A cold recycled fiber cold patch material based on fine stripping and screening technology and its preparation method

Abstract

The present invention discloses a cold recycled fiber cold patch material based on a fine stripping and screening technology and a preparation method thereof, belonging to the technical field of recycled asphalt mixtures. The raw materials of the cold recycled fiber cold patch material based on the fine stripping and screening technology include, by weight: 100 parts of fine stripping and screening RAP material, 0.2 - 1.2 parts of fiber stabilizer, 0.6 - 1.8 parts of cold asphalt liquid, and 1.2 - 2.6 parts of diluent one; among them, the raw materials of the cold asphalt liquid include: 70 - 85 parts of SBS modified asphalt, 12 - 30 parts of diluent two, 1 - 3 parts of polyvinyl acetate emulsion, 0.3 - 1 part of anti-stripping agent, and 0.3 - 0.7 part of antioxidant. The cold recycled fiber cold patch material based on the fine stripping and screening technology provided by the present invention has the advantages of low production cost, low carbon environmental protection, convenient prefabrication, good storage performance, strong adaptability, good water tightness, high thermal stability, excellent durability, etc., and can be quickly constructed in extreme environments such as overweight loads and rainy and snowy days without loosening and can quickly open to traffic, with obvious economic and environmental benefits.

Description

Technical Field

[0001] The present invention belongs to the technical field of recycled asphalt mixtures, and particularly relates to a cold recycled fiber cold patching material based on a fine peeling and screening technology and a preparation method thereof. Background Art

[0002] Each year, a large amount of waste road asphalt recycled materials (RAP) are generated due to the reconstruction, expansion and maintenance of asphalt pavements. However, the industry's recycling rate of RAP is insufficient, resulting in a huge pressure on ecological environment protection. During the service process of asphalt pavements, they are subjected to the dual coupling action of the environment and loads for a long time, which easily causes the aging of the asphalt surface layer. Coupled with a series of inducements such as base reflection cracks, strong erosion of rain, snow and freeze-thaw, and poor interlayer bonding, pavement diseases such as looseness, cracking and potholes are likely to occur during the pavement life cycle and continue to expand as the service time prolongs, reducing the service quality of the pavement, affecting driving comfort, and in serious cases, easily triggering traffic accidents and threatening driving safety. Therefore, "efficient and timely" treatment of pavement diseases has always been the top priority of the industry's maintenance work.

[0003] The common way to dispose of pavement diseases is to use hot mix asphalt mixture for hot patching of the damaged position of the pavement. Due to the need for high-temperature production and high-temperature construction of hot mix asphalt mixture, pre-treatments such as cutting the damaged position, cleaning and applying tack coat are required before patching. The patching material cannot be prefabricated and the construction process is greatly affected by the climate. Due to reasons such as the need for professional large-scale machinery and technical personnel in the specific construction, it has the disadvantages of high construction cost, long duration, large waste, many steps, large pollution, poor construction safety and poor patching timeliness of conventional hot patching maintenance projects. To better meet the development needs of "green, efficient and safe" modern highway maintenance, pavement cold patching materials have emerged. They are made by mixing a special asphalt cold liquid, aggregate and additive in a certain proportion and stirring. They are in a loose state at normal temperature, can be stored in sealed condition for a long time, and have the characteristics of low cost, convenient construction, little affected by the climate, rapid opening to traffic, no need for special construction technology, and the remaining materials can be recycled.

[0004] Currently, some deficiencies still emerge in the actual application process of conventional cold patching materials, specifically manifested as: (1) all or part of new stones and new asphalt are used in material production, and most are prepared by hot mix or warm mix processes, resulting in relatively high production costs; (2) the RAP used is put into use after conventional primary screening, and the content of false particle sizes in RAP is relatively high, the production gradation variability of the product is large, the quality fluctuation is relatively high and it is difficult to control; (3) it is only applicable to patching 2m 2For potholes on the road surface with the following areas, the repair coverage is small and the material storage stability is poor. The material is prone to caking and hardening; (4) Before repair, it is still necessary to perform pre-treatments such as grooving and drainage on the road surface diseases, which not only increases the repair labor and material costs, but also greatly affects the construction, driving safety and traffic flow of repairs on some special sections such as highways; (5) Conventional cold patch materials have low initial strength, slow strength growth, and poor durability. During the service life cycle of the repaired surface, secondary repairs are likely to occur due to the combined action of the environment and load, etc.

[0005] Therefore, it is very necessary to develop an environmentally friendly cold recycled asphalt cold patch material that is economical, environmentally friendly, has stable quality, strong adaptability, good storage performance, convenient use, good water tightness, good durability, and ideal strength, which can effectively extend the service life of the road surface and improve the road surface service quality. Summary of the Invention

[0006] To solve the above technical problems, the present invention provides a cold recycled fiber cold patch material based on fine peeling and screening technology and its preparation method. On the one hand, the cold patch material is all made by cold mixing fine peeling and screening RAP. While realizing the environmental protection, economy and convenience of product production, the introduction of this technology also effectively reduces the content of pseudo-coarse particles in RAP, controls the degree of RAP caking and variability, and realizes the application dosage of RAP can be increased to 100%. While effectively reducing the amount of new asphalt used, it simultaneously improves the low-temperature performance, water stability and other related road use performances of the recycled cold patch asphalt mixture, and realizes the comprehensive improvement of the cold patch repair quality of the road surface. On the other hand, by introducing special polyester fibers and additives into the cold patch material, not only the whole process of cold mixing production of the cold patch material is realized, but also the bonding performance of the material is effectively guaranteed. The flexible long-chain structure inside the material also improves the forming strength, toughness and fluffiness of the mixture, greatly improves the storage stability of the product, effectively ensures the paving and compaction convenience of the cold patch material when it is used again after long-term storage, makes the material not easy to produce road surface diseases such as peeling and cracking in low-temperature use environments, effectively improves the durability of the material, and also omits the pre-treatment steps such as grooving and drainage of the original road surface before the application of conventional cold patch materials, greatly simplifies the application procedure of the cold patch material, shortens the construction time to the greatest extent, effectively ensures the construction safety and road traffic flow during repair, and has great economic prospects and good social benefits.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] One of the technical solutions of the present invention: Provide a cold recycled fiber cold patch material based on fine peeling and screening technology. By weight, the raw materials include: 100 parts of fine peeling and screening RAP material, 0.2 - 1.2 parts of fiber stabilizer, 0.6 - 1.8 parts of asphalt cold liquid supplement, and 1.2 - 2.6 parts of diluent one;

