A laying method for a granular wood fiber modified asphalt pavement

Abstract

The invention discloses a laying method for a granular wood fiber modified asphalt pavement, which comprises four steps: mixing, paving, compaction and acceptance. This pavement laying method not only optimizes the composition, proportion and preparation method of the modified asphalt material specifically, so that the obtained modified asphalt material has better thermal stability, workability and compactness; but also uses a high-power full-width paver and a double-drum oscillating roller to carry out the laying operation of the granular wood fiber modified asphalt pavement completely mechanically, which can significantly improve the performance of the asphalt pavement, so that the laid pavement has higher flatness and compaction degree, better driving comfort, longer pavement service life, and this laying method has high construction efficiency, good universality and low construction cost, and is suitable for large-scale application in the construction of granular wood fiber modified asphalt pavements of domestic high-grade highways and urban arterial roads.

Description

Technical Field

[0001] The present invention relates to the field of infrastructure engineering, specifically to the field of road surface paving engineering, and particularly to a paving method for granular wood fiber modified asphalt pavement. Background Art

[0002] At present, most of the mixtures for highway asphalt pavement (the upper layer) are flocculent wood fiber modified asphalt materials. However, due to the defects of flocculent wood fiber such as being easy to get wet, poor heat stability, and weak durability, and the problems that the flocculent wood fiber modified asphalt is prone to form micro-wave-shaped road surface during the strong vibration paving construction with a double-drum vibratory roller and the compaction effect is weakened due to resonance, the existing flocculent wood fiber modified asphalt pavement has problems such as short service life, poor road surface flatness, and high porosity, seriously affecting the quality of highway engineering and road driving safety.

[0003] With the rapid development of expressways in China and the continuous improvement of road safety requirements, various new road construction materials are constantly applied to the construction of expressways. Granular wood fiber modified asphalt has attracted much attention due to its advantages of being not easy to absorb water, good environmental protection effect, strong heat stability, and good workability of the mixture, and it has been widely applied to the road surface construction project of expressways, also showing its important role in improving the quality of highway road surface. However, with the large-scale application of granular wood fiber modified asphalt in road construction projects, people have found that although the application of granular wood fiber modified asphalt can improve the quality of highway road surface to a certain extent, it does not meet people's expectations, and there is still a large difference from the expected effect obtained in the laboratory, thus affecting the larger-scale application of granular wood fiber modified asphalt. Through a large number of experiments and practices, it is found that the factors affecting the performance of asphalt pavement are not only related to road construction materials but also related to the specific paving process. And currently, granular wood fiber modified asphalt still uses the paving process of flocculent wood fiber modified asphalt pavement for paving, which obviously affects the performance of granular wood fiber modified asphalt pavement, resulting in the defects of low flatness and short service life of granular wood fiber modified asphalt pavement. Therefore, there is an urgent need for a paving method for granular wood fiber modified asphalt pavement to further improve the performance of granular wood fiber modified asphalt pavement. Summary of the Invention

[0004] The object of the present invention is to overcome the defects that the existing granular wood fiber modified asphalt pavement still has low flatness, low compaction degree and short pavement service life. A laying method for a granular wood fiber modified asphalt pavement is proposed. The pavement laying method fully mechanizes the laying operation of the granular wood fiber modified asphalt pavement through a high-power full-width paver and a double-drum oscillating roller, which can significantly improve the performance of the asphalt pavement, making the laid pavement have higher flatness and compaction degree, better driving comfort, longer pavement service life, and the laying method has high construction efficiency, good universality and low construction cost, and is suitable for large-scale application in the construction of granular wood fiber modified asphalt pavements of domestic high-grade highways and urban arterial roads.

