CN110330713A - A kind of asphalt reinforcing agent and preparation method thereof - Google Patents

Abstract

The invention discloses a reinforcing agent for asphalt mixture and a preparation method thereof. The reinforcing agent is made of the following raw materials in mass percentage: polyethylene 60%-80%, polyethylene wax 8%-20%, nano-carbon fiber 3 % to 10%, high oil-absorbing resin 3% to 8%, white oil 5% to 13%, superfine rubber powder 1% to 8%, and is prepared by kneading and extruding by a screw extruder. The invention overcomes the relatively large limitation of the existing asphalt mixture admixture and improves the overall strength of the asphalt mixture from multiple aspects. The elastomer formed by the reinforcing agent and the mineral material during the mixing process is filled between the asphalt and the aggregate to play the role of embedding, reinforcement and cementation. Secondly, the polyethylene wax and polyethylene in the present invention can improve the high temperature of the road surface. Anti-rutting and low-temperature anti-cracking ability; inorganic nano-carbon fiber can effectively improve the mechanical properties of the mixture; high oil-absorbing resin can achieve the purpose of oil absorption and oil retention by using its internal network structure to the van Walder force of oil molecules.

Description

A kind of asphalt mixture reinforcing agent and preparation method thereof

technical field

The invention belongs to the technical field of road construction and maintenance, and in particular relates to a novel asphalt mixture reinforcing material and a preparation method thereof.

Background technique

Asphalt mixture admixture is mainly used in the production and mixing of mixture, and has been widely used in the construction of asphalt pavement.

Existing asphalt mixture admixtures are often single-molecule materials, aiming at enhancing the single performance of the mixture, with strong directivity, which cannot meet the multi-performance requirements of the mixture, and have great limitations in application. For example, the low-temperature crack resistance of the surface layer of asphalt mixture is improved by adding polyester fiber, but its effect on improving high-temperature stability is not obvious; anti-rutting agent and high modulus agent are mainly used to improve the resistance of asphalt mixture to high-temperature rutting The ability to deform is relatively weak compared to its effect on improving the low-temperature crack resistance of asphalt mixtures; while high-viscosity additives are mainly used to improve the water stability and fatigue resistance of asphalt mixtures, and their contribution to the improvement of high and low temperature performance is very small. And poor oil absorption. Therefore, traditional asphalt mixture admixtures still have many limitations for improving the strength of asphalt mixture. Therefore, it is of great significance to develop a new type of admixture that is beneficial to improve the comprehensive road performance of asphalt mixture for the existing pavement construction technology.

Contents of the invention

The purpose of the present invention is to overcome the limitation of existing asphalt mixture admixture and provide a new type of asphalt mixture admixture—a reinforcing agent, and a preparation method of the reinforcing agent. The invention helps to improve the mechanical interlocking force between the mineral materials in the asphalt mixture and the binding force produced by the fiber net formed by melting to firmly restrict the mineral material particles in the grid through reasonable addition, so as to exert an interlocking effect on the mixture. , reinforcement and cementation, so that the overall strength of the asphalt mixture is improved. The invention adopts the high oil absorption of low cross-linking degree polymerization and the high adsorption and strengthening effect brought by polymer materials at the same time, so that the stiffness modulus of asphalt mixture is improved, and the toughness is enhanced, thereby comprehensively improving the overall quality of asphalt mixture pavement Strength, improve various road performance.

In order to achieve the above object, the asphalt mixture reinforcing agent of the present invention is made of the following raw materials in mass percentage:

Polyethylene 60%-80%, polyethylene wax 8%-20%, nano-carbon fiber 3%-10%, super oil-absorbing resin 3%-8%, white oil 5%-13%, superfine rubber powder 1%- 8%.

The reinforcing agent for asphalt mixture of the present invention is preferably made of the following raw materials in mass percentage:

Polyethylene 70%-78%, polyethylene wax 8%-15%, nano-carbon fiber 3%-5%, super oil-absorbing resin 3%-5%, white oil 5%-10%, superfine rubber powder 3%- 5%.

The polyethylene mentioned above is any one of high-density polyethylene, low-density polyethylene, and linear low-density polyethylene.

The above-mentioned nano-carbon fibers are preferably polyacrylonitrile carbon fibers or pitch carbon fibers.