[0009] By weight parts, the raw materials for the finely stripped and screened RAP material include: 80 - 90 parts of oil-rich fine aggregate and 10 - 20 parts of oil-poor coarse aggregate;

[0010] By weight parts, the raw materials for the cold asphalt replenishing liquid include: 70 - 85 parts of SBS modified asphalt, 12 - 30 parts of diluent two, 1 - 3 parts of polyvinyl acetate emulsion, 0.3 - 1 part of anti-stripping agent, and 0.3 - 0.7 part of antioxidant;

[0011] The particle size range of the oil-rich fine aggregate is ≤5mm, and the asphalt-aggregate ratio is 6.2 - 6.4%;

[0012] The particle size range of the oil-poor coarse aggregate is >5 and ≤mm, and the asphalt-aggregate ratio is 1.9 - 2.1%.

[0013] The present invention uses the alkaline basalt recycled aggregate obtained by finely stripping and screening of asphalt pavement as a mineral aggregate. Its particle size, surface oil content, and the content of pseudo-particles will directly affect the relevant properties of the cold asphalt replenishing material. Among them, too large or too small particle size is likely to reduce the compaction density of the cold asphalt replenishing material, leading to premature cracking of the material. Too high or too low total oil content of RAP will directly affect the bonding strength, anti-skid performance, and production economy of the cold asphalt replenishing material, while too high content of pseudo-particles in RAP will lead to excessive variability in the grading of the cold asphalt replenishing material, reducing the forming strength of the mixture and directly affecting the stability of the production quality of the cold asphalt replenishing material. By selecting 2 different specifications of finely stripped and screened oil-poor coarse aggregate and oil-rich fine aggregate, and continuously adjusting and optimizing the dosage of each component, the present invention can not only effectively reduce the content of pseudo-coarse particles in RAP, control the agglomeration degree and variability of RAP to ensure the accuracy of the production grading of the cold asphalt replenishing material, but also realize cold mixing of the whole process of the cold asphalt replenishing material and increase the application dosage of RAP to 100%, effectively reducing the consumption of new asphalt and new aggregate in the recycled material, and simultaneously improving the bearing strength, bonding performance, anti-skid performance, water stability and other relevant properties of the cold asphalt replenishing material.

[0014] The SBS modified asphalt in the asphalt cold repair liquid of the present invention has excellent bonding performance, which can effectively improve the bonding force between the cold repair material and the old road surface, and reduce cracking and peeling phenomena. At the same time, the modification of SBS can endow the asphalt with better flexibility, so that the cold repair material is not easily broken under temperature changes and load effects, and maintains its good working performance under different climatic conditions. In addition, the addition of SBS can improve the anti-aging performance and water damage resistance of the asphalt, reduce the deterioration of the binder under ultraviolet rays and temperature and humidity changes, and maintain the durability of the material properties to effectively extend the service life of the cold repair material. The research team of the present invention calculated and analyzed that although the cost of SBS modified asphalt is slightly higher than that of ordinary asphalt, when it is used as the asphalt binder in the asphalt cold repair liquid described in the present invention, the durability of the recycled cold repair material is significantly improved during the service process, the frequency of secondary repair of the material is greatly reduced, and the use and maintenance costs within the whole life cycle are lower. Calculated based on one ton of finished product, compared with ordinary hot repair materials, the present invention's material can save up to 100% of new aggregates and 2.3% of new asphalt during production, saving about 50 yuan / ton of stone material cost and about 142 yuan / ton of asphalt cost respectively. The heavy oil consumption corresponding to heating one cubic meter of conventional hot repair material from room temperature to the mixing temperature of 180°C is about 7 kg. If diesel is used for heating, the present invention's material can save up to about 54.5% of energy consumption and reduce greenhouse gas emissions by about 48%. It is estimated that the production heating cost can be reduced by 31.5 yuan / t, and the road surface repair grooving and labor miscellaneous costs are about 50 yuan / ton, with a total cost reduction of about 273.5 yuan / ton, showing significant economic and social benefits.

[0015] The polyvinyl acetate emulsion added to the asphalt cold repair liquid of the present invention is mainly used as a bonding supplement for cold repair recycled asphalt mixtures to ensure the bonding, crack resistance, anti-seepage and other properties of the recycled mixtures.

[0016] The anti-stripping agent added to the asphalt cold repair liquid of the present invention is mainly used to improve the adhesion between the asphalt and the aggregate, reduce the stripping of the asphalt from the aggregate due to external temperature and humidity changes, prevent water from seeping into the repair surface to reduce freeze-thaw damage and water erosion, ensure the water stability and integrity of the asphalt repair road surface, and thus improve the durability and anti-aging performance of the asphalt road surface and extend the service life of the repair surface.

[0017] The antioxidant added to the asphalt cold repair liquid of the present invention is mainly used to prevent the free radicals on the asphalt surface from being oxidized, and thus effectively prevent the aging and deterioration problems of the asphalt and extend the service life of the asphalt.

