clogging, making it difficult to effectively predict the performance attenuation trend of drained asphalt pavements during long-term use. Overall, existing research is difficult to effectively meet the needs of drained asphalt pavements for long-term clogging performance evaluation.

[0004] The existing domestic specifications for drained asphalt pavements focus on testing initial indicators such as void ratio and water permeability coefficient, but lack systematic evaluation standards and long-term test methods for void blockage. There are relatively few studies on simulating void blockage in drained asphalt pavements under laboratory conditions, and the existing test devices and test methods are difficult to simulate different stages of blockage development, thus failing to fully reflect the actual service conditions of drained asphalt pavements. In addition, the existing test devices are often independent of each other, and the water permeability coefficient test is separated from the blockage simulation device. There is a lack of integrated and systematic test devices, which makes the test process cumbersome and affects the continuity and accuracy of the data.

[0005] At present, there is a lack of suitable test equipment and supporting test methods at home and abroad to effectively simulate and evaluate the blockage characteristics of voids in drainage asphalt pavements, which hinders the in-depth understanding of the drainage performance degradation mechanism and the formulation of corresponding improvement measures. Existing test methods have many shortcomings in repeatability, controllability and simulation of different blockage development stages, and it is difficult to meet the complex needs of drainage asphalt pavements under actual service conditions.

[0006] Based on the above background, there is an urgent need to develop an integrated test device and test method for the seepage and blockage characteristics of drainage asphalt pavement, which can simulate the long-term blockage characteristics of the voids in drainage asphalt pavement under laboratory conditions, so as to systematically study and evaluate the functionality at different stages of blockage development.

[0007] The invention patent with application publication number CN114509379A discloses an integrated device and method for testing water permeability and water purification characteristics, which tests the water permeability and water purification characteristics of permeable paving materials on the same platform. However, the technical solution has the following problems: (1) It is only applicable to permeable cement concrete pavements, but not to drainage asphalt pavements, because the two pavements are different in material design, preparation method, road performance and use; (2) It can only test the water permeability and water purification characteristics of the pavement, but cannot test the blocking characteristics of the pavement; (3) Although the water permeability and water purification characteristics are tested on the same platform, the test process and test results of the two characteristics are independent and there is no correlation between the two; (4) Although multiple cycles are performed during the water purification test, it is still a short-term test, and a short-term test cannot predict the performance attenuation trend of the pavement during long-term use; (5) Rainfall sewage is directly used for testing. However, in actual service, whether it is a permeable cement concrete pavement or a drainage asphalt pavement, the debris accumulated in the gaps is not only the substances carried by rainfall sewage, but also other impurities such as dust, silt, and particulate matter. The test data obtained by only using rainfall sewage testing is less reliable. Summary of the invention

[0008] In order to solve the problems existing in the prior art, the present invention provides an integrated test device for water seepage and blockage characteristics of drainage asphalt pavement, the test device comprising a water storage and stirring circulation system, a sprinkling system, a water permeability coefficient test system, a filtrate collection system, and a specimen clamping and support assembly. The water storage and stirring circulation system is connected to the sprinkling system, the water permeability coefficient test system is located directly below the sprinkling system, the filtrate collection system is located directly below the water permeability coefficient test system and is connected to the water storage and stirring circulation system, and the specimen clamping and support assembly is located in the water permeability coefficient test system; the specimen clamping and support assembly is used to clamp and support a core sample of a drainage asphalt pavement, and a turbid liquid of a blockage circulates into the core sample of the drainage asphalt pavement.

[0009] Preferably, the water storage and stirring circulation system includes a fixed bracket, an agitator, a water tank and a water circulation component; the bottom of the fixed bracket is located on the outside of the water tank, the agitator is installed on the top of the fixed bracket, and the stirring rod of the agitator is vertically inserted into the water tank along the central axis of the water tank.

[0010] In any of the above schemes, it is preferred that the water circulation component includes a peristaltic pump, an inlet pipe, an outlet pipe, a return pipe and a valve I; one end of the inlet pipe is vertically inserted into the water storage tank, and the other end is horizontally connected to one end of the outlet pipe through the peristaltic pump, and the other end of the outlet pipe is connected to the spreading system; the return pipe is horizontally located directly below the inlet pipe and the outlet pipe, one end of the return pipe is connected to the water storage tank, and the other end is connected to the filtrate collection system; the valve I is arranged on the return pipe.

[0011] In any of the above schemes, it is preferred that the spreading system includes a spreading nozzle, a water dripping platform and an overflow port I; the spreading nozzle is located directly above the center of the water dripping platform and is connected to one end of the water outlet pipe, a mounting hole is provided in the center of the water dripping platform, the overflow port I is provided on the side of the water dripping platform, and the overflow port I is connected to the filtrate collection system through a hose.

[0012] In any of the above schemes, it is preferred that the water permeability coefficient testing system includes a support column, a water collecting tank, a permeable cylinder, an overflow port II, a valve II and a collecting container; the water collecting tank is located directly below the water flowing platform, and a support column is respectively arranged at the four corners of the bottom of the water collecting tank, an overflow port II is arranged on the side of the water collecting tank, the collecting container is arranged below the overflow port II, and the valve II is arranged on the overflow port II; the top of the permeable cylinder is vertically installed in the installation hole, and the bottom of the permeable cylinder is vertically inserted into the water collecting tank.

[0013] In any of the above schemes, it is preferred that the specimen clamping and supporting assembly is arranged at the central portion of the bottom of the water collecting tank, and a seepage hole is opened at the central portion of the bottom of the water collecting tank.

[0014] In any of the above schemes, it is preferred that the specimen clamping and supporting assembly includes a perforated steel plate, a support seat and a specimen fixture; one support seat is respectively arranged at the four corners of the bottom of the perforated steel plate, and an inclined surface is formed between the four support seats and the seepage holes; the specimen fixture is placed on the perforated steel plate, and a sealing sleeve is arranged on the inner wall of the specimen fixture; the top of the specimen fixture corresponds to the bottom of the water-permeable cylinder, and the top of the specimen fixture is flush with the overflow port II.

[0015] In any of the above schemes, it is preferred that the filtrate collection system includes a filtrate collection box, a filter box, a seepage conduit, a flow rate sensor and a valve III; the filtrate collection box is located directly below the water collecting tank, the seepage conduit is connected to the seepage hole, the flow rate sensor is arranged at the outlet of the seepage conduit and connected to a computer, and the valve III is arranged on the seepage conduit; the filter box is located directly below the seepage conduit and is fixed to the four support columns by ropes.

