Large-dosage viscosity-reducing special rubber powder, rubber asphalt based on special rubber powder and preparation method of rubber asphalt

Abstract

The invention discloses large-dosage viscosity-reducing special rubber powder, rubber asphalt based on the special rubber powder and a preparation method of the special rubber powder. The special rubber powder is prepared by the following steps: uniformly blending desulfurized rubber tire powder of 100-120 meshes and a viscosity reducer, and kneading and granulating to prepare rubber powder particles of 20-30 meshes; the rubber asphalt comprises matrix asphalt, special rubber powder, a viscosity reducer, a stabilizer, an SBS modifier and methyl methacrylate. When the special rubber powder is applied to preparation of rubber asphalt, large mixing amount and lower development temperature can be realized, and flue gas emission can be reduced while rapid and uniform dispersion in the asphalt can be realized; besides, the rubber asphalt prepared based on the special rubber powder is low in viscosity, can reach the viscosity suitable for paving at the paving temperature required by specifications, also has excellent mechanical properties, and exerts the performance advantages of the rubber asphalt.

Description

Technical Field

[0001] The invention belongs to the field of rubber asphalt, and in particular relates to a special rubber powder with a large amount of viscosity reduction, a rubber asphalt based on the special rubber powder, and a preparation method. Background Art

[0002] The application of rubber asphalt in the modern sense began in the United States in the 1940s. After the 1960s, the United States, Sweden, the United Kingdom and other countries have successively carried out research on the application of rubber asphalt and rubber asphalt concrete. my country's research on the application of rubber modified asphalt in highways began in the 1980s. Rubber asphalt refers to the modified asphalt binder material formed by first crushing waste tires into rubber powder, then combining them according to a certain gradation, adding some modifiers, and fully melting and expanding with the base asphalt under high temperature conditions (above 180°C) with full mixing. Compared with general asphalt, rubber asphalt has the following characteristics:

[0003] (1) It has excellent elasticity and deformation capacity, and is particularly suitable for engineering environments with high requirements for fatigue resistance;

[0004] (2) The needle penetration is reduced, the softening point is increased, the viscosity is increased, the high-temperature stability of the asphalt is improved, and the rutting and pushing phenomena under high temperature are significantly improved;

[0005] (3) Enhanced adhesion: The thickness of the rubber asphalt film adhered to the stone surface increases, which can improve the asphalt pavement's resistance to water damage and extend the life of the highway;

[0006] (4) Reduce and eliminate the "black pollution" of waste tires, pay attention to environmental protection while reusing resources.

[0007] However, as the amount of rubber powder increases, the viscosity of asphalt will inevitably increase, making it difficult to evenly disperse the rubber powder in the asphalt, thus affecting the thermal stability and construction performance of the asphalt.

[0008] Therefore, it is necessary to develop a rubber asphalt that can achieve a large amount of rubber powder, and the rubber asphalt can reach a suitable paving viscosity at the paving temperature required by the specification, and also has excellent mechanical properties, so as to give full play to the performance advantages of rubber asphalt. Summary of the invention

[0009] Purpose of the invention: The technical problem to be solved by the present invention is to provide a special rubber powder that can be added in large quantities in rubber asphalt and dispersed quickly and evenly. The rubber asphalt based on the special rubber powder has low viscosity and can reach a suitable viscosity for paving at the paving temperature required by the specification. At the same time, it also has excellent mechanical properties, thus giving full play to the performance advantages of rubber asphalt.

[0010] Technical solution: The high-volume viscosity-reducing special rubber powder of the present invention is prepared by the following steps: 100 parts of desulfurized rubber tire powder and 3.5-4.5 parts of viscosity reducer are uniformly blended, and the mixture is kneaded and granulated to form 20-30 mesh rubber powder particles, wherein the mesh number of the desulfurized rubber tire powder is 100-120 mesh.

[0011] The present invention adopts a viscosity reducer to be evenly blended with desulfurized rubber tire powder and then kneaded and granulated to form 20-30 mesh rubber powder particles. Based on the large-particle rubber powder condition, it can be quickly crushed and dispersed in asphalt to achieve a large mixing amount, and the larger particles can effectively reduce the dust pollution during the on-site production of modified asphalt and the combustion risk brought about by subsequent applications.