[0018] The preferred weight parts of the raw materials of the asphalt cold repair liquid described in the present invention are: 78 parts of SBS modified asphalt, 19 parts of diluent two, 2 parts of polyvinyl acetate emulsion, 0.5 part of anti-stripping agent and 0.5 part of antioxidant.

[0019] Preferably, the fiber stabilizer is polyester fiber, the fiber diameter is 40 - 50 μm, and the fiber length ≤ 7 mm.

[0020] The addition of polyester fiber can not only make components such as asphalt cold repair liquid and aggregate disperse evenly, not agglomerate and be fluffy in the mixture, but also make the asphalt cold patch material easy to compact and easy to harden after compaction. In addition, through the adsorption effect on the fiber surface, the bonding property between cold repair aggregate particles and the surface anti-skid property can be effectively enhanced, reducing the particle scattering caused by vehicle abrasion during the service process of the cold patch material, effectively improving the anti-skid durability and water stability of the cold patch material after forming, and being more obvious in improving the low-temperature ductility and anti-shear performance of the material in winter.

[0021] Preferably, both the first diluent and the second diluent are 0# diesel.

[0022] Compared with other professional diluents, 0# diesel not only has the advantages of low cost, controllable quality, good solubility, low volatility, etc., but also can effectively reduce the viscosity of modified asphalt, thus realizing the full cold mixing technology described in the present invention, effectively saving energy consumption in the production process, and having remarkable economic and environmental benefits.

[0023] Preferably, the anti-stripping agent is vinyl bisstearamide.

[0024] Preferably, the main component of the antioxidant is N-phenyl-1-naphthylamine.

[0025] The second technical solution of the present invention: provides a preparation method of the cold recycled fiber cold patch material based on the fine stripping and screening technology as described above, including the following steps:

[0026] Prepare each raw material by weight.

[0027] Heat the SBS modified asphalt to melting, add the second diluent and shear, then add the polyvinyl acetate emulsion, the anti-stripping agent and the antioxidant and continue to shear to obtain the asphalt cold repair liquid for standby.

[0028] Add the rich-oil fine aggregate, the lean-oil coarse aggregate, the fiber stabilizer and the first diluent to a stirring device, then add the asphalt cold repair liquid and mix evenly to obtain the cold recycled fiber cold patch material based on the fine stripping and screening technology.

[0029] Preferably, the shear rate after adding the second diluent is 2600 - 3,600 r / min, and the shear time is 3 - 5 min; more preferably, the shear rate is 3,200 r / min and the shear time is 4 min.

[0030] Preferably, after adding the polyvinyl acetate emulsion, the anti-stripping agent and the antioxidant, the shear rate is 3600-4700 r / min, and the shear time is 9-15 min; more preferably, the shear rate is 4200 r / min, and the shear time is 12 min.

[0031] Preferably, the temperature of the asphalt cold make-up fluid to be used is maintained at 140-150°C; more preferably 145°C.

[0032] The third technical solution of the present invention is to provide an application of the above-mentioned cold-recycled fiber cold patch material based on fine peeling and screening technology in road repair.

[0033] The beneficial technical effects of the present invention are as follows:

[0034] The fully cold-mixed fiber-type cold-patch asphalt mixture developed by the present invention is based on full-fine stripping and screening. It has excellent performance indicators and stable quality. The product has the advantages of low production cost, low carbon and environmental protection, convenient prefabrication, good storage, strong adaptability, good water tightness, high thermal stability, and excellent durability. It can be quickly constructed in extreme environments such as overload, rain and snow without loosening, and can be opened to traffic quickly, with obvious economic and environmental benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The present invention provides a flow chart for repairing a road surface using the cold-recycled fiber cold patch material prepared according to an embodiment of the present invention.

[0036] Figure 2 This is a picture of the Marshall stability tester.

[0037] Figure 3 These are macroscopic images of water resistance tests on some materials in Examples 1 to 13.

[0038] Figure 4 These are macroscopic images of the cold-regenerated fiber cold patch material prepared in Example 5 before and after the indoor rutting test, where (a) is before the test and (b) is after the test.

[0039] Figure 5 This is a picture of the indoor storage stability test of the present invention.

[0040] Figure 6 This is a macroscopic picture of the indoor low-temperature workability test of the cold-regenerated fiber cold patch material prepared in Example 5, where (a) is before freezing and (b) is after freezing.

[0041] Figure 7 This is a macroscopic image of a cohesiveness test of the cold-regenerated fiber cold patch material prepared using Example 5 of the present invention.

[0042] Figure 8Test diagram for repairing a bridge deck in a mining area using the cold recycled fiber cold patch material prepared in Example 5 of the present invention. Among them, (a) shows the situation just after repair, and (b) shows the situation 10 months after repair.

[0043] Figure 9 Test diagram for repairing a highway pavement using the cold recycled fiber cold patch material prepared in Example 5 of the present invention. Detailed implementation manners

[0044] Now, various exemplary implementation manners of the present invention will be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, characteristics, and implementation schemes of the present invention. It should be understood that the terms described in the present invention are only used to describe specific implementation manners and are not used to limit the present invention.

[0045] It should be noted that the aspects not described in detail in the present invention are all conventional operation means in the art and are not the focus of the present invention.

[0046] In addition, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded from the range.

[0047] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present invention.

[0048] Regarding the terms "comprising", "including", "having", "containing", etc. used herein, they are all open-ended terms, meaning including but not limited to.

[0049] The polyester fiber used in the embodiments of the present invention is a commercially available product, with a diameter of 40 - 50 μm and a fiber length ≤ 7 mm.