[0005] In order to achieve the above-mentioned invention object, the present invention provides a laying method for a granular wood fiber modified asphalt pavement, which includes the following steps:

[0006] Step 1, mixing: heating the asphalt for standby; mixing the aggregate, granular wood fiber and water stabilizer to obtain a mixture for standby; mixing the heated asphalt and the mixture under high temperature conditions to obtain a modified asphalt material;

[0007] Wherein, the aggregate is basalt particles and mineral powder; the water stabilizer is quicklime; in the modified asphalt material, the mass percentage of asphalt is 5.5 - 6.5%, the mass percentage of granular wood fiber is 0.2 - 0.5%, the mass percentage of aggregate is 91.5 - 93.3%, and the mass percentage of water stabilizer is 1 - 1.5%;

[0008] Step 2, paving: paving the modified asphalt material with a full-width paver; wherein, the paving speed is 2.5 - 3.5 m / s; the tamper speed is set at 35 - 45%; the loose paving coefficient is 1.23 - 1.26; the temperature of the screed plate of the paver is 110 - 120 °C; the temperature of the modified asphalt material during paving is not lower than 165 °C;

[0009] Step 3, compaction: using a combination of a double-drum oscillating roller and a rubber-tyred roller for rolling; the rolling includes initial compaction, re-compaction and final compaction; wherein, during initial compaction, the temperature of the modified asphalt material is not lower than 160 °C; during re-compaction, the temperature of the modified asphalt material is not lower than 140 °C; during final compaction, the temperature of the modified asphalt material is not lower than 110 °C;

[0010] Step 4, acceptance: detecting the pavement performance, and after meeting the requirements, completing the laying of the modified asphalt pavement.

[0011] The paving method of a granular wood fiber modified asphalt pavement in the present invention not only optimizes the composition, proportion and preparation method of the modified asphalt material specifically in advance, so that the obtained modified asphalt material has better thermal stability, workability and compactness, thus being more conducive to improving the flatness and compaction degree of the road surface, and also being more conducive to paving and compaction construction; then, paving construction is carried out by using a high-power full-width paver, taking advantage of its advantages in resisting transverse, longitudinal and high-speed segregation, and with the cooperation of measures such as a large-diameter spiral, installing reverse blades at the chain box and support, and reducing the working speed to fully bury the granular material in the cloth spiral, so as to significantly improve the paving quality of the granular wood fiber modified asphalt, and thus better improve the flatness of the road surface; finally, compaction is carried out by using the flexible start-stop vibration and oscillatory compaction technology of a double-drum oscillatory roller, which not only effectively improves the compactness and flatness of the road surface, but also eliminates the influence on the compaction degree caused by resonance during the rolling of the asphalt pavement on the bridge, reducing quality problems such as material congestion, waves, cracks and uneven compaction in road surface construction, and thus being able to better improve the various performances of the asphalt pavement, making the paved road surface have higher flatness and compaction degree, better driving comfort and longer road surface service life; this paving method has high construction efficiency, good universality and low construction cost, and is suitable for large-scale application in the construction of granular wood fiber modified asphalt pavements of domestic high-grade highways and urban arterial roads.

[0012] Among them, in step 1, the heating temperature of the asphalt is 160 - 165 °C; the preferred heating temperature is more conducive to the mixing of raw materials, and the performance of the modified asphalt material is better.

[0013] Preferably, the asphalt content in the granular wood fiber is 3%; the preferred asphalt content makes the granular wood fiber less likely to absorb water, has better workability and better dispersibility in asphalt.

[0014] Preferably, the mixing time of the aggregate, granular wood fiber and water stabilizer is 10 - 15 s; the preferred mixing time makes the mixing more uniform and the energy consumption lower.

[0015] Preferably, the high-temperature condition for mixing the asphalt and the mixture is 170 - 185 °C; the preferred mixing temperature is more conducive to the mixing of raw materials, and the performance of the modified asphalt material is better.