[0016] The present invention also provides a method for integrated testing of water seepage and blockage characteristics of a drainage asphalt pavement, using any of the above-mentioned integrated testing devices for water seepage and blockage characteristics of a drainage asphalt pavement, and comprising the following steps in chronological order:

[0017] Step 1: Assemble and connect the various components of the test device according to the design structure, debug the test device and check the sealing to ensure that it can be used normally during the test;

[0018] Step 2: Drill a core sample of the drainage asphalt pavement from the newly built drainage asphalt pavement, apply vaseline on the surface of the core sample, and then put the core sample of the drainage asphalt pavement into the sealing sleeve in the specimen fixture; apply butter on the top of the specimen fixture and the bottom of the water-permeable cylinder respectively, and then move the water-permeable cylinder downward so that the bottom of the water-permeable cylinder fits and seals with the top of the specimen fixture; at this time, the central axes of the spray nozzle, the water-flowing platform, the water-permeable cylinder, the water collection tank, the specimen fixture, the drainage asphalt pavement core sample, the perforated steel plate, the seepage hole, the seepage conduit, the filter box, and the filtrate collection box coincide, and at the same time, the top of the water-permeable cylinder and the water-flowing platform are on the same horizontal plane, and the top of the specimen fixture is flush with the overflow port II;

[0019] Step 3: Add clean water to the water storage tank, close valves Ⅰ and Ⅲ, and open valve Ⅱ; start the peristaltic pump, and the clean water will enter the drainage asphalt pavement core sample after passing through the water inlet pipe, the water outlet pipe, the spray nozzle, and the water permeable cylinder in sequence; after passing through the drainage asphalt pavement core sample, the clean water will flow out from the circular holes on the perforated steel plate and enter the water collecting tank; when the water level in the water collecting tank reaches the overflow port Ⅱ and the liquid level on the water platform reaches a stable state, start recording the time when the clean water flows out from the overflow port Ⅱ, and use a collection container to collect the clean water flowing out during this time period, and then test the original vertical water permeability coefficient of the drainage asphalt pavement core sample;

[0020] Step 4: Close the peristaltic pump and valve II, open valve I and valve III, and allow the clean water in the water collection tank and the drainage asphalt pavement core sample to flow into the filtrate collection tank through the seepage holes and the seepage conduit. At the same time, the clean water in the filtrate collection tank flows into the water storage tank through the return pipe, and then close valve I;

[0021] Step 5: Prepare the blockage according to the designed ratio, add clean water into the water tank according to the designed ratio, and then add the blockage into the clean water; start the agitator to stir the blockage and the clean water to mix them evenly, so as to obtain a turbid liquid of the blockage;

[0022] Step 6: Keep the agitator in a stirring state, start the peristaltic pump, and the turbid liquid of the blockage passes through the water inlet pipe, the water outlet pipe, the spray nozzle, and the water permeable cylinder in turn, and then enters the drainage asphalt pavement core sample. The turbid liquid of the blockage that fails to enter the water permeable cylinder flows into the filtrate collection box through the overflow port Ⅰ and the hose; after passing through the drainage asphalt pavement core sample, the turbid liquid of the blockage flows out from the circular hole on the perforated steel plate, passes through the seepage hole, the seepage conduit, and the filter box in turn, and then enters the filtrate collection box. In this process, the filter box collects the blockage, and the filtrate flows into the filtrate collection box. At the same time, the flow rate sensor and the computer are used to monitor the change of the seepage velocity of the drainage asphalt pavement core sample with the seepage time in real time; until the turbid liquid of the blockage in the water storage tank is completely drained, open valve Ⅰ, and the liquid in the filtrate collection box enters the water storage tank through the return pipe, and then close valve Ⅰ, that is, the first blockage simulation cycle is completed;

[0023] Step 7: Repeat step 6 several times, that is, complete several clogging simulation cycles. Each clogging simulation cycle requires real-time monitoring of the change of the seepage velocity of the drainage asphalt pavement core sample with the seepage time, until the change of the seepage velocity with the seepage time tends to be flat, that is, the first clogging cycle simulation test is completed;

[0024] Step 8: After the first blockage cycle simulation test is completed, move the permeable cylinder upward to expose the drainage asphalt pavement core sample, use a brush to collect the blockages remaining on the surface of the drainage asphalt pavement core sample into a container, and pour the blockages collected by the filter box into another container, dry and sieve the blockages in the two containers respectively, and then statistically analyze the blockage-sensitive particle size through the particle size distribution; move the permeable cylinder downward to re-fit the bottom of the permeable cylinder with the top of the specimen fixture, and re-add clean water to the water storage tank, repeat steps 3 to 4, and then test the vertical water permeability coefficient of the drainage asphalt pavement core sample;

[0025] Step 9: Repeat steps 5 to 8 for several times to complete several blockage cycle simulation tests. After each blockage cycle simulation test, it is necessary to analyze the blockage-sensitive particle size and test the vertical water permeability coefficient until the vertical water permeability coefficient of the current blockage cycle simulation test is close to that of the previous blockage cycle simulation test, thus completing the integrated test of long-term water permeability and blockage characteristics of drainage asphalt pavement.

[0026] Preferably, in step three, 12 L of clean water is added to the water storage cylinder; the control flow rate of the peristaltic pump is 100-300 mL / min; and the time for the clean water to flow out of the overflow port II is 1-3 min.

[0027] In any of the above schemes, preferably, in step 4, valve III is opened to allow the clean water in the water collection tank and the drainage asphalt pavement core sample to flow into the filtrate collection box through the seepage holes and the seepage conduit, and this process is maintained for 5-10 minutes.

[0028] In any of the above schemes, it is preferred that in step five, the plugging material is a mixture of soil, sand and gravel and rubber particles, wherein the mass percentage of each substance in the plugging material is 30-40wt% of soil, 50-65wt% of sand and gravel, and 5-10wt% of rubber particles; the sand and gravel include seven particle sizes, and the mass percentage of each particle size in the sand and gravel is 12-18wt% of particle size 2.36-4.75mm, 28-32wt% of particle size 1.18-2.36mm, 18-25wt% of particle size 0.6-1.18mm, and 0.3- 0.6mm accounts for 8-12wt%, particle size 0.15-0.3mm accounts for 10-15wt%, particle size 0.075-0.15mm accounts for 6-10wt%, and particle size 0-0.075mm accounts for 3-6wt%; the size of the rubber particles is 30 mesh or 40 mesh; add 8-12L of clean water and 8-15g of plugging material into the water storage cylinder, of which 8-15g of plugging material is the mass after drying, the drying temperature is 100-130℃, and the drying time is 2-4h; the stirring speed is 60-200rpm, and the stirring time is 2-5min.

[0029] In any of the above schemes, preferably, in step six, the stirrer is kept in a stirring state with a stirring speed of 60-200 rpm; and the control flow rate of the peristaltic pump is 120-250 mL / min.

[0030] In any of the above schemes, it is preferred that in step eight, a brush is used to collect the blockages remaining on the upper surface of the drainage asphalt pavement core sample into a container, that is, the blockages remaining on the upper surface of the drainage asphalt pavement core sample are collected; the blockages collected by the filter box are poured into another container, that is, the blockages flowing through the drainage asphalt pavement core sample are collected; the blockages in the two containers are dried and sieved respectively, and the drying temperature is 100-130°C and the drying time is 2-4h.

