Cold-mixed and cold-laid ultrathin overlay asphalt mixture and preparation process thereof

Abstract

The invention relates to the technical field of asphalt mixtures, in particular to a cold-mixed and cold-laid ultrathin overlay asphalt mixture and a preparation process thereof.The preparation process comprises the following steps that matrix asphalt is heated to be molten, then a reaction type cold-mixed diluent is added for mixing and stirring, and cold-mixed asphalt liquid is prepared; and mixing the cold-mixed asphalt liquid, aggregate, a curing agent, the modified basalt fiber, the modified graphene oxide and an interface coupling agent at normal temperature to prepare the cold-mixed and cold-laid ultrathin overlay asphalt mixture. According to the cold-mixed and cold-laid ultra-thin overlay asphalt mixture and the preparation process thereof provided by the invention, the curing process of the asphalt mixture is regulated and controlled by adopting a reactive cold-mixed diluent, so that the early curing strength can be remarkably improved; meanwhile, the modified basalt fibers and the modified graphene oxide are added, so that the structural strength and the crack resistance of the ultra-thin overlay are further enhanced, and the ultra-thin overlay is suitable for various scenes such as pavement pit slot cold patch, thin overlay layers and cold paving projects.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of asphalt mixture, in particular to a cold-mixed and cold-paved ultra-thin overlay asphalt mixture and a preparation process thereof. BACKGROUND

[0002] The green and low-carbon cold-mixed asphalt mixture technology is attracting widespread attention due to its significant environmental advantages. This technology breaks through the high energy consumption limitation of traditional hot-mixing process (construction temperature up to 185℃), realizes normal temperature construction, is not affected by seasonal temperature, and effectively solves the problems of resource waste and environmental pollution existing in the hot-mixing process. The current mainstream cold-mixed asphalt mixture includes solvent type cold-mixed asphalt mixture, emulsified type cold-mixed asphalt mixture and water-based epoxy type cold-mixed asphalt mixture. Although the scheme using unsaturated fatty acid compounded solvent is simple to operate, the early curing performance still needs to be improved due to the insufficient crosslinking network strength.

[0003] At the same time, with the increasingly prominent problem of road overload and the accelerated functional degradation of pavement, the development of high-performance overlay maintenance technology has become the focus of the industry. As a new preventive maintenance scheme, the ultra-thin overlay technology has advantages such as noise reduction, anti-skid, rapid drainage, etc., and is convenient to construct and fast to open traffic. However, the current domestic ultra-thin overlay mostly uses high-viscosity modified asphalt, which has problems such as large construction smoke and high temperature sensitivity; and the traditional cold-mixing process is difficult to meet the durability requirements due to the performance limitations of emulsified asphalt. Therefore, the development of a new type of cold-mixed ultra-thin overlay technology with environmental characteristics and engineering performance has become a key breakthrough to realize the greening and long-term effectiveness of road maintenance.

[0004] Therefore, we propose a cold-mixed and cold-paved ultra-thin overlay asphalt mixture and a preparation process thereof. SUMMARY

[0005] The purpose of the present application is to provide a cold-mixed and cold-paved ultra-thin overlay asphalt mixture and a preparation process thereof to solve the problems raised in the background art.

[0006] In order to solve the above technical problems, the present application provides the following technical scheme: Step 1: heat the base asphalt to make it melt and flow, then mix and stir the base asphalt with the reactive cold-mixing diluent according to a mass ratio of 10:1 to prepare a cold-mixed asphalt liquid; Step 2: mix 5-10 parts of the cold-mixed asphalt liquid, 90-100 parts of aggregate, 1-5 parts of curing agent, 1-1.5 parts of modified basalt fiber, 1-1.5 parts of modified graphene oxide and 0.5-1.5 parts of interface coupling agent at normal temperature to obtain a cold-mixed and cold-paved ultra-thin overlay asphalt mixture.

[0007] Further, the base asphalt is 90# asphalt.

[0008] Further, the preparation of the reactive cold-mixing diluent includes the following steps: Dissolve alanine and epoxy active diluent n-butyl glycidyl ether in a solvent, which is a mixture of ethanol and water in a mass ratio of 1:1; stir at a reaction temperature of 60-90℃ and a stirring rate of 50-200 rad / min for 1-10 h; cool to room temperature of 20℃ after reaction, and then perform extraction separation; the reaction product is mixed with methanol as an extractant in a mass ratio of 1:1; and remove residual solvent from the insoluble product obtained by extraction separation through reduced pressure distillation to prepare a reaction-type cold-mixing diluent.

[0009] In the technical solution, the reaction-type cold-mixing diluent is designed by grafting modification of an amino acid on an epoxy active diluent, and contains both an optimized aliphatic chain segment and a polar functional group in the molecular structure, and is a cold-mixing material with excellent compatibility with asphalt.

[0010] Further, the aggregate is basalt, and the aggregate has a mineral aggregate gradation as shown in Table 1. Table 1 .

[0011] Further, the curing agent is metakaolin.

[0012] Further, the interface coupling agent is a fatty alcohol polyoxyethylene ether.

