A reactive quick-setting high-strength recycled asphalt cold patch material, its preparation method and application

Abstract

The present invention relates to the technical field of road surface layer recycling, and in particular to a reactive quick-setting high-strength recycled asphalt cold patch material, a preparation method and an application thereof. The reactive quick-setting high-strength recycled asphalt cold patch material is prepared by using recycled milled materials as aggregates and mixing them with mineral powder and a reactive adhesive mother liquor, realizing the recycling of road surface milled materials, alleviating the dual problems of solid waste accumulation and shortage of high-quality stone resources, and solving the problem that RAP materials have been used only for light traffic and downgraded applications in the middle and lower layers in the past, and can be better applied to harsh repair operation environments such as high altitudes, large temperature differences, low-temperature rain and snow weather, and pothole ponding.

Description

Technical Field

[0001] The present invention relates to the technical field of road surface layer reuse, and in particular to a reactive quick-setting high-strength recycled asphalt cold patch material, a preparation method and an application thereof. Background Art

[0002] The reduction and resource utilization of solid waste has always been a difficult problem that has troubled governments and researchers around the world. In a circular economy, materials circulate in the economy for as long as possible at the highest value, which is achieved through upgrading, reuse, recycling and manufacturing.

[0003] The recycling of asphalt pavement is a common practice at home and abroad, and a complete set of asphalt recycling technology has been formed, reaching the level of normalization and standardization. However, when the factory-mixed hot recycling technology is currently used to recycle asphalt, the secondary high-temperature heating and mixing of the mixture (150-170°C) will cause the asphalt material to age again, reducing the reuse rate of old road materials. In addition, the test roads for recycling waste asphalt mixtures to different degrees are only used as waste materials, generally only for light traffic roads, sidewalks or road cushions, occupying and wasting limited high-quality stone and asphalt resources, and the economic benefits are poor.

[0004] Based on the above-mentioned existing technologies, there are technical problems that need to be solved urgently, such as low utilization rate and poor utilization effect of waste asphalt mixtures, poor performance of cold patch materials prepared after recycling, and difficulty in adapting to harsh repair working environments such as high altitudes, large temperature differences, low temperature rain and snow weather, and water accumulation in potholes. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a reactive quick-setting high-strength recycled asphalt cold patch material, wherein the cold patch material is prepared with recycled milling material as aggregate, mineral powder and reactive adhesive mother liquid;

[0006] By weight, the components and proportions of the reactive quick-setting high-strength recycled asphalt cold patch material are as follows:

[0007] Recycled milling material as aggregate: 90-96%;

[0008] Mineral powder: 4-7%;

[0009] Reactive adhesive masterbatch: 3-6%;

[0010] The stability of the reactive quick-setting high-strength recycled asphalt cold patch material is 28.6-31.2 kN, and the dynamic stability is 10000-12000 times•mm -1 , the low temperature strain is 2401-3015με, the freeze-thaw strength ratio is 84-89%, and the flying loss is 4.8-7.2%.

[0011] Further, the recycled milled material is the milled material from the surface layer of the asphalt pavement.

[0012] Further, the recycled milled material includes one or more of old asphalt and old aggregates.

[0013] Further, the old asphalt includes one or more of road petroleum asphalt and modified asphalt;

[0014] The old aggregates include one or more of basalt gravel, diabase gravel, and limestone gravel.

[0015] Further, the recycled milled material is divided into three particle sizes: 0 - 5mm, 5 - 10mm, and 10 - 15mm.

[0016] Further, the moisture content of the recycled milled material is less than or equal to 0.5%.

[0017] Further, the recycled milled material is recycled and pretreated according to the T0727 method in JTGE20 - 2011 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" to separate the old asphalt and old aggregates in the reclaimed asphalt pavement (RAP material).

[0018] Further, the penetration of the old asphalt is 24 - 25 0.1mm, the softening point is 55 - 60°C, the ductility at 5°C is 8 - 9cm, and the viscosity at 135°C is 2.5 - 3.5 Pa•s.

[0019] Further, the mineral powder is the mineral powder ground from limestone or basic rocks.

[0020] Further, the reactive adhesive mother liquor is prepared from liquid polyester polyol, diisocyanate, chain extender crosslinking agent, tackifying resin, defoaming agent, and regeneration liquid.

[0021] Further, by weight, the components and proportions for preparing the reactive adhesive mother liquor are as follows:

[0022] Liquid polyester polyol: 30 - 50%;

[0023] Diisocyanate: 10 - 40%;

[0024] Chain extender crosslinking agent: 1 - 3%;

[0025] Tackifying resin: 3 - 6%;

[0026] Defoaming agent: 1 - 2%;

[0027] The mass of the regeneration liquid is 8 - 15% of the old asphalt in the recycled milled material.

[0028] Further, the liquid polyester polyol is a polymer formed by polycondensation of one or more combinations of polypropylene glycol, polyethylene glycol, polytetrahydrofuran glycol, 4-cyclohexanedicarboxylic acid-3-methyl-1,5-pentanediol, and ester diol.

[0029] Further, the molecular weight of the liquid polyester polyol is 2000-7000.