[0016] Among them, the control of the mixing temperature plays a decisive role in the quality of the mixture. Excessive temperature will cause the asphalt to age and lose its viscosity, leading to easy peeling and loosening of the asphalt mixture, affecting its service life. Too low temperature will not only result in too large porosity of the mixture and low Marshall stability, but also affect the subsequent construction temperature and is not easy to control, thus affecting the construction. Preferably, the high-temperature condition during mixing is 170 - 185 °C; with the preferred mixing conditions, the performance of the modified asphalt material is better, which is more conducive to subsequent construction and has a positive effect on improving the pavement performance.

[0017] Among them, the mixing time should be strictly controlled during mixing. The mixing time of the mixture directly affects the uniformity and quality of the mixture. Uneven mixing will lead to the occurrence of asphalt sand agglomeration, white and gray materials, and segregation; preferably, the mixing time is 50 - 80 s; with the preferred mixing time, the mixing is more uniform and the energy consumption is lower.

[0018] Preferably, in the aggregate, the mass ratio of basalt particles to mineral powder is 90∶8.5 - 9.0; with the preferred aggregate ratio, the performance of the modified asphalt material is better.

[0019] Preferably, the basalt particles are basalt particles with a particle size of 10 - 15 mm, basalt particles with a particle size of 5 - 10 mm, and basalt particles with a particle size of 0 - 3 mm with a mass ratio of 44:33:13; with the preferred composition of basalt particles, the performance of the modified asphalt material is better.

[0020] Among them, the water damage of the asphalt pavement is one of the common quality problems of the asphalt pavement. The water stabilizer can improve the water stability of the asphalt pavement; preferably, the mass ratio of the mineral powder to the water stabilizer is 8.5 - 9.0∶1.0 - 1.5; with the preferred dosage of the water stabilizer, the water stability of the modified asphalt material is better.

[0021] Preferably, in the modified asphalt material, the mass percentage of asphalt is 5.9%, the mass percentage of granular lignin fiber is 0.3%, the mass percentage of aggregate is 92.58%, and the mass percentage of water stabilizer is 1.22%; through optimization, the performance of the modified asphalt material is better, its compatibility with the paving method is better, and the performance of the obtained asphalt pavement is better.

[0022] Preferably, the paving speed is 3 m / s; the rammer speed is set at 40%; with the preferred paving parameters, the paving efficiency and quality are higher.

[0023] Among them, in step 3, the compaction follows the principles of uniform speed, closely following and slow compaction, high frequency and low amplitude, first low then high, first slow then fast; the compaction is in a stepped shape. Every 30 - 40 m, use a tandem roller to roll along the steps in an arc to eliminate the heaving caused by too long compaction distance; during the compaction process, the driving direction of the roller is consistent and they are not allowed to drive in opposite directions, and a safe distance is maintained between the rollers.

[0024] Preferably, sharp turns, U-turns, and parking for waiting are prohibited during rolling construction. During rolling, it should be rolled from the low side to the high side, and each roller should be rolled in a stepped manner, closely following the paver; avoid turning the steering wheel sharply on hot materials to cause road surface rubbing; the overlapping width of the rolling belts of adjacent steel-wheel rollers is 1 / 3 of the roller width.

[0025] Preferably, the initial compaction is carried out with a double steel-wheel oscillating roller, with 1 static compaction pass and 1 vibratory compaction pass. The overlapping width of the roller tracks of the roller is 20 - 30 cm. Each roller takes full-width compaction and all roll from the lower part of the cross slope to the higher part, and the compaction length is arranged in a stepped shape longitudinally; the compaction speed of the initial compaction is 6 - 8 km / h.

[0026] Preferably, the intermediate compaction is carried out with a double steel-wheel oscillating roller, and the compaction method is the same as that of the initial compaction, with a total of 2 compaction passes; the compaction speed of the intermediate compaction is 5 - 7 km / h.

[0027] Preferably, the final compaction is carried out with a rubber-tyred roller for 2 static compaction passes to ensure that there are no roller tracks on the road surface after static compaction; the compaction speed of the final compaction is 4 - 6 km / h.

[0028] Among them, in step 4, the said properties include compactness, porosity, texture depth, permeability coefficient, friction coefficient, cross slope, and flatness; it can better evaluate the road surface quality and ensure driving safety.

