A method for reducing low temperature cracking of asphalt pavement

Abstract

The application provides a method for reducing low-temperature cracking of asphalt pavement, and belongs to the technical field of highway engineering. The method cuts joints in the asphalt pavement, and determines a proper joint spacing to adjust the stress of the asphalt pavement, so as to reduce the low-temperature cracking of the asphalt pavement. The results of the embodiments show that, after the method is used, the low-temperature cracking phenomenon of the asphalt pavement with a joint spacing of 27.9 m is basically eliminated, the low-temperature cracking phenomenon of the asphalt pavement with a joint spacing of 40 m is reduced by 10%, and the low-temperature cracking phenomenon of the asphalt pavement with a joint spacing of 5 m can also be eliminated, but the construction cost is increased.

Description

Technical Field

[0001] This invention relates to the field of highway engineering technology, and in particular to a method for reducing low-temperature cracking of asphalt pavement. Background Technology

[0002] Asphalt pavement is a common type of road surface, mainly composed of aggregates, asphalt, and admixtures. Due to its comfortable driving experience, low noise, and quick construction, asphalt pavement is widely used worldwide. However, it also suffers from various types of defects, which accelerate the deterioration of asphalt pavements. In northern my country, due to low winter temperatures, asphalt pavements primarily suffer from low-temperature cracking, leading to repairs starting within just two or three years of construction, significantly increasing operating costs.

[0003] Currently, the main method to improve low-temperature cracking in asphalt pavements is to use higher-performance asphalt materials. However, this method not only increases the cost of pavement construction but also has limited effectiveness in mitigating low-temperature cracking. Some have proposed using cutting methods to treat pavement cracks, but these methods are based on concrete pavements. Due to the significant differences in the properties of asphalt mixtures and concrete materials, cutting methods for concrete pavements are not suitable for asphalt pavements. Summary of the Invention

[0004] The purpose of this invention is to provide a method for reducing low-temperature cracking of asphalt pavements. The method provided by this invention can effectively slow down low-temperature cracking of asphalt pavements.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] This invention provides a method for reducing low-temperature cracking of asphalt pavement, comprising the following steps:

[0007] (1) Collect local meteorological and traffic data, and count the crack spacing of asphalt pavement caused by low temperature to obtain the average crack spacing H, the lowest temperature and the maximum vehicle load.

[0008] (2) The value L obtained by reducing the average crack spacing H obtained in step (1) by 95 to 100 times is used as the maximum length of the asphalt mixture specimen. Asphalt mixture specimens of different lengths are made, and the length of each asphalt mixture specimen decreases by 0.05L.

[0009] (3) The asphalt mixture specimens obtained in step (2) are subjected to low-temperature freezing fracture tests in order of decreasing length to obtain the fracture strength of the asphalt mixture specimens at the lowest temperature until the fracture strength of a certain asphalt mixture specimen is greater than the fracture strength of the longest asphalt mixture specimen. The cutting spacing is determined by the freezing fracture test by taking 95 to 100 times the length of the asphalt mixture specimen.

[0010] (4) Determine the spacing of asphalt pavement joints according to formula (I);

[0011] Asphalt pavement joint spacing = joint spacing determined by frost test - deformation caused by maximum vehicle load - deformation caused by temperature effect (Equation (I));

[0012] In equation (I), the formula for calculating the deformation ΔL caused by the maximum vehicle load is shown in equation (II):

[0013] ΔL=εH (Equation II)

[0014] In Equation (II), ε is the normal strain of the asphalt material under the maximum vehicle load, calculated according to Equation (III); H is the average value of the crack spacing described in step (1);

[0015] ε=σ x / E type (III)

[0016] In formula (III), E is the elastic modulus of the asphalt mixture at low temperature, and σ x The compressive stress induced by the vehicle is the ratio of the vehicle's maximum load to the total contact patch area of ​​all tires.

[0017] In the formula (I), the amount of deformation affected by temperature = the average value of the crack spacing in step (1) H × 1%;

[0018] (5) Cut the asphalt pavement with the asphalt pavement cut spacing determined in step (4), and then seal the cut.

[0019] Preferably, in step (2), the width of the asphalt mixture specimen is 35-45cm and the height of the asphalt mixture specimen is 35-45cm.