[0030] Further, the diisocyanate is one or several of diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, polymethylene polyphenyl polyisocyanate, 1,6-diisocyanato, hexamethylene diisocyanate, isophorone diisocyanate, 3,3'-dimethyl diphenylmethane-4,4'-diisocyanate.

[0031] Further, the chain extender crosslinking agent is one or several of diethylene glycol, neopentyl glycol, 1,4-butanediol, and 2-hydroxypropyl acrylate.

[0032] Further, the tackifying resin is one or several of terpene phenol resin, petroleum resin C5 or its hydride, rosin glyceride, and polyvinyl acetate.

[0033] Further, the defoaming agent is one or several of silicone defoaming agent, organofluorine defoaming agent, non-silicon defoaming agent, and mineral oil defoaming agent.

[0034] Further, the regeneration liquid is a composite solvent obtained by mixing light oil, lubricant, and stabilizer.

[0035] Further, by weight, the components and proportions for preparing the regeneration liquid are as follows:

[0036] Light oil: 80-100%;

[0037] Lubricant: 30-50%;

[0038] Stabilizer: 2-5%.

[0039] Further, the light oil is one or several of naphthenic oil and de-aromatic paraffin solvent oil.

[0040] Further, the lubricant is 6-hexanediol diglycidyl ether.

[0041] Further, the stabilizer is one or several of lauric acid, dianhydride, and octanoic acid.

[0042] The present invention also provides a preparation method for a reactive quick-setting and high-strength recycled asphalt cold patch material, including the following steps:

[0043] Step 1, Obtain the recycled milled material:

[0044] Step 2: Prepare the reactive adhesive mother liquor;

[0045] Step 3: Mix the milled materials recycled in Step 1, the reactive adhesive mother liquor in Step 2, and the mineral powder at a speed of 40 - 60 r / min for 60 - 70 s to prepare the reactive quick-setting high-strength recycled asphalt cold patch material.

[0046] Further, in Step 1, the milled materials are crushed into fine particles with a maximum nominal particle size of 19.5 mm, and then screened. The milled materials are divided into three types: 0 - 5 mm, 5 - 10 mm, and 10 - 15 mm.

[0047] Further, the preparation method of the reactive adhesive mother liquor in Step 2 includes the following steps:

[0048] Step 2 - 1: Polyol dehydration: Weigh each component by mass. Add the liquid polyester polyol and the recycled liquid into the reaction kettle and stir to mix. Use a temperature-controlled heating jacket to raise the temperature to 120 - 130 °C, and use a vacuum pump to reduce the pressure of the system to 0.67 ± 0.03 Kpa to evacuate water for 2 - 3 h. Then cool down to 60 - 70 °C and wait for standby;

[0049] Step 2 - 2: Preparation of prepolymer: Add the melted diisocyanate into the reaction kettle, slowly raise the temperature to 120 - 130 °C, and stir and react at a high speed of 400 - 600 r / min for 1 - 2 h in a nitrogen atmosphere to obtain the prepolymer;

[0050] Step 2 - 3: Synthesis of mother liquor: Add the chain extender crosslinking agent, tackifying resin, and defoaming agent to the prepolymer in sequence, keep stirring and reacting at a high speed under vacuum conditions for 2 - 3 h, cool down to 70 - 80 °C, and then quickly discharge and encapsulate in an aluminum foil bag to obtain the reactive adhesive mother liquor.

[0051] A solidified material, which is obtained by solidifying the above-mentioned reactive quick-setting high-strength recycled asphalt cold patch material.

[0052] Further, the Marshall stability of the solidified material at 1 d age is greater than 30 kN, which is 8 - 10 times that of the traditional cold patch material; the dynamic stability index ≥ 6000 times / mm, and the high-temperature stability is significantly better than that of the hot mix asphalt mixture. The residual stability ≥ 85%, and the freeze-thaw splitting strength ratio ≥ 80%, indicating excellent water stability.

[0053] The beneficial effects of the present invention are as follows:

[0054] 1. In the present invention, the main polymer of the reactive adhesive mother liquor is a terminal isocyanate group prepolymer synthesized from liquid polyester polyol and isocyanate, which can realize the transformation from thermoplastic binder to thermosetting binder. The process mainly includes initial curing and final curing. The initial curing is a physical process, involving crystallization, solvent evaporation, and preliminary cross-linking of the adhesive polymer, mainly related to adsorption and diffusion theories. The final curing is a chemical process, involving chemical bond formation. Through the -NCO at the end of the active end group molecular chain reacting with active hydrogens such as water adsorbed on the substrate surface and water (-OH) in the air for curing cross-linking, a urea bond structure is formed. At this time, the polymer contains a large number of carbamate groups (-NH-COO-), making the material properties stable. After heating, it does not have the ability to flow and deform, cannot be softened and remolded repeatedly, and cannot be dissolved in solvents, indicating that the curing process is completely completed.