[0031] The present invention can adjust the matching sizes between the components in the test device according to the actual use situation, for example: the water storage cylinder is 15L, the water storage cylinder is made of acrylic material, and scale lines can be set on the cylinder wall; the diameters of the water inlet pipe, the water outlet pipe and the water return pipe are all 20mm; the length of the water platform is 200mm, the width is 200mm, the height is 80mm, and the outlet diameter of the overflow port I is 10mm; the length of the outer shape of the permeable cylinder is 120mm, the width is 120mm, the height is 300±1mm, and the diameter of the inner cavity of the permeable cylinder is 100mm; the diameter of the water collecting tank is 100mm, and the diameter of the inner cavity of the water collecting tank is 100mm. The length is 400mm, the width is 400mm, the height is 300mm, the outlet diameter of overflow port II is 10mm; the inner cavity diameter of the specimen fixture is 105mm, the height is 100mm, the length of the perforated steel plate is 150mm, the width is 150mm, the height is 5mm, the diameter of the circular hole on the perforated steel plate is 5mm, the height of the support seat is 10mm; the diameter of the seepage hole is 20mm, the diameter of the seepage conduit is 25mm, and the length is 40mm; the diameter of the drainage asphalt pavement core sample is 100mm, and the height is 100mm, etc. The control flow of the peristaltic pump, that is, the spreading intensity, can be adjusted according to the actual local conditions.

[0032] Sand and gravel include seven particle sizes, namely 2.36-4.75mm, 1.18-2.36mm, 0.6-1.18mm, 0.3-0.6mm, 0.15-0.3mm, 0.075-0.15mm and 0-0.075mm, that is, 2.36mm≤particle size<4.75mm, 1.18mm≤particle size<2.36mm, 0.6mm≤particle size<1.18mm, 0.3mm≤particle size<0.6mm, 0.15mm≤particle size<0.3mm, 0.075mm≤particle size<0.15mm and 0mm≤particle size<0.075mm. For each particle size level, the sand and gravel are passed through the upper and lower sieve holes in sequence to obtain a particle size between the upper and lower sieve holes, for example: the particle size is 1.18-2.36mm (1.18mm≤particle size<2.36mm), that is, the sand and gravel are passed through the 2.36mm sieve hole and the 1.18mm sieve hole in sequence to obtain a particle size between 1.18-2.36mm.

[0033] The integrated testing device and method for water seepage and blockage characteristics of drainage asphalt pavement of the present invention have the following beneficial effects:

[0034] (1) The present invention is based on the principle of constant head permeability coefficient test, and realizes the accurate measurement of the permeability coefficient of the drainage asphalt pavement core sample. At the same time, the blockage turbid liquid spreading system is introduced to realize the accurate simulation of the development of void blockage disease of the drainage asphalt pavement. The controllable and highly repeatable test of the permeability coefficient at different stages of blockage development is completed through the integrated testing device.

[0035] (2) The present invention controls the liquid flow rate of the spray nozzle through a peristaltic pump, which can simulate different spraying intensities and provide a scientific basis for studying the water seepage characteristics of drainage asphalt pavement. At the same time, the water platform is used to collect the liquid that fails to enter the core sample of the drainage asphalt pavement. In conjunction with the overflow port and the filtrate collection system, the blockage process of the drainage asphalt pavement in the real environment is reproduced, which can help analyze the blockage development law of drainage asphalt pavements in different regions.

[0036] (3) In the present invention, an open overflow is used on the upper part of the permeable cylinder to let water in. The water flowing platform and the larger overflow port ensure that the constant head test device has a stable water head. At the same time, the core sample of the drainage asphalt pavement is strictly sealed to reduce the impact of side flow and improve the measurement accuracy.

[0037] (3) The setting height of the specimen fixture in the present invention can be applicable to various specimen forms such as field core samples and laboratory core samples, so that the device can be widely used in various test conditions and specimen types, meeting the different needs of field engineering testing and laboratory research, and has strong applicability and flexibility.

[0038] (4) The present invention adopts a high-precision flow velocity sensor to monitor the changes in the seepage velocity in real time through a computer, ensuring that the water flow data in each blockage cycle can be accurately recorded. Through the precise control of the flow velocity sensor, it can timely capture the subtle changes in the water flow in different blockage stages, thereby accurately analyzing the end period of the blockage cycle.

[0039] (5) The blockage simulation process of the present invention can test blockages of different components (soil and / or gravel and / or rubber particles, etc.), and can simulate the blockage process in an actual road environment under laboratory conditions; through multiple blockage cycles and monitoring the attenuation law of the water permeability coefficient, the influence of different blockage materials on the water permeability characteristics of the drainage asphalt pavement can be studied. In particular, the design of the filter box can collect blockage particles flowing through the core sample of the drainage asphalt pavement, and then realize the statistical analysis of the blockage-sensitive particle size, which provides a scientific basis for how to deal with different blockage situations in pavement design and maintenance.

[0040] (6) The present invention adopts an integrated design, integrating the water storage stirring circulation system, the blockage turbid liquid spreading system, the water permeability coefficient testing system and the filtrate collection system into an overall platform. During the test process, there is no need to repeatedly disassemble and reassemble the various components, which simplifies the test process, reduces the errors caused by human operation, greatly improves the convenience and efficiency of the test operation, and helps to obtain high-precision and high-consistency test results.

[0041] (7) The test device and test method developed in the present invention can simulate the void clogging characteristics of drainage asphalt pavement during long-term service under laboratory conditions, and achieve precise control and monitoring of the clogging process through a controllable test environment, thereby providing a scientific basis for the design, construction and maintenance of drainage asphalt pavement.

[0042] (8) The testing device and testing method developed in the present invention comprehensively consider the different blockage stages of drainage asphalt pavement, and can realize the long-term integrated simulation of the blockage development of drainage asphalt pavement. It can effectively obtain the changes in the permeability capacity and the blockage-sensitive particle size at different blockage stages, and can realize the controllable, standardized and highly repeatable detection of the long-term development characteristics of water seepage and blockage of drainage asphalt pavement.

[0043] (9) The testing device and testing method of the present invention can ensure that during the blockage simulation test, all blockages enter the drainage asphalt pavement core sample and will not adhere to other components of the testing device, thereby obtaining more accurate water permeability coefficient test results and blockage sensitive particle size analysis results. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A schematic diagram of the three-dimensional structure of a testing device in a preferred embodiment of an integrated testing device and method for water seepage and blockage characteristics of a drainage asphalt pavement according to the present invention;

[0045] Figure 2 for Figure 1 A front view of the test device in the illustrated embodiment;

[0046] Figure 3 for Figure 1 A schematic structural diagram of a water storage and stirring circulation system in the illustrated embodiment;

[0047] Figure 4 for Figure 1 A schematic diagram of the structure of the spreading system in the illustrated embodiment;

[0048] Figure 5 for Figure 1 A schematic structural diagram of a water permeability coefficient testing system in the illustrated embodiment;

[0049] Figure 6 for Figure 1 A schematic diagram of the structure of the filtrate collection system in the illustrated embodiment;

[0050] Figure 7 for Figure 1 A schematic diagram of the structure of the specimen clamping and supporting assembly in the illustrated embodiment.