[0029] Compared with the prior art, the beneficial effects of the present invention are:

[0030] 1. In the paving method of the asphalt pavement of the present invention, the composition, ratio, and preparation method of the modified asphalt material are optimized specifically, so that the obtained modified asphalt material has better thermal stability, workability, and compactness, which is more conducive to improving the flatness and compactness of the road surface, and is also more conducive to paving and compaction construction.

[0031] 2. In the paving method of the asphalt pavement of the present invention, a high-power full-width paver is used for paving construction, so that the paving quality of the granular wood fiber modified asphalt can be significantly improved, and thus the flatness of the road surface can be better improved.

[0032] 3. In the paving method of the asphalt pavement of the present invention, the flexible start-stop vibration and oscillatory compaction technology of the double steel-wheel oscillating roller is used for compaction, which not only effectively improves the compactness and flatness of the road surface, but also eliminates the influence of resonance on the compactness during the rolling of the asphalt pavement on the bridge, and reduces quality problems such as material congestion, waves, cracks, and uneven compaction in road surface construction.

[0033] 4. The paving method of the asphalt pavement of the present invention has high construction efficiency, good universality and low construction cost, and is suitable for large-scale application in the construction of granular wood fiber modified asphalt pavements of domestic high-grade highways and urban arterial roads. Detailed implementation manners

[0034] The present invention will be further described in detail below in conjunction with test examples and specific implementation manners. However, it should not be understood that the scope of the above-mentioned subject matter of the present invention is limited to the following embodiments. All technologies implemented based on the content of the present invention belong to the scope of the present invention.

[0035] Example 1:

[0036] Raw materials:

[0037] Name Basalt particles of 10 - 15 mm Basalt particles of 5 - 10 mm Basalt particles of 0 - 3 mm Mineral powder Asphalt Granular lignin fiber Quicklime Parts by weight 41.27 30.96 12.19 8.16 5.9 0.3 1.22

[0038] Step 1, mixing: Heat the asphalt to 162 °C for standby; Mix the aggregate, granular wood fiber and water stabilizer for 12 s to obtain a mixture for standby; Mix the heated asphalt and the mixture at 180 °C for 60 s to obtain a modified asphalt material;

[0039] Step 2, paving: Pave the modified asphalt material with a full-width paver; wherein, the paving speed is 3 m / s; the tamper speed is set at 40%; the loose paving coefficient is 1.25; the temperature of the screed plate of the paver is 115 °C; the temperature of the modified asphalt material during paving is 165 °C;

[0040] Step 3, compaction: Use a combination of a double steel wheel vibrating roller and a rubber tire roller for compaction; The compaction includes initial compaction, re-compaction and final compaction; wherein, the initial compaction is carried out with a double steel wheel vibrating roller, static compaction for 1 pass and vibrating compaction for 1 pass, the overlapping width of the roller tracks is 25 cm, each roller takes full-width compaction and all roll from the lower part of the cross slope to the higher part, the compaction length is arranged in a stepped shape longitudinally, the compaction speed of the initial compaction is 7 km / h, and the temperature is 160 °C; The re-compaction is carried out with a double steel vibrating roller, and the compaction method is the same as that of the initial compaction, with a total of 2 passes of compaction, the compaction speed of the re-compaction is 6 km / h; the temperature of the modified asphalt material is 140 °C; The final compaction is carried out with a rubber tire roller for static compaction twice, the compaction speed of the final compaction is 5 km / h, and the temperature of the modified asphalt material is 110 °C;

[0041] Step 4, acceptance: Detect the pavement compaction degree, porosity, texture depth, water permeability coefficient, friction coefficient, cross slope and flatness. After meeting the requirements, the paving of the modified asphalt pavement is completed.