The above-mentioned high oil-absorbing resin is preferably a polymethacrylate-based high oil-absorbing resin or a polyacrylate-based high oil-absorbing resin.

The preparation method of asphalt mixture reinforcing agent of the present invention is made up of following steps:

1. According to the above mass percentage, it is called polyethylene, polyethylene wax, nano-carbon fiber, super oil-absorbing resin, white oil, and superfine rubber powder.

2. Shearing and pulverizing the carbon nanofibers and the high oil-absorbing resin, stirring evenly to obtain the prepolymer A.

3. Stir the superfine rubber powder and white oil evenly to obtain prepolymer B.

4. Put polyethylene, polyethylene wax, prepolymer A, and prepolymer B into a mixer and stir evenly at a speed of 1000-2000 rpm for 10-20 minutes.

5. Add the uniformly stirred mixture in step 4 into the hopper of the screw extruder, turn on the temperature control switch of the screw extruder, and control the heating temperature of the first zone of the screw extruder to 120-130°C, and the heating of the second zone The temperature is 135-145°C, the heating temperature of the third zone is 150-160°C, the heating temperature of the fourth zone is 165-180°C, the speed of the screw extruder is 30-60 rpm, and the mixture is mixed. The kneading time is 30-60 minutes, and the semi-finished cylindrical strip is extruded, cooled in a water bath at room temperature, and the pellets with a length of 3-5 mm are evenly cut with a cold-stretched pelletizing equipment to prepare a finished product.

The preparation method of asphalt mixture reinforcing agent of the present invention is made up of following steps:

1. According to the above mass percentage, it is called polyethylene, polyethylene wax, nano-carbon fiber, super oil-absorbing resin, white oil, and superfine rubber powder.

2. Shearing and pulverizing the carbon nanofibers and the high oil-absorbing resin, stirring evenly to obtain the prepolymer A.

3. Stir the superfine rubber powder and white oil evenly to obtain prepolymer B.

4. Put polyethylene, polyethylene wax, prepolymer A, and prepolymer B into a mixer and stir evenly at a speed of 1000-2000 rpm for 10-20 minutes.

5. Add the uniformly stirred mixture in step 4 into the hopper of the screw extruder, turn on the temperature control switch of the screw extruder, and control the heating temperature of the first zone of the screw extruder to 120-130°C, and the heating of the second zone The temperature is 135-145°C, the heating temperature of the third zone is 150-160°C, the heating temperature of the fourth zone is 165-180°C, the speed of the screw extruder is 30-60 rpm, and the mixture is mixed. The kneading time is 30-60 minutes, and the semi-finished cylindrical strip is extruded, cooled in a water bath at room temperature, and the pellets with a length of 3-5 mm are evenly cut with a cold-stretched pelletizing equipment to prepare a finished product.

The present invention has the following beneficial effects:

1. The present invention overcomes the shortcomings of single molecular materials and improves the overall strength of asphalt mixture from multiple aspects. First, in the process of mixing with mineral materials, the present invention softens under the action of high temperature to form an elastomer, and under the action of high-speed mechanical stirring and shearing force, after melting, wire drawing, and elastic deformation, these elastomers will be filled into the asphalt Between the aggregate and the asphalt mixture, it plays the role of embedding, reinforcing and cementing. At the same time, the mixing and compaction temperature of the asphalt mixture is higher than the melting point of the reinforcing agent. The reinforcing agent particles are in a viscous flow state and have strong plasticity. Under the action of external force, the particles can form various shapes according to the gap between the mineral material particles. . When the temperature of the mixture drops, the material will return to the solid state and maintain the compacted shape, thereby limiting the relative sliding between the mineral particles and increasing the intercalation force between the mineral particles, thus improving the high temperature resistance of the mixture. deformability.

2. The polyethylene wax in the reinforcing agent of the present invention has good compatibility with polyethylene and plays an internal lubrication role. Through the characteristics of the material itself, the cold resistance and heat resistance of the asphalt mixture can be effectively improved, so that the asphalt The high temperature anti-rutting and low temperature anti-cracking ability of the pavement has been significantly improved and enhanced. At the same time, the inorganic nano-carbon fiber in the reinforcing agent of the present invention has the characteristics of low density, high strength and good toughness, which can effectively improve the mechanical properties of asphalt mixture, and at the same time, the composite modification with polyethylene can form a uniform and stable network inside The structure strengthens the integrity, elasticity and thermal stability of hot asphalt mixture, and also promotes the improvement of fatigue performance.