[0012] Furthermore, the viscosity reducing agent used in the special rubber powder includes at least one of paraffin oil, aromatic oil or rubber oil.

[0013] Furthermore, the desulfurization degree of the desulfurized rubber tire powder used in the special rubber powder is 40-90%.

[0014] The rubber asphalt of the present invention comprises the following raw materials by weight: 100 parts of base asphalt, 40-80 parts of the above-mentioned special rubber powder, 0.35-1.5 parts of viscosity reducer, 0.1-0.5 parts of stabilizer, 0.1-3 parts of SBS modifier and 0.1-0.5 parts of methyl methacrylate.

[0015] Based on the fact that the special rubber powder can be added in a large amount, methyl methacrylate and a viscosity reducer are further added to effectively reduce the viscosity of the rubber asphalt when compounded with the base asphalt, the stabilizer and the improver, thereby ensuring that the rubber asphalt reaches a viscosity suitable for paving at the paving temperature required by the specification, while also ensuring the performance of the rubber asphalt and giving full play to the performance advantages of the rubber asphalt.

[0016] Furthermore, the viscosity reducer used in the rubber asphalt may include at least one of paraffin oil, aromatic oil or rubber oil.

[0017] Furthermore, the stabilizer used in the rubber asphalt can be a sulfur-containing stabilizer, including elemental sulfur, sulfur-containing compounds or polysulfide.

[0018] The method for preparing the above-mentioned rubber asphalt of the present invention comprises the following steps:

[0019] (1) heating the base asphalt to 180-190°C to make it molten;

[0020] (2) Add special rubber powder, viscosity reducer, SBS modifier and methyl methacrylate into the molten base asphalt and stir thoroughly until the temperature returns to above 180°C;

[0021] (3) Shearing for 20-40 min at a shear temperature of 160-190° C. and a shear speed of 3000-6000 r / min;

[0022] (4) The mixture is then stirred at a speed of 400-1000 r / min for 3-8 h, and a stabilizer is added within 1-2 h before the end of the stirring to obtain a uniform high-performance rubber asphalt.

[0023] Beneficial effects: Compared with the prior art, the significant advantages of the present invention are: the special rubber powder can achieve large dosage and lower development temperature when used to prepare rubber asphalt, and can achieve rapid and uniform dispersion in asphalt while reducing smoke emissions; in addition, the rubber asphalt prepared based on the special rubber powder has low viscosity, and can reach a suitable viscosity for paving at the paving temperature required by the specification, and also has excellent mechanical properties, giving full play to the performance advantages of rubber asphalt. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is further described in detail below in conjunction with embodiments.

[0025] It should be noted that the raw materials used in the present invention are all well-known raw materials in the art and can be purchased from the market.

[0026] Example 1

[0027] The components of the rubber asphalt in Example 1 are shown in Table 1 below.

[0028] Table 1 Component contents of rubber asphalt in Example 1

[0029] Serial number raw material Content / portion 1 Base asphalt 100 2 Special rubber powder 50 3 15# paraffin oil 1 4 sulfur 0.2 5 SBS Modifier 2.5 6 Methyl Methacrylate 0.2

[0030] The rubber asphalt of this embodiment 1 is prepared by the following steps:

[0031] (1) Preparation of special rubber powder: 100 parts of 100 mesh, 60% desulfurized rubber tire powder and 4 parts of 15# paraffin oil were evenly blended, and then kneaded and granulated to obtain 25 mesh rubber powder particles.

[0032] (2) Heat the base asphalt to 185°C to make it molten.

[0033] (3) Add special rubber powder, 15# paraffin oil, SBS modifier and methyl methacrylate into the molten base asphalt and stir thoroughly until the temperature returns to 185°C.

[0034] (4) Shearing for 30 min at a shear temperature of 190°C and a shear speed of 4000 r / min.