[0013] Further, the preparation of the modified basalt fiber includes the following steps: Mix tetraethyl orthosilicate, distilled water and ethanol in a mass ratio of 1:4:15, stir the obtained solution at 50-55℃ for 3-4 h, and add ammonia water to the solution during stirring to maintain the pH value of the solution at 9.0 to prepare a nano-SiO2 precursor solution; purify the nano-SiO2 precursor through a membrane separation device, and the pore size of the membrane is 60 nm; modify the nano-SiO2 precursor and γ-aminopropyl triethoxysilane in a mass ratio of 100:3 at 80-90℃ for 3-4 h; mix the SiO2 nano-particle precursor solution and an epoxy resin solution in a mass ratio of 1:1, and stir at 50-55℃ for 3-4 h to obtain an epoxy / SiO2 solution; mix the epoxy / SiO2 solution and acetone in a mass ratio of 2:100 to prepare a sizing agent, and treat basalt fiber with 2.0% of the sizing agent by mass of the basalt fiber; and dry the basalt fiber in an oven at 90-100℃ after reaction for 30-40 min to obtain the modified basalt fiber.

[0014] In the technical solution, SiO2 nanoparticles are prepared by a sol-gel method, and macromolecular chains are grafted on the surface of the SiO2 nanoparticles by using a silane coupling agent. Subsequently, the synthesized epoxy resin / SiO2 composite slurry is used to modify the surface of basalt fibers, and the -NH2 on the surface of the SiO2 nanoparticles reacts with the epoxy groups to form a Si-O-C covalent bond network. After the modification, a uniform coating layer is formed on the surface of the fibers, the roughness and tensile strength of the fiber surface are significantly increased, and the interfacial bonding force with asphalt is also significantly improved. As a functional additive, the modified basalt fiber can significantly improve the comprehensive performance of asphalt mixture through its excellent interfacial adhesion properties. It can not only form a firm mechanical riveting structure with various organic and inorganic materials, but also enhance the hydrophobic performance of the system, thereby effectively improving the key road performance indicators of the mixture, such as water stability, high-temperature stability, and low-temperature crack resistance.

[0015] Further, the preparation of the modified graphene oxide comprises the following steps: The graphene oxide is dispersed in deionized water, ultrasonically treated for 15-20 min, then polyethyleneimine is added, and the reaction is continuously stirred at 80-90℃ for 8-10h. After the reaction is completed, the pretreated graphene oxide is obtained by centrifugal washing and freeze-drying. The amount of graphene oxide, polyethyleneimine and deionized water is 0.1:5:100 by mass ratio. Under the protection of nitrogen, the pretreated graphene oxide, sodium lignosulfonate and water are mixed and stirred at a mass ratio of 1:1:100, then potassium persulfate and N,N'-methylenebisacrylamide are added, and the temperature is raised to 85-95℃ for 2-3h. After the product is filtered, washed with water and dried, the modified graphene oxide is obtained.

[0016] Further, the added amount of potassium persulfate is 0.5% of the mass of sodium lignosulfonate, and the added amount of N,N'-methylenebisacrylamide is 0.2% of the mass of sodium lignosulfonate.

[0017] In the technical solution, the graphene oxide has a layer-by-layer stacked structure, which can effectively block the invasion of heat and oxygen. At the same time, the phenolic hydroxyl groups in the sodium lignosulfonate have the ability to combine with free radicals generated during the aging process. The synergistic effect of the two can further inhibit the thermal oxidation aging phenomenon of the asphalt mixture. In addition, the sodium lignosulfonate and the graphene oxide form a composite structure through grafting reaction, which can prevent the further expansion of microcracks, thereby enhancing the stability of the asphalt mixture and improving its low-temperature crack resistance, significantly improving the durability of the asphalt mixture.

[0018] Further, the heating temperature of the base asphalt in step 1 is 120-130℃, and the temperature of the normal temperature mixing in step 2 is 20-25℃.

[0019] Compared with the prior art, the application has the following beneficial effects: 1. The application describes a cold-mixed and cold-paved ultra-thin overlay asphalt mixture and its preparation process. The cold-mixed asphalt liquid, aggregate, curing agent, modified basalt fiber, modified graphene oxide, and interface coupling agent are mixed at room temperature to obtain a cold-mixed and cold-paved ultra-thin overlay asphalt mixture suitable for various scenarios such as cold-patch of road pits, thin overlay, and cold-paving engineering.

[0020] 2. The application describes a cold-mixed and cold-paved ultra-thin overlay asphalt mixture and its preparation process. The reaction process between the reactive cold-mixed diluent and the curing agent is relatively mild. During the reaction process, the organic carboxyl functional groups in the reactive cold-mixed diluent interact with the inorganic ions in the curing agent, thereby constructing an organic-inorganic three-dimensional network cross-linking structure, and finally forming a complete cross-linking curing system. This system effectively improves the early curing strength of the cold-mixed asphalt mixture. By precisely controlling the allocation ratio of each component in the asphalt mixture, the curing strength of the mixture gradually increases over time. Based on these characteristics, the cold-mixed asphalt mixture can be applied in the field of cold-mixed and cold-paved road engineering.

[0021] 3. The application describes a cold-mixed and cold-paved ultra-thin overlay asphalt mixture and its preparation process. The interface coupling agent is used to enhance the bonding force between the asphalt mixture and the original road surface, and to improve the adhesion performance of asphalt and aggregate. In addition, by adding modified basalt fiber, the structural strength and crack resistance of the thin overlay are further improved. This technology effectively solves the problems of poor workability, high temperature operation requirements, and serious environmental pollution of traditional hot-mixed ultra-thin overlay asphalt mixture, and significantly improves the durability of the cold-mixed asphalt mixture.