[0051] Notes in the figure:

[0052] 1-water storage and stirring circulation system, 101-fixed bracket, 102-stirrer, 103-water storage tank, 104-peristaltic pump, 105-water inlet pipe, 106-water outlet pipe, 107-water return pipe, 108-valve I;

[0053] 2-sprinkling system, 201-sprinkling nozzle, 202-water flowing platform, 203-overflow port I, 204-installation hole;

[0054] 3- water seepage coefficient test system, 301- support column, 302- water collecting tank, 303- water permeable cylinder, 304- overflow port II, 305- valve II, 306- collection container, 307- water seepage hole;

[0055] 4-filtrate collection system, 401-filtrate collection box, 402-filter box, 403-seepage conduit, 404-flow rate sensor, 405-valve III;

[0056] 5-specimen clamping and supporting assembly, 501-perforated steel plate, 502-support seat, 503-specimen clamp. DETAILED DESCRIPTION

[0057] In order to further understand the content of the present invention, the present invention will be described in detail below in conjunction with specific embodiments.

[0058] Embodiment 1:

[0059] like Figure 1-7 As shown, according to a preferred embodiment of the integrated test device for water seepage and blockage characteristics of drainage asphalt pavement of the present invention, the test device includes a water storage and stirring circulation system 1, a spreading system 2, a water permeability coefficient test system 3, a filtrate collection system 4, and a specimen clamping and supporting assembly 5. The water storage and stirring circulation system 1 is connected to the spreading system 2, the water permeability coefficient test system 3 is located directly below the spreading system 2, the filtrate collection system 4 is located directly below the water permeability coefficient test system 3 and is connected to the water storage and stirring circulation system 1, and the specimen clamping and supporting assembly 5 is located in the water permeability coefficient test system 3; the specimen clamping and supporting assembly 5 is used to clamp and support a drainage asphalt pavement core sample, and the blockage turbid liquid circulates into the drainage asphalt pavement core sample.

[0060] The water storage stirring circulation system 1 includes a fixed bracket 101, an agitator 102, a water tank 103 and a water circulation component; the bottom of the fixed bracket 101 is located on the outside of the water tank 103, the agitator 102 is installed on the top of the fixed bracket 101, and the stirring rod of the agitator 102 is vertically inserted into the water tank 103 along the central axis of the water tank 103.

[0061] The water circulation component includes a peristaltic pump 104, an inlet pipe 105, an outlet pipe 106, a return pipe 107 and a valve I 108; one end of the inlet pipe 105 is vertically inserted into the water storage tank 103, and the other end is horizontally connected to one end of the outlet pipe 106 through the peristaltic pump 104, and the other end of the outlet pipe 106 is connected to the spreading system 2; the return pipe 107 is horizontally located directly below the inlet pipe 105 and the outlet pipe 106, one end of the return pipe 107 is connected to the water storage tank 103, and the other end is connected to the filtrate collection system 4; the valve I 108 is arranged on the return pipe 107.

[0062] The spreading system 2 includes a spreading nozzle 201, a water dripping platform 202 and an overflow port I 203; the spreading nozzle 201 is located directly above the center of the water dripping platform 202 and is connected to one end of the water outlet pipe 106, a mounting hole 204 is provided in the center of the water dripping platform 202, and the overflow port I 203 is provided on the side of the water dripping platform 202, and the overflow port I 203 is connected to the filtrate collection system 4 through a hose.

[0063] The water permeability coefficient testing system 3 includes a support column 301, a water collecting box 302, a permeable cylinder 303, an overflow port II 304, a valve II 305 and a collecting container 306; the water collecting box 302 is located directly below the water-digging platform 202, and a support column 301 is respectively arranged at the four corners of the bottom of the water collecting box 302, an overflow port II 304 is arranged on the side of the water collecting box 302, the collecting container 306 is arranged below the overflow port II 304, and the valve II 305 is arranged on the overflow port II 304; the top of the permeable cylinder 303 is vertically installed in the installation hole 204, and the bottom of the permeable cylinder 303 is vertically inserted into the water collecting box 302.

[0064] The specimen clamping and supporting assembly 5 is disposed at the center of the bottom of the water collecting box 302 , and a seepage hole 307 is opened at the center of the bottom of the water collecting box 302 .

[0065] The specimen clamping and supporting assembly 5 includes a perforated steel plate 501, a support seat 502 and a specimen fixture 503; a support seat 502 is respectively arranged at the four corners of the bottom of the perforated steel plate 501, and an inclined surface is formed between the four support seats 502 and the seepage holes 307; the specimen fixture 503 is placed on the perforated steel plate 501, and a sealing sleeve is arranged on the inner wall of the specimen fixture 503; the top of the specimen fixture 503 corresponds to the bottom of the water-permeable cylinder 303, and the top of the specimen fixture 503 is flush with the overflow port II 304.

[0066] The filtrate collection system 4 includes a filtrate collection box 401, a filter box 402, a seepage conduit 403, a flow rate sensor 404 and a valve III 405; the filtrate collection box 401 is located directly below the water collecting box 302, the seepage conduit 403 is connected to the seepage hole 307, the flow rate sensor 404 is arranged at the outlet of the seepage conduit 403 and is connected to a computer, and the valve III 405 is arranged on the seepage conduit 403; the filter box 402 is located directly below the seepage conduit 403 and is fixed to the four support columns 301 by ropes.

[0067] This embodiment also provides a method for integrated testing of water seepage and blockage characteristics of drainage asphalt pavement, using the above-mentioned integrated testing device for water seepage and blockage characteristics of drainage asphalt pavement, and including the following steps in order:

[0068] Step 1: Assemble and connect the various components of the test device according to the design structure, debug the test device and check the sealing to ensure that it can be used normally during the test;

[0069] Step 2: Drill a core sample of the drainage asphalt pavement from the newly built drainage asphalt pavement, apply vaseline on the surface of the core sample, and then put the core sample of the drainage asphalt pavement into the sealing sleeve in the specimen fixture; apply butter on the top of the specimen fixture and the bottom of the water-permeable cylinder respectively, and then move the water-permeable cylinder downward so that the bottom of the water-permeable cylinder fits and seals with the top of the specimen fixture; at this time, the central axes of the spray nozzle, the water-flowing platform, the water-permeable cylinder, the water collection tank, the specimen fixture, the drainage asphalt pavement core sample, the perforated steel plate, the seepage hole, the seepage conduit, the filter box, and the filtrate collection box coincide, and at the same time, the top of the water-permeable cylinder and the water-flowing platform are on the same horizontal plane, and the top of the specimen fixture is flush with the overflow port II;