[0042] Test results:

[0043]

[0044] Example 2

[0045] Raw materials:

[0046] Name Basalt particles of 10 - 15 mm Basalt particles of 5 - 10 mm Basalt particles of 0 - 3 mm Mineral powder Asphalt Granular lignin fiber Quicklime Parts by weight 35.6 33.93 14.77 8.5 5.5 0.2 1.5

[0047] Step 1, mixing: Heat the asphalt to 160 °C for standby; Mix the aggregate, granular lignin fiber and water stabilizer for 12 s to obtain a mixture for standby; Mix the heated asphalt with the mixture at 170 °C for 60 s to obtain the modified asphalt material;

[0048] Step 2, paving: Pave the modified asphalt material with a full-width paver; Among them, the paving speed is 2.5 m / s; The tamper speed is set at 35%; The loose paving coefficient is 1.23; The temperature of the screed plate of the paver is 120 °C; The temperature of the modified asphalt material during paving is 165 °C;

[0049] Step 3, compaction: Use a combination of a double-drum vibratory roller and a rubber-tyred roller for compaction; The compaction includes initial compaction, re-compaction and final compaction; Among them, the initial compaction is carried out with a double-drum vibratory roller, static compaction for 1 pass and vibratory compaction for 1 pass, the overlapping width of the roller tracks is 30 cm, each roller takes full-width compaction and all roll from the lower part of the cross slope to the higher part, the compaction length is arranged in a stepped shape longitudinally, the compaction speed of the initial compaction is 6 km / h, and the temperature is 160 °C; The re-compaction is carried out with a double-drum vibratory roller, and the compaction method is the same as that of the initial compaction, with a total of 2 passes of compaction, the compaction speed of the re-compaction is 5 km / h; The temperature of the modified asphalt material is 140 °C; The final compaction is carried out with a rubber-tyred roller for 2 passes of static compaction, the compaction speed of the final compaction is 4 km / h, and the temperature of the modified asphalt material is 110 °C;

[0050] Step 4, acceptance: Detect the pavement compaction degree, porosity, texture depth, water permeability coefficient, friction coefficient, cross slope and flatness. After meeting the requirements, complete the paving of the modified asphalt pavement.

[0051] Test results:

[0052] Item Acceptance result National standard Pavement compactness 99.5 ≥98 Void ratio 4.3 4-6% Texture depth 0.84 ≥0.55 mm Permeability coefficient 58 ≤120 Friction coefficient 61 ≥54 Cross slope 0.1 ±0.3 Evenness 0.8 ≤1.2 mm

[0053] Example 3

[0054] Raw materials:

[0055] Name Basalt particles of 10 - 15 mm Basalt particles of 5 - 10 mm Basalt particles of 0 - 3 mm Mineral powder Asphalt Granular lignin fiber Quicklime Parts by weight 38.19 32.90 11.91 9 6.5 0.5 1.0

[0056] Step 1, mixing: Heat the asphalt to 165 °C for standby; Mix the aggregate, granular lignin fiber and water stabilizer for 12 s to obtain a mixture for standby; Mix the heated asphalt with the mixture at 170 - 185 °C for 60 s to obtain the modified asphalt material;

[0057] Step 2, Paving: Pave the modified asphalt material with a full-width paver; among them, the paving speed is 3.5 m / s; the rammer speed is set at 45%; the loose paving coefficient is 1.26; the temperature of the screed of the paver is 120 °C; the temperature of the modified asphalt material during paving is 165 °C;

[0058] Step 3, Compaction: Use a combination of a tandem steel wheel vibratory roller and a pneumatic tire roller for compaction; the compaction includes initial compaction, re-compaction and final compaction; among them, the initial compaction is carried out with a tandem steel wheel vibratory roller, static compaction for 1 pass and vibratory compaction for 1 pass, the overlapping width of the roller tracks is 30 cm, each roller adopts full-width compaction and all roll from the lower part of the cross slope to the higher part, the compaction length is arranged in a stepped shape longitudinally, the compaction speed of the initial compaction is 8 km / h, and the temperature is 160 °C; the re-compaction is carried out with a tandem steel wheel vibratory roller, and the compaction method is the same as that of the initial compaction, with a total of 2 passes of compaction, the compaction speed of the re-compaction is 7 km / h; the temperature of the modified asphalt material is 140 °C; the final compaction is carried out with a pneumatic tire roller for 2 passes of static compaction, the compaction speed of the final compaction is 6 km / h, and the temperature of the modified asphalt material is 110 °C;