[0022] 4. The application describes a cold-mixed and cold-paved ultra-thin overlay asphalt mixture and its preparation process. By using modified graphene oxide and modified basalt fiber as composite additives of the asphalt mixture, the comprehensive performance of the ultra-thin overlay paving material can be synergistically improved. Modified graphene oxide can form a stable solid cross-linking network in the mixture, which enhances the adhesion performance of asphalt by increasing its surface free energy; at the same time, the addition of modified basalt fiber can significantly improve the water stability, high-temperature stability, and low-temperature crack resistance of the mixture. The synergistic effect of the two further optimizes the overall performance of the asphalt mixture, making it more suitable for ultra-thin overlay paving engineering. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the application will be described below in a clear and complete manner. Obviously, the described embodiments are only a part of the embodiments of the application, not all embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0024] In the following detailed description, Matrix asphalt: Type 90# asphalt, from Xingtai Dejia Road Material Sales Co., Ltd.; Alanine: Item No. 251202, from Hebei Hongtao Biological Engineering Co., Ltd.; n-Butyl glycidyl ether: Item No. jzyj202505201744, from Jingzhou Yinjie Chemical Co., Ltd.; Aggregate: Basalt, from Yu County Xinyuan Basalt Mining Co., Ltd.; Metakaolin: Item No. A00379, from Wuhan Jiyesheng Chemical Co., Ltd.; Fatty alcohol polyoxyethylene ether: Item No. HC0376, from Tianmen Hengchang Chemical Co., Ltd.; Basalt fiber: from Shandong Oude Chemical Fiber Products Co., Ltd.; γ-Aminopropyl triethoxysilane: Item No. S15028, from Shanghai Yuan Ye Biological Technology Co., Ltd.; Tetraethyl orthosilicate: Item No. T110594, from Shanghai Aladdin Biochem Technology Co., Ltd.; Epoxy resin: E-51 epoxy resin with an epoxy value of 0.51, from Wuhan Jushun Chemical Co., Ltd.; Graphene oxide: Item No. 06-2545, from Beijing Bailingwei Technology Co., Ltd.; Polyethyleneimine: Item No. 294321, from Wuhan Shur Biological Technology Co., Ltd.; Sodium lignosulfonate: Item No. S30635, from Shanghai Yuan Ye Biological Technology Co., Ltd.; Potassium persulfate: Item No. CFEQ-4-120046-0500, from Shanghai Anpu Experimental Technology Co., Ltd.; N,N'-Methylenebisacrylamide: Item No. N74690, from Shanghai Jizhi Biological Technology Co., Ltd.; The following examples and comparative examples are described in the following detailed description.

[0025] Example 1: A cold-mixed and cold-paved ultra-thin overlay asphalt mixture and its preparation process, comprising the following steps: Step 1: Heat the matrix asphalt to 120°C to make it melt and flow, then mix and stir the matrix asphalt and the reactive cold-mixed diluent in a mass ratio of 10:1 to prepare a cold-mixed asphalt liquid; Step 2: Mix 5 parts of the cold-mixed asphalt liquid, 90 parts of aggregate, 1 part of curing agent, 1 part of modified basalt fiber, 1 part of modified graphene oxide, and 0.5 part of interface coupling agent at room temperature 20°C to obtain a cold-mixed and cold-paved ultra-thin overlay asphalt mixture; The preparation of the cold-mixed diluent comprises the following steps: Dissolve alanine and epoxy active diluent n-butyl glycidyl ether in a solvent, which is a mixture of ethanol and water with a mass ratio of 1:1, at a mass ratio of 1:10; stir at a reaction temperature of 60℃ and a stirring rate of 50 rad / min for 1h, then cool to room temperature of 20℃ and perform extraction separation; the reaction product and the extraction agent methanol are in a mass ratio of 1:1; remove the residual solvent by vacuum distillation at 60℃ and an absolute pressure of 20kPa to obtain the reaction-type cold-mixed diluent; The preparation of the modified basalt fiber comprises the following steps: Mix tetraethyl orthosilicate, distilled water and ethanol at a mass ratio of 1:4:15, stir the obtained solution at 50℃ for 3h, and add ammonia water to the solution during stirring to keep the pH value of the solution at 9.0 to prepare a nano-SiO2 precursor solution; purify the nano-SiO2 precursor through a membrane separation device, and the pore size of the membrane is 60nm; modify the nano-SiO2 precursor at 80℃ for 3h by mixing the nano-SiO2 precursor and γ-aminopropyl triethoxysilane at a mass ratio of 100:3; mix the SiO2 nano-particle precursor solution and an epoxy resin solution at a mass ratio of 1:1, and stir at 50℃ for 3h to obtain an epoxy / SiO2 solution; mix the epoxy / SiO2 solution and acetone at a mass ratio of 2:100 to prepare a sizing agent; take 2.0% of the sizing agent by mass of the basalt fiber to treat the basalt fiber, and dry the basalt fiber in an oven at 80℃ after reacting for 30min to obtain the modified basalt fiber; The preparation of the modified graphene oxide comprises the following steps: Disperse graphene oxide in deionized water, add polyethyleneimine after ultrasonic treatment for 15min, continuously stir at 80℃ for 8h, and obtain pretreated graphene oxide by centrifugal washing and freeze-drying after the reaction is completed; the dosages of graphene oxide, polyethyleneimine and deionized water are in a mass ratio of 0.1:5:100; mix pretreated graphene oxide, sodium lignosulfonate and water at a mass ratio of 1:1:100 under nitrogen protection, add 0.5% of potassium persulfate by mass of sodium lignosulfonate and 0.2% of N,N'-methylenebisacrylamide by mass of sodium lignosulfonate, heat to 85℃ and react for 2h, and obtain the modified graphene oxide by filtration, water washing and drying.