[0070] Step 3: Add clean water to the water storage tank, close valves Ⅰ and Ⅲ, and open valve Ⅱ; start the peristaltic pump, and the clean water will enter the drainage asphalt pavement core sample after passing through the water inlet pipe, the water outlet pipe, the spray nozzle, and the water permeable cylinder in sequence; after passing through the drainage asphalt pavement core sample, the clean water will flow out from the circular holes on the perforated steel plate and enter the water collecting tank; when the water level in the water collecting tank reaches the overflow port Ⅱ and the liquid level on the water platform reaches a stable state, start recording the time when the clean water flows out from the overflow port Ⅱ, and use a collection container to collect the clean water flowing out during this time period, and then test the original vertical water permeability coefficient of the drainage asphalt pavement core sample;

[0071] Step 4: Close the peristaltic pump and valve II, open valve I and valve III, and allow the clean water in the water collection tank and the drainage asphalt pavement core sample to flow into the filtrate collection tank through the seepage holes and the seepage conduit. At the same time, the clean water in the filtrate collection tank flows into the water storage tank through the return pipe, and then close valve I;

[0072] Step 5: Prepare the blockage according to the designed ratio, add clean water into the water tank according to the designed ratio, and then add the blockage into the clean water; start the agitator to stir the blockage and the clean water to mix them evenly, so as to obtain a turbid liquid of the blockage;

[0073] Step 6: Keep the agitator in a stirring state, start the peristaltic pump, and the turbid liquid of the blockage passes through the water inlet pipe, the water outlet pipe, the spray nozzle, and the water permeable cylinder in turn, and then enters the drainage asphalt pavement core sample. The turbid liquid of the blockage that fails to enter the water permeable cylinder flows into the filtrate collection box through the overflow port Ⅰ and the hose; after passing through the drainage asphalt pavement core sample, the turbid liquid of the blockage flows out from the circular hole on the perforated steel plate, passes through the seepage hole, the seepage conduit, and the filter box in turn, and then enters the filtrate collection box. In this process, the filter box collects the blockage, and the filtrate flows into the filtrate collection box. At the same time, the flow rate sensor and the computer are used to monitor the change of the seepage velocity of the drainage asphalt pavement core sample with the seepage time in real time; until the turbid liquid of the blockage in the water storage tank is completely drained, open valve Ⅰ, and the liquid in the filtrate collection box enters the water storage tank through the return pipe, and then close valve Ⅰ, that is, the first blockage simulation cycle is completed;

[0074] Step 7: Repeat step 6 several times, that is, complete several clogging simulation cycles. Each clogging simulation cycle requires real-time monitoring of the change of the seepage velocity of the drainage asphalt pavement core sample with the seepage time, until the change of the seepage velocity with the seepage time tends to be flat, that is, the first clogging cycle simulation test is completed;

[0075] Step 8: After the first blockage cycle simulation test is completed, move the permeable cylinder upward to expose the drainage asphalt pavement core sample, use a brush to collect the blockages remaining on the surface of the drainage asphalt pavement core sample into a container, and pour the blockages collected by the filter box into another container, dry and sieve the blockages in the two containers respectively, and then statistically analyze the blockage-sensitive particle size through the particle size distribution; move the permeable cylinder downward to re-fit the bottom of the permeable cylinder with the top of the specimen fixture, and re-add clean water to the water storage tank, repeat steps 3 to 4, and then test the vertical water permeability coefficient of the drainage asphalt pavement core sample;

[0076] Step 9: Repeat steps 5 to 8 for several times to complete several blockage cycle simulation tests. After each blockage cycle simulation test, it is necessary to analyze the blockage-sensitive particle size and test the vertical water permeability coefficient until the vertical water permeability coefficient of the current blockage cycle simulation test is close to that of the previous blockage cycle simulation test, thus completing the integrated test of long-term water permeability and blockage characteristics of drainage asphalt pavement.

[0077] In step three, 12L of clean water is added to the water storage cylinder; the control flow rate of the peristaltic pump is 200mL / min; and the time for the clean water to flow out of the overflow port II is 2min.

[0078] In step 4, valve III is opened to allow the clean water in the water collection tank and the drainage asphalt pavement core sample to flow into the filtrate collection box through the seepage holes and the seepage conduit. This process is maintained for 8 minutes.

[0079] In step 5, the plugging material is a mixture of soil, sand and gravel and rubber particles, wherein the mass percentage of each substance in the plugging material is 40wt% of soil, 50wt% of sand and gravel, and 10wt% of rubber particles; the sand and gravel include seven particle sizes, and the mass percentage of each particle size in the sand and gravel is 15wt% of particle size 2.36-4.75mm, 30wt% of particle size 1.18-2.36mm, 20wt% of particle size 0.6-1.18mm, and 0.3- 0.6mm accounts for 10wt%, particle size 0.15-0.3mm accounts for 12wt%, particle size 0.075-0.15mm accounts for 8wt%, and particle size 0-0.075mm accounts for 5wt%; the size of the rubber particles is 30 mesh; 10L of clean water and 8g of blockage are added to the water storage cylinder, of which 8g of blockage is the mass after drying, the drying temperature is 115℃, and the drying time is 3h; the stirring speed is 130rpm, and the stirring time is 3.5min.

[0080] In step six, the stirrer is kept in a stirring state at a stirring speed of 130 rpm; the control flow rate of the peristaltic pump is 185 mL / min.

[0081] In step eight, a brush is used to collect the blockages remaining on the surface of the drainage asphalt pavement core sample into a container, that is, the blockages remaining on the surface of the drainage asphalt pavement core sample are collected; the blockages collected by the filter box are poured into another container, that is, the blockages flowing through the drainage asphalt pavement core sample are collected; the blockages in the two containers are dried and sieved respectively, and the drying temperature is 115°C and the drying time is 3 hours.

[0082] The core sample of the drainage asphalt pavement tested in this embodiment was drilled from a newly built drainage asphalt pavement in a certain area of ​​Jiangsu Province. The specific material is PAC-13 asphalt mixture with a void ratio of 20%. During the entire test process, a total of five blocking cycle simulation tests were performed, of which the first four blocking cycle simulation tests each underwent four blocking simulation cycles, and the fifth blocking cycle simulation test underwent three blocking simulation cycles; after each blocking cycle simulation test, the vertical water permeability coefficient of the core sample of the drainage asphalt pavement was tested (calculated using Darcy's law), and the blocking sensitive particle size was analyzed at the same time. The specific test data are shown in Tables 1 to 5.

[0083] Table 1 Water permeability coefficient attenuation test during the blockage development process

[0084] Blockage cycle simulation test 0 Cycle 1 Cycle 2 Cycle 3 Cycle 4 Cycle 5 Blocking simulation loop 0 4 times 4 times 4 times 4 times 3 times Cumulative mass of blockage (g) 0 8 16 24 32 40 <![CDATA[Permeability coefficient (K / cm·s -1 )]]> 0.416 0.285 0.221 0.166 0.122 0.121

[0085] Table 2 Blockage-sensitive particle size test results after the first blockage cycle simulation test

[0086]

[0087]

[0088] Table 3 Blockage-sensitive particle size test results after the second blockage cycle simulation test

[0089]

[0090] Table 4 Blockage-sensitive particle size test results after the third blockage cycle simulation test

[0091]

[0092] Table 5 Blockage-sensitive particle size test results after the fourth blockage cycle simulation test

[0093]

[0094] In this embodiment, after the fifth blockage cycle simulation test, the water permeability coefficient has no obvious change, so it can be considered that the complete blockage state was reached in the fourth blockage cycle simulation test. In the fifth blockage cycle simulation test, no blockage entered the core sample, but gathered on the upper surface of the core sample. From the test data in Tables 1 to 5, it can be seen that the water permeability coefficient attenuation caused by the blockage of the drainage asphalt pavement generally shows a trend of first fast and then slow, which means that the gaps are quickly blocked at the beginning of the blockage, and then continue to develop; the proportion of blockages remaining in the core sample shows a trend of gradually decreasing, and for the core sample, the particle size of the blockage of 0.15-1.18mm is the sensitive particle size that affects the road blockage.