[0059] Step 4, Acceptance: Detect the pavement compaction degree, porosity, texture depth, permeability coefficient, friction coefficient, cross slope and flatness. After meeting the requirements, complete the paving of the modified asphalt pavement.

[0060] Test results:

[0061] Item Acceptance result National standard Pavement compactness 99.6 ≥98 Void ratio 4.4 4-6% Texture depth 0.82 ≥0.55 mm Permeability coefficient 68 ≤120 Friction coefficient 0.61 ≥54 Cross slope 0.1 ±0.3 Evenness 0.7 ≤1.2 mm

[0062] Comparative Example 1:

[0063] Use the raw materials of Example 1, but the specific paving method is the traditional paving method;

[0064] The specific paving method is as follows:

[0065] Step 1, Mixing: Heat the asphalt to 162 °C for standby; mix the aggregate, granular lignin fiber and water stabilizer for 12 s to obtain a mixture for standby; mix the heated asphalt and the mixture at 180 °C for 60 s to obtain the modified asphalt material;

[0066] Step 2, Paving: Pave the modified asphalt material in a stepped manner with a half-width paver; among them, the paving speed is 3 m / s; the rammer speed is set at 40%; the loose paving coefficient is 1.25; the temperature of the screed of the paver is 115 °C; the temperature of the modified asphalt material during paving is 165 °C;

[0067] Step 3, Compaction: Use a double-drum vibratory roller for compaction; the compaction includes initial compaction, re-compaction, and final compaction; among them, for initial compaction, use a double-drum vibratory roller for compaction, with 1 static compaction pass and 1 vibratory compaction pass, the overlapping width of the roller tracks is 25 cm, each roller performs full-width compaction and all start from the lower part of the cross slope to the higher part, the compaction length is arranged in a stepped pattern longitudinally, the compaction speed of the initial compaction is 7 km / h, and the temperature is 160 °C; for re-compaction, use a double-vibratory roller for compaction, the compaction method is the same as that of the initial compaction, with a total of 2 compaction passes, the compaction speed of the re-compaction is 6 km / h; the temperature of the modified asphalt material is 140 °C; for final compaction, use a rubber-tyred roller for 2 static compaction passes, the compaction speed of the final compaction is 5 km / h, and the temperature of the modified asphalt material is 110 °C;

[0068] Step 4, Acceptance: Detect the pavement compaction degree, porosity, texture depth, water permeability coefficient, friction coefficient, cross slope, and flatness. After meeting the requirements, complete the paving of the modified asphalt pavement.

[0069] Acceptance result:

[0070] Item Acceptance result National standard Pavement compactness 98.1 ≥98 Void ratio 4.8 4-6% Texture depth 0.95 ≥0.55 mm Permeability coefficient 80 ≤120 Friction coefficient 61 ≥54 Cross slope 0.2 ±0.3 Evenness 1.0 ≤1.2 mm

[0071] It can be seen from the acceptance results that without changing the raw materials of the asphalt pavement, when using traditional paving machinery to pave the asphalt pavement, although the performance of the asphalt pavement still meets the national requirements, due to its poor synergistic cooperation with granular wood fiber, the performance of granular wood fiber cannot be well reflected, resulting in a significant reduction in the performance of the paved asphalt pavement, especially the pavement cannot be well compacted, thus leading to a significant reduction in performance such as the water permeability coefficient and flatness.