[0050] The SBS modified asphalt used in the embodiments of the present invention is a commercially available product, purchased from Jiangxi Provincial Communications Investment Maintenance Technology Group Co., Ltd. The test results of its technical indicators are shown in Table 1.

[0051] Table 1 Test results of technical indicators of SBS modified asphalt

[0052]

[0053] The polyvinyl acetate emulsion used in the embodiments of the present invention is a commercially available product, purchased from Jiangxi Provincial Communications Investment Maintenance Technology Group Co., Ltd.

[0054] In the embodiments of the present invention, both diluent 1 and diluent 2 used are 0# diesel oil.

[0055] The anti-stripping agent used in the embodiments of the present invention is vinyl bisstearamide, which is a commercially available product and is purchased from Jiangxi Provincial Communications Investment Maintenance Technology Group Co., Ltd.

[0056] The main component of the antioxidant used in the embodiments of the present invention is N-phenyl-1-naphthylamine, which is a commercially available product and is purchased from Jiangxi Provincial Communications Investment Maintenance Technology Group Co., Ltd.

[0057] The particle size range of the rich-oil fine aggregate used in the embodiments of the present invention is ≤5 mm, and the test results of its technical indicators are shown in Table 2.

[0058] Table 2 Test Results of Technical Indicators of Refined Screening of Rich-Oil Fine Aggregate

[0059]

[0060]

[0061] The particle size range of the lean-oil fine aggregate used in the embodiments of the present invention is >5 and ≤11 mm, and the test results of its technical indicators are shown in Table 3.

[0062] Table 3 Test Results of Technical Indicators of Refined Screening of Lean-Oil Fine Aggregate

[0063] Test Items Test Values Standard Requirements Test Methods Bitumen Content (%) 2.02 Measured T0722 Water Content (%) 0.8 ≤3 T0305 Crushing Value (%) 21.3 ≤28 T0316 Flaky and Elongated Particle Content (%) 14.7 ≤15 T0312 Los Angeles Abrasion Loss (%) 25.8 ≤30 T0317 Apparent Relative Density 2.717 ≥2.50 T0304 Water Absorption (%) 0.47 ≤3.0 T0304 Soft Stone Content (%) 2.7 ≤5 T0320

[0064] The flow chart of repairing the road surface with the cold recycled fiber cold patch material prepared in the embodiments of the present invention is shown in Figure 1 .

[0065] Example 1

[0066] Preparation of cold recycled fiber cold patch material:

[0067] (1) Prepare raw materials by weight: 100 parts of finely stripped and screened RAP material, 0.8 part of asphalt cold replenishing liquid, 2 parts of diluent 1, and 0.5 part of polyester fiber; among them, the finely stripped and screened RAP material is composed of finely stripped and screened basic basalt stones of different specifications, specifically 85 parts of rich-oil fine aggregate and 15 parts of lean-oil coarse aggregate; the raw material weight parts of the asphalt cold replenishing liquid are 78 parts of SBS modified asphalt, 19 parts of diluent 2, 0.5 part of anti-stripping agent, 2 parts of polyvinyl acetate emulsion, and 0.5 part of antioxidant.

[0068] (2) Preparation steps:

[0069] Heat the SBS modified asphalt to 150°C until it is completely melted, pour it into a high-speed shear mixer together with diluent two, mix and shear at a rotational speed of 3200 r / min for 4 min. After shearing, add polyvinyl acetate emulsion, anti-stripping agent and antioxidant and mix and shear at a rotational speed of 4300 r / min for 12 min to obtain the asphalt cold replenishing liquid. Put it into a heat preservation box for heat preservation and keep the temperature at 140 - 150°C for standby;

[0070] Add the finely stripped and screened RAP material and polyester fiber into the mixing tank, and then add diluent one to ensure that diluent one completely penetrates the polyester fiber to prevent the materials from agglomerating during the mixing process; finally, add the asphalt cold replenishing liquid and mix for 3 min to obtain the cold recycled fiber cold patch material.

[0071] Example 2

[0072] Preparation of cold recycled fiber cold patch material:

[0073] (1) Prepare raw materials by weight: 100 parts of finely stripped and screened RAP material, 0.8 parts of asphalt cold replenishing liquid, 2 parts of diluent one and 0.5 parts of polyester fiber; among them, the finely stripped and screened RAP material is composed of finely stripped and screened alkaline basalt rocks of different specifications, specifically 85 parts of oil-rich fine aggregate and 15 parts of oil-poor coarse aggregate; the raw material weight parts of the asphalt cold replenishing liquid are 78 parts of SBS modified asphalt, 19 parts of diluent two, 0.4 parts of anti-stripping agent, 2 parts of polyvinyl acetate emulsion, and 0.5 parts of antioxidant.

[0074] (2) Preparation steps:

[0075] Heat the SBS modified asphalt to 150°C until it is completely melted, pour it into a high-speed shear mixer together with diluent two, mix and shear at a rotational speed of 3200 r / min for 5 min. After shearing, add polyvinyl acetate emulsion, anti-stripping agent and antioxidant and mix and shear at a rotational speed of 4300 r / min for 12 min to obtain the asphalt cold replenishing liquid. Put it into a heat preservation box for heat preservation and keep the temperature at 140 - 150°C for standby;

[0076] Add the finely stripped and screened RAP material and polyester fiber into the mixing tank, and then add diluent one to ensure that diluent one completely penetrates the polyester fiber to prevent the materials from agglomerating during the mixing process; finally, add the asphalt cold replenishing liquid and mix for 3 min to obtain the cold recycled fiber cold patch material.