[0055] 2. In the present invention, light oil, lubricant, and stabilizer are used as composite regeneration components to recover and strengthen the attenuation performance of the recycled milled materials. Using naphthenic oil and one or two of de-aromatic paraffin solvent oil and styrene-butadiene block copolymer mixed in any proportion as light oil is a good asphalt regeneration material, which can soften and adjust the problem of hardening and embrittlement caused by severe loss of saturates during asphalt aging, and adjust the migration and change ratio of the four components of asphalt. Using 6-hexanediol diglycidyl ether as a lubricant can reduce the macromolecular polymer of old asphalt to small molecule compounds. When asphalt is affected by light and oxygen, the unsaturated functional groups are unstable during the aging process and are prone to oxidation, dehydrogenation, polycondensation, addition, cross-linking and other reactions to produce macromolecular polymers such as carbonyl and sulfoxide groups. The lubricant component can degrade and reduce them to olefin compounds, further restoring the elasticity and flexibility and low-temperature ductility performance of asphalt.

[0056] 3. By combining the ambient temperature regeneration technology with the reactive cold patch technology and using the recycled milled materials as aggregates, 100% recycling of the pavement milled materials is achieved, alleviating the dual problems of solid waste accumulation and shortage of high-quality stone resources, and solving the problem that RAP materials were previously only used for downgraded applications in light traffic and the middle and lower layers. At the same time, the fatal disadvantage of traditional diluted cold patches is poor water resistance. Even with the addition of high-molecular materials such as anti-stripping agents, it is difficult to resist the damage of water to the oil film. The reactive quick-setting high-strength recycled asphalt cold patch prepared in the present invention uses water as an activator to promote the chemical gel curing of the binder, turning the disadvantages of traditional cold patches into advantages, and being more suitable for harsh repair operation environments such as high altitudes, large temperature differences, low-temperature rain and snow weather, and pothole water accumulation.

[0057] 4. Compared with traditional cold patch material technology, to ensure the workability of the mixture and reserve pores for later solvent volatilization, the mineral aggregate gradation mostly uses single-sized aggregates as the main component, with less use of crushed sand powder. As a result, the void ratio of the final mixture is relatively large, and it is difficult to ensure the density. The present invention has developed a special cold patch recycled mixture gradation with an extremely low porosity and a relatively low requirement for compaction work. The passing rate range of its gradation is as follows: the passing rate of the 16mm sieve hole is 100%, the passing rate of the 13.2mm sieve hole is 90 - 100%, the passing rate of the 9.5mm sieve hole is 68 - 82%, the passing rate of the 4.75mm sieve hole is 38 - 55%, the passing rate of the 2.36mm sieve hole is 21 - 32%, the passing rate of the 0.6mm sieve hole is 15 - 23%, the passing rate of the 0.3mm sieve hole is 9 - 14%, the passing rate of the 0.15mm sieve hole is 8 - 13%, and the passing rate of the 0.075mm sieve hole is 8 - 12%.

[0058] 5. The strength improvement of the present invention is achieved through a chemical curing process, with a fast reaction speed. The initial strength can be rapidly formed within 10 minutes, achieving surface hardening. And when combined with a special dense gradation, after complete curing, the Marshall stability of the mixture (1-day age) is greater than 30kN, which is 8 - 10 times that of traditional cold patch materials; the dynamic stability index ≥ 6000 times / mm, and the high-temperature stability is significantly better than that of hot mix asphalt mixtures. The residual stability ≥ 85%, and the freeze-thaw splitting strength ratio ≥ 80%, with excellent water stability. Detailed implementation mode

[0059] In the following examples, the recycled milled materials are sourced from the middle surface layer asphalt mixture on a secondary highway in Shanxi. Example 1

[0060] This example provides a reactive rapid-setting high-strength recycled asphalt cold patch material, which is prepared with recycled milled materials as the aggregate, together with mineral powder and a reactive adhesive mother liquor.

[0061] By weight, the components and proportions for preparing the reactive rapid-setting high-strength recycled asphalt cold patch material are as follows:

[0062] Recycled milled materials as the aggregate: 96%;

[0063] Mineral powder: 7%;

[0064] Reactive adhesive mother liquor: 3.311%;

[0065] The stability of the reactive rapid-setting high-strength recycled asphalt cold patch material is 31.2 kN, and the dynamic stability is 11000 times•mm -1 , the low-temperature strain is 2741 με, the freeze-thaw strength ratio is 87%, and the flushing loss is 5.4%.

[0066] The recycled milled material is the milled material from the surface layer of the asphalt pavement, including old asphalt and old aggregates.

[0067] The recycled milled material is divided into three particle sizes: 0 - 5mm, 5 - 10mm, and 10 - 15mm, with a moisture content less than or equal to 0.5%.

[0068] In this embodiment, the recycled milled material is recycled and pretreated according to the T0727 method in JTGE20 - 2011 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" to separate the old asphalt and old aggregates in the reclaimed asphalt pavement (RAP material).

[0069] The asphalt - aggregate ratio in the RAP is calculated to be 2.2%, and the performance of the old asphalt is detected. The test results are shown in Table 1 below.