[0095] In this embodiment, the matching sizes of the components in the test device can be adjusted according to the actual use conditions, wherein: the water storage cylinder is 15L, the water storage cylinder is made of acrylic material, and scale lines can be set on the cylinder wall; the diameters of the water inlet pipe, the water outlet pipe and the water return pipe are all 20mm; the length of the water platform is 200mm, the width is 200mm, the height is 80mm, and the outlet diameter of the overflow port I is 10mm; the length of the water permeable cylinder is 120mm, the width is 120mm, the height is 300±1mm, and the diameter of the inner cavity of the water permeable cylinder is 100mm; the diameter of the water collecting tank is 100mm. The length is 400mm, the width is 400mm, the height is 300mm, the outlet diameter of overflow port II is 10mm; the inner cavity diameter of the specimen fixture is 105mm, the height is 100mm, the length of the perforated steel plate is 150mm, the width is 150mm, the height is 5mm, the diameter of the circular hole on the perforated steel plate is 5mm, the height of the support seat is 10mm; the diameter of the seepage hole is 20mm, the diameter of the seepage conduit is 25mm, and the length is 40mm; the diameter of the drainage asphalt pavement core sample is 100mm, and the height is 100mm, etc. The control flow of the peristaltic pump, that is, the spreading intensity, can be adjusted according to the actual local conditions.

[0096] Sand and gravel include seven particle sizes, namely 2.36-4.75mm, 1.18-2.36mm, 0.6-1.18mm, 0.3-0.6mm, 0.15-0.3mm, 0.075-0.15mm and 0-0.075mm, that is, 2.36mm≤particle size<4.75mm, 1.18mm≤particle size<2.36mm, 0.6mm≤particle size<1.18mm, 0.3mm≤particle size<0.6mm, 0.15mm≤particle size<0.3mm, 0.075mm≤particle size<0.15mm and 0mm≤particle size<0.075mm. For each particle size level, the sand and gravel are passed through the upper and lower sieve holes in sequence to obtain a particle size between the upper and lower sieve holes, for example: the particle size is 1.18-2.36mm (1.18mm≤particle size<2.36mm), that is, the sand and gravel are passed through the 2.36mm sieve hole and the 1.18mm sieve hole in sequence to obtain a particle size between 1.18-2.36mm.

[0097] The integrated test device and test method for water seepage and blockage characteristics of drainage asphalt pavement of this embodiment have the following beneficial effects:

[0098] (1) The water permeability coefficient of the core sample of the drainage asphalt pavement is accurately measured. At the same time, the turbid liquid spreading system of the blockage is introduced to realize the accurate simulation of the development of the void blockage disease of the drainage asphalt pavement. (2) It is suitable for a variety of test specimens such as field core samples and laboratory core samples, so that the test device can be widely used in various test conditions and test specimen types to meet the different needs of field engineering inspections and laboratory research. (3) A high-precision flow sensor is used to monitor the changes in the seepage velocity in real time to ensure that the water flow data in each blockage cycle can be accurately recorded. Through the precise control of the flow sensor, the subtle changes in the water flow at different blockage stages can be captured in time, so as to accurately analyze the end cycle of the blockage cycle. (4) It can simulate the void blockage characteristics of the drainage asphalt pavement during long-term service under laboratory conditions. Through a controllable test environment, it can achieve accurate control and monitoring of the blockage process, providing a scientific basis for the design, construction and maintenance of drainage asphalt pavements. (5) The different clogging stages of drainage asphalt pavement are comprehensively considered, and the long-term integrated simulation of the development of drainage asphalt pavement clogging can be realized. The changes in water permeability and clogging sensitive particle size at different clogging stages can be effectively obtained, and the controllable, standardized and highly repeatable detection of the long-term development characteristics of water permeability and clogging of drainage asphalt pavement can be realized. (6) It can ensure that all the blockages enter the core sample of drainage asphalt pavement during the clogging simulation test and will not adhere to other components of the test device, thereby obtaining more accurate water permeability coefficient test results and blockage sensitive particle size analysis results.

[0099] Embodiment 2:

[0100] According to another preferred embodiment of the integrated test device and test method for water seepage and blockage characteristics of drainage asphalt pavement of the present invention, the test device, test method, technical principle and beneficial effects are basically the same as those of the first embodiment, except that:

[0101] In step three, 12L of clean water is added to the water storage cylinder; the control flow rate of the peristaltic pump is 100mL / min; and the time for the clean water to flow out of the overflow port II is 3min.

[0102] In step 4, valve III is opened to allow the clean water in the water collection tank and the drainage asphalt pavement core sample to flow into the filtrate collection box through the seepage holes and the seepage conduit. This process is maintained for 5 minutes.

[0103] In step five, the plugging material is a mixture of soil, gravel and rubber particles, wherein the mass percentage of each substance in the plugging material is 30wt% of soil, 65wt% of gravel and 5wt% of rubber particles; the gravel includes seven particle sizes, and the mass percentage of each particle size in the sand and gravel is 12wt% for particle size 2.36-4.75mm, 32wt% for particle size 1.18-2.36mm, 18wt% for particle size 0.6-1.18mm, 12wt% for particle size 0.3-0.6mm, 10wt% for particle size 0.15-0.3mm, 10wt% for particle size 0.075-0.15mm, and 6wt% for particle size 0-0.075mm; 8L of clean water and 12g of plugging material are added to the water storage cylinder, wherein 12g of plugging material is the mass after drying, the drying temperature is 100°C, and the drying time is 4h; the stirring speed is 60rpm and the stirring time is 5min.

[0104] In step six, the stirrer is kept in a stirring state at a stirring speed of 60 rpm; the control flow rate of the peristaltic pump is 255 mL / min.

[0105] In step eight, a brush is used to collect the blockages remaining on the surface of the drainage asphalt pavement core sample into a container, that is, the blockages remaining on the surface of the drainage asphalt pavement core sample are collected; the blockages collected by the filter box are poured into another container, that is, the blockages flowing through the drainage asphalt pavement core sample are collected; the blockages in the two containers are dried and sieved respectively, and the drying temperature is 100°C and the drying time is 4 hours.

