Cold regeneration fiber cold patch material based on fine stripping and screening technology and preparation method of cold regeneration fiber cold patch material

Abstract

The invention discloses a cold recycled fiber cold patch material based on a fine stripping and screening technology and a preparation method thereof, and belongs to the technical field of recycled asphalt mixtures. The cold regenerated fiber cold patch material based on the fine stripping and screening technology is prepared from the following raw materials in parts by weight: 100 parts of a fine stripping and screening RAP material, 0.2 to 1.2 parts of a fiber stabilizer, 0.6 to 1.8 parts of asphalt cold patch liquid and 1.2 to 2.6 parts of a diluent I, wherein the asphalt cold-patch liquid is prepared from the following raw materials: 70 to 85 parts of SBS (Styrene Butadiene Styrene) modified asphalt, 12 to 30 parts of diluent II, 1 to 3 parts of polyvinyl acetate emulsion, 0.3 to 1 part of anti-stripping agent and 0.3 to 0.7 part of antioxidant. The cold regeneration fiber cold patch material based on the fine stripping and screening technology has the advantages of being low in production cost, low in carbon, environmentally friendly, convenient to prefabricate, good in storage performance, high in adaptability, good in water tightness, high in thermal stability, excellent in durability and the like, can be rapidly constructed in extreme environments such as super-heavy loads and rainy and snowy days, does not loosen, is rapid in traffic opening and is suitable for large-scale popularization and application. The economic and environment-friendly benefits are obvious.

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 patch material based on a fine peeling and screening technology and a preparation method thereof. Background Art

[0002] Each year, a large amount of road waste asphalt recycled materials (RAP) are generated due to the reconstruction, expansion, and maintenance of asphalt pavements. However, the recycling rate of RAP in the industry 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 with the extension of the service time, reducing the service quality of the pavement, affecting driving comfort, and in severe cases, easily triggering traffic accidents and threatening driving safety. Therefore, the "efficient and timely" treatment of pavement diseases has always been the top priority of the industry's maintenance work.

[0003] The common method for treating pavement diseases is to use hot mix asphalt mixture for hot patching at 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. Specific construction requires professional large-scale machinery and technical personnel, etc., resulting in disadvantages such as high construction cost, long duration, large waste, many steps, high 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 patch materials have emerged. They are made by mixing a special asphalt cold liquid, aggregates, and additives in a certain proportion and stirring. They are in a loose state at normal temperature, can be stored in a sealed manner for a long time, and have the characteristics of low cost, convenient construction, little influence 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 patch materials, which are specifically manifested as follows: (1) When producing materials, all or part of new stones and new asphalt are used, and most are mixed by hot mix or warm mix processes, resulting in relatively high production costs; (2) The RAP used is often put into use after conventional primary screening. 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 difficult to control; (3) It is only applicable to repair 2m 2For potholes on the road surface with the following areas, the repair coverage is small and the storage stability of the materials is poor. The materials are 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 smoothness 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 coupled action of the environment and load, etc.

[0005] Therefore, it is very necessary to develop an environmentally friendly cold recycled asphalt cold patch material with "all-weather, all cold mixing, all recycled materials" that is economically friendly, has stable quality, strong adaptability, good storage performance, convenient use, good water tightness, good durability, and ideal strength, effectively extending the service life of the road surface and improving 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 a fine stripping and screening technology and its preparation method. On the one hand, the cold patch material is all cold mixed with finely stripped and screened 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 agglomeration degree and variability of RAP, and realizes the application dosage of RAP being 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, realizing 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 improving the storage stability of the product, effectively ensuring the paving and compaction convenience of the cold patch material when it is used again after long-term storage, making the material not easily produce road surface diseases such as peeling and cracking in a low-temperature use environment, effectively improving the durability of the material, and also omitting the pre-treatment steps such as grooving and drainage on the original road surface before the application of conventional cold patch materials, greatly simplifying the application procedure of the cold patch material, shortening the construction time to the greatest extent, effectively ensuring the construction safety and road traffic smoothness during repair, and having 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 a fine stripping and screening technology. By weight, the raw materials include: 100 parts of finely stripped and screened 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, 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, 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 patching material. Among them, too large or too small particle size is likely to reduce the compaction density of the cold asphalt patching material, leading to premature cracking of the material. Too high or too low total oil content in RAP will directly affect the bonding strength, anti-skid performance, and production economy of the cold patching material, while too high content of pseudo-particles in RAP will lead to excessive variability in the grading of the cold patching material, reducing the forming strength of the mixture and directly affecting the stability of the production quality of the cold patching 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 patching material, but also realize the full-process cold mixing of the cold patching material and increase the application dosage of RAP to 100%, effectively reducing the usage of new asphalt and new aggregate in the recycled material, and simultaneously improving the relevant properties such as the bearing strength, bonding performance, anti-skid performance, and water stability of the cold asphalt patching material.