[0070] Table 1 Performance Indexes of Old Asphalt in RAP

[0071]

[0072] The dense - type EA - 13 gradation specifically for pothole repair on roads is used as the target mix ratio. The milled material is screened by grading to determine the mineral aggregate gradation as 10 - 15mm:5 - 10mm:0 - 5mm:mineral powder = 21:40:32:7, and the asphalt - aggregate ratio is determined to be 5.6% through the Marshall test. The mineral aggregate gradation table is shown in Table 2 below.

[0073] Table 2 Gradation of Reactive Quick - setting High - strength Recycled Asphalt Cold Patch

[0074]

[0075] In this embodiment, the mineral powder is the mineral powder ground from limestone.

[0076] In this embodiment, the reactive adhesive mother liquor is prepared from liquid polyester polyol, diisocyanate, chain extender cross - linker, tackifying resin, defoaming agent, and regeneration liquid.

[0077] By weight, the components and proportions for preparing the reactive adhesive mother liquor are as follows:

[0078] Liquid polyester polyol, polyoxypropylene glycol: 40%;

[0079] Diisocyanate, diphenylmethane diisocyanate: 30%;

[0080] Chain extender cross - linker, diethylene glycol: 2%;

[0081] Tackifying resin, terpene phenol resin: 5%;

[0082] Defoaming agent, silicone defoaming agent: 1%;

[0083] The mass of the regeneration liquid is 9% of the old asphalt in the recycled milled material.

[0084] According to the dense gradation as the target mix ratio, the dosage of each gradation of materials is determined for gradation design, and it is formulated into a mixed milled material. The dosage of the reactive adhesive mother liquid is determined through the Marshall test.

[0085] In this embodiment, based on the determined mineral aggregate gradation 10 - 15mm:5 - 10mm:0 - 5mm:mineral powder = 21:40:32:7, the asphalt - aggregate ratio is 5.6%. After testing, the asphalt - aggregate ratio in the RAP material is 2.2%. The penetration of the aged asphalt after extraction treatment is 24.6 dmm. The test shows that when 9% of the regeneration liquid is added to the aged asphalt in the RAP material, the attenuation performance of the aged asphalt can be better restored and improved. Therefore, the proportion of the aged asphalt is 96×2.2% = 2.1%, the corresponding proportion of the regeneration liquid is 2.1%×9% = 0.189%, and the proportion of the reactive adhesive mother liquid added is 5.6 - 2.1 - 0.189 = 3.311%.

[0086] In this embodiment, the regeneration liquid is a composite solvent obtained by mixing light oil, lubricant, and stabilizer.

[0087] By weight, the components and their proportions for preparing the regeneration liquid are as follows:

[0088] Light oil, naphthenic oil: 90%;

[0089] Lubricant, 6 - hexanediol diglycidyl ether: 50%;

[0090] Stabilizer, lauric acid: 3%.

[0091] In this embodiment, the preparation method of the above - mentioned reactive quick - setting high - strength recycled asphalt cold patch material includes the following steps:

[0092] Step 1: Obtain the recycled milled material, crush the milled material into fine particles with a maximum nominal particle size of 19.5 mm, and then perform screening treatment to divide the milled material into three types: 0 - 5 mm, 5 - 10 mm, and 10 - 15 mm.

[0093] Step 2: Prepare the reactive adhesive mother liquid, which specifically includes the following steps:

[0094] Step 2 - 1: Polyol dehydration: Weigh each component by mass, add the liquid polyester polyol and the regeneration liquid into the reaction kettle and stir - mix. Use a temperature - controlled heating jacket to raise the temperature to 120°C, use a vacuum pump to reduce the pressure of the system to 0.67±0.03 Kpa to pump out the vacuum and dehydrate for 2 h, and cool down to 70°C for standby.

[0095] Step 2-2, Preparation of prepolymer: Add the melted diisocyanate into the reaction kettle, slowly heat up to 125 °C, and carry out high-speed stirring reaction at a speed of 400 r / min under a nitrogen atmosphere for 1 h to obtain the prepolymer;

[0096] Step 2-3, Synthesis of mother liquor: Sequentially add chain extender crosslinking agent, tackifying resin, and defoaming agent to the prepolymer, maintain high-speed stirring reaction for 2 h under vacuum conditions, cool down to 80 °C, quickly discharge the material and encapsulate it in an aluminum foil bag to obtain the reaction-type adhesive mother liquor;

[0097] Step 3, Mix the milled materials recovered in Step 1, the reaction-type adhesive mother liquor in Step 2, and mineral powder at a speed of 40 r / min for 60 s to prepare the reaction-type rapid-setting high-strength recycled asphalt cold patch material. Example 2

[0098] This example provides a reaction-type rapid-setting high-strength recycled asphalt cold patch material, which is prepared with the recovered milled materials as the aggregate, together with mineral powder and reaction-type adhesive mother liquor;

[0099] By weight, the components and proportions for preparing the reaction-type rapid-setting high-strength recycled asphalt cold patch material are as follows:

[0100] Recovered milled materials as aggregate: 94%;

[0101] Mineral powder: 7%;

[0102] Reaction-type adhesive mother liquor: 3.348%;

[0103] The stability of the reaction-type rapid-setting high-strength recycled asphalt cold patch material is 28.6 kN, the dynamic stability is 12,000 times•mm -1 , the low-temperature strain is 3015 με, the freeze-thaw strength ratio is 85%, and the scatter loss is 6.1%.