[0077] Example 3

[0078] Preparation of cold recycled fiber cold patch material:

[0079] (1) Prepare raw materials by weight: 100 parts of finely stripped and screened RAP material, 0.8 part of cold asphalt replenisher, 2.3 parts of diluent one, and 0.7 part of polyester fiber; among them, the finely stripped and screened RAP material is composed of finely stripped and screened alkaline basalt rocks of different specifications, specifically 85 parts of oil-rich fine aggregate and 15 parts of oil-poor coarse aggregate; the raw material weight parts of the cold asphalt replenisher are 78 parts of SBS modified asphalt, 19 parts of diluent two, 0.3 part of anti-stripping agent, 2 parts of polyvinyl acetate emulsion, and 0.5 part of antioxidant.

[0080] (2) Preparation steps:

[0081] Heat the SBS modified asphalt to 150 °C until it is completely melted, pour it into a high-speed shearer together with diluent two, mix and shear at a speed of 3200 r / min for 5 min. After shearing, add polyvinyl acetate emulsion, anti-stripping agent and antioxidant and mix and shear at a speed of 4300 r / min for 12 min to obtain the cold asphalt replenisher. Put it into a heat preservation box to keep warm and maintain the temperature at 140 - 150 °C for standby;

[0082] Add the finely stripped and screened RAP material and polyester fiber to the mixing tank, and then add diluent one to ensure that diluent one completely penetrates the polyester fiber to prevent material agglomeration during the mixing process; finally, add the cold asphalt replenisher and mix for 3 min to obtain the cold recycled fiber cold patch material.

[0083] Example 4

[0084] Preparation of cold recycled fiber cold patch material:

[0085] (1) Prepare raw materials by weight: 100 parts of finely stripped and screened RAP material, 1 part of cold asphalt replenisher, 1.7 parts of diluent one, and 0.3 part of polyester fiber; among them, the finely stripped and screened RAP material is composed of finely stripped and screened alkaline basalt rocks of different specifications, specifically 85 parts of oil-rich fine aggregate and 15 parts of oil-poor coarse aggregate; the raw material weight parts of the cold asphalt replenisher are 78 parts of SBS modified asphalt, 19 parts of diluent two, 2 parts of polyvinyl acetate emulsion, and 0.5 part of antioxidant.

[0086] (2) Preparation steps:

[0087] Heat the SBS modified asphalt to 150 °C until it is completely melted, pour it into a high-speed shearer together with diluent two, mix and shear at a speed of 3200 r / min for 5 min. After shearing, add polyvinyl acetate emulsion and antioxidant and mix and shear at a speed of 4300 r / min for 12 min to obtain the cold asphalt replenisher. Put it into a heat preservation box to keep warm and maintain the temperature at 140 - 150 °C for standby;

[0088] Add the finely stripped and screened RAP material and polyester fiber into the mixing tank, then add Diluent 1 to ensure that Diluent 1 completely penetrates the polyester fiber to prevent material agglomeration during mixing; finally, add the cold asphalt replenisher and mix for 3 minutes to obtain the cold recycled fiber cold patch material.

[0089] Example 5

[0090] Preparation of cold recycled fiber cold patch material:

[0091] (1) Prepare raw materials by weight: 100 parts of finely stripped and screened RAP material, 1 part of cold asphalt replenisher, 2 parts of Diluent 1, and 0.5 part of polyester fiber; among them, the finely stripped and screened RAP material is composed of finely stripped and screened alkaline basalt rocks of different specifications, specifically 85 parts of oil-rich fine aggregate and 15 parts of oil-poor coarse aggregate; the raw material weight parts of the cold asphalt replenisher are 78 parts of SBS modified asphalt, 19 parts of Diluent 2, 0.4 part of anti-stripping agent, 2 parts of polyvinyl acetate emulsion, and 0.5 part of antioxidant.

[0092] (2) Preparation steps:

[0093] Heat the SBS modified asphalt to 150 °C until it is completely melted, pour it into a high-speed shearer together with Diluent 2, mix and shear at a speed of 3200 r / min for 5 minutes. After shearing, add the polyvinyl acetate emulsion, anti-stripping agent and antioxidant and mix and shear at a speed of 4300 r / min for 12 minutes to obtain the cold asphalt replenisher, put it into an incubator for heat preservation and keep the temperature at 140 - 150 °C for standby;

[0094] Add the finely stripped and screened RAP material and polyester fiber into the mixing tank, then add Diluent 1 to ensure that Diluent 1 completely penetrates the polyester fiber to prevent material agglomeration during mixing; finally, add the cold asphalt replenisher and mix for 3 minutes to obtain the cold recycled fiber cold patch material.

[0095] Example 6

[0096] Preparation of cold recycled fiber cold patch material:

[0097] (1) Prepare raw materials by weight: 100 parts of finely stripped and screened RAP material, 1 part of cold asphalt replenisher, 2.3 parts of Diluent 1, and 0.7 part of polyester fiber; among them, the finely stripped and screened RAP material is composed of finely stripped and screened alkaline basalt rocks of different specifications, specifically 85 parts of oil-rich fine aggregate and 15 parts of oil-poor coarse aggregate; the raw material weight parts of the cold asphalt replenisher are 78 parts of SBS modified asphalt, 19 parts of Diluent 2, 0.3 part of anti-stripping agent, 2 parts of polyvinyl acetate emulsion, and 0.5 part of antioxidant.

[0098] (2) Preparation steps:

[0099] Heat the SBS modified asphalt to 150 °C until it is completely melted, pour it into a high-speed shear mixer together with diluent two, mix and shear at a rotation speed of 3200 r / min for 5 min. After shearing, add polyvinyl acetate emulsion, anti-stripping agent and antioxidant and mix and shear at a rotation speed of 4300 r / min for 12 min to obtain the cold asphalt replenisher. Place it in a heat preservation box to keep warm and maintain the temperature at 140-150 °C for standby.