[0014] The SBS modified asphalt in the asphalt cold patching fluid of the present invention has excellent bonding performance, which can effectively improve the bonding strength between the cold patch material and the old road surface, and reduce cracking and peeling phenomena. At the same time, the modification of SBS can give asphalt better flexibility, so that the cold patch material is not easy to break under temperature changes and loads, and maintain its good working performance under different climatic conditions. The addition of SBS can improve the anti-aging and water damage resistance of asphalt, reduce the degradation of the binder under ultraviolet rays and temperature and humidity changes, and maintain the durability of material performance to effectively extend the service life of the cold patch material. The team of the present invention has 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 used in the asphalt cold patching fluid of the present invention, the durability of the recycled cold patch material during service is significantly improved, the frequency of secondary repair of the material is greatly reduced, and the use and maintenance cost during the whole life cycle is lower. Based on one ton of finished products, compared with ordinary hot patch materials, the material of the present invention saves up to 100% of new aggregate and 2.3% of new asphalt during production, saving about 50 yuan / ton of stone cost and about 142 yuan / ton of asphalt cost respectively. Conventional hot patch materials consume about 7 kg of heavy oil per cubic meter of mixture heated from room temperature to a stirring temperature of 180°C. If diesel is used for heating, the material of the present invention can save 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 repair grooving and labor miscellaneous costs can be reduced by about 50 yuan / ton, with a total cost reduction of about 273.5 yuan / ton, with significant economic and social benefits.

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

[0016] The anti-stripping agent added to the asphalt cold patching fluid of the present invention is mainly used to improve the adhesion between asphalt and aggregate, reduce the peeling of asphalt from aggregate due to changes in external temperature and humidity, prevent moisture from penetrating into the repair surface to reduce freeze-thaw damage and water erosion, ensure the water stability and integrity of the asphalt repair road surface, thereby improving the durability and anti-aging performance of the asphalt road surface and extending the service life of the repair surface.

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

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

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

[0020] The addition of polyester fiber can make components such as asphalt cold patch fluid and aggregate disperse evenly in the mixture, without forming agglomerates and being fluffy. At the same time, it can 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 patch 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 according to parts 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 patch fluid for later use;

[0028] Add the rich-oil fine aggregate, the lean-oil coarse aggregate, the fiber stabilizer and the first diluent into a stirring device, then add the asphalt cold patch fluid 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 - 3600 r / min, and the shear time is 3 - 5 min; more preferably, the shear rate is 3200 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 replenishment liquid 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-regenerated fiber cold patch material based on fine stripping 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 based on full fine stripping and screening 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 is a flowchart of using the cold-regenerated fiber cold patch material prepared by the embodiment of the present invention to repair a road surface.

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

[0037] Figure 3 This is a macroscopic picture of the water resistance test of 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, wherein (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, wherein (a) is before freezing and (b) is after freezing.

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

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

[0043] Figure 9 Test diagram of using the cold recycled fiber cold patch material prepared in Example 5 of the present invention for repairing the highway pavement. 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 should be understood 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 operations not detailed 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. Each 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, that is, they are intended to mean 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., and 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 composed of 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 sieving 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 sieving 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 sieved RAP material, 0.8 part of asphalt cold liquid, 2 parts of diluent 1, and 0.5 part of polyester fiber; among them, the finely stripped and sieved RAP material is composed of finely stripped and sieved basic 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 asphalt cold 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 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 speed of 4300 r / min for 12 min to obtain 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 patching material.

[0071] Example 2

[0072] Preparation of cold recycled fiber cold patching 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 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 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 patching material.