[0104] The recovered milled materials are the milled materials from the surface layer of the asphalt pavement, including old asphalt and old aggregates.

[0105] The recovered milled materials are divided into three particle sizes of 0-5 mm, 5-10 mm, and 10-15 mm, and the moisture content is less than or equal to 0.5%.

[0106] In this example, the recovered milled materials are recovered and pretreated according to the T0727 method in JTGE20-2011 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" to separate the old asphalt and old aggregates in the recycled asphalt mixture (RAP material). The performance indicators of the old asphalt are the same as those in Example 1.

[0107] In this example, the mineral powder is the mineral powder ground from limestone. The mineral aggregate gradation steps are the same as those in Example 1.

[0108] In this embodiment, the reactive adhesive mother liquor is prepared from a liquid polyester polyol, a diisocyanate, a chain extender crosslinking agent, a tackifying resin, an antifoaming agent, and a regeneration liquid.

[0109] By weight, the components and proportions for preparing the reactive adhesive mother liquor are as follows:

[0110] The liquid polyester polyol is polyethylene glycol: 30%;

[0111] The diisocyanate is 1,5-naphthalene diisocyanate: 10%;

[0112] The chain extender crosslinking agent is neopentyl glycol: 1%;

[0113] The tackifying resin is petroleum resin C5: 6%;

[0114] The antifoaming agent is an organofluorine antifoaming agent: 2%;

[0115] The mass of the regeneration liquid is 12% of the old asphalt in the recycled milled material.

[0116] According to the dense gradation as the target mix ratio, the dosage of each size of aggregate is determined for gradation design, and it is formulated into a mixed milled material. The dosage of the reactive adhesive mother liquor is determined through the Marshall test, and the determination method is the same as that in Embodiment 1.

[0117] In this embodiment, the regeneration liquid is a composite solvent obtained by mixing a light oil, a lubricant, and a stabilizer.

[0118] By weight, the components and proportions for preparing the regeneration liquid are as follows:

[0119] The light oil is a de-aromatic paraffinic solvent oil: 80%;

[0120] The lubricant is 6-hexanediol diglycidyl ether: 35%;

[0121] The stabilizer is dianhydride: 5%.

[0122] In this embodiment, the preparation method of the above-mentioned reactive quick-setting and high-strength recycled asphalt cold patch material includes the following steps:

[0123] Step 1: Obtain the recycled milled material, crush the milled material into fine particles with a maximum nominal particle size of 19.5 mm, and then perform screening treatment to divide the milled material into three types: 0 - 5 mm, 5 - 10 mm, and 10 - 15 mm;

[0124] Step 2: Prepare the reactive adhesive mother liquor, which specifically includes the following steps:

[0125] Step 2-1, Polyol dehydration: Weigh each component by mass. Add the liquid polyester polyol and the regenerant into the reaction kettle, stir and mix them. Use a temperature-controlled heating jacket to raise the temperature to 120°C, and use a vacuum pump to reduce the pressure of the system to 0.67±0.03 Kpa to pump out the water under vacuum for 2 hours. Then cool down to 70°C and wait for further use;

[0126] Step 2-2, Preparation of prepolymer: Add the melted diisocyanate into the reaction kettle, slowly raise the temperature to 125°C, and stir and react at a high speed of 400 r / min under a nitrogen atmosphere for 1 hour to obtain the prepolymer;

[0127] Step 2-3, Synthesis of mother liquor: Add the chain extender crosslinking agent, tackifying resin, and defoaming agent to the prepolymer in sequence, keep stirring and reacting at a high speed under vacuum conditions for 2 hours, cool down to 80°C, then quickly discharge the material and encapsulate it in an aluminum foil bag to obtain the reactive adhesive mother liquor;

[0128] Step 3, Mix the milled material recovered in Step 1, the reactive adhesive mother liquor in Step 2, and the mineral powder at a speed of 40 r / min for 60 s to prepare the reactive rapid-setting high-strength recycled asphalt cold patch material. Example 3

[0129] This example provides a reactive rapid-setting high-strength recycled asphalt cold patch material, which is prepared with the recovered milled material as the aggregate, together with mineral powder and a reactive adhesive mother liquor;

[0130] By weight, the components and ratios for preparing the reactive rapid-setting high-strength recycled asphalt cold patch material are as follows:

[0131] Recovered milled material as aggregate: 92%;

[0132] Mineral powder: 7%;

[0133] Reactive adhesive mother liquor: 3.3%;

[0134] The stability of the reactive rapid-setting high-strength recycled asphalt cold patch material is 30.2 kN, the dynamic stability is 10000 times•mm -1 , the low-temperature strain is 2898 με, the freeze-thaw strength ratio is 89%, and the flushing loss is 4.8%.

[0135] The recovered milled material is the milled material from the surface layer of the asphalt pavement, including old asphalt and old aggregates.

[0136] The recovered milled material is divided into three particle sizes of 0-5 mm, 5-10 mm, and 10-15 mm, and the moisture content is less than or equal to 0.5%.