[0020] Preferably, the initial stress during the low-temperature freeze-break test in step (3) is 0.1 MPa.

[0021] Preferably, the cooling rate during the low-temperature freezing test in step (3) is 9-10℃ / h.

[0022] Preferably, the depth of the cut in step (5) is the depth of the top layer of the asphalt pavement.

[0023] Preferably, the width of the slit in step (5) is ≤0.5cm.

[0024] Preferably, sealant is used for sealing in step (5).

[0025] Preferably, the sealant includes silicone sealant.

[0026] This invention provides a method for reducing low-temperature cracking of asphalt pavement, comprising the following steps: (1) collecting local meteorological and traffic data, and statistically analyzing the crack spacing of asphalt pavement caused by low temperature, obtaining the average crack spacing H, the lowest temperature, and the maximum vehicle load; (2) using the value L obtained by reducing the average crack spacing H obtained in step (1) by 95 to 100 times as the maximum length of the asphalt mixture specimen, and preparing asphalt mixture specimens of different lengths, with the length of each asphalt mixture specimen decreasing by 0.05L; (3) sequentially processing each asphalt mixture specimen obtained in step (2) according to the decreasing length order. A low-temperature freezing test was conducted to obtain the fracture strength of the asphalt mixture specimen at the lowest temperature. The fracture strength of a certain asphalt mixture specimen was greater than that of the longest asphalt mixture specimen. The joint spacing determined by the freezing test was 95 to 100 times the length of the asphalt mixture specimen. (4) The joint spacing of the asphalt pavement was determined according to formula (I). The joint spacing of the asphalt pavement = the joint spacing determined by the freezing test - the deformation caused by the maximum vehicle load - the deformation caused by the temperature (I). (5) The asphalt pavement was cut with the joint spacing determined in step (4), and then the joint was sealed. The present invention cuts the asphalt pavement and determines a suitable joint spacing to adjust the stress of the asphalt pavement, thereby reducing the cracking of the asphalt pavement at low temperatures. The research results show that after treatment with the method of the present invention, the low-temperature cracking phenomenon of the asphalt pavement with a joint spacing of 27.9m was basically eliminated compared with the asphalt pavement without joints, while the low-temperature cracking phenomenon of the asphalt pavement with a joint spacing of 40m was reduced by 10%. Attached Figure Description

[0027] Figure 1 This is a process flow diagram of the method for reducing low-temperature cracking of asphalt pavement according to the present invention. Detailed Implementation

[0028] This invention provides a method for reducing low-temperature cracking of asphalt pavement, comprising the following steps:

[0029] (1) Collect local meteorological and traffic data, and count the crack spacing of asphalt pavement caused by low temperature to obtain the average crack spacing H, the lowest temperature and the maximum vehicle load.

[0030] (2) The value L obtained by reducing the average crack spacing H obtained in step (1) by 95 to 100 times is used as the maximum length of the asphalt mixture specimen. Asphalt mixture specimens of different lengths are made, and the length of each asphalt mixture specimen decreases by 0.05L.

[0031] (3) The asphalt mixture specimens obtained in step (2) are subjected to low-temperature freezing fracture tests in order of decreasing length to obtain the fracture strength of the asphalt mixture specimens at the lowest temperature until the fracture strength of a certain asphalt mixture specimen is greater than the fracture strength of the longest asphalt mixture specimen. The cutting spacing is determined by the freezing fracture test by taking 95 to 100 times the length of the asphalt mixture specimen.

[0032] (4) Determine the spacing of asphalt pavement joints according to formula (I);

[0033] Asphalt pavement joint spacing = joint spacing determined by frost test - deformation caused by maximum vehicle load - deformation caused by temperature effect (Equation (I));

[0034] In equation (I), the formula for calculating the deformation ΔL caused by the maximum vehicle load is shown in equation (II):

[0035] ΔL=εH (Equation II)

[0036] In Equation (II), ε is the normal strain of the asphalt material under the maximum vehicle load, calculated according to Equation (III); H is the average value of the crack spacing described in step (1);

[0037] ε=σ x / E type (III)

[0038] In formula (III), E is the elastic modulus of the asphalt mixture at low temperature, and σ x The compressive stress induced by the vehicle is the ratio of the vehicle's maximum load to the total contact patch area of ​​all tires.