[0106] Embodiment three:

[0107] According to another preferred embodiment of the integrated test device and test method for water seepage and blockage characteristics of drainage asphalt pavement of the present invention, the test device, test method, technical principle and beneficial effects are basically the same as those of the first embodiment, except that:

[0108] In step three, 12L of clean water is added to the water storage cylinder; the control flow rate of the peristaltic pump is 300mL / min; and the time for the clean water to flow out of the overflow port II is 1min.

[0109] In step 4, valve III is opened to allow the clean water in the water collection tank and the drainage asphalt pavement core sample to flow into the filtrate collection box through the seepage holes and the seepage conduit. This process is maintained for 10 minutes.

[0110] In step five, the plugging material is a mixture of soil, gravel and rubber particles, wherein the mass percentage of each substance in the plugging material is 35wt% of soil, 57wt% of gravel and 8wt% of rubber particles; the gravel includes seven particle sizes, and the mass percentage of each particle size in the sand and gravel is 15wt% of particle size 2.36-4.75mm, 28wt% of particle size 1.18-2.36mm, 25wt% of particle size 0.6-1.18mm, 8wt% of particle size 0.3-0.6mm, 15wt% of particle size 0.15-0.3mm, 6wt% of particle size 0.075-0.15mm and 3wt% of particle size 0-0.075mm; 12L of clean water and 15g of plugging material are added to the water storage cylinder, wherein 15g of the plugging material is the mass after drying, the drying temperature is 130°C and the drying time is 2h; the stirring speed is 200rpm and the stirring time is 2min.

[0111] In step six, the stirrer is kept in a stirring state at a stirring speed of 200 rpm; the control flow rate of the peristaltic pump is 120 mL / min.

[0112] In step eight, a brush is used to collect the blockages remaining on the surface of the drainage asphalt pavement core sample into a container, that is, the blockages remaining on the surface of the drainage asphalt pavement core sample are collected; the blockages collected by the filter box are poured into another container, that is, the blockages flowing through the drainage asphalt pavement core sample are collected; the blockages in the two containers are dried and sieved respectively, and the drying temperature is 130°C and the drying time is 2 hours.

[0113] Special note: The technical solution of the present invention involves many parameters, and the synergistic effects between the various parameters need to be comprehensively considered to obtain the beneficial effects and significant progress of the present invention. Moreover, the value ranges of the various parameters in the technical solution are obtained after a large number of experiments. For each parameter and the combination of each parameter, the inventor has recorded a large amount of experimental data. Due to space limitations, the specific experimental data will not be disclosed here.

[0114] It is not difficult for those skilled in the art to understand that the present invention includes any combination of the invention content and specific implementation methods of the above-mentioned invention specification and the various parts shown in the drawings. Due to the limited space and to make the specification concise, the various schemes composed of these combinations are not described one by one. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An integrated test device for water seepage and blockage characteristics of drainage asphalt pavement, characterized by: The test device comprises a water storage stirring circulation system, a spreading system, a water permeability coefficient testing system, a filtrate collection system, and a specimen clamping and supporting assembly. The water storage stirring circulation system is connected to the spreading system, the water permeability coefficient testing system is located directly below the spreading system, the filtrate collection system is located directly below the water permeability coefficient testing system and is connected to the water storage stirring circulation system, and the specimen clamping and supporting assembly is located in the water permeability coefficient testing system; The specimen clamping and supporting assembly is used for clamping and supporting a core sample of a drainage asphalt pavement, into which a turbid liquid of a blockage circulates.

2. The integrated test device for water seepage and blockage characteristics of drainage asphalt pavement according to claim 1 is characterized by: The water storage stirring circulation system includes a fixed bracket, an agitator, a water tank and a water circulation component; the bottom of the fixed bracket is located on the outside of the water tank, the agitator is installed on the top of the fixed bracket, and the stirring rod of the agitator is vertically inserted into the water tank along the central axis of the water tank.

3. The integrated test device for water seepage and blockage characteristics of drainage asphalt pavement according to claim 2 is characterized by: The water circulation component includes a peristaltic pump, an inlet pipe, an outlet pipe, a return pipe and a valve I; one end of the inlet pipe is vertically inserted into the water storage tank, and the other end is horizontally connected to one end of the outlet pipe through the peristaltic pump, and the other end of the outlet pipe is connected to the spreading system; the return pipe is horizontally located directly below the inlet pipe and the outlet pipe, one end of the return pipe is connected to the water storage tank, and the other end is connected to the filtrate collection system; the valve I is arranged on the return pipe.

4. The integrated test device for water seepage and blockage characteristics of drainage asphalt pavement according to claim 3 is characterized by: The spreading system includes a spreading nozzle, a water flowing platform and an overflow port I; the spreading nozzle is located directly above the center of the water flowing platform and is connected to one end of the water outlet pipe, a mounting hole is provided at the center of the water flowing platform, and the overflow port I is provided on the side of the water flowing platform, and the overflow port I is connected to the filtrate collection system through a hose.

5. The integrated test device for water seepage and blockage characteristics of drainage asphalt pavement according to claim 4 is characterized by: The water permeability coefficient testing system includes a support column, a water collecting tank, a permeable cylinder, an overflow port II, a valve II and a collecting container; the water collecting tank is located directly below the water-digging platform, a support column is respectively arranged at the four corners of the bottom of the water collecting tank, an overflow port II is arranged on the side of the water collecting tank, the collecting container is arranged below the overflow port II, and the valve II is arranged on the overflow port II; the top of the permeable cylinder is vertically installed in the installation hole, and the bottom of the permeable cylinder is vertically inserted into the water collecting tank.

6. The integrated test device for water seepage and blockage characteristics of drainage asphalt pavement according to claim 5, characterized in that: The test piece clamping and supporting assembly is arranged at the central part of the bottom of the water collecting tank, and a seepage hole is opened at the central part of the bottom of the water collecting tank.

7. The integrated test device for water seepage and blockage characteristics of drainage asphalt pavement according to claim 6, characterized in that: The specimen clamping and supporting assembly includes a perforated steel plate, a support seat and a specimen fixture; a support seat is respectively arranged at the four corners of the bottom of the perforated steel plate, and an inclined surface is formed between the four support seats and the seepage holes; the specimen fixture is placed on the perforated steel plate, and a sealing sleeve is arranged on the inner wall of the specimen fixture; the top of the specimen fixture corresponds to the bottom of the water-permeable cylinder, and the top of the specimen fixture is flush with the overflow port II.

8. The integrated test device for water seepage and blockage characteristics of drainage asphalt pavement according to claim 7, characterized in that: The filtrate collection system includes a filtrate collection box, a filter box, a seepage conduit, a flow rate sensor and a valve III; the filtrate collection box is located directly below the water collecting box, the seepage conduit is connected to the seepage hole, the flow rate sensor is arranged at the outlet of the seepage conduit and is connected to a computer, and the valve III is arranged on the seepage conduit; the filter box is located directly below the seepage conduit and is fixed to the four support columns by ropes.