[0137] In this embodiment, the recycled milled materials are recycled and pretreated according to the T0727 method in JTGE20-2011 "Test Procedures for Bitumen and Bituminous Mixtures in Highway Engineering" to separate the old bitumen and old aggregates in the recycled asphalt mixture (RAP materials). They have the same performance indicators as the old bitumen in Embodiment 1.

[0138] In this embodiment, the mineral powder is the mineral powder ground from basic rocks. The aggregate gradation steps are the same as those in Embodiment 1.

[0139] In this embodiment, the reactive adhesive mother liquor is prepared from liquid polyester polyol, diisocyanate, chain extender crosslinking agent, tackifying resin, defoaming agent, and regeneration liquid.

[0140] By weight, the components and proportions for preparing the reactive adhesive mother liquor are as follows:

[0141] Liquid polyester polyol, which is polytetrahydrofuran diol: 50%;

[0142] Diisocyanate, which is 1,6-diisocyanatohexane: 40%;

[0143] Chain extender crosslinking agent, which is 1,4-butanediol: 3%;

[0144] Tackifying resin, which is glycerol ester of rosin: 6%;

[0145] Defoaming agent, which is non-silicon defoaming agent: 2%;

[0146] The mass of the regeneration liquid is 15% of the old bitumen in the recycled milled materials.

[0147] The aggregate gradation design is carried out according to the dense gradation as the target mix ratio to determine the dosage of each grade of materials, and it is formulated into a mixed milled material. The dosage of the reactive adhesive mother liquor is determined through the Marshall test, and the determination method is the same as that in Embodiment 1.

[0148] In this embodiment, the regeneration liquid is a composite solvent obtained by mixing light oil, lubricant, and stabilizer.

[0149] By weight, the components and proportions for preparing the regeneration liquid are as follows:

[0150] Light oil, which is naphthenic oil: 90%;

[0151] Lubricant, which is 6-hexanediol diglycidyl ether: 40%;

[0152] Stabilizer, which is octanoic acid: 5%.

[0153] In this embodiment, the preparation method of the above-mentioned reactive quick-setting and high-strength recycled asphalt cold patch material includes the following steps:

[0154] Step 1: Obtain the recycled milled materials, crush the milled materials into fine particles with a maximum nominal particle size of 19.5 mm, and then perform screening. The milled materials are divided into three types: 0 - 5 mm, 5 - 10 mm, and 10 - 15 mm.

[0155] Step 2: Prepare a reactive adhesive mother liquor, which specifically includes the following steps:

[0156] Step 2 - 1: Polyol dehydration: Weigh each component by mass. Add the liquid polyester polyol and the recycled liquid into the reaction kettle, stir and mix them. Use a temperature - controlled heating jacket to raise the temperature to 120°C, and use a vacuum pump to reduce the pressure of the system to 0.67 ± 0.03 Kpa to pump out the vacuum and dehydrate for 2 h. Then cool down to 70°C and wait for standby.

[0157] Step 2 - 2: Preparation of prepolymer: Add the melted diisocyanate into the reaction kettle, slowly raise the temperature to 125°C, and carry out high - speed stirring reaction at a speed of 400 r / min for 1 h in a nitrogen atmosphere to obtain the prepolymer.

[0158] Step 2 - 3: Synthesis of mother liquor: Add the chain extender cross - linker, tackifying resin, and defoaming agent to the prepolymer in sequence, maintain high - speed stirring reaction for 2 h under vacuum conditions, quickly discharge the material after cooling to 80°C, and encapsulate it in an aluminum foil bag to obtain the reactive adhesive mother liquor.

[0159] Step 3: Mix the milled materials recycled in Step 1, the reactive adhesive mother liquor in Step 2, and the mineral powder at a speed of 40 r / min for 60 s to prepare a reactive quick - setting high - strength recycled asphalt cold patch material. Example 4

[0160] This example provides a reactive quick - setting high - strength recycled asphalt cold patch material, which is prepared with recycled milled materials as the aggregate, together with mineral powder and a reactive adhesive mother liquor.

[0161] By weight, the components and proportions for preparing the reactive quick - setting high - strength recycled asphalt cold patch material are as follows:

[0162] Recycled milled materials as aggregate: 90%;

[0163] Mineral powder: 7%;

[0164] Reactive adhesive mother liquor: 3.46%;

[0165] The stability of the reactive quick - setting high - strength recycled asphalt cold patch material is 29.8 kN, the dynamic stability is 11500 times•mm -1 , the low - temperature strain is 2401 με, the freeze - thaw strength ratio is 84%, and the scatter loss is 7.2%.

[0166] The recycled milled materials are the milled materials from the surface layer of the asphalt pavement, including old asphalt and old aggregates.

[0167] The recovered milled materials are divided into three types with particle sizes of 0 - 5 mm, 5 - 10 mm, and 10 - 15 mm, and the moisture content is less than or equal to 0.5%.