[0072] Comparative Example 2:

[0073] Adjust the raw material ratio in Example 1, and the paving method is the same as that in Example 1;

[0074] Raw materials:

[0075] Name Basalt particles of 10 - 15 mm Basalt particles of 5 - 10 mm Basalt particles of 0 - 3 mm Mineral powder Asphalt Granular lignin fiber Quicklime Parts by weight 39.25 30.96 12.19 8.0 7 0.8 1.8

[0076] Acceptance result:

[0077] Item Acceptance result National standard Pavement compactness 98.3 ≥98 Void ratio 4.7 4-6% Texture depth 0.92 ≥0.55 mm Permeability coefficient 76 ≤120 Friction coefficient 64 ≥54 Cross slope 0.2 ±0.3 Evenness 1.1 ≤1.2 mm

[0078] It can be seen from the acceptance results that after changing the raw material ratio of the asphalt pavement, although using the same paving method to pave the asphalt pavement, the performance of the asphalt pavement still meets the national requirements, but the change in the raw material ratio leads to a deterioration in its synergistic cooperation with the paving method (especially the various targeted paving parameters in the method), and the performance of granular wood fiber cannot be well reflected, resulting in a greater degree of reduction in the performance of the paved asphalt pavement.

[0079] Comparative Example 3:

[0080] Replace the granular wood fiber in the raw materials of Example 1 with flocculent wood fiber, and keep other raw materials and paving methods the same as those in Example 1;

[0081] Acceptance result:

[0082] Item Acceptance result National standard Pavement compactness 98.8 ≥98 Void ratio 4.4 4-6% Texture depth 0.78 ≥0.55 mm Permeability coefficient 75 ≤120 Friction coefficient 58 ≥54 Cross slope 0.2 ±0.3 Evenness 1.0 ≤1.2 mm

[0083] It can be seen from the acceptance results that when the traditional flocculent wood fiber is used to replace the granular wood fiber of the present invention and the paving machine of the present invention is still used for paving the asphalt pavement, although the performance of the asphalt pavement still meets the national requirements, due to its poor synergistic cooperation with the flocculent wood fiber, the performance of the paved asphalt pavement is reduced to a large extent.

[0084] Comparative Example 4:

[0085] Raw materials:

[0086] Name Basalt particles of 10 - 15 mm Basalt particles of 5 - 10 mm Basalt particles of 0 - 3 mm Mineral powder Asphalt Flocculent lignin fiber Quicklime Parts by weight 41.27 30.96 12.19 8.16 5.9 0.3 1.22

[0087] The specific paving method is as follows:

[0088] Step 1, mixing: Heat the asphalt to 162 °C for standby; Mix the aggregate, granular wood fiber and water stabilizer for 12 s to obtain a mixture for standby; Mix the heated asphalt and the mixture at 180 °C for 60 s to obtain a modified asphalt material;

[0089] Step 2, paving: Use a half-width paver to pave the modified asphalt material in a stepped manner; Among them, the paving speed is 3 m / s; The tamper speed is set at 40%; The loose paving coefficient is 1.25; The temperature of the screed of the paver is 115 °C; The temperature of the modified asphalt material during paving is 165 °C;

[0090] Step 3, compaction: Use a double-drum vibratory roller for compaction; The compaction includes initial compaction, re-compaction and final compaction; Among them, the initial compaction is carried out with a double-drum vibratory roller, static compaction for 1 pass and vibratory compaction for 1 pass, the overlapping width of the roller tracks is 25 cm, each roller takes full-width compaction and all roll from the lower part of the cross slope to the higher part, the compaction length is arranged in a stepped shape longitudinally, the compaction speed of the initial compaction is 7 km / h and the temperature is 160 °C; The re-compaction is carried out with a double-drum vibratory roller, and the compaction method is the same as that of the initial compaction, with a total of 2 passes of compaction, the compaction speed of the re-compaction is 6 km / h; The temperature of the modified asphalt material is 140 °C; The final compaction is carried out with a rubber-tyred roller for static compaction twice, the compaction speed of the final compaction is 5 km / h, and the temperature of the modified asphalt material is 110 °C;

[0091] Step 4, Acceptance: Detect the pavement compactness, porosity, texture depth, permeability coefficient, friction coefficient, cross slope and flatness. After meeting the requirements, complete the paving of the modified asphalt pavement.