[0026] Example 2: A cold-mixed and cold-laid ultra-thin overlay asphalt mixture and a preparation process thereof, comprising the following steps: Step 1: heat the base asphalt to 125℃ to make it melt and flow, then mix and stir the base asphalt and the reaction-type cold-mixed diluent at a mass ratio of 10:1 to prepare a cold-mixed asphalt liquid; Step 2: 7 parts of cold-mixed asphalt liquid, 95 parts of aggregate, 3 parts of curing agent, 1.3 parts of modified basalt fiber, 1.3 parts of modified graphene oxide, and 1 part of interface coupling agent are mixed at room temperature 23℃ to obtain a cold-mixed and cold-paved ultra-thin overlay asphalt mixture; The preparation of the cold-mixed diluent comprises the following steps: The alanine and epoxy active diluent n-butyl glycidyl ether are dissolved in a solvent in a mass ratio of 1:10, and the solvent is a mixture of ethanol and water in a mass ratio of 1:1; the reaction is stirred at a reaction temperature of 75℃ and a stirring rate of 150 rad / min for 5h, and after the reaction is completed, it is cooled to room temperature of 20℃ and then extracted and separated, with the reaction product and the extraction agent methanol in a mass ratio of 1:1; the insoluble substance obtained by extraction and separation is subjected to vacuum distillation to remove residual solvent at 80℃ and an absolute pressure of 30kPa, to obtain a reaction-type cold-mixed diluent; The preparation of the modified basalt fiber comprises the following steps: Ethyl silicate, distilled water and ethanol are mixed in a mass ratio of 1:4:15, the obtained solution is stirred at 53℃ for 3.5h, and ammonia water is added to the solution during stirring to keep the pH value of the solution at 9.0, to prepare a nano-SiO2 precursor solution; the nano-SiO2 precursor is purified by a membrane separation device, and the pore size of the membrane is 60nm; the nano-SiO2 precursor is modified with γ-aminopropyl triethoxysilane at 85℃ for 3.5h in a mass ratio of 100:3; the SiO2 nano-particle precursor solution is mixed with an epoxy resin solution in a mass ratio of 1:1 at 53℃ for 3.5h, to obtain an epoxy / SiO2 solution; the epoxy / SiO2 solution is mixed with acetone in a mass ratio of 2:100 to prepare a sizing agent; the basalt fiber is treated with 2.0% of the sizing agent by mass, and after reaction for 35min, the basalt fiber is dried in an oven at 85℃, to finally obtain the modified basalt fiber; The preparation of the modified graphene oxide comprises the following steps: The graphene oxide is dispersed in deionized water, and after ultrasonic treatment for 17min, polyethyleneimine is added, and the reaction is continuously stirred at 85℃ for 9h; after the reaction is completed, the pretreated graphene oxide is obtained by centrifugal washing and freeze-drying, and the dosages of the graphene oxide, polyethyleneimine and deionized water are in a mass ratio of 0.1:5:100; under nitrogen protection, the pretreated graphene oxide, sodium lignosulfonate and water are mixed and stirred in a mass ratio of 1:1:100, and then 0.5% of potassium persulfate by mass of the sodium lignosulfonate and 0.2% of N,N'-methylenebisacrylamide by mass of the sodium lignosulfonate are added; the temperature is raised to 90℃, and the reaction is carried out for 2.5h; the product is subjected to suction filtration, water washing and drying treatment, to obtain the modified graphene oxide.