[0039] In the formula (I), the amount of deformation affected by temperature = the average value of the crack spacing in step (1) H × 1%;

[0040] (5) Cut the asphalt pavement with the asphalt pavement cut spacing determined in step (4), and then seal the cut.

[0041] This invention collects local meteorological and traffic data, and statistically analyzes the crack spacing of asphalt pavement caused by low temperatures, obtaining the average crack spacing H, the lowest temperature, and the maximum vehicle load.

[0042] This invention collects local meteorological and traffic data to obtain the local minimum temperature and maximum vehicle load.

[0043] This invention statistically analyzes the crack spacing of asphalt pavements caused by local low temperatures, and calculates the average crack spacing H.

[0044] The present invention does not have any particular limitation on the method of collecting local meteorological and traffic data and statistically analyzing the crack spacing of asphalt pavement caused by low temperature. Any data collection and statistical method known to those skilled in the art can be used.

[0045] After obtaining the average crack spacing H, the lowest temperature, and the maximum vehicle load, this invention uses the value L, which is the result of reducing the average crack spacing H by 95 to 100 times, as the maximum length of the asphalt mixture specimen. Asphalt mixture specimens of different lengths are made, with the length of each asphalt mixture specimen decreasing by 0.05L.

[0046] The present invention uses the value L, which is the average crack spacing H reduced by 95 to 100 times, as the maximum length of the asphalt mixture specimen, preferably using the value L, which is the average crack spacing H reduced by 100 times, as the maximum length of the asphalt mixture specimen.

[0047] In this invention, the length of each asphalt mixture specimen decreases by 0.05L, i.e., the lengths of the asphalt mixture specimens are L, 0.95L, 0.9L, 0.85L, and so on. This invention does not impose a specific minimum length on the asphalt mixture specimens; the minimum is sufficient to ensure that an asphalt mixture specimen with a fracture strength greater than that of the longest asphalt mixture specimen is found during the low-temperature freeze-thaw test.

[0048] In this invention, the width of the asphalt mixture specimen is preferably 35-40 cm; the height of the asphalt mixture specimen is preferably 35-40 cm.

[0049] The present invention preferably uses a wheel-rolling molding method to prepare asphalt mixture specimens. The present invention does not impose any special limitations on the specific operation of the wheel-rolling molding method; any wheel-rolling molding method well-known to those skilled in the art can be used.

[0050] In this invention, the composition of the asphalt mixture is preferably consistent with the composition of the asphalt pavement.

[0051] After obtaining asphalt mixture specimens of different lengths, the present invention conducts low-temperature freezing tests on each asphalt mixture specimen in descending order of length to obtain the fracture strength of the asphalt mixture specimen at the lowest temperature, until the fracture strength of a certain asphalt mixture specimen is greater than the fracture strength of the longest asphalt mixture specimen. The cutting spacing determined by the freezing test is 95 to 100 times the length of the asphalt mixture specimen.

[0052] The present invention preferably uses epoxy resin to bond the asphalt mixture specimen to the specimen clamp of the instrument, and then after standing for 23 to 24 hours, the specimen is installed in the instrument. After being kept at a constant temperature in the instrument environment for 1 to 1.5 hours, a low-temperature fracture test is carried out. The test ends when the specimen fractures at a certain temperature.

[0053] The present invention preferably utilizes the instruments used in the low-temperature freezing fracture test to automatically record temperature, stress and displacement, and plot the temperature-stress curve, and then obtains the fracture strength through the temperature-stress curve.

[0054] The present invention does not impose any special limitations on the instruments used in the low-temperature fracture test; any instruments well known to those skilled in the art can be used.

[0055] In this invention, the initial stress during the low-temperature freeze-break test is preferably 0.1 MPa; the cooling rate during the low-temperature freeze-break test is preferably 9–10 °C / h. By limiting the initial stress and cooling rate during the low-temperature freeze-break test to the above ranges, this invention enables a more accurate temperature-stress curve and is more conducive to obtaining an accurate cut spacing.