[0077] Example 3

[0078] Preparation of cold recycled fiber cold patching 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 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.

[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 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 an incubator for heat preservation and keep the temperature at 140 - 150 °C for standby;

[0082] 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 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 1, 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 2, 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 2, 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 an incubator for heat preservation and keep 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 the mixing process; finally, add the cold asphalt replenisher and mix for 3 minutes to obtain the cold recycled fiber cold patching material.

[0089] Example 5

[0090] Preparation of cold recycled fiber cold patching 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 the mixing process; finally, add the cold asphalt replenisher and mix for 3 minutes to obtain the cold recycled fiber cold patching material.

[0095] Example 6

[0096] Preparation of cold recycled fiber cold patching 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 asphalt cold replenishing liquid. Put it into 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 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 patching material.

[0101] Example 7

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

[0103] (1) Prepare raw materials by weight: 100 parts of finely stripped and screened RAP material, 1 part of asphalt cold replenishing liquid, 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 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, 0.5 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 asphalt cold replenishing liquid. Put it into 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 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 patching material.

[0107] Example 8

[0108] Preparation of cold recycled fiber cold patching 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 part of anti-stripping agent, 2 parts of polyvinyl acetate emulsion, and 0.5 part 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 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.

[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 patch material.

[0119] Example 10

[0120] Preparation of the cold recycled fiber cold patch 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 parts of polyester fiber; among them, the finely stripped and screened RAP material is composed of finely stripped and screened basic 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 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;

[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 patch material.

[0125] Example 11

[0126] Preparation of the cold recycled fiber cold patch 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 the cold recycled fiber cold patch 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 Recycling Fiber Cold Patch Material

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

[0134] Perform the following performance tests on the cold recycling fiber cold patch materials prepared in Examples 1 to 13 above:

[0135] 1. Initial Marshall Stability (for the Marshall Stability Tester, see Figure 2 )

[0136] Weigh 1200 g of the cold recycling fiber cold patch materials of Examples 1 to 13 respectively. Under the condition of 20 °C, compact them double-sidedly 75 times, and control the height of the specimen at 63.5 ± 1.3 mm. Conduct the Marshall test with reference to JTGE20-2019 (Test Procedures for Bitumen and Bituminous Mixtures for Highway Engineering), and the results are shown in Table 4.

[0137] 2. Final Marshall Stability

[0138] Weigh 1200 g of the cold recycling fiber cold patch materials of Examples 1 to 13 respectively. Under the condition of 20 °C, compact them double-sidedly 50 times, place them in an oven at 110 °C for 24 h, and then compact them double-sidedly 25 times. Control the height of the specimen at 63.5 ± 1.3 mm. Conduct the Marshall test with reference to JTGE20-2019 (Test Procedures for Bitumen and Bituminous Mixtures for Highway Engineering), and the results are shown in Table 4.

[0139] 3. Water Resistance

[0140] Conduct the water resistance test on the cold recycling fiber cold patch materials of Examples 1 to 13 with reference to JTGE20-2019 (Test Procedures for Bitumen and Bituminous Mixtures for Highway Engineering), and the test results are shown in Table 4. The macroscopic diagrams of the water resistance test for some of the materials in Examples 1 to 13 are shown in Figure 3 .

[0141] 4. Residual Stability

[0142] Conduct the residual stability test on the cold recycling fiber cold patch materials of Examples 1 to 13 with reference to JTGE20-2019 (Test Procedures for Bitumen and Bituminous Mixtures for Highway Engineering), and the test results are shown in Table 4.

[0143] 5. Rutting Test

[0144] Conduct the rutting test on the cold recycling fiber cold patch materials of Examples 1 to 13 with reference to JTGE20-2019 (Test Procedures for Bitumen and Bituminous Mixtures for Highway Engineering), and the test results are shown in Table 4. The macroscopic diagrams of the cold recycling fiber cold patch material prepared in Example 5 before and after the indoor rutting test are shown in Figure 4 , (a) is before the test, and (b) is after the test.