[0092] Acceptance result:

[0093] Item Acceptance result National standard Pavement compactness 99.2 ≥98 Void ratio 4.2 4-6% Texture depth 0.87 ≥0.55 mm Permeability coefficient 59 ≤120 Friction coefficient 61 ≥54 Cross slope 0.1 ±0.3 Evenness 1.9 ≤1.2 mm

[0094] From the acceptance results, it can be seen that when using traditional flocculent wood fibers and corresponding paving methods, although the performance of the asphalt pavement has decreased compared with this application, the decrease is not obvious, and it is significantly higher than that of granular wood fibers and traditional paving methods, as well as the combination of flocculent wood fibers and new paving methods. It can be seen that during the paving process of the asphalt pavement, the selection of raw materials and the paving method of the asphalt pavement interact with each other, and the two have a synergistic effect. Only when the appropriate raw material composition and the appropriate paving method are combined with each other can the various performances of the paved asphalt pavement be significantly increased.

Claims

1. A laying method for a granular wood fiber modified asphalt pavement, characterized in that, It includes the following steps: Step 1, mixing: Heat the asphalt for standby; Mix the aggregate, granular wood fiber and water stabilizer to obtain a mixture for standby; Mix the heated asphalt and the mixture under high temperature conditions to obtain a modified asphalt material; Among them, the aggregate is basalt particles and mineral powder with a mass ratio of 90∶8.5 - 9.0; The water stabilizer is quicklime; In the modified asphalt material, the mass percentage of asphalt is 5.5 - 6.5%, the mass percentage of granular wood fiber is 0.2 - 0.5%, the mass percentage of aggregate is 91.5 - 93.3%, and the mass percentage of water stabilizer is 1 - 1.5%; The basalt particles are basalt particles with a particle size of 10 - 15mm, basalt particles with a particle size of 5 - 10mm, and basalt particles with a particle size of 0 - 3mm with a mass ratio of 44:33:13; The mass ratio of the mineral powder to the water stabilizer is 8.5 - 9.0∶1.0 - 1.5; Step 2, paving: Pave the modified asphalt material with a full-width paver; Among them, the paving speed is 2.5 - 3.5m / s; The rammer speed is set at 35 - 45%; The loose paving coefficient is 1.23 - 1.26; The temperature of the screed plate of the paver is 110 - 120℃; The temperature of the modified asphalt material during paving is not lower than 165℃; Step 3, compaction: Use a combination of a double-drum oscillating roller and a rubber-tyred roller for rolling; The rolling includes initial compaction, re-compaction and final compaction; Among them, during initial compaction, the temperature of the modified asphalt material is not lower than 160℃; During re-compaction, the temperature of the modified asphalt material is not lower than 140℃; During final compaction, the temperature of the modified asphalt material is not lower than 110℃; The compaction speed during initial compaction is 6 - 8km / h; The compaction speed during re-compaction is 5 - 7km / h; The compaction speed during final compaction is 4 - 6 km / h; Step 4, acceptance: Detect the pavement performance. After meeting the requirements, complete the paving of the modified asphalt pavement.

2. The laying method according to claim 1, wherein In Step 1, the heating temperature of the asphalt is 160 - 165℃; The high temperature condition during the mixing of the asphalt and the mixture is 170 - 185℃.

3. The laying method according to claim 1, wherein, In Step 1, the high temperature condition during the mixing is 170 - 185℃.

4. The laying method according to claim 1, characterized in that, In Step 1, in the modified asphalt material, the mass percentage of asphalt is 5.9%, the mass percentage of granular wood fiber is 0.3%, the mass percentage of aggregate is 92.58%, and the mass percentage of water stabilizer is 1.22%.

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