3. The oil-absorbing principle of the high-oil-absorbing resin in the reinforcing agent of the present invention is different from that of traditional oil-absorbing materials. It mainly utilizes the Van Walder force of its internal network structure on oil molecules, and the solvent action between lipophilic groups and oil molecules in the molecule. This material can form a three-dimensional cross-linked network structure with certain micropores. Due to the existence of the network cross-linked structure, the polymer material swells and does not dissolve, and the oil molecules are wrapped in the macromolecular network structure, and the oil absorbed in the material It is not easy to release under the action of external pressure, so as to achieve the purpose of oil absorption and oil retention. When the temperature is high in summer, the asphalt softens, and the oil concentration difference between the inside and outside of the polymer network structure increases. At this time, the material can absorb more softened asphalt through van der Waals force, thereby increasing the viscosity of the asphalt and improving the high temperature stiffness of the mixture. Modulus, reduces rutting caused by asphalt softening. When the temperature is low in winter, the asphalt is hardened, and the three-dimensional network structure binds the oil through the van der Waals force. The oil is difficult to release, and the asphalt will not move, reducing the occurrence of cracks.

Detailed ways

The present invention will be further described in detail below in conjunction with specific examples, but the protection scope of the present invention is not limited to these examples.

Example 1

The asphalt mixture reinforcing agent of the present embodiment is made up of polyethylene, polyethylene wax, nano-carbon fiber, high oil-absorbing resin, white oil and superfine rubber powder, and its mass percentage is: polyethylene 65%, polyethylene wax 15% , Nano-carbon fiber 4%, super oil-absorbing resin 4%, white oil 8%, superfine rubber powder 4%. Among them, polyethylene is low-density polyethylene obtained by copolymerization of ethylene and a small amount of butene, nano-carbon fiber is polyacrylonitrile-based nano-carbon fiber, high oil-absorbing resin is polyhexadecyl methacrylate high oil-absorbing resin, and polyethylene wax is domestic polyester. Ethylene wax has a melting point of 100°C and a molecular weight of 2500, the white oil is 55# industrial grade white oil, and the superfine rubber powder is 120 mesh superfine rubber powder.

The preparation method of the asphalt mixture reinforcing agent of this embodiment is:

1. According to the above mass percentage, weigh 65g low-density polyethylene, 15g polyethylene wax, 4g polyacrylonitrile-based nano-carbon fiber, 4g polyhexadecyl methacrylate super oil-absorbing resin, 8g 55# white oil, 4g superfine rubber powder.

2. The polyacrylonitrile-based nano-carbon fiber and polyhexadecyl methacrylate super oil-absorbing resin were sheared and pulverized, and stirred evenly to obtain prepolymer A.

3. Stir the superfine rubber powder and 55# white oil evenly to obtain prepolymer B.

4. Put polyethylene, polyethylene wax, prepolymer A, and prepolymer B into a mixer and stir evenly at a speed of 2000 rpm for 20 minutes.

5. Add the uniformly stirred mixture in step 4 into the hopper of the screw extruder, turn on the temperature control switch of the screw extruder, and control the heating temperature of the first zone of the screw extruder to 130°C, and the heating temperature of the second zone to 135°C, the heating temperature of the third zone is 150°C, the heating temperature of the fourth zone is 165°C, the speed of the screw extruder is 60 rpm, and the mixture is mixed for 60 minutes, and the cylinder is extruded The strip-shaped semi-finished product is cooled in a water bath at room temperature, and the granules with a length of 3-5 mm are evenly cut with a cold-stretched strip cutting equipment to prepare a finished product.

Example 2

The asphalt mixture reinforcing agent of the present invention is made of 75g polyethylene, 10g polyethylene wax, 4g nano-carbon fiber, 4g super oil-absorbing resin, 5g white oil, and 2g ultrafine rubber powder. The preparation method is the same as that of Example 1. Wherein, the polyethylene is low-density polyethylene obtained by copolymerization of ethylene and a small amount of butene; the nano-carbon fiber is polyacrylonitrile-based nano-carbon fiber; the high oil-absorbing resin is polyhexadecyl methacrylate high oil-absorbing resin, polyethylene The wax is a domestic polyethylene wax with a melting point of 100°C and a molecular weight of 2500, the white oil is 55# industrial grade white oil, and the superfine rubber powder is 120 mesh superfine rubber powder.