[0100] Add the finely stripped and screened RAP material and polyester fiber to the mixing tank, and then add diluent one to ensure that diluent one completely penetrates the polyester fiber to prevent the materials from agglomerating during mixing. Finally, add the cold asphalt replenisher and mix for 3 min to obtain the cold recycled fiber cold patch material.

[0101] Example 7

[0102] Preparation of cold recycled fiber cold patch material:

[0103] (1) Prepare raw materials by weight: 100 parts of finely stripped and screened RAP material, 1 part of cold asphalt replenisher, 2.3 parts of diluent one and 0.5 part of polyester fiber; among them, the finely stripped and screened RAP material is composed of finely stripped and screened alkaline basalt rocks of different specifications, specifically 85 parts of rich-oil fine aggregate and 15 parts of lean-oil coarse aggregate; the raw material weight parts of the cold asphalt replenisher are 78 parts of SBS modified asphalt, 19 parts of diluent two, 0.5 part of anti-stripping agent, 2 parts of polyvinyl acetate emulsion and 0.5 part of antioxidant.

[0104] (2) Preparation steps:

[0105] Heat the SBS modified asphalt to 150 °C until it is completely melted, pour it into a high-speed shear mixer together with diluent two, mix and shear at a rotation speed of 3200 r / min for 5 min. After shearing, add polyvinyl acetate emulsion, anti-stripping agent and antioxidant and mix and shear at a rotation speed of 4300 r / min for 12 min to obtain the cold asphalt replenisher. Place it in a heat preservation box to keep warm and maintain the temperature at 140-150 °C for standby.

[0106] Add the finely stripped and screened RAP material and polyester fiber to the mixing tank, and then add diluent one to ensure that diluent one completely penetrates the polyester fiber to prevent the materials from agglomerating during mixing. Finally, add the cold asphalt replenisher and mix for 3 min to obtain the cold recycled fiber cold patch material.

[0107] Example 8

[0108] Preparation of cold recycled fiber cold patch material:

[0109] (1) Prepare raw materials by weight: 100 parts of finely stripped and screened RAP material, 1.2 parts of cold asphalt replenisher, 1.7 parts of diluent 1, and 0.3 parts of polyester fiber; among them, the finely stripped and screened RAP material is composed of finely stripped and screened alkaline basalt rocks of different specifications, specifically 85 parts of oil-rich fine aggregate and 15 parts of oil-poor coarse aggregate; the raw material weight parts of the cold asphalt replenisher are 78 parts of SBS modified asphalt, 19 parts of diluent 2, 0.5 parts of anti-stripping agent, 2 parts of polyvinyl acetate emulsion, and 0.5 parts of antioxidant.

[0110] (2) Preparation steps:

[0111] Heat the SBS modified asphalt to 150 °C until it is completely melted, pour it into a high-speed shearer together with diluent 2, mix and shear at a speed of 3200 r / min for 5 min. After shearing, add polyvinyl acetate emulsion, anti-stripping agent and antioxidant and mix and shear at a speed of 4300 r / min for 12 min to obtain the cold asphalt replenisher. Put it into a heat preservation box to keep warm and maintain the temperature at 140 - 150 °C for standby;

[0112] Add the finely stripped and screened RAP material and polyester fiber to the mixing tank, and then add diluent 1 to ensure that diluent 1 completely penetrates the polyester fiber to prevent material agglomeration during the mixing process; finally, add the cold asphalt replenisher and mix for 3 min to obtain the cold recycled fiber cold patch material.

[0113] Example 9

[0114] Preparation of cold recycled fiber cold patch material:

[0115] (1) Prepare raw materials by weight: 100 parts of finely stripped and screened RAP material, 1.2 parts of cold asphalt replenisher, 2 parts of diluent 1, and 0.5 parts of polyester fiber; among them, the finely stripped and screened RAP material is composed of finely stripped and screened alkaline basalt rocks of different specifications, specifically 85 parts of oil-rich fine aggregate and 15 parts of oil-poor coarse aggregate; the raw material weight parts of the cold asphalt replenisher are 78 parts of SBS modified asphalt, 19 parts of diluent 2, 0.5 parts of anti-stripping agent, 2 parts of polyvinyl acetate emulsion, and 0.5 parts of antioxidant.

[0116] (2) Preparation steps:

[0117] Heat the SBS modified asphalt to 150 °C until it is completely melted, pour it into a high-speed shearer together with diluent 2, mix and shear at a speed of 3200 r / min for 5 min. After shearing, add polyvinyl acetate emulsion, anti-stripping agent and antioxidant and mix and shear at a speed of 4300 r / min for 12 min to obtain the cold asphalt replenisher. Put it into a heat preservation box to keep warm and maintain the temperature at 140 - 150 °C for standby;

[0118] Add the finely stripped and screened RAP material and polyester fiber into the mixing tank, and then add Diluent 1 to ensure that Diluent 1 completely penetrates the polyester fiber to prevent the materials from agglomerating during the mixing process; finally, add the cold asphalt replenisher and mix for 3 minutes to obtain the cold recycled fiber cold patching material.

[0119] Example 10

[0120] Preparation of cold recycled fiber cold patching material:

[0121] (1) Prepare raw materials by weight: 100 parts of finely stripped and screened RAP material, 1.2 parts of cold asphalt replenisher, 2.3 parts of Diluent 1, and 0.7 part of polyester fiber; among them, the finely stripped and screened RAP material is composed of finely stripped and screened alkaline basalt rocks of different specifications, specifically 85 parts of oil-rich fine aggregate and 15 parts of oil-poor coarse aggregate; the raw material weight parts of the cold asphalt replenisher are 78 parts of SBS modified asphalt, 19 parts of Diluent 2, 0.5 part of anti-stripping agent, 2 parts of polyvinyl acetate emulsion, and 0.5 part of antioxidant.