[0035] (5) The mixture was then stirred at a speed of 600 r / min for 6 h, and stabilizer sulfur was added 1 h before the end of the stirring to obtain a uniform high-performance rubber asphalt.

[0036] Example 2

[0037] The components of the rubber asphalt in Example 2 are shown in Table 2 below.

[0038] Table 2 Component contents of rubber asphalt in Example 2

[0039]

[0040]

[0041] The rubber asphalt of this embodiment 2 is prepared by the following steps:

[0042] (1) Preparation of special rubber powder: 100 parts of desulfurized rubber tire powder with a desulfurization degree of 80% and 100 mesh are uniformly blended with 3.5 parts of aromatic oil, and the mixture is kneaded and granulated to obtain 20 mesh rubber powder particles.

[0043] (2) heating the base asphalt to 185° C. to make it molten;

[0044] (3) Add special rubber powder, 15# paraffin oil, SBS modifier and methyl methacrylate into the molten base asphalt and stir thoroughly until the temperature returns to 185°C;

[0045] (4) Shearing for 30 min at a shear temperature of 190°C and a shear speed of 4000 r / min;

[0046] (5) The mixture was then stirred at a speed of 600 r / min for 6 h, and stabilizer sulfur was added 1 h before the end of the stirring to obtain a uniform high-performance rubber asphalt.

[0047] Example 3

[0048] The components of the rubber asphalt in Example 3 are shown in Table 3 below.

[0049] Table 3 Component contents of rubber asphalt in Example 3

[0050] Serial number raw material Content / portion 1 Base asphalt 100 2 Special rubber powder 40 3 Rubber Oil 0.35 4 sulfur 0.1 5 SBS Modifier 0.1 6 Methyl Methacrylate 0.1

[0051] The rubber asphalt of this embodiment 3 is prepared by the following steps:

[0052] (1) Preparation of special rubber powder: 100 parts of 100-mesh, 40% desulfurized rubber tire powder and 4.5 parts of rubber oil are uniformly blended and granulated to obtain 20-mesh rubber powder particles.

[0053] (2) heating the base asphalt to 180° C. to make it molten;

[0054] (3) Add special rubber powder, rubber oil, SBS modifier and methyl methacrylate into the molten base asphalt and stir thoroughly until the temperature returns to 180°C;

[0055] (4) Shearing for 40 min at a shear temperature of 160°C and a shear speed of 3000 r / min;

[0056] (5) The mixture was then stirred at a speed of 400 r / min for 8 h, and stabilizer sulfur was added 1 h before the end of the stirring to obtain a uniform high-performance rubber asphalt.

[0057] Example 4

[0058] The components of the rubber asphalt of Example 4 are shown in Table 4 below.

[0059] Table 4 Component contents of rubber asphalt in Example 4

[0060] Serial number raw material Content / portion 1 Base asphalt 100 2 Special rubber powder 80 3 15# paraffin oil 1.5 4 sulfur 0.5 5 SBS Modifier 3 6 Methyl Methacrylate 0.5

[0061] The rubber asphalt of this embodiment 4 is prepared by the following steps:

[0062] (1) Preparation of special rubber powder: 100 parts of 120 mesh, 90% desulfurized rubber tire powder and 3.5 parts of 15# paraffin oil were evenly blended, and the mixture was kneaded and granulated to obtain 30 mesh rubber powder particles.

[0063] (2) heating the base asphalt to 190° C. to make it molten;

[0064] (3) Add special rubber powder, 15# paraffin oil, SBS modifier and methyl methacrylate into the molten base asphalt and stir thoroughly until the temperature returns to 190°C;

[0065] (4) Shearing for 20 min at a shear temperature of 190 °C and a shear speed of 6000 r / min;

[0066] (5) The mixture was then stirred at a stirring speed of 1000 r / min for 3 h, and stabilizer sulfur was added 1 h before the end of the stirring to obtain a uniform high-performance rubber asphalt.

[0067] Comparative Example 1

[0068] The basic steps are the same as those in Example 1, except that the special rubber powder is replaced with desulfurized rubber tire powder with a mesh size of 100 and a desulfurization degree of 60%.