Example 3

The asphalt mixture reinforcing agent of the present invention is made of 72g polyethylene, 8g polyethylene wax, 4g nano-carbon fiber, 4g resin, 8g white oil, 4g ultrafine rubber powder, and the preparation method is the same as that of Example 1. Wherein, the polyethylene is low-density polyethylene obtained by copolymerization of ethylene and a small amount of butene; the nano-carbon fiber is polyacrylonitrile-based nano-carbon fiber; the high oil-absorbing resin is polyhexadecyl methacrylate high oil-absorbing resin, polyethylene The wax is a domestic polyethylene wax with a melting point of 100°C and a molecular weight of 2500, the white oil is 55# industrial grade white oil, and the superfine rubber powder is 120 mesh superfine rubber powder.

Example 4

The asphalt mixture reinforcing agent of the present invention is made of 75g polyethylene, 8g polyethylene wax, 4g nano-carbon fiber, 4g super oil-absorbing resin, 5g white oil, and 4g ultrafine rubber powder. The preparation method is the same as that of Example 1. Wherein, the polyethylene is low-density polyethylene obtained by copolymerization of ethylene and a small amount of butene; the nano-carbon fiber is pitch carbon fiber; the high oil-absorbing resin is polyhexadecyl methacrylate high oil-absorbing resin; Ethylene wax has a melting point of 100°C and a molecular weight of 2500, the white oil is 55# industrial grade white oil, and the superfine rubber powder is 120 mesh superfine rubber powder.

Example 5

The asphalt mixture reinforcing agent of the present invention is made of 75g polyethylene, 9g polyethylene wax, 3g nano-carbon fiber, 3g super oil-absorbing resin, 6g white oil, and 4g ultrafine rubber powder. The preparation method is the same as that of Example 1. Wherein, the polyethylene is low-density polyethylene obtained by copolymerization of ethylene and a small amount of butene; the nano-carbon fiber is polyacrylonitrile-based nano-carbon fiber; the high oil-absorbing resin is polyhexadecyl methacrylate high oil-absorbing resin, polyethylene The wax is a domestic polyethylene wax with a melting point of 100°C and a molecular weight of 2500, the white oil is 55# industrial grade white oil, and the superfine rubber powder is 120 mesh superfine rubber powder.

Example 6

The asphalt mixture reinforcing agent of the present invention is made of 78g polyethylene, 8g polyethylene wax, 5g nano-carbon fiber, 3g super oil-absorbing resin, 4g white oil, and 2g ultrafine rubber powder. The preparation method is the same as that of Example 1. Wherein, the polyethylene is low-density polyethylene obtained by copolymerization of ethylene and a small amount of butene; the nano-carbon fiber is polyacrylonitrile-based nano-carbon fiber; the high oil-absorbing resin is polyhexadecyl methacrylate high oil-absorbing resin, polyethylene The wax is a domestic polyethylene wax with a melting point of 100°C and a molecular weight of 2500, the white oil is 55# industrial grade white oil, and the superfine rubber powder is 120 mesh superfine rubber powder.

In order to prove the beneficial effects of the present invention, the reinforcing agents prepared in the above-mentioned examples 1 to 6 were added to the asphalt mixture in an addition amount of 0.5% and made into test pieces for bending test, high temperature anti-rutting test and freeze-thaw test. Splitting strength test. The specific test method is as follows:

Bending test test method: the asphalt mixture added with the reinforcing agent of Examples 1 to 6 was respectively cut into prism specimens, and the specimen size was 250mm long, 30mm wide and 35mm high. Put the specimen in a constant temperature water tank until the internal temperature of the specimen reaches 15°C, then take it out and fix it on the testing machine for bending test.

High-temperature anti-rutting test method: make plate-shaped test pieces for the asphalt mixtures added with the reinforcing agents of Examples 1 to 6. The test piece size is 300mm long, 300mm wide, and 50mm thick. Place the formed test piece for 48 hours and then place the test piece together with the test mold in a thermostatic chamber with a constant temperature of 60°C for more than 5 hours. The rutting test was carried out on a wheel rutting testing machine.