[0056] In this invention, when conducting low-temperature fracture tests, each asphalt mixture specimen of a certain length is preferably tested three times. After plotting the temperature-stress curve, this invention preferably determines the freezing point temperature and the strength at freezing point of three asphalt mixture specimens of the same length. Then, the freezing point temperature and the strength at freezing point of the three asphalt mixture specimens of the same length are checked. When the coefficient of variation of the freezing point temperature is not greater than 10% and the coefficient of variation of the strength at freezing point is not greater than 20%, the average value is taken as the final result of the test for the asphalt mixture specimen of that length. When the coefficient of variation of the freezing point temperature of the three asphalt mixture specimens of the same length is greater than 10% or the coefficient of variation of the strength at freezing point is greater than 20%, this invention preferably retests the asphalt mixture specimen of that length.

[0057] After obtaining the fracture strength of asphalt mixture specimens of different lengths at the lowest temperature, the present invention compares the fracture strength of asphalt mixture specimens of different lengths at the lowest temperature. If the fracture strength of a certain asphalt mixture specimen is greater than that of the longest asphalt mixture specimen, the cutting spacing determined by the freeze-thaw test is taken as 95 to 100 times the length of the asphalt mixture specimen, preferably 100 times the length of the asphalt mixture specimen.

[0058] After obtaining the joint spacing determined by the frost fracture test, the present invention determines the joint spacing of asphalt pavement according to formula (I).

[0059] In this invention, the formula (I) is: Asphalt pavement joint spacing = joint spacing determined by frost test - deformation caused by maximum vehicle load - deformation affected by temperature (I).

[0060] In equation (I), the formula for calculating the deformation ΔL caused by the maximum load on the vehicle is shown in equation (II):

[0061] ΔL=εH (Equation II)

[0062] In Equation (II), H is the average value of the crack spacing; ε is the normal strain of the asphalt material under the maximum vehicle load.

[0063] In this invention, ε is calculated according to formula (III);

[0064] ε=σ x / E type (III)

[0065] In formula (III), E is the elastic modulus of the asphalt mixture at low temperature, and σ x The compressive stress caused by the vehicle.

[0066] In this invention, the σ x The value is the ratio of the vehicle's maximum load to the total contact patch area of ​​all tires.

[0067] In the formula (I), the deformation caused by temperature is equal to the average value of the crack spacing H × 1%.

[0068] The asphalt pavement joint spacing determined by the method of the present invention can further reduce the stress of asphalt pavement at low temperatures and reduce low-temperature cracking of asphalt pavement.

[0069] After determining the joint spacing of the asphalt pavement, the present invention cuts joints in the asphalt pavement according to the determined joint spacing, and then seals the joints.

[0070] In this invention, the asphalt pavement is preferably an asphalt pavement that has passed the acceptance test according to the "Standard for Construction and Acceptance of Asphalt Pavement" (GB50092-2018).

[0071] In this invention, when the asphalt pavement fails the acceptance test, the invention preferably treats the unqualified pavement and cuts the joints after the acceptance test is passed.

[0072] In this invention, before cutting the asphalt pavement, it is preferable to understand the engineering design of the asphalt pavement, including the thickness of the asphalt pavement, especially the thickness and width of the top layer of the asphalt pavement, as well as the construction process.

[0073] In this invention, the depth of the cut is preferably the depth of the top layer of the asphalt pavement; the width of the cut is preferably ≤0.5cm.

[0074] In this invention, the cut is preferably made using a concrete cutter.

[0075] In this invention, before cutting the joint, it is preferable to use materials such as paint to mark lines on the asphalt pavement according to the determined asphalt pavement joint spacing, and then cut the joint.

[0076] In this invention, the direction of the cut is preferably perpendicular to the length direction of the asphalt pavement; the length of the cut is preferably the same as the width of the asphalt pavement.

[0077] The present invention does not impose any special limitations on the operation of the slits; any slit cutting technique known to those skilled in the art can be used, with a determined slit spacing, depth, and width.

[0078] After the slit is cut, the present invention preferably cleans the cut slit to ensure that there is no dust or debris before sealing the slit.

[0079] The present invention does not have any special limitations on the cleaning operation of the cut gap, and any cleaning method known to those skilled in the art can be used.

[0080] In this invention, a sealant is preferably used for sealing; the sealant is preferably a silicone sealant.