[0027] Embodiment 3: A cold-mixed and cold-laid ultra-thin overlay asphalt mixture and a preparation process thereof, comprising the following steps: Step 1: After the base asphalt is heated to 130 DEG C to melt and flow, the base asphalt is mixed and stirred with a reactive cold-mixed diluent at a mass ratio of 10:1 to prepare a cold-mixed asphalt liquid; Step 2: 10 parts of the cold-mixed asphalt liquid, 100 parts of aggregate, 5 parts of a curing agent, 1.5 parts of modified basalt fiber, 1.5 parts of modified graphene oxide, and 1.5 parts of an interface coupling agent are mixed at room temperature 25 DEG C to obtain a cold-mixed and cold-laid ultra-thin overlay asphalt mixture; The preparation of the cold-mixed diluent comprises the following steps: Alanine and epoxy active diluent n-butyl glycidyl ether are dissolved in a solvent at a mass ratio of 1:10, and the solvent is a mixture of ethanol and water at a mass ratio of 1:1; the reaction is carried out at a reaction temperature of 90 DEG C, a stirring rate of 200 rad / min, and a stirring time of 10 h; after the reaction is completed, the solution is cooled to room temperature 20 DEG C and then extracted and separated; the reaction product is mixed with methanol as an extractant at a mass ratio of 1:1; the insoluble substance obtained by extraction and separation is subjected to vacuum distillation at 100 DEG C and an absolute pressure of 40 kPa to remove residual solvent, thereby obtaining a reactive cold-mixed diluent; The preparation of the modified basalt fiber comprises the following steps: Ethyl silicate, distilled water, and ethanol are mixed at a mass ratio of 1:4:15, and the obtained solution is stirred at 55 DEG C for 4 h; during the stirring process, ammonia water is added to the solution to maintain the pH value of the solution at 9.0, thereby preparing a nano-SiO2 precursor solution; the nano-SiO2 precursor is purified by a membrane separation device, and the pore size of the membrane is 60 nm; the nano-SiO2 precursor is modified with gamma-aminopropyl triethoxysilane at a mass ratio of 100:3 at 90 DEG C for 4 h; the SiO2 nano-particle precursor solution is mixed with an epoxy resin solution at a mass ratio of 1:1 and stirred at 55 DEG C for 4 h, thereby obtaining an epoxy / SiO2 solution; the epoxy / SiO2 solution is mixed with acetone at a mass ratio of 2:100 to prepare a sizing agent; the basalt fiber is treated with the sizing agent at a mass fraction of 2.0% of the mass of the basalt fiber; after the reaction is carried out for 40 min, the basalt fiber is dried in an oven at 90 DEG C, and finally the modified basalt fiber is obtained; The preparation of the modified graphene oxide comprises the following steps: The graphene oxide is dispersed in deionized water, after ultrasonic treatment for 20 min, polyethyleneimine is added, and the reaction is continuously stirred at 90 DEG C for 10 h. After the reaction is completed, the pretreated graphene oxide is obtained by centrifugal washing and freeze drying. The dosages of graphene oxide, polyethyleneimine and deionized water are 0.1:5:100 by mass ratio. Under the protection of nitrogen, the pretreated graphene oxide, sodium lignosulfonate and water are mixed and stirred at a mass ratio of 1:1:100, and then 0.5% of the mass of the sodium lignosulfonate potassium persulfate and 0.2% of the mass of the sodium lignosulfonate N,N'-methylene bisacrylamide are added. The temperature is raised to 95 DEG C and the reaction is carried out for 3 h. The product is treated by suction filtration, water washing and drying to obtain modified graphene oxide.

[0028] Comparative Example 1: A cold-mixed and cold-paved ultra-thin overlay asphalt mixture and a preparation process thereof, comprising the following steps: Compared with Example 1, no curing agent is added in Comparative Example 1; Step 1: The base asphalt is heated to 120 DEG C to melt and flow, and then mixed and stirred with the reactive cold-mixed diluent at a mass ratio of 10:1 to prepare a cold-mixed asphalt liquid; Step 2: 5 parts of the cold-mixed asphalt liquid, 90 parts of aggregate, 1 part of modified basalt fiber, 1 part of modified graphene oxide and 0.5 part of interface coupling agent are mixed at room temperature 20 DEG C to obtain a cold-mixed and cold-paved ultra-thin overlay asphalt mixture; The preparation of the cold-mixed diluent comprises the following steps: Alanine and epoxy active diluent n-butyl glycidyl ether are dissolved in a solvent at a mass ratio of 1:10, and the solvent is a mixture of ethanol and water at a mass ratio of 1:1. The reaction is carried out at a reaction temperature of 60 DEG C, a stirring rate of 50 rad / min and a stirring time of 1 h. After the reaction is completed, the reaction product is cooled to room temperature 20 DEG C and then extracted and separated. The mass ratio of the reaction product to the extractant methanol is 1:1. The insoluble material obtained by extraction and separation is subjected to vacuum distillation at 60 DEG C and an absolute pressure of 20 kPa to remove residual solvents, and a reactive cold-mixed diluent is prepared; The preparation of the modified basalt fiber comprises the following steps: The tetraethyl orthosilicate, distilled water and ethanol are mixed in a mass ratio of 1:4:15, the obtained solution is stirred at 50 DEG C for 3h, and ammonia water is added to the solution during stirring to keep the pH value of the solution at 9.0, a nano-SiO2 precursor solution is prepared, the nano-SiO2 precursor is purified through a membrane separation device, the pore size of the membrane is 60nm; the nano-SiO2 precursor is modified with gamma-aminopropyl triethoxysilane at a mass ratio of 100:3 at 80 DEG C for 3h; the SiO2 nano-particle precursor solution is mixed with an epoxy resin solution at a mass ratio of 1:1, stirred at 50 DEG C for 3h, and an epoxy / SiO2 solution is obtained; the epoxy / SiO2 solution is mixed with acetone at a mass ratio of 2:100 to prepare a sizing agent, 2.0% of the sizing agent by mass of the basalt fiber is used to treat the basalt fiber, and after reaction for 30min, the basalt fiber is dried in an oven at 80 DEG C to obtain modified basalt fiber; The preparation of the modified graphene oxide comprises the following steps: The graphene oxide is dispersed in deionized water, ultrasonic treatment is carried out for 15min, then polyethyleneimine is added, and continuous stirring reaction is carried out at 80 DEG C for 8h; after the reaction is completed, pretreated graphene oxide is obtained through centrifugal washing and freeze-drying; the dosages of graphene oxide, polyethyleneimine and deionized water are in a mass ratio of 0.1:5:100; under nitrogen protection, pretreated graphene oxide, sodium lignosulfonate and water are mixed and stirred at a mass ratio of 1:1:100, then 0.5% of potassium persulfate by mass of the sodium lignosulfonate and 0.2% of N,N'-methylenebisacrylamide by mass of the sodium lignosulfonate are added, the temperature is raised to 85 DEG C, and reaction is carried out for 2h; the product is subjected to suction filtration, water washing and drying treatment to prepare modified graphene oxide.