[0122] (2) Preparation steps:

[0123] Heat the SBS modified asphalt to 150 °C to completely melt it, pour it into a high-speed shearer together with Diluent 2, mix and shear at a speed of 3200 r / min for 5 minutes. After shearing, add the polyvinyl acetate emulsion, anti-stripping agent and antioxidant and mix and shear at a speed of 4300 r / min for 12 minutes to obtain the cold asphalt replenisher, put it into an incubator for heat preservation and keep the temperature at 140 - 150 °C for standby;

[0124] Add the finely stripped and screened RAP material and polyester fiber into the mixing tank, and then add Diluent 1 to ensure that Diluent 1 completely penetrates the polyester fiber to prevent the materials from agglomerating during the mixing process; finally, add the cold asphalt replenisher and mix for 3 minutes to obtain the cold recycled fiber cold patching material.

[0125] Example 11

[0126] Preparation of cold recycled fiber cold patching material:

[0127] The difference from Example 5 is that the oil-rich fine aggregate is 78 parts and the oil-poor coarse aggregate is 22 parts.

[0128] Example 12

[0129] Preparation of cold recycled fiber cold patching material:

[0130] The difference from Example 5 is that the oil-rich fine aggregate is 82 parts and the oil-poor coarse aggregate is 18 parts.

[0131] Example 13

[0132] Preparation of cold recycled fiber cold patch material:

[0133] The difference from Example 5 is that the oil-rich fine aggregate is 87 parts and the oil-poor coarse aggregate is 13 parts.

[0134] The cold-regenerated fiber cold patch materials prepared in Examples 1 to 13 above were subjected to the following performance tests:

[0135] 1. Initial forming Marshall stability (Marshall stability tester see Figure 2 )

[0136] 1200 g of the cold recycled fiber cold patch material of Examples 1 to 13 was weighed respectively. At 20°C, both sides were compacted 75 times. The specimen height was controlled at 63.5±1.3 mm. The Marshall test was carried out with reference to JTGE20-2019 (Test Procedure for Asphalt and Asphalt Mixtures in Highway Engineering). The results are shown in Table 4.

[0137] 2. Final Marshall Stability

[0138] 1200g of the cold recycled fiber cold patch material of Examples 1 to 13 was weighed respectively. At 20°C, it was compacted 50 times on both sides. After being placed in a 110°C oven for 24 hours, it was compacted 25 times on both sides. The specimen height was controlled at 63.5±1.3mm. The Marshall test was carried out with reference to JTGE20-2019 (Test Procedure for Asphalt and Asphalt Mixtures in Highway Engineering). The results are shown in Table 4.

[0139] 3. Water resistance

[0140] The cold recycled fiber cold patch materials of Examples 1 to 13 were tested for water resistance in accordance with JTGE20-2019 (Test Procedure for Asphalt and Asphalt Mixtures in Highway Engineering). The test results are shown in Table 4. The macroscopic images of the water resistance tests of some materials in Examples 1 to 13 are shown in Table 4. Figure 3 .

[0141] 4. Residual stability

[0142] The cold recycled fiber cold patch materials of Examples 1 to 13 were subjected to residual stability tests with reference to JTGE20-2019 (Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering). The test results are shown in Table 4.

[0143] 5. Rutting test

[0144] The cold recycled fiber cold patch materials of Examples 1 to 13 were subjected to rutting tests according to JTGE20-2019 (Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering). The test results are shown in Table 4. The macroscopic images of the cold recycled fiber cold patch material prepared in Example 5 before and after the indoor rutting test are shown in Table 4. Figure 4 , (a) is before the test, (b) is after the test.

[0145] 6. Strength Growth

[0146] The adhesion tests of Examples 1 to 13 were cured at 0 °C, and the Marshall stabilities at 1 d, 3 d, and 7 d were tested respectively. The test results are shown in Table 4.

[0147] 7. Storage Stability

[0148] Take 2 kg of the cold recycled fiber cold patch materials of Examples 1 to 13, heat them under a load of (10 kg) at 70 °C for 3 d, take them out and let them stand at room temperature under a load of (10 kg) for 3 d, pour out the cold patch materials, separate the agglomerated lumps, and calculate the agglomeration rate according to Equation (1). The test results are shown in Table 4. The pictures during the indoor storage stability test are shown in Figure 5 .

[0149]

[0150] In Equation (1): G a --- The total mass of the agglomerated lumps inside the specimen after the cold patch material stands for 6 d / kg;

[0151] G b --- The total mass of the cold patch material after standing for 6 d / kg;

[0152] GR --- The agglomeration rate of the cold patch material / %.

[0153] 8. Workability at Low Temperature

[0154] Take 2 kg of the cold recycled fiber cold patch materials of Examples 1 to 13, freeze them at -10 °C for 1 d, take them out and spread them out at room temperature to observe whether there is agglomeration or caking of the materials. The test results are shown in Table 4. The macroscopic pictures of the indoor workability test at low temperature of the cold recycled fiber cold patch material prepared in Example 5 are shown in Figure 6 , where (a) is before freezing and (b) is after freezing.