[0081] The present invention does not impose any special limitations on the sealing operation; it is sufficient to seal the gap adequately. In the present invention, the seal can prevent rainwater and other substances from entering the pavement interior or subgrade through the cut and causing pavement damage.

[0082] After sealing is completed, the present invention preferably uses a scraper to smooth the sealed surface.

[0083] The method of this invention can effectively reduce low-temperature cracking of asphalt pavement, improve the durability of asphalt pavement, and reduce the operating cost of asphalt pavement.

[0084] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0085] Example 1

[0086] (1) By checking local meteorological data, the lowest temperature in the area was found to be -30℃;

[0087] (2) Local traffic statistics show that the area is mainly occupied by family cars and small trucks during the day, while there are more large trucks at night, with the largest tonnage being 200 tons. Statistics also show that the average crack spacing H caused by low-temperature cracking in the area is 30m.

[0088] (3) The average crack spacing H of the asphalt pavement was reduced by 100 times and the value L (L is 30cm) was taken as the maximum length of the asphalt mixture specimen. Asphalt mixture specimens of different lengths were made by roller rolling. The length of each asphalt mixture specimen decreased by 0.05L, and the longest asphalt mixture specimen was 30cm and another specimen with a length of 0.95L (30*0.95=28.5cm), that is, a specimen with a length of 28.5cm.

[0089] (4) Asphalt mixture specimens of different lengths were bonded to the specimen clamps with epoxy resin. After bonding, the specimens were placed at room temperature for 24 hours. Then, the specimens were installed on the testing machine. After the specimens were kept at a constant temperature for 1 hour, an initial stress (0.1 MPa) was applied to the specimens, and the temperature was lowered at a set cooling rate (10℃ / h). The instrument automatically measured and recorded the temperature, stress, and displacement, and plotted the temperature-stress curve. When the specimen fractured at a certain temperature (i.e., the stress suddenly dropped to a very small value), the cooling was stopped, and the test ended. The temperature-stress curves corresponding to the asphalt mixture specimens of different lengths were plotted. The fracture temperature, fracture strength at fracture, and inflection point temperature of the specimens were determined by plotting the temperature-stress curves. Each length of asphalt mixture specimen was tested 3 times. The test data were checked, and the coefficient of variation of the fracture temperature was 5%, which is not significant. The coefficient of variation of the fracture strength was 11%, and the variability was less than 20%. The fracture strength of asphalt mixture specimens of different lengths at the local lowest temperature was obtained from the temperature-stress curve. The fracture strengths of specimens with a length of 0.95L were 3.65MPa, 3.72MPa and 3.85MPa, respectively, and the fracture strengths of specimens with a length of 30cm were 3.22MPa, 3.52MPa and 3.61MPa, respectively. The average fracture strength of the specimen with a length of 0.95L was 3.74MPa, which was greater than the average fracture strength of the specimen with a length of 30cm (3.44MPa). The cut spacing determined by the frost fracture test was 100 times the length of the 0.95L asphalt mixture specimen, i.e., the cut spacing determined by the frost fracture test = 28.5cm * 100 = 28.5m.

[0090] (5) Determination of the spacing of asphalt pavement joints: Asphalt pavement joint spacing = joint spacing determined by freezing test - deformation caused by vehicle load - deformation caused by temperature = 28.5 - 0.3 - 0.33 = 27.87m ≈ 27.9m;

[0091] The deformation of asphalt pavement caused by vehicle load is calculated according to formula (II):

[0092] ΔL=εH=0.011×30=0.33m Formula (II)

[0093] Where ε is the normal strain of the asphalt mixture under vehicle load, calculated according to formula (III); H is the average crack spacing caused by low-temperature cracking of local asphalt pavement;

[0094] ε=σ x / E type (III)

[0095] The vehicle load is considered to be 200 tons, and the tire contact area is 617 cm². 2 The elastic modulus at low temperature is 24425.6 MPa;

[0096] The deformation of asphalt pavement affected by temperature = local average crack spacing H × 1% = 30 × 1% = 0.3m;

[0097] (6) According to the design and construction data, the highway uses SBS modified asphalt, the aggregate is granite, and the surface layer is 6cm thick.

[0098] (7) According to the "Standard for Construction and Acceptance of Asphalt Pavement" (GB50092-2018), the asphalt pavement thickness, compaction, smoothness and skid resistance of this asphalt pavement are all excellent, and it is ready for joint cutting.