[0168] In this embodiment, the recovered milled materials are recovered and pretreated according to the T0727 method in JTGE20 - 2011 "Test Procedures for Bitumen and Bituminous Mixtures in Highway Engineering" to separate the old bitumen and old aggregates in the recycled asphalt mixture (RAP material). The performance indicators of the old bitumen are the same as those in Example 1.

[0169] In this embodiment, the mineral powder is the mineral powder ground from basic rocks. The mineral aggregate gradation steps are the same as those in Example 1.

[0170] In this embodiment, the reactive adhesive mother liquor is prepared from liquid polyester polyol, diisocyanate, chain extender crosslinking agent, tackifying resin, defoaming agent, and regeneration liquid.

[0171] By weight, the components and proportions for preparing the reactive adhesive mother liquor are as follows:

[0172] Liquid polyester polyol, polyoxypropylene glycol: 40%;

[0173] Diisocyanate, hexamethylene diisocyanate: 40%;

[0174] Chain extender crosslinking agent, 2 - hydroxypropyl acrylate: 3%;

[0175] Tackifying resin, polyvinyl acetate: 5%;

[0176] Defoaming agent, mineral oil defoaming agent: 2%;

[0177] The mass of the regeneration liquid is 8% of the old bitumen in the recovered milled materials.

[0178] The dosages of each grade of materials are determined according to the dense - type gradation as the target mix ratio for gradation design to prepare the mixed milled materials. The dosage of the reactive adhesive mother liquor is determined through the Marshall test, and the determination method is the same as that in Example 1.

[0179] In this embodiment, the regeneration liquid is a composite solvent obtained by mixing light oil, lubricant, and stabilizer.

[0180] By weight, the components and proportions for preparing the regeneration liquid are as follows:

[0181] Light oil, de - aromatic paraffin solvent oil: 90%;

[0182] Lubricant, 6 - hexanediol diglycidyl ether: 40%;

[0183] Stabilizer, lauric acid: 5%.

[0184] In this embodiment, the preparation method of the above reactive quick-setting high-strength recycled asphalt cold patch material includes the following steps:

[0185] Step 1: Obtain the recycled milled material, crush the milled material into fine particles with a maximum nominal particle size of 19.5 mm, and then perform screening treatment to divide the milled material into three types: 0-5 mm, 5-10 mm, and 10-15 mm.

[0186] Step 2: Prepare the reactive adhesive mother liquor, which specifically includes the following steps:

[0187] Step 2-1: Polyol dehydration: Weigh each component by mass, add the liquid polyester polyol and the recycled liquid into the reaction kettle and stir and mix. Use a temperature-controlled heating jacket to raise the temperature to 120 °C, use a vacuum pump to reduce the pressure of the system by 0.67 ± 0.03 Kpa and evacuate water for 2 h, and cool down to 70 °C for standby.

[0188] Step 2-2: Preparation of prepolymer: Add the melted diisocyanate into the reaction kettle, slowly raise the temperature to 125 °C, and carry out high-speed stirring reaction at a speed of 400 r / min in a nitrogen atmosphere for 1 h to obtain the prepolymer.

[0189] Step 2-3: Synthesis of mother liquor: Add the chain extender crosslinking agent, tackifying resin, and defoaming agent to the prepolymer in sequence, maintain high-speed stirring reaction under vacuum conditions for 2 h, quickly discharge the material after cooling to 80 °C and encapsulate it in an aluminum foil bag to obtain the reactive adhesive mother liquor.

[0190] Step 3: Mix the milled material recovered in Step 1, the reactive adhesive mother liquor in Step 2, and the mineral powder at a speed of 40 r / min for 60 s to prepare the reactive quick-setting high-strength recycled asphalt cold patch material.

[0191] Comparative Example 1

[0192] Hot mix asphalt mixture, that is, hot mix AC-13 asphalt mixture. Comparative Example 2

[0193] Commercially available cold patch materials with high market sales.

[0194] In the above examples and comparative examples, specimens were molded in accordance with the provisions of JTG E20-2011 "Test Procedures for Bitumen and Bituminous Mixtures for Highway Engineering". The strength index was tested by stability, the high and low temperature performance was tested by rutting test and bending creep test, and the water stability was tested by freeze-thaw splitting test and Cantabro abrasion test. The specific test results are shown in Table 3 below.

[0195] Table 3 Material Performance Indexes of Asphalt Mixtures

[0196]

[0197] As can be seen from Table 3, the stability of the 4 examples is greater than 28 kN, the dynamic stability is greater than 10,000 times, the low-temperature strain is greater than 2,500 με, the freeze-thaw strength ratio is greater than 85%, and the flushing loss is less than 10%. Compared with hot mix asphalt mixture and commercial cold patch material, the reactive quick-setting high-strength recycled asphalt cold patch material prepared by the present invention has excellent performance.

[0198] Based on the comprehensive preparation process and the properties of each component, the reactive quick-setting high-strength recycled asphalt cold patch material has excellent high-temperature stability, water stability, and low-temperature crack resistance. The utilization rate of RAP material in the present invention is 90-96%, which greatly improves the recycling rate of milled materials, alleviates the dual problems of solid waste accumulation and shortage of high-quality stone resources, and the application of RAP material in cold patch material enables its efficient and high-quality recycling. The combination of the two technologies achieves the effect of 1+1>2, and has good application value and economic benefits.