9. An integrated test method for water seepage and blockage characteristics of drainage asphalt pavement, characterized by: The integrated test device for water seepage and blockage characteristics of drainage asphalt pavement according to any one of claims 1 to 8 comprises the following steps in chronological order: Step 1: Assemble and connect the various components of the test device according to the design structure, debug the test device and check the sealing to ensure that it can be used normally during the test; Step 2: Drill a core sample of the drainage asphalt pavement from the newly built drainage asphalt pavement, apply vaseline on the surface of the core sample, and then put the core sample of the drainage asphalt pavement into the sealing sleeve in the specimen fixture; apply butter on the top of the specimen fixture and the bottom of the water-permeable cylinder respectively, and then move the water-permeable cylinder downward so that the bottom of the water-permeable cylinder fits and seals with the top of the specimen fixture; at this time, the central axes of the spray nozzle, the water-flowing platform, the water-permeable cylinder, the water collection tank, the specimen fixture, the drainage asphalt pavement core sample, the perforated steel plate, the seepage hole, the seepage conduit, the filter box, and the filtrate collection box coincide, and at the same time, the top of the water-permeable cylinder and the water-flowing platform are on the same horizontal plane, and the top of the specimen fixture is flush with the overflow port II; Step 3: Add clean water to the water storage tank, close valves Ⅰ and Ⅲ, and open valve Ⅱ; start the peristaltic pump, and the clean water will enter the drainage asphalt pavement core sample after passing through the water inlet pipe, the water outlet pipe, the spray nozzle, and the water permeable cylinder in sequence; after passing through the drainage asphalt pavement core sample, the clean water will flow out from the circular holes on the perforated steel plate and enter the water collecting tank; when the water level in the water collecting tank reaches the overflow port Ⅱ and the liquid level on the water platform reaches a stable state, start recording the time when the clean water flows out from the overflow port Ⅱ, and use a collection container to collect the clean water flowing out during this time period, and then test the original vertical water permeability coefficient of the drainage asphalt pavement core sample; Step 4: Close the peristaltic pump and valve II, open valve I and valve III, and allow the clean water in the water collection tank and the drainage asphalt pavement core sample to flow into the filtrate collection tank through the seepage holes and the seepage conduit. At the same time, the clean water in the filtrate collection tank flows into the water storage tank through the return pipe, and then close valve I; Step 5: Prepare the blockage according to the designed ratio, add clean water to the water tank according to the designed ratio, and then add the blockage into the clean water; Start the agitator to stir the blockage and clean water to make them evenly mixed, thus obtaining a turbid solution of the blockage; Step 6: Keep the agitator in a stirring state, start the peristaltic pump, and the turbid liquid of the blockage passes through the water inlet pipe, the water outlet pipe, the spray nozzle, and the water permeable cylinder in turn, and then enters the drainage asphalt pavement core sample. The turbid liquid of the blockage that fails to enter the water permeable cylinder flows into the filtrate collection box through the overflow port Ⅰ and the hose; after passing through the drainage asphalt pavement core sample, the turbid liquid of the blockage flows out from the circular hole on the perforated steel plate, passes through the seepage hole, the seepage conduit, and the filter box in turn, and then enters the filtrate collection box. In this process, the filter box collects the blockage, and the filtrate flows into the filtrate collection box. At the same time, the flow rate sensor and the computer are used to monitor the change of the seepage velocity of the drainage asphalt pavement core sample with the seepage time in real time; until the turbid liquid of the blockage in the water storage tank is completely drained, open valve Ⅰ, and the liquid in the filtrate collection box enters the water storage tank through the return pipe, and then close valve Ⅰ, that is, the first blockage simulation cycle is completed; Step 7: Repeat step 6 several times, that is, complete several clogging simulation cycles. Each clogging simulation cycle requires real-time monitoring of the change of the seepage velocity of the drainage asphalt pavement core sample with the seepage time, until the change of the seepage velocity with the seepage time tends to be flat, that is, the first clogging cycle simulation test is completed; Step 8: After the first blockage cycle simulation test is completed, move the permeable cylinder upward to expose the drainage asphalt pavement core sample, use a brush to collect the blockages remaining on the surface of the drainage asphalt pavement core sample into a container, and pour the blockages collected by the filter box into another container, dry and sieve the blockages in the two containers respectively, and then statistically analyze the blockage-sensitive particle size through the particle size distribution; move the permeable cylinder downward to re-fit the bottom of the permeable cylinder with the top of the specimen fixture, and re-add clean water to the water storage tank, repeat steps 3 to 4, and then test the vertical water permeability coefficient of the drainage asphalt pavement core sample; Step 9: Repeat steps 5 to 8 for several times to complete several blockage cycle simulation tests. After each blockage cycle simulation test, it is necessary to analyze the blockage-sensitive particle size and test the vertical water permeability coefficient until the vertical water permeability coefficient of the current blockage cycle simulation test is close to that of the previous blockage cycle simulation test, thus completing the integrated test of long-term water permeability and blockage characteristics of drainage asphalt pavement.

10. The integrated test method for water seepage and blockage characteristics of drainage asphalt pavement according to claim 9, characterized in that: In step 3, 12L of clean water is added to the water storage cylinder; the control flow rate of the peristaltic pump is 100-300mL / min; the time for the clean water to flow out of the overflow port II is 1-3min; In step 4, valve III is opened to allow the clean water in the water collection tank and the drainage asphalt pavement core sample to flow into the filtrate collection tank through the seepage holes and the seepage conduit. This process is maintained for 5-10 minutes. In step 5, the plugging material is a mixture of soil, sand and gravel and rubber particles, wherein the mass percentage of each substance in the plugging material is 30-40wt% of soil, 50-65wt% of sand and gravel, and 5-10wt% of rubber particles; the sand and gravel include seven particle sizes, and the mass percentage of each particle size in the sand and gravel is 12-18wt% of particle size 2.36-4.75mm, 28-32wt% of particle size 1.18-2.36mm, 18-25wt% of particle size 0.6-1.18mm, and 8wt% of particle size 0.3-0.6mm. -12wt%, particle size 0.15-0.3mm accounts for 10-15wt%, particle size 0.075-0.15mm accounts for 6-10wt%, particle size 0-0.075mm accounts for 3-6wt%; the size of the rubber particles is 30 mesh or 40 mesh; add 8-12L of clean water and 8-15g of plugging material into the water storage cylinder, where 8-15g of plugging material is the mass after drying, the drying temperature is 100-130℃, and the drying time is 2-4h; the stirring speed is 60-200rpm, and the stirring time is 2-5min; In step 6, the stirrer is kept in a stirring state at a stirring speed of 60-200 rpm; the peristaltic pump is controlled to have a flow rate of 120-250 mL / min; In step eight, a brush is used to collect the blockages remaining on the surface of the drainage asphalt pavement core sample into a container, that is, the blockages remaining on the surface of the drainage asphalt pavement core sample are collected; the blockages collected by the filter box are poured into another container, that is, the blockages flowing through the drainage asphalt pavement core sample are collected; the blockages in the two containers are dried and sieved respectively, and the drying temperature is 100-130°C and the drying time is 2-4h.

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