[0155] Table 4 Indoor Performance Test Results of the Cold Recycled Fiber Cold Patch Materials Prepared in Examples 1 to 13

[0156]

[0157]

[0158] As can be seen from the test data in Table 4, by comparing the three different groups of examples with different dosages of cold asphalt replenishing liquid in Examples 1-3, 5-7, and 8-10, the storage stability and low-temperature performance of the three groups of materials are all excellent. Among them, the cold recycled fiber cold patch materials in Examples 5-7 have good performance in all aspects. In Example 4, due to the absence of an anti-stripping agent, the final forming stability and material adhesion grade of the prepared cold asphalt patch material are both lower than those in Example 5, and the material strength increases relatively slowly, but it has no significant impact on other properties. By comparing Examples 5, 6, and 7, it can be seen that under the same conditions, as the dosage of 0# diesel diluent continuously increases, the Marshall stability of the mixture first increases and then decreases. It is analyzed that when the dosage of cold asphalt replenishing liquid is certain, as the dosage of the diluent inside the material continuously increases, the viscosity of the modified asphalt continuously decreases, making it better mix and bond with the aggregate. The fluidity of the asphalt mixture continuously improves, ultimately enhancing the uniformity of the asphalt mixture and increasing the strength. With the continuous increase in the dosage of the diluent, the viscosity of the asphalt continuously decreases. Excessive diluent weakens the bonding force between the asphalt and the aggregate, and the structure of the asphalt may become too thin to effectively support the aggregate and be stored in the asphalt mixture for a long time and volatilize completely, thereby reducing the overall strength of the mixture.

[0159] By comprehensively comparing the test performance detection results of Examples 1-~10 in Table 4, it can be seen that the cold patch material for asphalt pavement in Example 5 is superior in all aspects compared with the other nine examples. Based on this, the research team of the present invention also carried out relevant performance tests and comparisons of cold mix cold patch materials under different aggregate ratios, that is, Examples 11-13 (part). By deeply comparing the relevant performance indicators such as the strength, water stability, and temperature stability of cold asphalt patch materials under different gradations, it is found that Example 5 has the best comprehensive performance and can be widely used as a repair material for highway pavements.

[0160] The macroscopic diagram of the cohesion test using the cold recycled fiber cold patch material prepared in Example 5 of the present invention is shown in Figure 7 . As can be seen from Figure 7 , after the cold patch material composed of the material ratio in Example 5 undergoes the standard cohesion test, very few particles fall off, and the cohesion performance is excellent.

[0161] The test diagram of using the cold recycled fiber cold patch material prepared in Example 5 of the present invention for repairing a mining area bridge deck is shown in Figure 8 , where (a) is when it is just repaired, and (b) is 10 months after the repair. As can be seen from Figure 8 , after 10 months of field application, the cold patch material composed of the material ratio in Example 5 does not show diseases such as cracking and particle shedding. The surface texture at the repair site remains intact, and the comprehensive durability of the material is excellent.

[0162] The test diagram of using the cold recycled fiber cold patch material prepared in Embodiment 5 of the present invention for highway pavement repair is shown in Figure 9 .

[0163] The above embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A cold recycling fiber cold patch material based on fine peeling and screening technology, characterized in that By weight parts, the raw materials include: 100 parts of finely peeled and screened RAP material, 0.2 - 1.2 parts of fiber stabilizer, 0.6 - 1.8 parts of cold asphalt replenishing liquid, and 1.2 - 2.6 parts of diluent 1; By weight parts, the raw materials of the finely peeled and screened RAP material include: 80 - 90 parts of oil-rich fine aggregate and 10 - 20 parts of oil-poor coarse aggregate; By weight parts, the raw materials of the cold asphalt replenishing liquid include: 70 - 85 parts of SBS modified asphalt, 12 - 30 parts of diluent 2, 1 - 3 parts of polyvinyl acetate emulsion, 0.3 - 1 part of anti-stripping agent, and 0.3 - 0.7 part of antioxidant; The particle size range of the oil-rich fine aggregate is ≤5mm, and the asphalt-aggregate ratio is 6.2 - 6.4%; The particle size range of the oil-poor coarse aggregate is >5 and ≤11mm, and the asphalt-aggregate ratio is 1.9 - 2.1%.

2. The cold recycled fiber cold patch material based on the fine peeling and screening technology according to claim 1, wherein The fiber stabilizer is polyester fiber, the fiber diameter is 40 - 50μm, and the fiber length is ≤7mm.

3. The cold recycled fiber cold patch material based on the fine peeling and screening technology according to claim 1, wherein Both the diluent 1 and the diluent 2 are 0# light diesel oil.

4. The cold recycled fiber cold patch material based on the fine stripping and screening technology according to claim 1, wherein The anti-stripping agent is vinyl bis-stearamide.

5. The cold recycled fiber cold patch material based on the fine stripping and screening technology according to claim 1, characterized in that, The main component of the antioxidant is N-phenyl-1-naphthylamine.

6. A method for preparing a cold recycled fiber cold patch material based on a fine peeling and screening technology according to any one of claims 1 to 5, characterized in that, It includes the following steps: Prepare each raw material according to weight parts; Heat the SBS modified asphalt to melting, add the diluent 2 for shearing, then add the polyvinyl acetate emulsion, the anti-stripping agent, and the antioxidant and continue shearing to obtain the cold asphalt replenishing liquid for standby; Add the oil-rich fine aggregate, the oil-poor coarse aggregate, the fiber stabilizer, and the diluent 1 into a stirring device, then add the cold asphalt replenishing liquid and mix evenly to obtain the cold recycled fiber cold patch material based on the fine peeling and screening technology.

7. The preparation method according to claim 6, characterized in that, The shearing rate after adding the diluent 2 is 2600 - 3600r / min, and the shearing time is 3 - 5min.

8. The preparation method according to claim 6, wherein The shearing rate after adding the polyvinyl acetate emulsion, the anti-stripping agent, and the antioxidant is 3600 - 4700r / min, and the shearing time is 9 - 15min.

9. The preparation method according to claim 6, characterized in that, The temperature of the standby cold asphalt replenishing liquid is maintained at 140 - 150°C.

10. Application of the cold recycled fiber cold patch material based on the fine peeling and screening technology according to any one of claims 1 - 5 in road surface repair.

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