[0199] It should be understood that the present invention is not limited to the content described above and can be modified and changed without departing from its scope. The scope of the present invention is only limited by the appended claims.

Claims

1. A reactive quick-setting high-strength recycled asphalt cold patch material, characterized in that: The cold patch material is prepared with recycled milling material as aggregate, mineral powder and reactive adhesive mother liquid; By weight, the components and proportions of the reactive quick-setting high-strength recycled asphalt cold patch material are as follows: Recycled milling material as aggregate: 90-96%; Mineral powder: 4-7%; Reactive adhesive masterbatch: 3-6%; The stability of the reactive quick-setting high-strength recycled asphalt cold patch material is 28.6-31.2 kN, and the dynamic stability is 10000-12000 times•mm -1 , low temperature strain is 2401-3015με, freeze-thaw strength ratio is 84-89%, and flying loss is 4.8-7.2%; The recycled milling material includes one or more of old asphalt and old aggregate; The reactive adhesive mother solution is prepared from liquid polyester polyol, diisocyanate, chain extender crosslinking agent, tackifying resin, defoamer and regeneration liquid; By weight, the components and proportions for preparing the reactive adhesive mother solution are as follows: Liquid polyester polyol: 30-50%; Diisocyanate: 10-40%; Chain extender crosslinker: 1-3%; Tackifying resin: 3-6%; Defoaming agent: 1-2%; The mass of the regeneration fluid is 8-15% of the old asphalt in the recovered milling material.

2. The reactive quick-setting high-strength recycled asphalt cold patch material according to claim 1, characterized in that: The mineral powder is obtained by grinding limestone or strong basic rock.

3. The reactive quick-setting high-strength recycled asphalt cold patch material according to claim 1, characterized in that: The liquid polyester polyol is a polymer formed by polycondensation of one or more combinations of polyoxypropylene glycol, polyoxyethylene glycol, polytetrahydrofuran diol, 4-cyclohexanedicarboxylic acid-3-methyl-1,5-pentanediol, and ester diol; The diisocyanate is one or more of diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, polymethylene polyphenyl polyisocyanate, 1,6-diisocyanato, hexamethylene diisocyanate, isophorone diisocyanate, and 3,3'-dimethyldiphenylmethane-4,4' diisocyanate; The chain extending cross-linking agent is one or more of diethylene glycol, neopentyl glycol, 1,4-butanediol, and 2-hydroxypropyl 2-acrylate; The tackifying resin is one or more of terpene phenol resin, petroleum resin C5 or its hydrogenated product, rosin glycerol ester, and polyvinyl acetate; The defoamer is one or more of an organosilicon defoamer, an organofluorine defoamer, a non-silicon defoamer, and a mineral oil defoamer; The regeneration liquid is a composite solvent obtained by mixing light oil, lubricant and stabilizer.

4. The reactive quick-setting high-strength recycled asphalt cold patch material according to claim 3 is characterized in that: In terms of weight, the components and proportions for preparing the regeneration solution are as follows: Light oil: 80-100%; Lubricant: 30-50%; Stabilizer: 2-5%.

5. A method for preparing a reactive quick-setting high-strength recycled asphalt cold patch material according to any one of claims 1 to 4, characterized in that: The steps include: Step 1: Get the recycled milling material: Step 2, preparing a reactive adhesive mother solution; Step 3: stir the milling material recovered in step 1, the reactive adhesive mother liquor in step 2 and the mineral powder at a speed of 40-60 r / min for 60-70 s to prepare a reactive quick-setting high-strength recycled asphalt cold patch material.

6. The method for preparing the reactive quick-setting high-strength recycled asphalt cold patch material according to claim 5, characterized in that: In step 1, the milling material is crushed into fine particles with a maximum nominal particle size of 19.5 mm, and then sieved to separate the milling material into three types: 0-5 mm, 5-10 mm, and 10-15 mm; The method for preparing the reactive adhesive mother solution in step 2 comprises the following steps: Step 2-1, polyol dehydration: weigh each component by mass, add liquid polyester polyol and regeneration liquid into the reaction kettle and stir to mix, heat to 120-130°C with a temperature-controlled heating jacket, use a vacuum pump to reduce the system pressure by 0.67±0.03Kpa to evacuate and dehydrate for 2-3h, cool to 60-70°C and wait for use; Step 2-2, preparation of prepolymer: adding the melted diisocyanate into a reaction kettle, slowly heating to 120-130° C., stirring at a speed of 400-600 r / min under a nitrogen atmosphere for 1-2 h to obtain a prepolymer; Step 2-3, synthesizing mother liquor: add chain extender crosslinking agent, tackifying resin and defoaming agent to the prepolymer in sequence, keep stirring at high speed under vacuum conditions for 2-3 hours, cool to 70-80°C and then quickly discharge and package in an aluminum foil bag to obtain a reactive adhesive mother liquor.

7. A curing material, characterized in that: The solidified material is obtained by solidifying the reactive quick-setting high-strength recycled asphalt cold patch material according to any one of claims 1 to 4.

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