[0099] (8) The asphalt pavement structure has a surface layer thickness of 6cm, so the cutting depth is 6cm.

[0100] (9) A concrete cutting machine was used for construction, with a joint width of 0.5cm;

[0101] (10) Based on the determined cutting spacing, first draw the position of the cutting joint with paint in the direction perpendicular to the length of the asphalt pavement for 300m. The length of the cutting joint is the same as the width of the pavement. Then operate the cutting machine to cut. After the cutting is completed, clean the dust and debris in the cutting joint, then inject silicone sealant and scrape it flat.

[0102] Comparative Example 1

[0103] The asphalt pavement was the same as in Example 1, but without joint cutting.

[0104] Comparative Example 2

[0105] The asphalt pavement is the same as in Example 1, with a joint spacing of 40m.

[0106] Comparative Example 3

[0107] The asphalt pavement is the same as in Example 1, with a joint spacing of 5m.

[0108] Numerical simulations were performed on the pavements of Example 1 and Comparative Examples 1-3. Compared with Comparative Example 1, the low-temperature cracking phenomenon of the pavement was basically eliminated after treatment using the method of Example 1. After treatment using the method of Comparative Example 2, the low-temperature cracking phenomenon of the pavement was reduced by 10%. Compared with Comparative Example 3, both 27.9m and 5m of joint spacing can eliminate the low-temperature cracking phenomenon of asphalt pavement. However, in actual engineering, the more joints there are, the higher the construction cost. Therefore, the method with a joint spacing of 29.7m is more suitable. This proves that the joint spacing of asphalt pavement determined by the method of this invention can better reduce the low-temperature cracking phenomenon of asphalt pavement.

[0109] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for reducing low-temperature cracking of asphalt pavement, comprising the following steps: (1) Collect local meteorological and traffic data, and count the crack spacing of asphalt pavement caused by low temperature to obtain the average crack spacing H, the lowest temperature and the maximum vehicle load. (2) The value L obtained by reducing the average crack spacing H obtained in step (1) by 95 to 100 times is used as the maximum length of the asphalt mixture specimen. Asphalt mixture specimens of different lengths are made, and the length of each asphalt mixture specimen decreases by 0.05L. (3) The asphalt mixture specimens obtained in step (2) are subjected to low-temperature freezing fracture tests in descending order of length to obtain the fracture strength of the asphalt mixture specimens at the lowest temperature, until the fracture strength of a certain asphalt mixture specimen is greater than the fracture strength of the longest asphalt mixture specimen. The slit spacing determined by the freezing fracture test is 95 to 100 times the length of the asphalt mixture specimen. The initial stress during the low-temperature freezing fracture test is 0.1 MPa. The cooling rate during the low-temperature freezing fracture test is 9 to 10 °C / h. (4) Determine the spacing of asphalt pavement joints according to formula (I); Asphalt pavement joint spacing = joint spacing determined by frost test - deformation caused by maximum vehicle load - deformation affected by temperature (Formula I). In equation (I), the deformation caused by the maximum vehicle load is... The formula for calculating L is shown in equation (II): L=εH Formula (II) In Equation (II), ε is the normal strain of the asphalt material under the maximum vehicle load, calculated according to Equation (III); H is the average value of the crack spacing described in step (1); ε=σ x / E Formula (III) In formula (III), E is the elastic modulus of the asphalt mixture at low temperature, and σ x The compressive stress induced by the vehicle is the ratio of the vehicle's maximum load to the total contact patch area of ​​all tires. In the formula (I), the deformation due to temperature influence = the average value of the crack spacing H described in step (1) × 1%; (5) Cut the asphalt pavement with the asphalt pavement cut spacing determined in step (4), and then seal the cut; the depth of the cut is the depth of the top layer of the asphalt pavement; the width of the cut is ≤0.5cm.

2. The method according to claim 1, characterized in that, In step (2), the width of the asphalt mixture specimen is 35-45cm and the height of the asphalt mixture specimen is 35-45cm.

3. The method according to claim 1, characterized in that, In step (5), sealant is used for sealing.

4. The method according to claim 3, characterized in that, The sealant includes silicone sealant.

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