[0069] Comparative Example 2

[0070] The basic steps are the same as those in Example 1, except that methyl methacrylate is not added to the rubber asphalt.

[0071] Performance Testing

[0072] The rubber asphalt prepared in the above examples and comparative examples was tested for performance, and the results obtained are shown in Table 9 below.

[0073] Table 9 Rubber asphalt performance test table

[0074]

[0075] It can be seen from Examples 1 to 4 in Table 9 that the rubber asphalt prepared by the present invention has a rotational viscosity of no more than 3.3 at 180° C. and has excellent mechanical properties.

[0076] Combining Example 1 and Comparative Example 1, it can be seen that by first adding a viscosity reducer for granulation, on the one hand, the content of the viscosity reducer is increased in the rubber asphalt system, and the viscosity of the prepared rubber asphalt is further reduced; on the other hand, by first preparing the desulfurized rubber tire powder into large-particle rubber powder of 20-30 mesh, and then when compounding with the matrix asphalt, its rapid dispersion ability can be improved, avoiding the floating, agglomeration and wall sticking problems of finer rubber powder in the preparation process, and achieving a more ideal modification effect.

[0077] Combining Example 1 and Comparative Example 2, it can be seen that when only the special rubber powder is used without methyl methacrylate, the rotational viscosity is also very high. This further verifies that the present invention can effectively reduce the viscosity under the combined effect of the special rubber powder and methyl methacrylate, and can also ensure the performance of rubber asphalt and give full play to the performance advantages of rubber asphalt.

[0078] In addition to the above embodiments, the high modulus and high toughness asphalt modifier and high modulus modified asphalt prepared by the raw material components and preparation process of the present invention can achieve the technical effects claimed by the present invention. For example, the viscosity reducer used can be a combination of paraffin oil, aromatic oil or rubber oil; the stabilizer can also be a sulfur-containing compound and / or polysulfide. The specific substances covered by the specific sulfur-containing compound or polysulfide are also well-known and commonly used substances in the art.

Claims

1. A special rubber powder with large amount of viscosity reduction, characterized in that: The rubber powder is prepared by the following steps: 100 parts of desulfurized rubber tire powder and 3.5-4.5 parts of viscosity reducer are uniformly blended, and then kneaded and granulated to form 20-30 mesh rubber powder particles, wherein the mesh number of the desulfurized rubber tire powder is 100-120 meshes.

2. The high-volume viscosity-reducing special rubber powder according to claim 1, characterized in that: The viscosity reducer includes at least one of paraffin oil, aromatic oil or rubber oil.

3. The high-volume viscosity-reducing special rubber powder according to claim 1, characterized in that: The desulfurization degree of the desulfurized rubber tire powder is 40-90%.

4. A rubber asphalt, characterized in that: The rubber asphalt comprises the following raw materials by weight: 100 parts of base asphalt, 40-80 parts of the special rubber powder according to claim 1, 0.35-1.5 parts of a viscosity reducer, 0.1-0.5 parts of a stabilizer, 0.1-3 parts of an SBS modifier and 0.1-0.5 parts of methyl methacrylate.

5. The rubber asphalt according to claim 4, characterized in that: The viscosity reducer includes at least one of paraffin oil, aromatic oil or rubber oil.

6. The rubber asphalt according to claim 4, characterized in that: The stabilizer is a sulfur-containing stabilizer, including elemental sulfur, sulfur-containing compounds or polysulfide.

7. A method for preparing the rubber asphalt according to claim 4, characterized in that: The steps include: (1) heating the base asphalt to 180-190°C to make it molten; (2) Add special rubber powder, viscosity reducer, SBS modifier and methyl methacrylate into the molten base asphalt and stir thoroughly until the temperature returns to above 180°C; (3) Shearing for 20-40 min at a shear temperature of 160-190° C. and a shear speed of 3000-6000 r / min; (4) The mixture is then stirred at a speed of 400-1000 r / min for 3-8 h, and a stabilizer is added 1-2 h before the end of the stirring process to produce a uniform high-performance rubber asphalt.

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