[0145] 6. Strength Growth

[0146] The adhesion tests of Examples 1 to 13 were cured under the condition of 0°C, and the Marshall stabilities at 1d, 3d, and 7d 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 3d, take them out and let them stand at normal temperature under a load of (10 kg) for 3d, 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 sample after the cold patch material stands for 6d / kg;

[0151] G b --- The total mass of the cold patch material after standing for 6d / 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 1d, take them out and spread them out at normal temperature to observe whether there is agglomeration and caking phenomenon. The test results are shown in Table 4. The macroscopic pictures of the cold recycled fiber cold patch material prepared in Example 5 during the indoor workability test at low temperature 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 Examples 1-3, 5-7, and 8-10 with three different dosages of cold asphalt replenisher, it can be known that the storage stability and low-temperature performance of the three groups of materials are 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 are 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 increases continuously, the Marshall stability of the mixture first increases and then decreases. It is analyzed that when the dosage of cold asphalt replenisher is certain, as the dosage of the diluent inside the material increases continuously, the viscosity of the modified asphalt decreases continuously, making it better mix and bond with the aggregate. The fluidity of the asphalt mixture increases continuously, ultimately enhancing the uniformity of the asphalt mixture and improving the strength. With the continuous increase of the diluent dosage, the viscosity of the asphalt continues to decrease. 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 known that the cold patch material for asphalt pavement in Example 5 is superior in various performances 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 patches 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, there are very few dropped particles, 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 the cold patch material composed of the material ratio in Example 5 undergoes 10 months of field application, the material does not show diseases such as cracking and dropping particles, the surface texture of the repaired area 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 embodiments described above are only descriptions of the preferred modes 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-regenerated fiber cold patch material based on fine stripping and screening technology, characterized in that: The raw materials include, by weight: 100 parts of finely stripped and screened RAP material, 0.2-1.2 parts of fiber stabilizer, 0.6-1.8 parts of asphalt cold make-up liquid and 1.2-2.6 parts of diluent; The raw materials of the finely stripped and screened RAP material include, by weight: 80-90 parts of oil-rich fine aggregate and 10-20 parts of oil-poor coarse aggregate; The raw materials of the asphalt cold patching fluid include, by weight: 70-85 parts of SBS modified asphalt, 12-30 parts of diluent II, 1-3 parts of polyvinyl acetate emulsion, 0.3-1 parts of anti-stripping agent and 0.3-0.7 parts of antioxidant; The particle size of the oil-rich fine aggregate is ≤5 mm, and the oil-stone ratio is 6.2-6.4%; The particle size range of the oil-poor coarse aggregate is greater than 5 and less than or equal to 11 mm, and the oil-stone ratio is 1.9-2.1%.

2. The cold regenerated fiber cold patch material based on fine stripping and screening technology according to claim 1 is characterized in that: The fiber stabilizer is polyester fiber with a fiber diameter of 40 to 50 μm and a fiber length of ≤7 mm.

3. The cold regenerated fiber cold patch material based on fine peeling and screening technology according to claim 1 is characterized in that: The diluent 1 and the diluent 2 are both 0# light diesel.

4. The cold regenerated fiber cold patch material based on fine peeling and screening technology according to claim 1 is characterized in that: The anti-stripping agent is vinyl bisstearamide.

5. The cold regenerated fiber cold patch material based on fine peeling and screening technology according to claim 1 is characterized in that: The antioxidant is mainly composed of N-phenyl-1-naphthylamine.

6. A method for preparing a cold-regenerated fiber cold patch material based on fine peeling and screening technology according to any one of claims 1 to 5, characterized in that: The following steps are involved: Prepare the raw materials according to weight; The SBS modified asphalt is heated until it is melted, the diluent 2 is added to perform shearing, and then the polyvinyl acetate emulsion, the anti-stripping agent and the antioxidant are added to continue shearing to obtain the asphalt cold patching liquid for standby use; The oil-rich fine aggregate, the oil-poor coarse aggregate, the fiber stabilizer and the diluent are added into a stirring device, and then the asphalt cold patch liquid is added and mixed evenly to obtain the cold recycled fiber cold patch material based on fine stripping and screening technology.

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

8. The preparation method according to claim 6, characterized in that: 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.

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

10. Use of the cold recycled fiber cold patch material based on fine stripping and screening technology as claimed in any one of claims 1 to 5 in road repair.

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