[0029] Comparative Example 2: A kind of cold-mixed cold-paved ultra-thin overlay asphalt mixture and its preparation process, comprising the following steps: Compared with Example 1, no modified basalt fiber is added in Comparative Example 2; Step 1: after the matrix asphalt is heated to 120 DEG C to make it melt and flow, the matrix asphalt is mixed and stirred with a reactive cold-mixed diluent at a mass ratio of 10:1 to prepare a cold-mixed asphalt liquid; Step 2: 5 parts of the cold-mixed asphalt liquid, 90 parts of aggregate, 1 part of curing agent, 1 part of modified graphene oxide and 0.5 part of interface coupling agent are mixed at room temperature 20 DEG C to obtain a cold-mixed cold-paved ultra-thin overlay asphalt mixture; The preparation of the cold-mixed diluent comprises the following steps: The alanine and epoxy active diluent n-butyl glycidyl ether are dissolved in a solvent in a mass ratio of 1:10, and the solvent is a mixture of ethanol and water in a mass ratio of 1:1; the reaction is stirred at a reaction temperature of 60 DEG C and a stirring rate of 50 rad / min for 1 h, and then cooled to room temperature of 20 DEG C for extraction separation; the reaction product is separated by extraction with methanol in a mass ratio of 1:1; the insoluble substance obtained by extraction separation is subjected to vacuum distillation at 60 DEG C and an absolute pressure of 20 kPa to remove residual solvent, thereby preparing a reaction-type cold-mixing diluent; The preparation of the modified graphene oxide comprises the following steps: The graphene oxide is dispersed in deionized water, and after ultrasonic treatment for 15 min, polyethyleneimine is added, and the reaction is continuously stirred at 80 DEG C for 8 h; after the reaction is completed, the pretreated graphene oxide is obtained by centrifugal washing and freeze-drying; the dosages of graphene oxide, polyethyleneimine and deionized water are in a mass ratio of 0.1:5:100; under the protection of nitrogen, the pretreated graphene oxide, sodium lignosulfonate and water are mixed and stirred in a mass ratio of 1:1:100, and then 0.5% of potassium persulfate based on the mass of sodium lignosulfonate and 0.2% of N,N'-methylenebisacrylamide based on the mass of sodium lignosulfonate are added; the temperature is raised to 85 DEG C for reaction for 2 h; the product is subjected to suction filtration, water washing and drying treatment, thereby preparing the modified graphene oxide.

[0030] Comparative Example 3: A cold-mixing and cold-paving ultra-thin overlay asphalt mixture and a preparation process thereof, comprising the following steps: In comparison with Example 1, no modified graphene oxide is added in Comparative Example 3; Step 1: The base asphalt is heated to 120 DEG C to make it melt and flow, and then mixed and stirred with the reaction-type cold-mixing diluent in a mass ratio of 10:1, thereby preparing a cold-mixing asphalt liquid; Step 2: 5 parts of the cold-mixing asphalt liquid, 90 parts of aggregate, 1 part of curing agent, 1 part of modified basalt fiber and 0.5 part of interface coupling agent are mixed at room temperature of 20 DEG C, thereby obtaining the cold-mixing and cold-paving ultra-thin overlay asphalt mixture; The preparation of the cold-mixing diluent comprises the following steps: The alanine and epoxy active diluent n-butyl glycidyl ether are dissolved in a solvent in a mass ratio of 1:10, and the solvent is a mixture of ethanol and water in a mass ratio of 1:1; the reaction is stirred at a reaction temperature of 60 DEG C and a stirring rate of 50 rad / min for 1 h, and then cooled to room temperature of 20 DEG C for extraction separation; the reaction product is separated by extraction with methanol in a mass ratio of 1:1; the insoluble substance obtained by extraction separation is subjected to vacuum distillation at 60 DEG C and an absolute pressure of 20 kPa to remove residual solvent, thereby preparing a reaction-type cold-mixing diluent; The preparation of the modified basalt fiber comprises the following steps: The tetraethyl orthosilicate, distilled water and ethanol are mixed in a mass ratio of 1:4:15, the obtained solution is stirred at 50 DEG C for 3h, and ammonia water is added to the solution during stirring to keep the pH value of the solution at 9.0, a nano-SiO2 precursor solution is prepared, the nano-SiO2 precursor is purified through a membrane separation device, the pore size of the membrane is 60nm; the nano-SiO2 precursor is modified with gamma-aminopropyl triethoxysilane at a mass ratio of 100:3 at 80 DEG C for 3h; the SiO2 nanoparticle precursor solution is mixed with an epoxy resin solution at a mass ratio of 1:1, stirred at 50 DEG C for 3h to obtain an epoxy / SiO2 solution; the epoxy / SiO2 solution is mixed with acetone at a mass ratio of 2:100 to prepare a sizing agent, 2.0% of the sizing agent by mass of the basalt fiber is used to treat the basalt fiber, and after reacting for 30min, the basalt fiber is dried in an oven at 80 DEG C to obtain the modified basalt fiber.