Freeze-thaw splitting strength test method: 8 cylindrical specimens were made for the asphalt mixture added with the reinforcing agents of Examples 1 to 6, and the specimen size was 101.6 mm in diameter and 63.5 mm in height. Both sides of the specimen were compacted 50 times with a Marshall compaction instrument. Put the specimen into a plastic bag and add 10mL of water, freeze it in a constant temperature refrigerator at -18°C for 16 hours, take it out, and conduct a splitting test at a loading rate of 50min/mm.

The experimental indicators are shown in Table 1:

Table 1 Technical requirements for asphalt mixture

The experimental results are shown in Table 2:

Table 2 Experimental results of asphalt mixture

index Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Low temperature bending failure strain (με) 2980 2885 3050 2850 2860 2820 Rutting test (times/mm) >6000 >6000 >6000 >6000 >6000 ＜6000 Freeze-thaw splitting strength ratio (%) 80.2 80.8 81.1 80.3 80.6 80.5

As can be seen from Table 1, the low-temperature bending failure strain, rutting test, and freeze-thaw splitting strength ratio of the asphalt mixture prepared by adding the reinforcing agent of the present invention all meet the technical requirements of the asphalt mixture, indicating that the asphalt after adding the reinforcing agent of the present invention The mixture has excellent road performance, high strength and toughness. At the same time, the high-temperature anti-rutting ability, low-temperature crack resistance and fatigue resistance of asphalt mixture have been improved.

The asphalt mixture reinforcing agent of the invention comprehensively improves the road performance of the asphalt mixture such as high temperature resistance, low temperature resistance, and fatigue resistance, and improves the overall strength of the asphalt pavement, which is of great significance to the existing pavement technology.

Claims (6)

1. a kind of asphalt reinforcing agent, it is characterised in that it is made of the raw material of following mass percents:

Polyethylene 60%~80%, polyethylene wax 8%~20%, carbon nano-fiber 3%~10%, high oil-absorbing resin 3%~ 8%, white oil 5%~13%, ultra-fine rubber powder 1%~8%.

2. asphalt reinforcing agent according to claim 1, it is characterised in that it by following mass percents raw material It is made:

Polyethylene 70%~78%, polyethylene wax 8%~15%, carbon nano-fiber 3%~5%, high oil-absorbing resin 3%~ 5%, white oil 5%~10%, ultra-fine rubber powder 3%~5%.

3. asphalt reinforcing agent according to claim 1 or 2, it is characterised in that: the polyethylene is high density Polyethylene, low density polyethylene (LDPE), any one in linear low density polyethylene.

4. asphalt reinforcing agent according to claim 1 or 2, it is characterised in that: the carbon nano-fiber is poly- Acrylic carbon fibre or asphalt-based carbon fiber.

5. asphalt reinforcing agent according to claim 1 or 2, it is characterised in that: the high oil-absorbing resin is Polymethacrylate high oil-absorbing resin or polyacrylate high oil-absorbing resin.

6. a kind of preparation method of asphalt reinforcing agent described in Claims 1 to 5 any one, it is characterised in that the party Method is made of following step:

(1) it is formed according to above-mentioned mass percent meter, claims polyethylene, polyethylene wax, carbon nano-fiber, high oil-absorbing tree respectively Rouge, white oil, ultra-fine rubber powder；

(2) carbon nano-fiber and high oil-absorbing resin shearing are crushed, stirs evenly, obtains performed polymer A；

(3) ultra-fine rubber powder is stirred evenly with white oil, obtains performed polymer B；

(4) polyethylene, polyethylene wax and performed polymer A, performed polymer B are put into blender and are stirred evenly, revolving speed be 1000~ 2000 revs/min, mixing time is 10~20 minutes；

(5) mixture stirred evenly in step (4) is added into the hopper of screw extruder, opens the temperature of screw extruder Control switch is spent, the heating temperature in control one area of screw extruder is 120~130 DEG C, the heating temperature in 2nd area is 135~145 DEG C, the heating temperature in 3rd area be 150~160 DEG C, the heating temperature in 4th area is 165~180 DEG C, the revolving speed of screw extruder is 30 ~60 revs/min, mixture is kneaded, mixing time is 30~60 minutes, squeezes out cylinder strip semi-finished product, room temperature water-bath It is cooling, it is 3~5mm particle with the uniform Cutting Length of cold drawn bar granulate equipment, is prepared into finished product.