[0031] Comparative Example 4: A cold-mixed and cold-laid ultra-thin overlay asphalt mixture and a preparation process thereof, comprising the following steps: Compared with Example 1, the modified basalt fiber and the modified graphene oxide in Comparative Example 4 are replaced by unmodified basalt fiber and unmodified graphene oxide; Step 1: After the base asphalt is heated to 120 DEG C to melt and flow, the base asphalt is mixed and stirred with a reactive cold-mixed diluent at a mass ratio of 10:1 to prepare a cold-mixed asphalt liquid; Step 2: 5 parts of the cold-mixed asphalt liquid, 90 parts of aggregate, 1 part of curing agent, 1 part of unmodified basalt fiber, 1 part of unmodified graphene oxide and 0.5 part of interface coupling agent are mixed at room temperature 20 DEG C to obtain a cold-mixed and cold-laid ultra-thin overlay asphalt mixture; The preparation of the cold-mixed diluent comprises the following steps: Alanine and epoxy active diluent n-butyl glycidyl ether are dissolved in a solvent at a mass ratio of 1:10, and the solvent is a mixture of ethanol and water at a mass ratio of 1:1; the reaction is carried out at a reaction temperature of 60 DEG C, a stirring rate of 50 rad / min, and stirring for 1h; after the reaction is completed, the reaction product is cooled to room temperature 20 DEG C and then extracted and separated, and the mass ratio of the reaction product to the extractant methanol is 1:1; the insoluble substance obtained by extraction and separation is subjected to vacuum distillation at 60 DEG C and an absolute pressure of 20kPa to remove residual solvent, and a reactive cold-mixed diluent is prepared.

[0032] Experiment: The cold-mixed and cold-laid ultra-thin overlay asphalt mixtures obtained in Examples 1-3 and Comparative Examples 1-4 are used to prepare samples, and the performance of the samples is detected and the detection results are recorded: Marshall stability test: with T 0709-2011 in the Ministry of Transport "Highway Engineering Asphalt and Asphalt Mixture Test Regulations" (JTGE20-2011) as the reference standard, the Marshall test piece size is φ101.6mm×63.5mm, the temperature is 60℃, the loading speed is 50mm / min, and the pressure is applied under the condition of testing the stability of the sample; Kentucky Spatter Test: with T 0733-2011 in the Ministry of Transport "Highway Engineering Asphalt and Asphalt Mixture Test Regulations" (JTGE20-2011) as the reference standard, the Marshall test piece size is φ101.6mm×63.5mm, the test temperature is 20℃, the Los Angeles test machine speed is 30r / min, and the rotation is 300 revolutions; Construction depth test: with T 0961-1995 in "Highway Subgrade and Pavement Field Test Regulations" (JTG 3450-2019) as the reference standard, the construction depth test is performed on the sample; APA Anti-Reflective Cracking Test: with AASHTO TP 63-2009 as the reference standard, the sample is detected under the condition of temperature 25℃ and loading frequency 60 times / min; The results are shown in Table 2.

[0033] Table 2 According to the data in Table 2, the following conclusions can be clearly drawn: The cold-mixed cold-paved ultra-thin overlay asphalt mixture obtained in Examples 1-3 is compared with the cold-mixed cold-paved ultra-thin overlay asphalt mixture obtained in Comparative Examples 1-4, and the test results show that, Compared with the comparative examples, the cold-mixed cold-paved ultra-thin overlay asphalt mixture obtained in Examples 1-3 has lower Kentucky Spatter and higher stability, construction depth and anti-reflective cracking ability, which fully demonstrates that the cold-mixed cold-paved ultra-thin overlay asphalt mixture prepared by the present application has good anti-spatter, anti-deformation and anti-reflective cracking ability and anti-skid performance.

[0034] Compared with Example 1, Comparative Examples 2 and 3 do not add modified basalt fiber and modified graphene oxide, and the prepared asphalt mixture is used as the cold-mixed cold-paved ultra-thin overlay asphalt mixture in Comparative Examples 2 and 3; its stability decreases significantly, and the Kentucky Spatter data increases significantly, indicating that the addition of modified basalt fiber and modified graphene oxide in the asphalt mixture can provide its anti-deformation ability and anti-spatter property.

[0035] Compared with example 1, the basalt fiber and graphene oxide used in comparative example 4 are not modified, and the prepared asphalt mixture is used as a cold-mixed and cold-paved ultra-thin overlay asphalt mixture in comparative example 4; the Marshall stability, construction depth and anti-reflection crack resistance of the asphalt mixture are obviously reduced, and the Kentucky flying data are increased; it can be known that the process setting of the modified basalt fiber and the modified graphene oxide in the application can improve the problems of poor anti-flying property, anti-deformation ability, anti-sliding, anti-reflection crack resistance of the prepared cold-mixed and cold-paved ultra-thin overlay asphalt mixture.

[0036] It should be noted that, in this document, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0037] Finally, it should be noted that: the above only describes the preferred embodiments of the present application, and is not used to limit the present application, although the foregoing embodiments of the present application are described in detail, for those skilled in the art, the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced. Any modification, equivalent replacement, improvement and the like within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A process for preparing a cold-mixed, cold-laid, ultra-thin overlay asphalt mixture, characterized by: The following steps are involved: Step 1: After heating the base asphalt to make it melt and flow, the base asphalt is mixed with a reactive cold mix diluent in a mass ratio of 10:1 to prepare a cold mix asphalt liquid; Step 2: By mass, mix 5 to 10 parts of cold-mix asphalt liquid, 90 to 100 parts of aggregate, 1 to 5 parts of curing agent, 1 to 1.5 parts of modified basalt fiber, 1 to 1.5 parts of modified graphene oxide and 0.5 to 1.5 parts of interfacial coupling agent at room temperature to obtain a cold-mixed and cold-laid ultra-thin overlay asphalt mixture.

2. The process for preparing a cold-mixed and cold-laid ultra-thin overlay asphalt mixture according to claim 1, characterized in that: The matrix asphalt is 90# asphalt.

3. The process for preparing a cold-mixed and cold-laid ultra-thin overlay asphalt mixture according to claim 1, characterized in that: The preparation of the reactive cold mix diluent comprises the following steps: Alanine and epoxy reactive diluent n-butyl glycidyl ether are dissolved in a solvent at a mass ratio of 1:10, wherein the solvent is a mixture of ethanol and water at a mass ratio of 1:1; the reaction is carried out at a reaction temperature of 60-90°C and a stirring rate of 50-200 rad / min, and the stirring reaction is carried out for 1-10 hours. After the reaction is completed, the mixture is cooled to room temperature of 20°C and then extracted and separated, wherein the mass ratio of the reaction product to the extractant methanol is 1:1; the insoluble matter obtained by extraction and separation is subjected to reduced pressure distillation to prepare a reactive cold mix diluent.

4. The process for preparing a cold-mixed and cold-laid ultra-thin overlay asphalt mixture according to claim 1, characterized in that: The aggregate is basalt.

5. The process for preparing a cold-mixed and cold-laid ultra-thin overlay asphalt mixture according to claim 1, characterized in that: The curing agent is metakaolin, and the interface coupling agent is fatty alcohol polyoxyethylene ether.

6. The process for preparing a cold-mixed and cold-laid ultra-thin overlay asphalt mixture according to claim 1, characterized in that: The preparation of the modified basalt fiber comprises the following steps: Tetraethyl orthosilicate, distilled water and ethanol were mixed in a mass ratio of 1:4:15, and the resulting solution was stirred at 50-55°C for 3-4 hours. During the stirring process, ammonia water was added to the solution to maintain the pH value of the solution at 9.0 to prepare a nano-SiO2 precursor solution. The nano-SiO2 precursor was purified by a membrane separation device with a pore size of 60 nm. The nano-SiO2 precursor was stirred with γ-aminopropyltriethoxysilane in a mass ratio of 100:3 at 80-90°C for 3-4 hours. Modification: A SiO2 nanoparticle precursor solution and an epoxy resin solution are mixed in a mass ratio of 1:1, and stirred at 50-55°C for 3-4 hours to obtain an epoxy / SiO2 solution; the epoxy / SiO2 solution and acetone are mixed in a mass ratio of 2:100 to prepare a sizing agent, and the basalt fiber is treated with the sizing agent in an amount equivalent to 2.0% of the mass of the basalt fiber. After reacting for 30-40 minutes, the basalt fiber is placed in an oven at 90-100°C to dry, and finally the modified basalt fiber is obtained.

7. The process for preparing a cold-mixed and cold-laid ultra-thin overlay asphalt mixture according to claim 1, characterized in that: The preparation of the modified graphene oxide comprises the following steps: Graphene oxide was dispersed in deionized water and ultrasonically treated for 15 to 20 minutes. Polyethyleneimine was then added and the mixture was stirred at 80 to 90°C for 8 to 10 hours. After the reaction was completed, pretreated graphene oxide was obtained by centrifugal washing and freeze-drying. The mass ratio of graphene oxide, polyethyleneimine and deionized water was 0.1:5:

100. Under nitrogen protection, the pretreated graphene oxide, sodium lignin sulfonate and water were mixed and stirred at a mass ratio of 1:1:100, and potassium persulfate and N,N′-methylenebisacrylamide were added. The mixture was heated to 85 to 95°C and reacted for 2 to 3 hours. The product was filtered, washed with water and dried to obtain modified graphene oxide.

8. The process for preparing a cold-mixed and cold-laid ultra-thin overlay asphalt mixture according to claim 7, characterized in that: The amount of potassium persulfate added is 0.5% of the mass of the sodium lignin sulfonate, and the amount of N,N'-methylenebisacrylamide added is 0.2% of the mass of the sodium lignin sulfonate.

9. The process for preparing a cold-mixed and cold-laid ultra-thin overlay asphalt mixture according to claim 1, characterized in that: The heating temperature in step 1 is 120-130° C.; the normal temperature in step 2 is 20-25° C.

10. A cold-mixed, cold-laid, ultra-thin overlay asphalt mixture prepared according to the preparation process according to any one of claims 1 to 9.

Images